WorldWideScience

Sample records for dryland farming

  1. Agricultural water-saving potential and feasibility of developing semi-dryland farming in Henan Province

    Institute of Scientific and Technical Information of China (English)

    Huang Xiuqiao; Wang Jinglei

    2013-01-01

    Based on the collected data in the current status of developing and utilizing water resources and imple-menting water-saving agriculture in Henan Province,and taking into account the influence of engineering,agro-nomic and management measures,the water-saving potential in past years and the feasibility of implementing semi-dryland farming were analyzed in Henan Province. Finally,specific technical measures of developing semi-dryland farming in different areas of Henan Province were proposed.

  2. Optimizing soil and water management in dryland farming systems in Cabo Verde

    NARCIS (Netherlands)

    Santos Baptista Costa, Dos I.

    2016-01-01

     “Optimizing Soil and Water Management in Dryland Farming Systems in Cabo Verde” Isaurinda Baptista Summary Soil and land degradation poses a great challenge for sustainable development worldwide and, in Cabo Verde, has strongly affected both people

  3. Optimizing soil and water management in dryland farming systems in Cabo Verde

    NARCIS (Netherlands)

    Santos Baptista Costa, Dos I.

    2016-01-01

     “Optimizing Soil and Water Management in Dryland Farming Systems in Cabo Verde” Isaurinda Baptista Summary Soil and land degradation poses a great challenge for sustainable development worldwide and, in Cabo Verde, has strongly affected both

  4. Effects of straw mulch on soil water and winter wheat production in dryland farming.

    Science.gov (United States)

    Peng, Zhang; Ting, Wei; Haixia, Wang; Min, Wang; Xiangping, Meng; Siwei, Mou; Rui, Zhang; Zhikuan, Jia; Qingfang, Han

    2015-06-02

    The soil water supply is the main factor that limits dryland crop production in China. In a three-year field experiment at a dryland farming experimental station, we evaluated the effects of various straw mulch practices on soil water storage, grain yield, and water use efficiency (WUE) of winter wheat (Triticum aestivum). Field experiments were conducted with six different mulch combinations (two different mulch durations and three different mulch amounts): high (SM1; 9000 kg ha(-1)), medium (SM2; 6000 kg ha(-1)), and low (SM3; 3000 kg ha(-1)) straw mulch treatments for the whole period; and high (SM4), medium (SM5) and low (SM6) straw mulch treatments during the growth period only, where the control was the whole period without mulch (CK). Throughout the whole growth period of the three-year experiment, the average soil water content in the 0-200 cm soil layer increased by 0.7-22.5% compared with CK, while the WUE increased significantly by 30.6%, 32.7% and 24.2% with SM1, SM2, and SM3, respectively (P < 0.05). The yield increased by 13.3-23.0% when mulch was provided during the growth period, while the WUE increased by 15.2%, 17.2% and 18.0% with SM4, SM5, and SM6, respectively, compared with CK.

  5. From Theory to Rural Farms: Testing the Efficacy of the Dryland Development Paradigm of Desertification

    Science.gov (United States)

    Reynolds, J. F.; Herrick, J.; Huber-Sannwald, E.; Ayarza, M.

    2011-12-01

    The social and economic systems of humans (H) are inextricably linked with environmental (E) systems. This tight coupling is especially relevant in drylands, where ecosystem goods and services vital to sustaining the livelihoods of human populations are constantly changing over time. The Dryland Development Paradigm (DDP; Reynolds et al. 2007, Science 316, 847-851) was proposed as an integrated framework for dealing with the enormous complexity associated with coupled H-E systems. The DDP consists of five principles: (1) the structure, function and interrelationships that characterize H-E systems are always changing so both H and E factors must always be considered simultaneously; (2) a limited suite of "slow" variables are critical determinants of H-E dynamics; (3) thresholds in both H and E systems are vital: if a key slow variable crosses a threshold this can lead to a different state or condition (a switch in culture resistance to the introduction of new technology such as tractors to plow fields); (4) H-E systems are hierarchical in nature and because of the many cross-scale linkages and feedbacks, adaptation, surprises and self-organization are the norm; and (5) lastly, "solving" land degradation problems cannot be accomplished without drawing upon the firsthand experience and insights (local knowledge) of local stakeholders. For the past 7 years, ARIDnet-AMERICAS, an NSF-supported coordination research network, has applied these five principles via 11 case studies at diverse locations in Argentina, Bolivia, Chile, Columbia, Honduras, Mexico and the United States with the goal to compare and contrast the causes and processes of land degradation and their effects on the balance between the demand for, and supply of, ecosystem services. We present a summary of our initial synthesis. The causal human-environmental processes driving land degradation (e.g., overgrazing, government policies, international markets) are often similar but with differing levels of

  6. The possibility of crop cultivation and utilization of edible gum from herb (Dorema ammoniacum D. Don in dryland farming

    Directory of Open Access Journals (Sweden)

    Gholami Barat Ali

    2015-01-01

    Full Text Available Gum ammoniacum (Dorema ammoniacum D. Don is one of the most important food, industrial and medicinal plants of Iran which is mainly distributed in semi-arid and desert areas. It is endangered due to superfluous and unsustainable harvesting methods. The objective of this study was to evaluate the possibility of crop cultivation in terms of dryland farming and the best operation method for collecting gum resin. For this purpose, the effects of different scarification methods (traditional, concave and staircase and cut-off frequencies (5, 10 and 13 times on gum yield of the five-year-old plants were studied at Toroq farm in Mashhad. The treatments were studied under a split plot structure in time experiment which was arranged in a completely randomized design with three replications. The rate of the root gum production and the rate of plant survival in the years after the withdrawal were measured, and finally the data were analyzed. Results showed no significant differences among cutting methods at p<0.05. The yield of gum was affected by times of harvesting and the highest yield was observed (p<0.01 in 13 cut-off times with 31.67 g/plant. The lowest gum yields were seen in 5 cut-off times with 5.84 g/plant. The traditional cutting method destroyed crown buds and caused the death of the plant (p<0.01. Reasonable gum yields and plant regeneration rates were obtained with the use of stairs method which is an easy method to be applied by the farmers or beneficiaries.

  7. Dryland systems

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2006-01-01

    Full Text Available of the drylands and their impaired development. The chapter also explores options for the sustainable use of drylands and points to human and societal responses that have succeeded or failed. ‘‘Desertification’’ means land degradation in arid, semiarid, and dry...

  8. Long-term effect of manure and fertilizer on soil organic carbon pools in dryland farming in northwest China.

    Science.gov (United States)

    Liu, Enke; Yan, Changrong; Mei, Xurong; Zhang, Yanqing; Fan, Tinglu

    2013-01-01

    An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. The objectives of this study were to investigate the effects of long-term fertilization on SOC and SOC fractions for the whole soil profile (0-100 cm) in northwest China. The study was initiated in 1979 in Gansu, China and included six treatments: unfertilized control (CK), nitrogen fertilizer (N), nitrogen and phosphorus (P) fertilizers (NP), straw plus N and P fertilizers (NP+S), farmyard manure (FYM), and farmyard manure plus N and P fertilizers (NP+FYM). Results showed that SOC concentration in the 0-20 cm soil layer increased with time except in the CK and N treatments. Long-term fertilization significantly influenced SOC concentrations and storage to 60 cm depth. Below 60 cm, SOC concentrations and storages were statistically not significant between all treatments. The concentration of SOC at different depths in 0-60 cm soil profile was higher under NP+FYM follow by under NP+S, compared to under CK. The SOC storage in 0-60 cm in NP+FYM, NP+S, FYM and NP treatments were increased by 41.3%, 32.9%, 28.1% and 17.9%, respectively, as compared to the CK treatment. Organic manure plus inorganic fertilizer application also increased labile soil organic carbon pools in 0-60 cm depth. The average concentration of particulate organic carbon (POC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) in organic manure plus inorganic fertilizer treatments (NP+S and NP+FYM) in 0-60 cm depth were increased by 64.9-91.9%, 42.5-56.9%, and 74.7-99.4%, respectively, over the CK treatment. The POC, MBC and DOC concentrations increased linearly with increasing SOC content. These results indicate that long-term additions of organic manure have the most beneficial effects in building carbon pools among the investigated types of fertilization.

  9. Long-term effect of manure and fertilizer on soil organic carbon pools in dryland farming in northwest China.

    Directory of Open Access Journals (Sweden)

    Enke Liu

    Full Text Available An understanding of the dynamics of soil organic carbon (SOC as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. The objectives of this study were to investigate the effects of long-term fertilization on SOC and SOC fractions for the whole soil profile (0-100 cm in northwest China. The study was initiated in 1979 in Gansu, China and included six treatments: unfertilized control (CK, nitrogen fertilizer (N, nitrogen and phosphorus (P fertilizers (NP, straw plus N and P fertilizers (NP+S, farmyard manure (FYM, and farmyard manure plus N and P fertilizers (NP+FYM. Results showed that SOC concentration in the 0-20 cm soil layer increased with time except in the CK and N treatments. Long-term fertilization significantly influenced SOC concentrations and storage to 60 cm depth. Below 60 cm, SOC concentrations and storages were statistically not significant between all treatments. The concentration of SOC at different depths in 0-60 cm soil profile was higher under NP+FYM follow by under NP+S, compared to under CK. The SOC storage in 0-60 cm in NP+FYM, NP+S, FYM and NP treatments were increased by 41.3%, 32.9%, 28.1% and 17.9%, respectively, as compared to the CK treatment. Organic manure plus inorganic fertilizer application also increased labile soil organic carbon pools in 0-60 cm depth. The average concentration of particulate organic carbon (POC, dissolved organic carbon (DOC and microbial biomass carbon (MBC in organic manure plus inorganic fertilizer treatments (NP+S and NP+FYM in 0-60 cm depth were increased by 64.9-91.9%, 42.5-56.9%, and 74.7-99.4%, respectively, over the CK treatment. The POC, MBC and DOC concentrations increased linearly with increasing SOC content. These results indicate that long-term additions of organic manure have the most beneficial effects in building carbon pools among the investigated types of fertilization.

  10. Priority regions for research on dryland cereals and legumes

    Science.gov (United States)

    Hyman, Glenn; Barona, Elizabeth; Biradar, Chandrashekhar; Guevara, Edward; Dixon, John; Beebe, Steve; Castano, Silvia Elena; Alabi, Tunrayo; Gumma, Murali Krishna; Sivasankar, Shoba; Rivera, Ovidio; Espinosa, Herlin; Cardona, Jorge

    2016-01-01

    Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes. PMID:27303632

  11. Priority regions for research on dryland cereals and legumes [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Glenn Hyman

    2016-05-01

    Full Text Available Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes.

  12. Priority regions for research on dryland cereals and legumes [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Glenn Hyman

    2016-07-01

    Full Text Available Dryland cereals and legumes  are important crops in farming systems across the world.  Yet they are frequently neglected among the priorities for international agricultural research and development, often due to lack of information on their magnitude and extent. Given what we know about the global distribution of dryland cereals and legumes, what regions should be high priority for research and development to improve livelihoods and food security? This research evaluated the geographic dimensions of these crops and the farming systems where they are found worldwide. The study employed geographic information science and data to assess the key farming systems and regions for these crops. Dryland cereal and legume crops should be given high priority in 18 farming systems worldwide, where their cultivated area comprises more than 160 million ha. These regions include the dryer areas of South Asia, West and East Africa, the Middle East and North Africa, Central America and other parts of Asia. These regions are prone to drought and heat stress, have limiting soil constraints, make up half of the global population and account for 60 percent of the global poor and malnourished. The dryland cereal and legume crops and farming systems merit more research and development attention to improve productivity and address development problems. This project developed an open access dataset and information resource that provides the basis for future analysis of the geographic dimensions of dryland cereals and legumes.

  13. Global temperate drylands climate change vulnerability

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in distribution and...

  14. Modeling Responses of Dryland Spring Triticale, Proso Millet and Foxtail Millet to Initial Soil Water in the High Plains

    Science.gov (United States)

    Dryland farming strategies in the High Plains must make efficient use of limited and variable precipitation and stored water in the soil profile for stable and sustainable farm productivity. Current research efforts focus on replacing summer fallow in the region with more profitable and environmenta...

  15. A case study of energy use and economical analysis of irrigated and dryland wheat production systems

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Reza; Mondani, Farzad; Amirmoradi, Shahram; Feizi, Hassan; Khorramdel, Surror; Teimouri, Mozhgan; Sanjani, Sara; Anvarkhah, Sepideh; Aghel, Hassan [Faculty of Agriculture, Ferdowsi University of Mashhad, P.O. Box 91775-1163, Mashhad (Iran)

    2011-01-15

    Current conventional agricultural systems using intensive energy has to be re-vitalized by new integrated approaches relying on renewable energy resources, which can allow farmers to stop depending on fossil resources. The aim of the present study was to compare wheat production in dryland (low input) and irrigated (high input) systems in terms of energy ratio, energy efficiency, benefit/cost ratio and amount of renewable energy use. Data were collected from 50 irrigated and 50 dryland wheat growers by using a face-to-face questionnaire in 2009. The results showed that the total energy requirement under low input was 9354.2 MJ ha{sup -1}, whereas under high input systems it was 45367.6 MJ ha{sup -1}. Total energy input consumed in both dryland and irrigated systems could be classified as direct, indirect, renewable and non-renewable energies which average in two wheat production systems were 47%, 53%, 24% and 76%, respectively. Energy ratios of 3.38 in dryland and 1.44 in irrigated systems were achieved. The benefit-cost ratios were 2.56 in dryland and 1.97 in irrigated wheat production systems. Based on the results of the present study, dry-land farming can have a significant positive effect on energy-related factors especially in dry and semi-dry climates such as Iran. (author)

  16. Accelerated dryland expansion under climate change

    Science.gov (United States)

    Huang, Jianping; Yu, Haipeng; Guan, Xiaodan; Wang, Guoyin; Guo, Ruixia

    2016-02-01

    Drylands are home to more than 38% of the total global population and are one of the most sensitive areas to climate change and human activities. Projecting the areal change in drylands is essential for taking early action to prevent the aggravation of global desertification. However, dryland expansion has been underestimated in the Fifth Coupled Model Intercomparison Project (CMIP5) simulations considering the past 58 years (1948-2005). Here, using historical data to bias-correct CMIP5 projections, we show an increase in dryland expansion rate resulting in the drylands covering half of the global land surface by the end of this century. Dryland area, projected under representative concentration pathways (RCPs) RCP8.5 and RCP4.5, will increase by 23% and 11%, respectively, relative to 1961-1990 baseline, equalling 56% and 50%, respectively, of total land surface. Such an expansion of drylands would lead to reduced carbon sequestration and enhanced regional warming, resulting in warming trends over the present drylands that are double those over humid regions. The increasing aridity, enhanced warming and rapidly growing human population will exacerbate the risk of land degradation and desertification in the near future in the drylands of developing countries, where 78% of dryland expansion and 50% of the population growth will occur under RCP8.5.

  17. 休闲期耕作配施磷肥对旱地小麦越冬期幼苗生长的影响%Effect of Fallow Farming with Phosphorus Fertilization on Seedling Growth of Dryland Over-wintering Wheat

    Institute of Scientific and Technical Information of China (English)

    白冬; 高志强; 李光; 赵红梅; 任爱霞; 孙敏; 杨珍平

    2012-01-01

    采用大田试验,研究了休闲期不同耕作配施磷肥对旱地小麦越冬期幼苗生长特性的影响.结果表明,旱地小麦休闲期深松较深翻可显著提高越冬期0~ 60 cm土壤蓄水量以及小麦幼苗的分蘖数、单株叶面积、单株干物质量、根系活力、可溶性糖含量、氮素积累量,可提高低磷(LP)、中磷(MP)条件下植株含氮率;且增加施磷量均可显著提高越冬期0~60 cm土壤蓄水量,可增加分蘖数、主茎叶龄、单株叶面积、根系活力、植株含氮率及其氮素积累量;单株干物质量在深松条件下以高磷(HP)最高,在深翻条件下以MP最高,且休闲期深松较深翻有利于磷的吸收.%Field experiment was carried out to study the effect of different fallow farming with phosphorus fertilization on seedling growth characteristics of dryland wheat. The results showed that fallow deep loosening could significantly improve the 0 -60 cm soil water storage capacity of dryland over-wintering wheat than deep tillage, and increasing of phosphorus fertilization could significantly improve the 0 ~ 60 cm soil water storage capacity, and improve the tiller number, leaf area, plant weight, root activity, soluble sugar content, and nitrogen accumulation content, and could also improve plant nitrogen rate in LP, MP conditions. Increasing the application of phosphorus fertilizer could improve the tiller number, main stem leaf age, leaf area, root activity, nitrogen content, and nitrogen accumulation content. Among plant dry mass in the deep loose condition, and HP was the highest; in deep tillage condition, MP was the highest. Fallow deep loosening could increase the effect of phosphorus fertilization rather than deep tillage.

  18. Re-spacing African drylands

    DEFF Research Database (Denmark)

    Korf, Benedikt; Hagmann, Tobias; Emmenegger, Rony Hugo

    2015-01-01

    This paper traces the re-spacing of pastoral drylands in Africa. We argue that rendering pastoral resources legible and profitable occurs both within and beyond the state. Through a multi-sited case study from Ethiopia's Somali region, we excavate different mechanisms of sedentarization, whereby...... claims to territory, capital investment and new technopolitics through which indigenous (pastoral, Somali) merchants and politicians become complicit with the state's project of territorialization and sedentarization in a self-governing fashion. The irony of this situation is that the (Ethiopian) state...... has failed to consolidate sedentarization through planned interventions. Instead, capital investment by local and transnational Somali merchants has opened up a neoliberal frontier that re-spaces drylands towards increasing sedentarization....

  19. Nested archetypes of vulnerability in African drylands: where lies potential for sustainable agricultural intensification?

    Science.gov (United States)

    Sietz, D.; Ordoñez, J. C.; Kok, M. T. J.; Janssen, P.; Hilderink, H. B. M.; Tittonell, P.; Van Dijk, H.

    2017-09-01

    Food production is key to achieving food security in the drylands of sub-Saharan Africa. Since agricultural productivity is limited, however, due to inherent agro-ecological constraints and land degradation, sustainable agricultural intensification has been widely discussed as an opportunity for improving food security and reducing vulnerability. Yet vulnerability determinants are distributed heterogeneously in the drylands of sub-Saharan Africa and sustainable intensification cannot be achieved everywhere in cost-effective and efficient ways. To better understand the heterogeneity of farming systems’ vulnerability in order to support decision making at regional scales, we present archetypes, i.e. socio-ecological patterns, of farming systems’ vulnerability in the drylands of sub-Saharan Africa and reveal their nestedness. We quantitatively indicated the most relevant farming systems’ properties at a sub-national resolution. These factors included water availability, agro-ecological potential, erosion sensitivity, population pressure, urbanisation, remoteness, governance, income and undernourishment. Cluster analysis revealed eight broad archetypes of vulnerability across all drylands of sub-Saharan Africa. The broad archetype representing better governance and highest remoteness in extremely dry and resource-constrained regions encompassed the largest area share (19%), mainly indicated in western Africa. Moreover, six nested archetypes were identified within those regions with better agropotential and prevalent agricultural livelihoods. Among these patterns, the nested archetype depicting regions with highest erosion sensitivity, severe undernourishment and lower agropotential represented the largest population (30%) and area (28%) share, mainly found in the Sahel region. The nested archetype indicating medium undernourishment, better governance and lowest erosion sensitivity showed particular potential for sustainable agricultural intensification, mainly in

  20. Confronting Drought in Africa’s Drylands

    OpenAIRE

    Cervigni, Raffaello; Morris, Michael

    2016-01-01

    Drylands make up about 43 percent of the region’s land surface, account for about 75 percent of the area used for agriculture, and are home to about 50 percent of the population, including many poor. Involving complex interactions among many factors, vulnerability in drylands is rising, jeopardizing the livelihood for of millions.

  1. Dryland maize yields and water use efficiency in response to tillage/crop stubble and nutrient management practices in China

    NARCIS (Netherlands)

    Wang, X.B.; Dai, K.; Zhang, D.; Zhang, X.; Wang, Y.; Zhao, Q.; Cai, D.X.; Hoogmoed, W.B.; Oenema, O.

    2011-01-01

    Rainfed crop production in northern China is constrained by low and variable rainfall. This study explored the effects of tillage/crop residue and nutrient management practices on maize (Zea mays L.) yield, water use efficiency (WUE), and N agronomic use efficiency (NAE) at Shouyang Dryland Farming

  2. Dryland maize yields and water use efficiency in response to tillage and nutrient management practices in China

    NARCIS (Netherlands)

    Wang, X.B.; Dai, K.; Zhao, Q.; Cai, D.X.; Hoogmoed, W.B.; Oenema, O.

    2009-01-01

    Rainfed crop production in northern China is constrained by low and variable rainfall. This study explored the effects of tillage and nutrient management practices on maize (Zea mays L.) yield and water use efficiency (WUE), at Shouyang Dryland Farming Experimental Station in northern China during 2

  3. The extent of forest in dryland biomes

    Science.gov (United States)

    Jean-Francois Bastin; Nora Berrahmouni; Alan Grainger; Danae Maniatis; Danilo Mollicone; Rebecca Moore; Chiara Patriarca; Nicolas Picard; Ben Sparrow; Elena Maria Abraham; Kamel Aloui; Ayhan Atesoglu; Fabio Attore; Caglar Bassullu; Adia Bey; Monica Garzuglia; Luis G. GarcÌa-Montero; Nikee Groot; Greg Guerin; Lars Laestadius; Andrew J. Lowe; Bako Mamane; Giulio Marchi; Paul Patterson; Marcelo Rezende; Stefano Ricci; Ignacio Salcedo; Alfonso Sanchez-Paus Diaz; Fred Stolle; Venera Surappaeva; Rene Castro

    2017-01-01

    Dryland biomes cover two-fifths of Earth’s land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high...

  4. A New Dryland Development Paradigm Grounded in Empirical Analysis of Dryland Systems Science

    NARCIS (Netherlands)

    Stringer, Lindsay C.; Reed, Mark S.; Fleskens, Luuk; Thomas, Richard J.; Le, Quang Bao; Lala-Pritchard, Tana

    2017-01-01

    Global drylands face a host of urgent human and environmental challenges with far-reaching impacts. Improving smallholder agriculture remains a key development pathway to tackle these challenges. The dryland development paradigm (DDP), introduced in 2007, presented a highly influential framework

  5. Mechanisms of Physiological Regulation for Improving Dryland Crop Water Use

    Institute of Scientific and Technical Information of China (English)

    SHANGGUAN Zhou-ping; XUE Qing-wu

    2003-01-01

    This paper briefly reviews the physiological mechanisms for improving crop water use and water use efficiency in dryland farming regions of Loess Plateau on the basis of its environmental conditions and progress in crop water relations and the biological basis of water-saving agriculture, especially in non-uniform stomatal closure, ABA effects, communication between root and shoot, and water use efficiency. Root chemical signals about water shortage are feedforward effect which contributes to balanced water relations within the plant compartment of the soil-plant-atmosphere continuum. ABA production is increased in tissues during these stresses, and this causes a variety of physiological effects, including stomata closure in leaves. It is concluded that the root chemical signal ABA is very important to improve the crop water use efficiency in semi-arid area of Loess Plateau.

  6. Expansion of World Drylands Under Global Warming

    Science.gov (United States)

    Feng, S.; Fu, Q.; Hu, Q. S.

    2012-12-01

    The world drylands including both semi-arid and arid regions comprise of one-third of the global land surfaces, which support 14% of the world's inhabitants and a significant share of the world agriculture. Because of meager annual precipitation and large potential evaporative water loss, the ecosystems over drylands are fragile and sensitive to the global change. By analyzing the observations during 1948-2008 and 20 fully coupled climate model simulations from CMIP5 for the period 1900-2100, this study evaluated the changes of the world drylands that are defined with a modified form of the Thornthwaite's moisture index. The results based on observational data showed that the world drylands are steadily expanding during the past 60 years. The areas occupied by drylands in 1994-2008 is about 2.0×10^6km^2 (or 4%) larger than the average during the 1950s. Such an expansion is also a robust feature in the simulations of the 20 global climate models, though the rate is much smaller in the models. A stronger expanding rate is projected during the first half of this century than the simulations in the last century, followed by accelerating expansion after 2050s under the high greenhouse gas emission scenario (RCP8.5). By the end of this century, the world drylands are projected to be over 58×10^6km^2 (or 11% increase compared to the 1961-1990 climatology). The projected expansion of drylands, however, is not homogeneous over the world drylands, with major expansion of arid regions over the southwest North America, the northern fringe of Africa, southern Africa and Australia. Major expansions of semi-arid regions are projected over the north side of the Mediterranean, southern Africa, North and South America. The global warming is the main factor causing the increase of potential evapotranspiration estimated by Penman-Monteith algorithm, which in turn dominants the expansion of drylands. The widening of Hadley cell, which has impact on both temperature and precipitation

  7. Considerations on Sustainable Agriculture and Rural Development in Dryland Areas

    Institute of Scientific and Technical Information of China (English)

    LI Li; TSUNEKAWA Atsushi; TSUBO Mitsuru; KOIKE Atsushi

    2010-01-01

    Drylands of the world cover 41% of the Earth's land surface and are a direct source of livelihood for 6.5 billion people, especially in developing countries. However, nearly all drylands are at risk of land degradation as a result of human activities. Poverty and desertification in dryland areas are major problems threatening sustainable agriculture and rural development in dryland areas. Several topics that are significant for sustainable agriculture and rural development for food security and environmental rehabilitation in dryland areas were stressed in this paper.

  8. Biological phosphorus cycling in dryland regions

    Science.gov (United States)

    Belnap, Jayne; Bunemann, Else; Oberson, Astrid; Frossard, Emmanuel

    2011-01-01

    The relatively few studies done on phosphorus (P) cycling in arid and semiarid lands (drylands) show many factors that distinguish P cycling in drylands from that in more mesic regions. In drylands, most biologically relevant P inputs and losses are from the deposition and loss of dust. Horizontal and vertical redistribution of P is an important process. P is concentrated at the soil surface and thus vulnerable to loss via erosion. High pH and CaCO3 limit P bioavailability, and low rainfall limits microbe and plant ability to free abiotically bound P via exudates, thus making it available for uptake. Many invasive plants are able to access recalcitrant P more effectively than are native plants. As P availability depends on soil moisture and temperature, climate change is expected to have large impacts on P cycling

  9. The extent of forest in dryland biomes.

    Science.gov (United States)

    Bastin, Jean-François; Berrahmouni, Nora; Grainger, Alan; Maniatis, Danae; Mollicone, Danilo; Moore, Rebecca; Patriarca, Chiara; Picard, Nicolas; Sparrow, Ben; Abraham, Elena Maria; Aloui, Kamel; Atesoglu, Ayhan; Attore, Fabio; Bassüllü, Çağlar; Bey, Adia; Garzuglia, Monica; García-Montero, Luis G; Groot, Nikée; Guerin, Greg; Laestadius, Lars; Lowe, Andrew J; Mamane, Bako; Marchi, Giulio; Patterson, Paul; Rezende, Marcelo; Ricci, Stefano; Salcedo, Ignacio; Diaz, Alfonso Sanchez-Paus; Stolle, Fred; Surappaeva, Venera; Castro, Rene

    2017-05-12

    Dryland biomes cover two-fifths of Earth's land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high temporal resolution, which are available through the Google Earth platform. We show that in 2015, 1327 million hectares of drylands had more than 10% tree-cover, and 1079 million hectares comprised forest. Our estimate is 40 to 47% higher than previous estimates, corresponding to 467 million hectares of forest that have never been reported before. This increases current estimates of global forest cover by at least 9%. Copyright © 2017, American Association for the Advancement of Science.

  10. Monitoring and Assessment of US Drylands

    Science.gov (United States)

    Washington-Allen, R. A.; Johnson, J. S.; van Riper, C.; Modala, N. R.; Barnes, M.; Brademan, C.; Bruton, R.; Delgado, A.; Kim, J.; March, R.; Saenz, N.; Srinivasan, S.; Reeves, M. C.

    2012-12-01

    Monitoring of drylands requires time scales of 15 years or more in order to replicate twice the major climatic phenomena such as El Niño that have both proximal and ultimate consequences in this ecosystems. Spatially, federal agencies such as the USFS must comply with laws that request they report the condition and trend of US drylands at the national spatial scale. The MODIS sensor on both TERRA and AQUA platforms has been collecting data operational data since 2000 that include value added products such as the enhanced vegetation index (EVI), leaf area index (LAI), Land Cover, Burn Area, and net primary productivity (NPP) that can provide multiple indicators of Dryland condition and trend for now 13-years. Consequently, this sensor meets the space and time criteria necessary to begin monitoring US drylands. Additionally, the USDA National Agricultural Statistics Service has been collecting data on the spatial distribution and numbers of livestock including sheep, goats, and cattle, since the 1890's and contemporary and reconstructed climatic records at national scales go back even further in time. Time series data on climatic and land management drivers provides a basis for assessment of the causes of possible land degradation. We provide here an assessment of US Dryland condition and trend in regards to multiple indicators including land cover change in patch dynamics, NPP, and land surface temperature. For instance we show that from 2000 to 2011 US Drylands exhibit a net carbon gain that is reflected in increased connectivity of US grasslands, but conversely a decrease in surface temperatures that are indicative of increased woody encroachment. We also show that both climate, particularly drought, and livestock grazing are drivers of these dynamics.

  11. Nitrogen Rates for Dryland Triticale Hay

    Science.gov (United States)

    Dryland farmers/ranchers in the CGPR have recently taken an interest in triticale as a hay crop. Triticale is well adapted and its forage is palatable and nutritionally competitive with other annual forages grown in the region. On deficient soils, triticale’s forage-yield response to applied fertili...

  12. Remote sensing of vegetation dynamics in drylands

    DEFF Research Database (Denmark)

    Tian, Feng; Brandt, Martin Stefan; Liu, Yi Y.

    2016-01-01

    Monitoring long-term biomass dynamics in drylands is of great importance for many environmental applications including land degradation and global carbon cycle modeling. Biomass has extensively been estimated based on the normalized difference vegetation index (NDVI) as a measure of the vegetatio...

  13. Improving evapotranspiration estimates in Mediterranean drylands

    DEFF Research Database (Denmark)

    Morillas, Laura; Leuning, Ray; Villagarcia, Luis

    2013-01-01

    measurements from eddy covariance systems located in two functionally different sparsely vegetated drylands sites: a littoral Mediterranean semiarid steppe and a dry-subhumid Mediterranean montane site. The method providing the best results in both areas was fdrying (mean absolute error of 0.17 mm day−1) which...

  14. Nested archetypes of vulnerability in African drylands

    NARCIS (Netherlands)

    Sietz, D.; Ordoñez, J.; Kok, M.; Janssen, P.; Hilderink, H.; Tittonell, P.A.; Dijk, H.

    2017-01-01

    Food production is key to achieving food security in the drylands of sub-Saharan Africa. Since agricultural productivity is limited, however, due to inherent agro-ecological constraints and land degradation, sustainable agricultural intensification has been widely discussed as an opportunity for

  15. Sustainable land management (SLM) practices in drylands: how do they address desertification threats?

    Science.gov (United States)

    Schwilch, G; Liniger, H P; Hurni, H

    2014-11-01

    Managing land sustainably is a huge challenge, especially under harsh climatic conditions such as those found in drylands. The socio-economic situation can also pose challenges, as dryland regions are often characterized by remoteness, marginality, low-productive farming, weak institutions, and even conflict. With threats from climate change, disputes over water, competing claims on land, and migration increasing worldwide, the demands for sustainable land management (SLM) measures will only increase in the future. Within the EU-funded DESIRE project, researchers and stakeholders jointly identified existing SLM technologies and approaches in 17 dryland study sites located in the Mediterranean and around the world. In order to evaluate and share this valuable SLM experience, local researchers documented the SLM technologies and approaches in collaboration with land users, utilizing the internationally recognized WOCAT questionnaires. This article provides an analysis of 30 technologies and 8 approaches, enabling an initial evaluation of how SLM addresses prevalent dryland threats, such as water scarcity, soil degradation, vegetation degradation and low production, climate change, resource use conflicts, and migration. Among the impacts attributed to the documented technologies, those mentioned most were diversified and enhanced production and better management of water and soil degradation, whether through water harvesting, improving soil moisture, or reducing runoff. Favorable local-scale cost-benefit relationships were mainly found when considered over the long term. Nevertheless, SLM was found to improve people's livelihoods and prevent further outmigration. More field research is needed to reinforce expert assessments of SLM impacts and provide the necessary evidence-based rationale for investing in SLM.

  16. Navigating challenges and opportunities of land degradation and sustainable livelihood development in dryland social-ecological systems: a case study from Mexico.

    Science.gov (United States)

    Huber-Sannwald, Elisabeth; Palacios, Mónica Ribeiro; Moreno, José Tulio Arredondo; Braasch, Marco; Peña, Ruth Magnolia Martínez; Verduzco, Javier García de Alba; Santos, Karina Monzalvo

    2012-11-19

    Drylands are one of the most diverse yet highly vulnerable social-ecological systems on Earth. Water scarcity has contributed to high levels of heterogeneity, variability and unpredictability, which together have shaped the long coadaptative process of coupling humans and nature. Land degradation and desertification in drylands are some of the largest and most far-reaching global environmental and social change problems, and thus are a daunting challenge for science and society. In this study, we merged the Drylands Development Paradigm, Holling's adaptive cycle metaphor and resilience theory to assess the challenges and opportunities for livelihood development in the Amapola dryland social-ecological system (DSES), a small isolated village in the semi-arid region of Mexico. After 450 years of local social-ecological evolution, external drivers (neoliberal policies, change in land reform legislation) have become the most dominant force in livelihood development, at the cost of loss of natural and cultural capital and an increasingly dysfunctional landscape. Local DSESs have become increasingly coupled to dynamic larger-scale drivers. Hence, cross-scale connectedness feeds back on and transforms local self-sustaining subsistence farming conditions, causing loss of livelihood resilience and diversification in a globally changing world. Effective efforts to combat desertification and improve livelihood security in DSESs need to consider their cyclical rhythms. Hence, we advocate novel dryland stewardship strategies, which foster adaptive capacity, and continuous evaluation and social learning at all levels. Finally, we call for an effective, flexible and viable policy framework that enhances local biotic and cultural diversity of drylands to transform global drylands into a resilient biome in the context of global environmental and social change.

  17. Microbial colonization and controls in dryland systems

    Science.gov (United States)

    Pointing, Stephen B.; Belnap, Jayne

    2012-01-01

    Drylands constitute the most extensive terrestrial biome, covering more than one-third of the Earth's continental surface. In these environments, stress limits animal and plant life, so life forms that can survive desiccation and then resume growth following subsequent wetting assume the foremost role in ecosystem processes. In this Review, we describe how these organisms assemble in unique soil- and rock-surface communities to form a thin veneer of mostly microbial biomass across hot and cold deserts. These communities mediate inputs and outputs of gases, nutrients and water from desert surfaces, as well as regulating weathering, soil stability, and hydrological and nutrient cycles. The magnitude of regional and global desert-related environmental impacts is affected by these surface communities; here, we also discuss the challenges for incorporating the consideration of these communities and their effects into the management of dryland resources.

  18. Remote sensing of vegetation dynamics in drylands

    DEFF Research Database (Denmark)

    Tian, Feng; Brandt, Martin Stefan; Liu, Yi Y.

    2016-01-01

    Monitoring long-term biomass dynamics in drylands is of great importance for many environmental applications including land degradation and global carbon cycle modeling. Biomass has extensively been estimated based on the normalized difference vegetation index (NDVI) as a measure of the vegetation...... greenness. The vegetation optical depth (VOD) derived from satellite passive microwave observations is mainly sensitive to the water content in total aboveground vegetation layer. VOD therefore provides a complementary data source to NDVI for monitoring biomass dynamics in drylands, yet further evaluations...... based on ground measurements are needed for an improved understanding of the potential advantages. In this study, we assess the capability of a long-term VOD dataset (1992-2011) to capture the temporal and spatial variability of in situ measured green biomass (herbaceous mass and woody plant foliage...

  19. Regime shifts in models of dryland vegetation

    CERN Document Server

    Zelnik, Yuval R; Yizhaq, Hezi; Bel, Golan; Meron, Ehud

    2013-01-01

    Drylands are pattern-forming systems showing self-organized vegetation patchiness, multiplicity of stable states and fronts separating domains of alternative stable states. Pattern dynamics, induced by droughts or disturbances, can result in desertification shifts from patterned vegetation to bare soil. Pattern-formation theory suggests various scenarios for such dynamics; an abrupt global shift involving a fast collapse to bare soil, a gradual global shift involving the expansion and coalescence of bare-soil domains, and an incipient shift to a hybrid state consisting of stationary bare-soil domains in an otherwise periodic pattern. Using models of dryland vegetation we address the question which of these scenarios can be realized. We found that the models can be split into two groups: models that exhibit multiplicity of periodic-pattern and bare-soil states, and models that exhibit, in addition, multiplicity of hybrid states. Furthermore, in all models we could not identify parameter regimes in which bare-s...

  20. Ecology, equity and economics: reframing dryland policy

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, Ced

    2011-11-15

    Drylands are among the world's most variable and unpredictable environments. But people here have long learnt how to live with and harness this variability to support sustainable and productive economies, societies and ecosystems. Policymakers have for too long ignored this wealth of experience and expertise with dire consequences. Attempts to replace traditional land use practices with modern techniques have simply exacerbated poverty, degradation and conflict. In the face of climate change and increasing uncertainty in the drylands, the need to reframe policy and practice has never been greater. The future must be built on sound scientific information, local knowledge, informed participation and the wisdom of customary institutions that emphasise social equity, ecological integrity and economic development.

  1. Effects of Super Absorbent Resin on Leaf Water Use Efficiency and Yield in Dry-land Wheat

    Directory of Open Access Journals (Sweden)

    Liyuan Yan

    2013-06-01

    Full Text Available The effect of Super Absorbent Resin (SAR on soil characteristics and production of wheat was conducted to study in a potted cultivated experiment, with Jimai 22 as experimental material and adopted single factor block design under the dry farming condition. The results show that: the application of SAR in dry-land wheat, increases degree of soil Relative water content among the whole growth period, especially in tiller stage, heading stage, grain-filling stage, but in Jointing stage and mature stage (require less water, it effected less obviously. Within a certain range, SAR can increase leaf water use efficiency in dry-land wheat and the more SAR, the bigger soil water content and leaf water use efficiency. But litter effect on Wheat Soil hydrogen ion concentration (pH. The SAR has positive impact on wheat yield component factors and yield

  2. Categorisation of typical vulnerability patterns in global drylands

    NARCIS (Netherlands)

    Sietz, D.; Lûdeke, M.K.B.; Walther, C.

    2011-01-01

    Drylands display specific vulnerability-creating mechanisms which threaten ecosystems and human well-being. The upscaling of successful interventions to reduce vulnerability arises as an important, but challenging aim, since drylands are not homogenous. To support this aim, we present the first atte

  3. Dryland ecohydrology and climate change: critical issues and technical advances

    Directory of Open Access Journals (Sweden)

    L. Wang

    2012-04-01

    Full Text Available Drylands cover about 40% of the terrestrial land surface and account for approximately 40% of global net primary productivity. Water is fundamental to the biophysical processes that sustain ecosystem function and food production, particularly in drylands, where a tight coupling exists between water resource availability and ecosystem productivity, surface energy balance, and biogeochemical cycles. Currently, drylands support at least 2 billion people and comprise both natural and managed ecosystems. In this synthesis, we identify some current critical issues in the understanding of dryland systems and discuss how arid and semiarid environments are responding to the changes in climate and land use. Specifically, we focus on dryland agriculture and food security, dryland population growth, desertification, shrub encroachment and dryland development issues as factors of change requiring increased understanding and management. We also review recent technical advances in the quantitative assessment of human versus climate change related drivers of desertification, evapotranspiration partitioning using field deployable stable water isotope systems and the remote sensing of key ecohydrological processes. These technological advances provide new tools that assist in addressing major critical issues in dryland ecohydrology under climate change

  4. Categorisation of typical vulnerability patterns in global drylands

    NARCIS (Netherlands)

    Sietz, D.; Lûdeke, M.K.B.; Walther, C.

    2011-01-01

    Drylands display specific vulnerability-creating mechanisms which threaten ecosystems and human well-being. The upscaling of successful interventions to reduce vulnerability arises as an important, but challenging aim, since drylands are not homogenous. To support this aim, we present the first atte

  5. Elevated CO2 as a driver of global dryland greening

    KAUST Repository

    Lu, Xuefei

    2016-02-12

    While recent findings based on satellite records indicate a positive trend in vegetation greenness over global drylands, the reasons remain elusive. We hypothesize that enhanced levels of atmospheric CO2 play an important role in the observed greening through the CO2 effect on plant water savings and consequent available soil water increases. Meta-analytic techniques were used to compare soil water content under ambient and elevated CO2 treatments across a range of climate regimes, vegetation types, soil textures and land management practices. Based on 1705 field measurements from 21 distinct sites, a consistent and statistically significant increase in the availability of soil water (11%) was observed under elevated CO2 treatments in both drylands and non-drylands, with a statistically stronger response over drylands (17% vs. 9%). Given the inherent water limitation in drylands, it is suggested that the additional soil water availability is a likely driver of observed increases in vegetation greenness.

  6. What controls sediment flux in dryland channels?

    Science.gov (United States)

    Michaelides, K.; Singer, M. B.

    2010-12-01

    Theories for the development of longitudinal and grain size profiles in perennial fluvial systems are well developed, allowing for generalization of sediment flux and sorting in these fluvial systems over decadal to millennial time scales under different forcings (e.g., sediment supply, climate changes, etc). However, such theoretical frameworks are inadequate for understanding sediment flux in dryland channels subject to spatially and temporally discontinuous streamflow, where transport capacity is usually much lower than sediment supply. In such fluvial systems, channel beds are poorly sorted with weak vertical layering, poorly defined bar forms, minimal downstream fining, and straight longitudinal profiles. Previous work in dryland channels has documented sediment flux at higher rates than their humid counterparts once significant channel flow develops, pulsations in bed material transport under constant discharge, and oscillations in dryland channel width that govern longitudinal patterns in erosion and deposition. These factors point to less well appreciated controls on sediment flux in dryland valley floors that invite further study. This paper investigates the relative roles of hydrology, bed material grain size, and channel width on sediment flux rates in the Rambla de Nogalte in southeastern Spain. Topographic valley cross sections and hillslope and channel particle sizes were collected from an ephemeral-river reach. Longitudinal grain-size variation on the hillslopes and on the channel bed were analysed in order to determine the relationship between hillslope supply characteristics and channel grain-size distribution and longitudinal changes. Local fractional estimates of bed-material transport in the channel were calculated using a range of channel discharge scenarios in order to examine the effect of channel hydrology on sediment transport. Numerical modelling was conducted to investigate runoff connectivity from hillslopes to channel and to examine the

  7. Pastoralism in the drylands of Latin America: Argentina, Chile, Mexico and Peru.

    Science.gov (United States)

    Grünwaldt, J M; Castellaro, G; Flores, E R; Morales-Nieto, C R; Valdez-Cepeda, R D; Guevera, J C; Grünwaldt, E G

    2016-11-01

    This article discusses various aspects of pastoralism in the Latin American countries with the largest dryland areas. The topics covered include: social, economic and institutional issues; grasslands and their carrying capacity; production systems and productivity rates; competition for forage resources between domestic livestock and wildlife; and the health status of livestock and wildlife. Most grasslands exhibit some degree of degradation. The percentage of offspring reaching weaning age is low: 47-66% of calves and 40-80% of lambs. Some pastoralists adopt patterns of transhumance. In the main, pastoralists experience a high poverty rate and have poor access to social services. For many pastoralists, wildlife is a source of food and by-products. Argentina, Chile, Mexico and Peru have animal health control agencies, are members of the World Organisation for Animal Health (OIE) and have signed the United Nations Convention to Combat Desertification. Pastoral systems subsist mainly on income unrelated to pastoral farming. The OIE recognises all four countries as free from infection with peste des petits ruminants virus, and from rinderpest and African horse sickness. It is difficult to predict the future of pastoralism in Latin America because the situation differs from country to country. For instance, pastoralism is more important in Peru than in Argentina, where it is a more marginal activity. In the future, lack of promotion and protection policies could lead to a decline in pastoralism or to an adverse environmental impact on drylands.

  8. Can biofuel crops alleviate tribal poverty in India's drylands?

    Energy Technology Data Exchange (ETDEWEB)

    Agoramoorthy, Govindasamy [College of Environmental and Health Sciences, Tajen University, Yanpu, Pingtung 907 (China); Sadguru Foundation, Dahod, Gujarat State (India); Hsu, Minna J. [Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804 (China); Chaudhary, Sunita [Sadguru Foundation, Dahod, Gujarat State (India); Shieh, Po-Chuen [College of Environmental and Health Sciences, Tajen University, Yanpu, Pingtung 907 (China)

    2009-11-15

    The on-going climate change concerns have stimulated heavy interest in biofuels, and supporters of biofuels hail that they are considered naturally carbon-neutral. Critiques on the other hand cry that the large-scale production of biofuels can not only strain agricultural resources, but also threaten future food security. People who live in the drylands of India are often faced with challenges and constraints of poverty. Foremost among the challenges are the marginal environmental conditions for agriculture, often influenced by low and erratic rainfall, frequent droughts, poor soil condition, unreliable irrigation water supply, and rural migration to urban areas in search of work. In this paper, we have analyzed a case study of community lift irrigation practiced in India and its impact in boosting agricultural productivity and enhancing local food security. The lift-irrigation model practiced in the drylands of India to grow food crops can be adopted for the expansion of biofuel crops that has the potential to eradicate poverty among farming communities if appropriate sustainable development measures are carefully implemented. (author)

  9. Structure and functioning of dryland ecosystems in a changing world

    Science.gov (United States)

    Maestre, Fernando T.; Eldridge, David J.; Soliveres, Santiago; Kéfi, Sonia; Delgado-Baquerizo, Manuel; Bowker, Matthew A.; García-Palacios, Pablo; Gaitán, Juan; Gallardo, Antonio; Lázaro, Roberto; Berdugo, Miguel

    2017-01-01

    Understanding how drylands respond to ongoing environmental change is extremely important for global sustainability. Here we review how biotic attributes, climate, grazing pressure, land cover change and nitrogen deposition affect the functioning of drylands at multiple spatial scales. Our synthesis highlights the importance of biotic attributes (e.g. species richness) in maintaining fundamental ecosystem processes such as primary productivity, illustrate how N deposition and grazing pressure are impacting ecosystem functioning in drylands worldwide, and highlight the importance of the traits of woody species as drivers of their expansion in former grasslands. We also emphasize the role of attributes such as species richness and abundance in controlling the responses of ecosystem functioning to climate change. This knowledge is essential to guide conservation and restoration efforts in drylands, as biotic attributes can be actively managed at the local scale to increase ecosystem resilience to global change. PMID:28239303

  10. The abiotic litter decomposition in the drylands

    Science.gov (United States)

    Lee, H.; Throop, H.; Rahn, T. A.

    2009-12-01

    The decomposition of litter is an important ecosystem function that controls carbon and nutrient cycling, which is well understood from the relationship between temperature and moisture. However, the decomposition in the arid and semiarid environments (hereafter drylands) is relatively poorly predicted due to several abiotic factors such as the effect of ultraviolet radiation and physical mixing of fallen litter with soil. The relative magnitude of these abiotic factors to ecosystem scale litter decomposition is still in debate. Here, we examine the effect of two major abiotic factors in the drylands litter decomposition by conducting a controlled laboratory study using plant litter and soil collected from Sonoran and Chihuahuan desert areas. The first part of the experiment focused on the effect of soil-litter mixing. We established a complete block design of three levels of soil and litter mixing (no mixing, light soil-litter mixing, and complete soil-litter mixing) in combination with three levels of soil moisture (1%, 2%, and 6% volumetric water content) using 2g of two most dominant species litter, grass and mesquite, and 50g of air-dried soils in 500ml mason jar and incubated them under 25C. We measured CO2 fluxes from these soil-litter incubations and harvested the soil and litter at 0, 1, 2, 4, 8, and 16 weeks and analyzed them of carbon and nitrogen content as well as the actual mass loss in the litter. The second part of the experiment focused on the effect of ultraviolet radiation. We established short-term litter incubation on a quartz chamber and used different temperature, moisture, and minerals to find the mechanism of photodegradation of litter. We measured CO2 fluxes from the litter incubation under ultraviolet radiation and also measured 13CO2 from these emissions. We were able to detect changes in the rate of carbon mineralization as a result of our treatments in the first week of soil-litter mixing experiment. The carbon mineralization rate was

  11. Earth Observation of Vegetation Dynamics in Global Drylands

    DEFF Research Database (Denmark)

    Tian, Feng

    and exploring the widely used long-term datasets and 2) mapping trends in woody vegetation. A highlight of the thesis is the mapping of trends in the non-green woody vegetation component in global tropical drylands, which is obtained for the first time from combing satellite optical and passive microwave...... trends in the woody cover between humid areas and drylands in Africa, which are explained by human activities and climate changes, respectively....

  12. Dryland ecohydrology and climate change: critical issues and technical advances

    Directory of Open Access Journals (Sweden)

    L. Wang

    2012-08-01

    Full Text Available Drylands cover about 40% of the terrestrial land surface and account for approximately 40% of global net primary productivity. Water is fundamental to the biophysical processes that sustain ecosystem function and food production, particularly in drylands where a tight coupling exists between ecosystem productivity, surface energy balance, biogeochemical cycles, and water resource availability. Currently, drylands support at least 2 billion people and comprise both natural and managed ecosystems. In this synthesis, we identify some current critical issues in the understanding of dryland systems and discuss how arid and semiarid environments are responding to the changes in climate and land use. The issues range from societal aspects such as rapid population growth, the resulting food and water security, and development issues, to natural aspects such as ecohydrological consequences of bush encroachment and the causes of desertification. To improve current understanding and inform upon the needed research efforts to address these critical issues, we identify some recent technical advances in terms of monitoring dryland water dynamics, water budget and vegetation water use, with a focus on the use of stable isotopes and remote sensing. These technological advances provide new tools that assist in addressing critical issues in dryland ecohydrology under climate change.

  13. Dryland ecohydrology and climate change: critical issues and technical advances

    Science.gov (United States)

    Wang, L.; D'Odorico, P.; Evans, J. P.; Eldridge, D. J.; McCabe, M. F.; Caylor, K. K.; King, E. G.

    2012-08-01

    Drylands cover about 40% of the terrestrial land surface and account for approximately 40% of global net primary productivity. Water is fundamental to the biophysical processes that sustain ecosystem function and food production, particularly in drylands where a tight coupling exists between ecosystem productivity, surface energy balance, biogeochemical cycles, and water resource availability. Currently, drylands support at least 2 billion people and comprise both natural and managed ecosystems. In this synthesis, we identify some current critical issues in the understanding of dryland systems and discuss how arid and semiarid environments are responding to the changes in climate and land use. The issues range from societal aspects such as rapid population growth, the resulting food and water security, and development issues, to natural aspects such as ecohydrological consequences of bush encroachment and the causes of desertification. To improve current understanding and inform upon the needed research efforts to address these critical issues, we identify some recent technical advances in terms of monitoring dryland water dynamics, water budget and vegetation water use, with a focus on the use of stable isotopes and remote sensing. These technological advances provide new tools that assist in addressing critical issues in dryland ecohydrology under climate change.

  14. Conservation tillage in dryland agriculture impacts watershed hydrology

    Science.gov (United States)

    Van Wie, J. B.; Adam, J. C.; Ullman, J. L.

    2013-03-01

    SummaryDryland (non-irrigated) crop production in semi-arid regions requires sufficient water storage in the soil profile to ensure adequate plant available water, particularly in areas where the majority of annual precipitation occurs during the non-growing season. Producers can increase soil water storage through the adoption of best management practices (BMPs) for tillage and crop residue management. The objective of this study was to assess our hypothesis that watershed-wide adoption of no-till (NT) farming would decrease winter water losses and increase early growing season plant available water as compared with conventional tillage (CT) methods. We analyzed water storage potential under assumed full-scale adoption of NT and CT cropping practices in the Palouse region of eastern Washington State by applying the Distributed Hydrology Soil Vegetation Model (DHSVM) with modifications to represent the physical changes to infiltration, evaporation, and runoff that result from tillage management. DHSVM yielded a Nash-Sutcliffe model efficiency (NSE) for streamflow of 0.69 for the watershed-scale simulations over the Palouse River basin, which falls within the NSE ranges reported for DHSVM (0.57-0.91). Surface temperature predictions resulted in an NSE of 0.60, and the model was able to predict the soil state (frozen or unfrozen) 81% of the time. Simulated soil moisture was approximately 50% greater under widespread adoption of CT versus NT management during the majority of the winter months. Predicted volumetric soil moisture content for April 1, 2005 was 29% and 34% under CT and NT management, respectively. This difference in winter and spring soil moisture was caused primarily by decreased evaporation under NT, with minimal effects resulting from changes in infiltration. Two simple crop yield estimation methods indicated that increased spring soil moisture under NT management may result in a 21-26% wheat yield increase. We concluded that NT has the potential to

  15. Drought preparedness and drought mitigation in the developing world׳s drylands

    Directory of Open Access Journals (Sweden)

    Mahmoud Solh

    2014-06-01

    Drought is a climatic event that cannot be prevented, but interventions and preparedness to drought can help to: (i be better prepared to cope with drought; (ii develop more resilient ecosystems (iii improve resilience to recover from drought; and (iv mitigate the impacts of droughts. Preparedness strategies to drought include: (a geographical shifts of agricultural systems; (b climate-proofing rainfall-based systems; (c making irrigated systems more efficient; (d expanding the intermediate rainfed–irrigated systems. The paper presents successful research results and case studies applying some innovative techniques where clear impact is demonstrated to cope with drought and contribute to food security in dry areas. The CGIAR Consortium Research Program (CRP on “Integrated and Sustainable Agricultural Production Systems for Improved Food Security and Livelihoods in Dry Areas” (in short, “Dryland Systems”, led by ICARDA, was launched in May 2013 with many partners and stakeholders from 40 countries. It addresses farming systems in dry areas, at a global level, involving 80 partner institutions. The Dryland Systems Program aims at coping with drought and water scarcity to enhance food security and reduce poverty in dry areas through an integrated agro-ecosystem approach. It will also deliver science-based solutions that can be adopted in regions that are not yet experiencing extreme shocks, but will be affected in the medium to long-term. The approach entails shifting the thinking away from the traditional focus on a small number of research components to take an integrated approach aiming to address agro-ecosystems challenges. Such an approach involves crops, livestock, rangeland, trees, soils, water and policies. It is one of the first global research for development efforts that brings “systems thinking” to farming innovations leading to improved livelihoods in the developing world. The new technique uses modern innovation platforms to involve all

  16. Climate Science, Development Practice, and Policy Interactions in Dryland Agroecological Systems

    NARCIS (Netherlands)

    Twyman, C.; Fraser, E.D.G.; Stringer, L.C.; Quinn, C.; Dougill, A.J.; Crane, T.A.; Sallu, S.M.

    2011-01-01

    The literature on drought, livelihoods, and poverty suggests that dryland residents are especially vulnerable to climate change. However, assessing this vulnerability and sharing lessons between dryland communities on how to reduce vulnerability has proven difficult because of multiple definitions o

  17. Climate change reduces extent of temperate drylands and intensifies drought in deep soils

    Science.gov (United States)

    Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, William K.; Munson, Seth M.; Tietjen, Britta; Hall, Sonia A.; Wilson, Scott D.; Duniway, Michael C.; Jia, Gensuo; Pyke, David A.; Lkhagva, Ariuntsetseg; Jamiyansharav, Khishigbayar

    2017-01-01

    Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in extent and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the twenty first century, temperate drylands may contract by a third, primarily converting to subtropical drylands, and that deep soil layers could be increasingly dry during the growing season. These changes imply major shifts in vegetation and ecosystem service delivery. Our results illustrate the importance of appropriate drought measures and, as a global study that focuses on temperate drylands, highlight a distinct fate for these highly populated areas.

  18. Climate change reduces extent of temperate drylands and intensifies drought in deep soils

    Science.gov (United States)

    Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, William K.; Munson, Seth M.; Tietjen, Britta; Hall, Sonia A.; Wilson, Scott D.; Duniway, Michael C.; Jia, Gensuo; Pyke, David A.; Lkhagva, Ariuntsetseg; Jamiyansharav, Khishigbayar

    2017-01-01

    Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in extent and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the twenty first century, temperate drylands may contract by a third, primarily converting to subtropical drylands, and that deep soil layers could be increasingly dry during the growing season. These changes imply major shifts in vegetation and ecosystem service delivery. Our results illustrate the importance of appropriate drought measures and, as a global study that focuses on temperate drylands, highlight a distinct fate for these highly populated areas.

  19. Animal Farm

    Institute of Scientific and Technical Information of China (English)

    徐蓉蓉

    2015-01-01

    This essay first introduce the background of Animal Farm and a brief introduction of the author.Then it discuss three thesis about this novel and briefly discussed about it.At last it give highly review on Animal Farm.

  20. Dryland degradation: Measurement and effects on ecosystems

    Science.gov (United States)

    Noojipady, P.; Prince, S. D.; Rishmawi, K.

    2012-12-01

    Land degradation is frequently described as a global crisis, affecting large areas globally and large numbers of people. Nevertheless, the location and severity of degradation globally with a resolution relevant to human activities is unknown. Beyond the direct stress of degradation on human livelihoods, there are important effects on the physical and biological environment. Examples include loss of potential primary production, changes in the surface water and energy balances, erosion, sediment transport and lofting of dust aerosols. Globally , degradation is mainly associated with drylands, such as the US dustbowl of the 1930s and, supposedly, ongoing loss of crop and livestock production in desert margins on all continents. The alarm over loss of land to deserts, particularly early 1980s in the African Sahel, led to the adoption of the term "desertification". Such degradation is said to have two components; a physical environment that reduces productivity; and human land use that exceeds the resilience of the land. Ecological theory suggests that land can exist in multiple stable states with transitions between them. Some experimental evidence suggests that one such state is degradation from which there can be no recovery. Clearly the occurrence of such stable degradation, where land is unable to recover when the physical conditions such as rainfall and human land use are ameliorated, is of theoretical and practical importance. The aim of this work is to contribute to the resolution of two issues: (i) are there significant areas in which land has been degraded by human actions and, (ii), have any of these areas entered a stable degraded state? Detection of the human component necessarily requires control of the physical component of degradation. We have developed a technique to detect areas that are at their potential production and to assess other areas relative to these. Satellite measurements of vegetation indices are used as a surrogate for Net Primary

  1. Anticipating Vulnerability to Climate Change in Dryland Pastoral Systems: Using Dynamic Systems Models for the Kalahari

    Directory of Open Access Journals (Sweden)

    Andrew J. Dougill

    2010-06-01

    Full Text Available It is vitally important to identify agroecosystems that may cease functioning because of changing climate or land degradation. However, identifying such systems is confounded on both conceptual and methodological grounds, especially in systems that are moving toward thresholds, a common trait of dryland environments. This study explores these challenges by analyzing how a range of external pressures affect the vulnerability of dryland pastoral systems in the Kalahari. This is achieved by employing dynamic systems modeling approaches to understand the pathways by which communities became vulnerable to drought. Specifically, we evaluate how external pressures have changed: (1 different agroecosystems' abilities to tolerate drought, i.e., ecosystem resilience; (2 rural communities' abilities to adapt to drought, mediated via their access to assets; and (3 the ability of institutions and policy interventions to play a role in mediating drought-related crises, i.e., socio-political governance. This is done by reanalyzing ecological and participatory research findings along with farm-scale livestock offtake data from across the Kalahari in Botswana. An iterative process was followed to establish narratives exploring how external drivers led to changes in agroecosystem resilience, access to assets, and the institutional capacity to buffer the system. We use "causal loop diagrams" and statistical dynamic system models to express key quantitative relationships and establish future scenarios to help define where uncertainties lie by showing where the system is most sensitive to change. We highlight how that greater sharing of land management knowledge and practices between private and communal land managers can provide 'win-win-win' benefits of reducing system vulnerability, increasing economic income, and building social capital. We use future scenario analyses to identify key areas for future studies of climate change adaptation across the Kalahari.

  2. Effects of two new dryland farming technologies on growth and fruit bearing of pear jujube trees in hilly regions%两种新的旱作管理技术对山地梨枣树生长及结果的影响

    Institute of Scientific and Technical Information of China (English)

    赵霞; 汪有科; 刘守阳; 魏新光; 黎朋红

    2012-01-01

    Under the condition of non-irrigation, the 9 year-old pear-jujube ( Ziziphus jujuba Mill.) trees [grafted on wild jujube ( Ziziphus jujuba Mill, var. spinoaa ( Bungge) Hu ex H. F. Chow.) J was set as study material with different dryland fanning technologies, which included water-saving type pruning technology, bamboo-type poly ditch technology and conventional dwarf pruning. And, comparison was made of the effects of each treatment on vegetative growth and reproduction growth of pear jujube trees. The results showed that water-saving pruning and bamboo-type contour ditch, either singly or in combination, could increase significantly the growth leaf area, the area of each leaf and the content of chlorophyll. and increase significantly the number of bearing branchlets and number of flowers. Compared with the control, water-saving pruning (HL) could raise the yield by 83.14% . and bamboo-type poly ditch (CJ) could raise it by 38.44%, while treatment HJ, combined with the HL and CJ technologies, harvested the most and the yield was 155% of the control. In Loess hilly regions in Northern Shaanxi, under the condition of non-irrigation, the water-saving pruning technology could play a jruin positive role in raising pear jujube yield, especially combining the bamboo-type contour ditch technology.%以9a生梨枣树(Ziziphus jujuba Mill.)为试材,在无灌溉条件下,研究节水型修剪技术和竹节式聚水沟技术及常规矮化修剪技术(CK)对梨枣营养生长及生殖生长的影响.结果表明:节水型修剪与竹节武聚水沟技术的单独及联合应用,能有效提高叶面积增长量、梨枣单叶面积和叶绿素含量,有效提高枣吊个数和着花数量;与对照相比,节水型修剪技术可提高产量83.1%,竹节式聚水沟技术可提高产量38.4%,节水型修剪技术+竹节式聚水沟技术效果更好,产量可提高155%.综合分析认为在旱地无灌溉条件下的陕北黄土丘陵区,以节水型修剪树体管理

  3. N response of no-till dryland winter triticale forage

    Science.gov (United States)

    Triticale’s forage-yield response to fertilizer nitrogen (N) is impressive on soils testing low in available N. Our objective is to quantify the forage yield response of dryland winter triticale to applied N and to residual NO3-N. A second objective is to fit the yield data to a regression equation ...

  4. Expansion of global drylands under a warming climate

    Directory of Open Access Journals (Sweden)

    S. Feng

    2013-06-01

    Full Text Available Global drylands encompassing hyper-arid, arid, semiarid, and dry subhumid areas cover about 41% of the earth's terrestrial surface and are home to more than a third of the world's population. By analyzing observations for 1948–2008 and climate model simulations for 1948–2100, we show that global drylands have expanded in last sixty years and will continue to expand in the 21st century. By the end of this century, the world's drylands under a high greenhouse gas emission scenario are projected to be 5.8 × 106 km2 (or 10% larger than in the 1961–1990 climatology. The major expansion of arid regions will occur over southwest North America, the northern fringe of Africa, southern Africa, and Australia, while major expansions of semiarid regions will occur over the north side of the Mediterranean, southern Africa, and North and South America. The global dryland expansions will increase the population affected by water scarcity and land degradations.

  5. A morphometric analysis of vegetation patterns in dryland ecosystems.

    Science.gov (United States)

    Mander, Luke; Dekker, Stefan C; Li, Mao; Mio, Washington; Punyasena, Surangi W; Lenton, Timothy M

    2017-02-01

    Vegetation in dryland ecosystems often forms remarkable spatial patterns. These range from regular bands of vegetation alternating with bare ground, to vegetated spots and labyrinths, to regular gaps of bare ground within an otherwise continuous expanse of vegetation. It has been suggested that spotted vegetation patterns could indicate that collapse into a bare ground state is imminent, and the morphology of spatial vegetation patterns, therefore, represents a potentially valuable source of information on the proximity of regime shifts in dryland ecosystems. In this paper, we have developed quantitative methods to characterize the morphology of spatial patterns in dryland vegetation. Our approach is based on algorithmic techniques that have been used to classify pollen grains on the basis of textural patterning, and involves constructing feature vectors to quantify the shapes formed by vegetation patterns. We have analysed images of patterned vegetation produced by a computational model and a small set of satellite images from South Kordofan (South Sudan), which illustrates that our methods are applicable to both simulated and real-world data. Our approach provides a means of quantifying patterns that are frequently described using qualitative terminology, and could be used to classify vegetation patterns in large-scale satellite surveys of dryland ecosystems.

  6. A morphometric analysis of vegetation patterns in dryland ecosystems

    NARCIS (Netherlands)

    Mander, Luke; Dekker, Stefan C.; Li, Mao; Mio, Washington; Punyasena, Surangiw; Lenton, Timothy M.

    2017-01-01

    Vegetation in dryland ecosystems often forms remarkable spatial patterns. These range from regular bands of vegetation alternating with bare ground, to vegetated spots and labyrinths, to regular gaps of bare ground within an otherwise continuous expanse of vegetation. It has been suggested that

  7. Rainfall probability and EONR for dryland corn in Colorado

    Science.gov (United States)

    Nitrogen fertilizer costs have increased 70% in the last 6 yrs in the Central Great Plains Region (CGPR). This cost increase coincides with a decrease in dryland grain yields due to drought. How does the economic optimum N rate (EONR) change with grain price and fertilizer cost? Here we evaluated 11...

  8. Expansion of global drylands under a warming climate

    Directory of Open Access Journals (Sweden)

    S. Feng

    2013-10-01

    Full Text Available Global drylands encompassing hyper-arid, arid, semiarid, and dry subhumid areas cover about 41 percent of the earth's terrestrial surface and are home to more than a third of the world's population. By analyzing observations for 1948–2008 and climate model simulations for 1948–2100, we show that global drylands have expanded in the last sixty years and will continue to expand in the 21st~century. By the end of this century, the world's drylands (under a high greenhouse gas emission scenario are projected to be 5.8 × 106 km2 (or 10% larger than in the 1961–1990 climatology. The major expansion of arid regions will occur over southwest North America, the northern fringe of Africa, southern Africa, and Australia, while major expansions of semiarid regions will occur over the north side of the Mediterranean, southern Africa, and North and South America. The global dryland expansions will increase the population affected by water scarcity and land degradations.

  9. Earth Observation of Vegetation Dynamics in Global Drylands

    DEFF Research Database (Denmark)

    Tian, Feng

    Land degradation in global drylands has been a concern related to both the local livelihoods and the changes in terrestrial biosphere, especially in the context of substantial global environmental changes. Earth Observation (EO) provides a unique way to assess the vegetation dynamics over the past...

  10. Farm Team.

    Science.gov (United States)

    Gordon, Debra

    2001-01-01

    Describes a Philadelphia high school in which urban students study agricultural sciences to prepare for college and careers. The campus has a complete working farm, and students are exposed to a wide range of agricultural career opportunities while also studying core academic subjects. The school's farm units are real businesses, so students are…

  11. Evaluating Impact of Land Use Changes and Climate Variability on Economic Efficiency of Farming in Transboundary Watershed of Timor Island

    Directory of Open Access Journals (Sweden)

    Werenfridus Taena

    2016-07-01

    Full Text Available Indonesia and Timor-Leste development of border regions in Timor Island has brought land use changes, and when combined with climate variability it may cause flooding, drought, and impact of economic efficiency of farm crop. The research aimed to analyze: (i the effect of land use changes and climate variability on the floods and drought on the Tono Watershed, (ii the impact of flood, drought and production factors in yield and the economic efficiency of food crop farming. The analysis applied logit method for flood and drought. Frontier analysis to evaluate economic efficiency of farming. Logit analysis showed that the increase in the monthly rainfall and mix dryland farming, along with the decrease of forestry and paddy fields increase the flooding on Tono Watershed. The result further suggested by this analysis showed drought has caused by the increase of mix dryland farming and monthly temperature, and decrease of monthly rainfall. This led to a reduction in yield and economic efficiency of farm crops. Frontier analysis confirms the low economic efficiency of farming, whereas monoculture farming was 0.36 (affected by floods and drought and multicrop farming was 0.30 (affected by drought which is far from the efficiency standard ≥ 0.8.

  12. Plant species richness and ecosystem multifunctionality in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Quero, Jose L.; Gotelli, Nicholas J.; Escudero, Adrian; Ochoa, Victoria; Delgado-Baquerizo, Manuel; Garcia-Gomez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; Garcia-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceicao, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitan, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gomez-Gonzalez, Susana; Gutie, Julio R.; Hernandez, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Anibal; Pucheta, Eduardo; Ramirez-Collantes, David A.; Romao, Roberto; Tighe, Matthew; Torres-Diaz, Cristian; Val, James; Veiga, Jose P.; Wang, Deli; Zaady, Eli

    2012-01-01

    Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

  13. Arid waste? Reassessing the value of dryland pastoralism

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, Ced; MacGregor, James

    2009-06-15

    East Africa has a huge hidden asset – but risks throwing it away in the quest for economic development. This is its millions-strong herds of dryland livestock managed by pastoralists. New findings show that pastoralism has immense potential value for reducing poverty, managing the environment, promoting sustainable development and building climate resilience. In Kenya alone, the sector is worth an estimated three-quarters of a billion dollars a year. Yet pastoralism is seen by many as archaic, economically inefficient, chaotic and environmentally destructive – perceptions that are not evidence-based, yet drive much regional policy. Inadequate, inaccurate national statistics on pastoralism do little to alter this view. Persistent undervaluation has effectively trapped up to 20 million dryland pastoralists in a cycle of poverty, conflict and environmental degradation. Now, with climate change biting, the time is ripe for a conceptual framework that captures the total economic benefits of this livelihood.

  14. Dryland salinity in Western Australia: managing a changing water cycle.

    Science.gov (United States)

    Taylor, R J; Hoxley, G

    2003-01-01

    Clearing of agricultural land has resulted in significant changes to the surface and groundwater hydrology. Currently about 10% of agricultural land in Western Australia is affected by dryland salinity and between a quarter and a third of the area is predicted to be lost to salinity before a new hydrological equilibrium is reached. This paper develops a general statement describing the changes to the surface and groundwater hydrology of the wheatbelt of Western Australia between preclearing, the year 2000 and into the future. For typical catchments in the wheatbelt it is estimated that average groundwater recharge and surface runoff have increased about tenfold when comparing the current hydrology to that preclearing. Saline groundwater discharge and flood volumes have also increased significantly. Saline groundwater discharge and associated salt load will probably double in the future in line with the predicted increase in the area of dryland salinity. In addition, future increases in the area of dryland salinity/permanent waterlogging will probably double the volumes in flood events and further increase surface runoff in average years. The outcomes of surface and groundwater management trials have been briefly described to estimate how the hydrology would be modified if the trials were implemented at a catchment scale. These results have been used to formulate possible integrated revegetation and drainage management strategies. The future hydrology and impacts with and without integrated management strategies have been compared.

  15. Realities, Perceptions, Challenges and Aspirations of Rural Youth in Dryland Agriculture in the Midelt Province, Morocco

    Directory of Open Access Journals (Sweden)

    Alessandra Giuliani

    2017-05-01

    Full Text Available Active involvement of youth in agriculture is necessary for sustainable agricultural systems but is currently a challenge in many areas. Using a combination of qualitative and quantitative participatory research methods, this study analyses rural youth’s realities, perspectives and aspirations in dryland Agricultural Livelihood Systems (ALSs in the Midelt Province, Morocco, with a particular focus on gender. The data collected are an important first step in understanding the target group and working with youth to identify and develop appropriate programmatic interventions to improve their livelihoods and rural futures. Prior to expressing their aspirations for their rural life and career, the youth first raised the issue of unfulfilled primary needs: access to education, potable water, heath care, and lack of infrastructure in their villages. The issue of outmigration from rural areas is controversial and not so widespread. The youth’s dream village is envisioned as a rural place where people have a more comfortable life with their own families, farming better and more sustainably rather than seeking a job in urban areas. To support the youth’s aspirations and their willingness to stay in agriculture, there is a need for infrastructural and regulatory interventions and specific training in agricultural practices targeting and engaging youth.

  16. Farm Animals

    Science.gov (United States)

    ... same bacterium that has become resistant to certain antibiotics, which can make infections harder to treat. MRSA can be passed back and forth between people and farm animals through direct contact. In humans, MRSA can cause ...

  17. Planting geometry and plant population affect dryland maize grain yield and harvest index

    Science.gov (United States)

    Water for dryland grain production in the Texas panhandle is limited. Agronomic practices such as reduction in plant population or change in sowing time may help increase maize (Zea mays L.) yield potential. Tiller formation under dryland conditions leads to more vegetative growth and reduced yield....

  18. Rainwater harvesting for dryland agriculture in the Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.

    2012-01-01

    The Ethiopian drylands occupy about 65% of the total land mass (close to 700,000km2) of the country. The predominantly rainfed agriculture in these drylands is highly constrained due to erratic rainfall, long dry-spells and excessive loss of rainwater through non-productive pathways (surf

  19. Water use efficiency of dryland cowpea, sorghum and sunflower under reduced tillage

    Science.gov (United States)

    Drought-adapted, early maturing crops combined with reduced tillage systems have the potential to stabilize and increase dryland crop yields in the Southern High Plains. The objective of this study was to evaluate dryland grain yield response and soil water use for cowpea [Vigna Unguiculata (L.) Wal...

  20. Aboveground total and green biomass of dryland shrub derived from terrestrial laser scanning

    Science.gov (United States)

    The distribution of many dryland vegetation species are expected to shift based on predictions of future increases in global temperatures. Quantifying aboveground biomass in dryland systems is important for assessing global carbon storage and monitoring the presence and distribution of these rapidl...

  1. Impact of climate change on drylands with a focus on West Africa

    NARCIS (Netherlands)

    Dietz, A.J.; Verhagen, A.; Ruben, R.

    2001-01-01

    Sahelian West Africa has recovered from the disastrous droughts of the 1970s and 1980s. People have learned to adapt to risk and uncertainty in fragile dryland environments. They, as well as global change scientists, are worried about the impact of climate change on these West African drylands. What

  2. Rainwater harvesting for dryland agriculture in the Rift Valley of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.

    2012-01-01

    The Ethiopian drylands occupy about 65% of the total land mass (close to 700,000km2) of the country. The predominantly rainfed agriculture in these drylands is highly constrained due to erratic rainfall, long dry-spells and excessive loss of rainwater through non-productive pathways

  3. Dryland malt barley yield and quality affected by tillage, cropping sequence, and nitrogen fertilization

    Science.gov (United States)

    Information is needed on the effects of management practices on dryland malt barley (Hordeum vulgaris L.) and pea (Pisum sativum L.) yields and quality. We evaluated the effects of tillage and cropping sequence combination and N fertilization on dryland malt barley and pea yields, grain characterist...

  4. Remote sensing in dryland cotton: relation to yield potential and soil properties

    Science.gov (United States)

    Read, John J.; Iqbal, Javed; Thomasson, John A.; Willers, Jeffrey L.; Jenkins, Johnie N.

    2004-01-01

    bands could be used to produce estimated field maps of plant height, leaf area index and yield, which offer a potentially attractive mid-season management tool for site specific farming in dryland cotton.

  5. Farm Tourism

    DEFF Research Database (Denmark)

    Blichfeldt, Bodil Stilling; Nielsen, Niels Christian; Nissen, Kathrine Aae

    2011-01-01

    This paper draws on a study of one specific type of small tourism enterprises (i.e. farm tourism enterprises) and argues that these enterprises differ from other enterprises in relation to a series of issues other than merely size. The analysis shows that enterprises such as these are characterized...... by blurriness of boundaries between „home spheres‟ and work situations as well as by a unique blend of commercial and private hospitality. Furthermore, the study shows that „social‟ motivations and non-monetary benefits gained through host-guest interactions are of great importance to the hosts. In particular......, our study suggests that it is problematic to threat farm tourism enterprises as if they have much in common with both larger corporations and other types of SMTEs. Farm tourism enterprises seem to differ significantly from other enterprises as the hosts are not in the tourism business because...

  6. Biological soil crusts: a fundamental organizing agent in global drylands

    Science.gov (United States)

    Belnap, J.; Zhang, Y.

    2013-12-01

    Ecosystem function is profoundly affected by plant community composition, which is ultimately determined by factors that govern seed retention. Dryland ecosystems constitute ~35% of terrestrial surfaces, with most soils in these regions covered by biological soil crusts (biocrusts), a community whose autotrophs are dominated by cyanobacteria, lichens, and mosses. Studies at 550 sites revealed that plant community composition was controlled by the interaction among biocrust type, disturbance regime, and external morphology of seeds. In bare soils (due to disturbance), all seed types were present in the seedbank and plant community. As biocrusts became better developed (i.e., the cover of lichens and mosses increased), they more strongly filtered out seeds with appendages. Thus, soils under late successional biocrusts contained seedbanks dominated by smooth seeds and vascular plants growing in late successional biocrusts were dominated by those with smooth seeds. Therefore, the tension between the removal of biocrusts by soil surface disturbance and their recovery creates a shifting mosaic of plant patch types in both space and time. Because changes in vascular plant communities reverberate throughout both below ground and above ground food webs and thus affect multiple trophic levels, we propose that biocrusts are a fundamental organizing agent in drylands worldwide. Future increased demand for resources will intensify land use both temporally and spatially, resulting in an increased rate of biocrust loss across larger areas. As a result, we can expect shifts in the composition and distribution of plant communities, accompanied by concomitant changes in many aspects of dryland ecosystems. Conceptual model of shifting dryland plant mosaics through space and time. Within the large circles, soil surface type changes with time in the same space, going from bare uncrusted soil (B) to cyanobacterial biocrust (C) to lichen/moss (L/M) biocrust. Disturbance (D) drives the

  7. Diagnosis of GLDAS LSM based aridity index and dryland identification.

    Science.gov (United States)

    Ghazanfari, Sadegh; Pande, Saket; Hashemy, Mehdy; Sonneveld, Ben

    2013-04-15

    The identification of dryland areas is crucial for guiding policy aimed at intervening in water-stressed areas and addressing the perennial livelihood or food insecurity of these areas. However, the prevailing aridity indices (such as UNEP aridity index) have methodological limitations that restrict their use in delineating drylands and may be insufficient for decision-making frameworks. In this study, we propose a new aridity index based on based on 3 decades of soil moisture time series by accounting for site-specific soil and vegetation that partitions precipitation into the competing demands of evaporation and runoff. Our proposed aridity index is the frequency at which the dominant soil moisture value at a location is not exceeded by the dominant soil moisture values in all of the other locations. To represent the dominant spatial template of the soil moisture conditions, we extract the first eigenfunction from the empirical orthogonal function (EOF) analysis from 3 GLDAS land surface models (LSMs): VIC, MOSAIC and NOAH at 1 × 1 degree spatial resolution. The EOF analysis reveals that the first eigenfunction explains 33%, 43% and 47% of the VIC, NOAH and MOSAIC models, respectively. We compare each LSM aridity indices with the UNEP aridity index, which is created based on LSM data forcings. The VIC aridity index displays a pattern most closely resembling that of UNEP, although all of the LSM-based indices accurately isolate the dominant dryland areas. The UNEP classification identifies portions of south-central Africa, southeastern United States and eastern India as drier than predicted by all of the LSMs. The NOAH and MOSAIC LSMs categorize portions of southwestern Africa as drier than the other two classifications, while all of the LSMs classify portions of central India as wetter than the UNEP classification. We compare all aridity maps with the long-term average NDVI values. Results show that vegetation cover in areas that the UNEP index classifies as

  8. Ant Farm

    OpenAIRE

    2012-01-01

    Publié à l’occasion de l’exposition d’Ant Farm au Frac Centre du 12 au 23 décembre 2007, ce très beau catalogue, qui fait état des dix ans de création du collectif californien, propose un nombre important de documents iconographiques, de notices et de textes concernant leurs différents projets. Fondé en 1968 par Doug Michels et Chip Lord, rejoints par la suite par Curtis Schreier, Hudson Marquez, Douglas Hurr et d’autres encore, le collectif Ant Farm a marqué les esprits par quelques œuvres s...

  9. National Farm Medicine Center

    Science.gov (United States)

    Research Areas Applied Sciences Biomedical Informatics Clinical Research Epidemiology Farm Medicine Human Genetics Oral-Systemic Health Clinical ... Consulting Agritourism Farm MAPPER Lyme Disease ROPS Rebate Zika Virus National Farm Medicine Center The National Farm ...

  10. Amaranth farming

    DEFF Research Database (Denmark)

    Bjarklev, Araceli; Kjær, Tyge; Kjærgård, Bente

    2008-01-01

    natural resources that small-scale farmers have to combat the abovementioned problems. The study identified several local and regional barriers for increasing the level of farming, production, processing and consumption. A striking and paradoxical limitation is the monopolization practices developed...... by some of the associations in relation to knowledge and technology transfer, seeds distribution and contact to potential national and foreign buyers....

  11. Molecular farming

    NARCIS (Netherlands)

    Merck, K.B.; Vereijken, J.M.

    2006-01-01

    Molecular Farming is a new and emerging technology that promises relatively cheap and flexible production of large quantities of pharmaceuticals in genetically modified plants. Many stakeholders are involved in the production of pharmaceuticals in plants, which complicates the discussion on the poss

  12. Drylands face potential threat under 2 °C global warming target

    Science.gov (United States)

    Huang, Jianping; Yu, Haipeng; Dai, Aiguo; Wei, Yun; Kang, Litai

    2017-06-01

    The Paris Agreement aims to limit global mean surface warming to less than 2 °C relative to pre-industrial levels. However, we show this target is acceptable only for humid lands, whereas drylands will bear greater warming risks. Over the past century, surface warming over global drylands (1.2-1.3 °C) has been 20-40% higher than that over humid lands (0.8-1.0 °C), while anthropogenic CO2 emissions generated from drylands (~230 Gt) have been only ~30% of those generated from humid lands (~750 Gt). For the twenty-first century, warming of 3.2-4.0 °C (2.4-2.6 °C) over drylands (humid lands) could occur when global warming reaches 2.0 °C, indicating ~44% more warming over drylands than humid lands. Decreased maize yields and runoff, increased long-lasting drought and more favourable conditions for malaria transmission are greatest over drylands if global warming were to rise from 1.5 °C to 2.0 °C. Our analyses indicate that ~38% of the world's population living in drylands would suffer the effects of climate change due to emissions primarily from humid lands. If the 1.5 °C warming limit were attained, the mean warming over drylands could be within 3.0 °C therefore it is necessary to keep global warming within 1.5 °C to prevent disastrous effects over drylands.

  13. Impacts of manure application on soil environment, rainfall use efficiency and crop biomass under dryland farming

    Science.gov (United States)

    Wang, Xiaojuan; Jia, Zhikuan; Liang, Lianyou; Yang, Baoping; Ding, Ruixia; Nie, Junfeng; Wang, Junpeng

    2016-02-01

    Because of inadequate nutrient and water supply, soils are often unproductive in Northwest China. We studied the effects of manure application at low (LM 7.5  t ha–1), medium (MM 15 t ha–1), and high (HM 22.5 t ha–1) rates combined with fixed levels of chemical fertilizers on maize growth and rainfall use efficiency compared with chemical fertilizers (CK) under semi-arid conditions over a three-year period. HM and MM treatments could significantly increase soil water storage (0–120 cm) at tasseling stage of maize compared with LM treatment and CK (P efficiency increased as manure application rate increasing (P efficiency by 6.5–12.7% at big trumpeting – tasseling stage compared with LM and MM treatments. HM and MM treatments increased rainfall use efficiency by 8.6–18.1% at tasseling – grain filling stage compared with CK. There was no significant difference on biomass between HM and MM treatments at grain filling and maturity stages of maize in 2009 and 2010.

  14. Can landscape memory affect vegetation recovery in drylands?

    Science.gov (United States)

    Baartman, Jantiene; Garcia Mayor, Angeles; Temme, Arnaud; Rietkerk, Max

    2016-04-01

    Dryland ecosystems are water-limited and therefore vegetation typically forms banded or patchy patterns with high vegetation cover, interspersed with bare soil areas. In these systems, a runoff-runon system is often observed with bare areas acting as sources and vegetation patches acting as sinks of water, sediment and other transported substances. These fragile ecosystems are easily disturbed by overgrazing, removing above-ground vegetation. To avoid desertification, vegetation recovery after a disturbance is crucial. This poster discusses the potential of 'landscape memory' to affect the vegetation recovery potential. Landscape memory, originating in geomorphology, is the concept that a landscape is the result of its past history, which it 'remembers' through imprints left in the landscape. For example, a past heavy rainstorm may leave an erosion gully. These imprints affect the landscape's contemporary functioning, for example through faster removal of water from the landscape. In dryland ecosystems vegetation is known to affect the soil properties of the soil they grow in, e.g. increasing porosity, infiltration, organic matter content and soil structure. After a disturbance of the banded ecosystem, e.g. by overgrazing, this pattern of soil properties - favourable for regrowth, stays in the landscape. However, removal of the above-ground vegetation also leads to longer runoff pathways and increased rill and gully erosion, which may hamper vegetation regrowth. I hypothesize that vegetation recovery after a disturbance, depends on the balance between these two contrasting types of landscape memory (i.e. favourable soil properties and erosion rills/gullies).

  15. Abkhandari (Aquifer Management): a Green Path to the Sustainable Development of Marginal Drylands

    Institute of Scientific and Technical Information of China (English)

    Sayyed Ahang Kowsar

    2005-01-01

    Recurrent droughts and occasional floods are the facts of life in drylands. The presence of innumerable societies in deserts is the living proof that even the extremely dry environments are livable;the secret is how to adapt to the situation. Floodwater management, the most important art of sedentarized desert dwellers, is the secret of living with deserts.Floodwater irrigation alone, or in combination with the artificial recharge of groundwater (ARG), has sustained the Persians for millennia. The scientists at the Kowsar Floodwater Spreading and Aquifer Management Research, Training and Extension Station in the Gareh Bygone Plain have been working since January 1983 to revive this ancient art and upgrade it to the level of science. A summary of important findings is provided as follows:1. Debris cones and coarse alluvial fans are the best places for the ARG as they provide the potential aquifer for groundwater storage. The recharged water may be used for irrigation on the lower lying, fine alluvium;2. Flood is not a proverbial curse but a blessing in disguise, and the turbid floodwater is the best resource for the sustainable development of drylands;3. Translocation of fine Clay minerals eventually makes the vadose zone impermeable. Planting deep-rooted, drought-resistent trees and shrubs, and introducing sowbugs (Hemilepistus shirazi Schuttz)are reliable methods to increase infiltration rate and the saturated hydraulic conductivity of the ARG systems;4. The moving sand stabilization is best achieved by spreading turbid floodwater onto them. Establishing of living windbreaks and planting of fodder trees and shrubs turn a sand menace into a verdant pasture; 5. The 10 year average of native forage yield in the Atriplex lentiformis (Torr.) Wats. can annually yield 1500 kg ha-1 of dry matter and support 3 heads of sheep;6. The stem- and fuel wood yield of 18 year old Eucalyptus camaldulensis Dehnh. in the ARG system The mean annual carbon sequestration of this tree

  16. Amaranth farming

    DEFF Research Database (Denmark)

    Bjarklev, Araceli; Kjær, Tyge; Kjærgård, Bente

    2008-01-01

    Though amaranth has been studied intensively for its exceptional nutritional properties, little has been reported about its capacity for fighting poverty, securing food supplies, turning migrations, or its impact on the environment and the prospect for mprovement of living conditions of those...... natural resources that small-scale farmers have to combat the abovementioned problems. The study identified several local and regional barriers for increasing the level of farming, production, processing and consumption. A striking and paradoxical limitation is the monopolization practices developed...

  17. Edge of Field Nitrate Loss and Oxygen-18 Dynamics in a Dryland Agriculture Setting

    Science.gov (United States)

    Wannamaker, C. N.; Goodwin, A. J.; Keller, C.; Allen-King, R.; Smith, J. L.

    2004-12-01

    Four complete water years of nitrate concentrations and oxygen isotope (δ O18) ratios have been monitored in a tile drain and adjacent soil-water sampling lysimeters beneath a dryland, agricultural field in the Palouse Region of Washington State, USA. The Palouse is semi-arid and is characterized by undulating loess hills and swales drained by ephemeral to perennial streams. Soil type is dominated by silt-loam Mollisols. Our field is subject to typical farming practices and crop rotations, receiving ammonia fertilizer during fall and spring planting at a rate of ˜70kg of nitrogen per acre. Tile drains play an essential role in environmental nitrogen dynamics in this region as they are widely utilized to drain water from lower fields. Nitrate concentrations in tile drainage fluctuate on a seasonal basis ranging from low concentrations of ˜1mg/ NO3-N/L in late October/November to higher concentrations of 20-30mg NO3-N/L in late January/February. Rise in concentration occurs rapidly with the onset of high flow conditions differing from a typical dilution effect. Lysimeter waters show similar nitrate patterns ranging in concentration from ~10mg NO3-N/L to as high as 120mg NO3-N/L. In the lysimeters, nitrate concentrations are apparently positively correlated with δ O18 values. Precipitation collected at the field site shows a 12 per mil seasonal variation in δ O18. A seasonal pattern is also observed in soil water with a smaller range of about 6 per mil. These seasonal fluctuations are not observed in tile drainage, where values vary only 2 per mil with a mean of -15 per ml. We hypothesize that residence-time and scaling effects can explain the δ O18 fluctuation differences between soil water and tile drainage. The very large nitrate fluctuations throughout the system may be due in part to the seasonality of soil nitrogen cycling.

  18. Anticipating Vulnerability to Climate Change in Dryland Pastoral Systems: Using Dynamic Systems Models for the Kalahari

    OpenAIRE

    Dougill, AJ; Fraser, EDG; Reed, MS

    2010-01-01

    It is vitally important to identify agroecosystems that may cease functioning because of changing climate or land degradation. However, identifying such systems is confounded on both conceptual and methodological grounds, especially in systems that are moving toward thresholds, a common trait of dryland environments. This study explores these challenges by analyzing how a range of external pressures affect the vulnerability of dryland pastoral systems in the Kalahari. This is achieved by empl...

  19. Effects of Controlled Release Fertilizer on the Flag Leaves Senescence in Dry-land Wheat

    OpenAIRE

    Dandan Liu; Yan Shi

    2013-01-01

    In order to select a reasonable controlled release fertilizer application method to slow down the senescence of flag leaf in dry-land wheat. The effects of controlled release fertilizer on soluble protein content, MDA content, the Catalase (CAT) activity, the Superoxide Dismutase (SOD) activity on the flag leaves senescence in dry-land wheat had been studied in the open field with the variety wheat Jimai22. The results indicated that, the combination application of controlled release fertiliz...

  20. Effects of Controlled Release Fertilizer on the Flag Leaves Senescence in Dry-land Wheat

    OpenAIRE

    Dandan Liu; Yan Shi

    2013-01-01

    In order to select a reasonable controlled release fertilizer application method to slow down the senescence of flag leaf in dry-land wheat. The effects of controlled release fertilizer on soluble protein content, MDA content, the Catalase (CAT) activity, the Superoxide Dismutase (SOD) activity on the flag leaves senescence in dry-land wheat had been studied in the open field with the variety wheat Jimai22. The results indicated that, the combination application of controlled release fertiliz...

  1. Population of Aerobic Heterotrophic Nitrogen-Fixing Bacteria Associated with Wetland and Dryland Rice

    OpenAIRE

    Barraquio, W.L.; de Guzman, M. R.; Barrion, M.; Watanabe, I.

    1982-01-01

    Nitrogen-fixing activity and populations of nitrogen-fixing bacteria associated with two varieties of rice grown in dryland and wetland conditions were measured at various growth stages during the dry season. Acetylene reduction activities were measured both in the field and for the hydroponically grown rice, which was transferred from the field to water culture 1 day before assay. The activities measured by both methods were higher in wetland than in dryland rice. The population of nitrogen-...

  2. Legacies of flood reduction on a dryland river

    Science.gov (United States)

    Stromberg, J.C.; Shafroth, P.B.; Hazelton, A.F.

    2012-01-01

    The Bill Williams (Arizona) is a regulated dryland river that is being managed, in part, for biodiversity via flow management. To inform management, we contrasted riparian plant communities between the Bill Williams and an upstream free-flowing tributary (Santa Maria). Goals of a first study (1996-1997) were to identify environmental controls on herbaceous species richness and compare richness among forest types. Analyses revealed that herbaceous species richness was negatively related to woody stem density, basal area and litter cover and positively related to light levels. Introduced Tamarix spp. was more frequent at the Bill Williams, but all three main forest types (Tamarix, Salix/Populus, Prosopis) had low understory richness, as well as high stem density and low light, on the Bill Williams as compared to the Santa Maria. The few edaphic differences between rivers (higher salinity at Bill Williams) had only weak connections with richness. A second study (2006-2007) focused on floristic richness at larger spatial scales. It revealed that during spring, and for the study cumulatively (spring and fall samplings combined), the riparian zone of the unregulated river had considerably more plant species. Annuals (vs. herbaceous perennials and woody species) showed the largest between-river difference. Relative richness of exotic (vs. native) species did not differ. We conclude that: (1) The legacy of reduced scouring frequency and extent at the Bill Williams has reduced the open space available for colonization by annuals; and (2) Change in forest biomass structure, more so than change in forest composition, is the major driver of changes in plant species richness along this flow-altered river. Our study informs dryland river management options by revealing trade-offs that exist between forest biomass structure and plant species richness. ?? 2010 John Wiley & Sons, Ltd.

  3. Interactions among hydrology, geomorphology and vegetation on dryland hillslopes

    Science.gov (United States)

    Parsons, Anthony

    2016-04-01

    On dryland hillslopes vegetation is typically patchy, and areas bare of vegetation are likely to be either stony or crusted. These bare areas promote Hortonian runoff, the pathways of which interact with the patchy vegetation. This interaction leads to a characteristic microrelief. On hillslopes dominated by woody shrubs there is a pronounced across-slope microrelief in which shrubs sit atop mounds and intershrub areas form swales. This microrelief concentrates runoff into the swales resulting in relatively efficient, connected runoff pathways which concentrates erosion and sediment transport within the swales. On hillslopes dominated by grass there is a pronounced downslope microrelief of small steps and risers. These steps create a disconnected pattern of runoff that traps runoff and sediment behind clumps of grass providing both water and nutrients to the grass. Both ecosystems are dominated by positive feedbacks implying stability; yet records show that locations may switch from one ecosystem to the other. To understand the conditions under which such switches may occur we have developed a modelling framework for the analysis of ecosystem change in drylands that is rooted in the concept of connectivity and is derived from a detailed process-based understanding of interactions among hydrology, geomorphology and vegetation. The model has been implemented in the deserts of the American Southwest both to test hypotheses of the causes of the invasion of woody shrubs, and to test its ability to reproduce observed spatial differences in response to drought in the 20th century. The modelling results show the importance of local conditions in determining the susceptibility of a location to ecosystem change and the significance of grazing in causing such changes.

  4. Performance of dryland and wetland plant species on extensive green roofs

    Science.gov (United States)

    MacIvor, J. Scott; Ranalli, Melissa A.; Lundholm, Jeremy T.

    2011-01-01

    Background and Aims Green roofs are constructed ecosystems where plants perform valuable services, ameliorating the urban environment through roof temperature reductions and stormwater interception. Plant species differ in functional characteristics that alter ecosystem properties. Plant performance research on extensive green roofs has so far indicated that species adapted to dry conditions perform optimally. However, in moist, humid climates, species typical of wetter soils might have advantages over dryland species. In this study, survival, growth and the performance of thermal and stormwater capture functions of three pairs of dryland and wetland plant species were quantified using an extensive modular green roof system. Methods Seedlings of all six species were germinated in a greenhouse and planted into green roof modules with 6 cm of growing medium. There were 34 treatments consisting of each species in monoculture and all combinations of wet- and dryland species in a randomized block design. Performance measures were survival, vegetation cover and roof surface temperature recorded for each module over two growing seasons, water loss (an estimate of evapotranspiration) in 2007, and albedo and water capture in 2008. Key Results Over two seasons, dryland plants performed better than wetland plants, and increasing the number of dryland species in mixtures tended to improve functioning, although there was no clear effect of species or habitat group diversity. All species had survival rates >75 % after the first winter; however, dryland species had much greater cover, an important indicator of green roof performance. Sibbaldiopsis tridentata was the top performing species in monoculture, and was included in the best treatments. Conclusions Although dryland species outperformed wetland species, planting extensive green roofs with both groups decreased performance only slightly, while increasing diversity and possibly habitat value. This study provides further

  5. Land degradation in drylands: Interactions among hydrologic-aeolian erosion and vegetation dynamics

    Science.gov (United States)

    Ravi, Sujith; Breshears, David D.; Huxman, Travis E.; D'Odorico, Paolo

    2010-04-01

    Land degradation in drylands is one of the major environmental issues of the 21st century particularly due to its impact on world food security and environmental quality. Climate change, shifts in vegetation composition, accelerated soil erosion processes, and disturbances have rendered these landscapes susceptible to rapid degradation that has important feedbacks on regional climate and desertification. Even though the role of hydrologic-aeolian erosion and vegetation dynamic processes in accelerating land degradation is well recognized, most studies have concentrated only on the role of one or two of these components, and not on the interactions among all three. Drawing on relevant published studies, here we review recent contributions to the study of biotic and abiotic drivers of dryland degradation and we propose a more holistic perspective of the interactions between wind and water erosion processes in dryland systems, how these processes affect vegetation patterns and how vegetation patterns, in turn, affect these processes. Notably, changing climate and land use have resulted in rapid vegetation shifts, which alter the rates and patterns of soil erosion in dryland systems. With the predicted increase in aridity and an increase in the frequency of droughts in drylands around the world, there could be an increasing dominance of abiotic controls of land degradation, in particular hydrologic and aeolian soil erosion processes. Further, changes in climate may alter the relative importance of wind versus water erosion in dryland ecosystems. Therefore acquiring a more holistic perspective of the interactions among hydrologic-aeolian erosion and vegetation dynamic processes is fundamental to quantifying and modeling land degradation processes in drylands in changing climate, disturbance regimes and management scenarios.

  6. Beyond Monitoring: A Brief Review of the Use of Remote Sensing Technology for Assessing Dryland Sustainability

    Science.gov (United States)

    Washington-Allen, R. A.

    2015-12-01

    Drylands cover 41% of the terrestrial surface and provide > $1 trillion in ecosystem services to one-third of the global population, yet are not well studied with estimates of degradation ranging from 10 - 80%. Here I will present an abbreviated history of the use of remote sensing (RS) to monitor Dryland degradation, review contemporary applications, and provide guidance for future directions. These early monitoring attempts (and some recent efforts) assumed the social model of "Tragedy of the Commons" and the ecological model of "the Balance of Nature". These assumptions justified a monitoring approach rather than an assessment, where land degradation was understood to be primarily a function of human action through livestock grazing management. The perceived linear impact of grazing on grassland biomass led to the early development of a remote sensing-based proxy of vegetation response: the normalized difference vegetation index (NDVI). Many RS studies of Drylands are biased towards the NDVI or variants, whereas the contemporary view of Drylands as complex systems has led to a new synthesis of approaches from ecological modeling, ecohydrology, landscape ecology, and remote sensing that now explicitly confront both multiple drivers that include land-use policy, droughts & floods, fire, and responses that include increased soil erosion and changes in soil quality, landscape composition, pattern, and structure. However, problems still abound including 1) a consensus on the definition of Drylands, 2) the need for time series of drivers to conduct assessments, 3) a lack of understanding of below-ground biomass dynamics, 4) improved mapping of grassland, shrubland, and savanna dryland cover types and their 3D structure. There are new technologies in Dryland RS including multi-frequency ground penetrating radar (GPR), RADAR, IFSAR, LIDAR, and MISR that may lead to the development of new indicators to address these issues.

  7. Assessing Dryland Ecosystem Services in Xinjiang, Northwest China

    Science.gov (United States)

    Siew, T. F.; Brauman, K. A.; Zuo, L.; Doll, P. M.

    2014-12-01

    Dryland ecosystems, including grassland, forest, and irrigated cropland, cover about 41% of earth's land area and are inhabited by over two billion people. In drylands, particularly arid and semiarid areas, the production of ecosystem services is primarily constrained by freshwater availability. Often, water allocated to production by one ecosystem or of one ecosystem service negatively impacts other ecosystems or ecosystem services (ESS). The challenge is to determine how much water should be allocated to which ecosystems (natural and manmade) such that multiple ESS are maximized, thus improving overall well-being. This strategic management decision must be supported by knowledge about spatial and temporal availability of water and its relationship to production (location and scale) of ESS that people receive. We assess the spatial and temporal relationships between water availability and ESS production in Xinjiang, Northwest China. We address four questions: (1) What services are produced by which ecosystems with water available? (2) Where are these services produced? (3) Who uses the services produced? (4) How the production of services changes with variability of water available? Using existing global, national, and regional spatial and statistical data, we assess food, fiber, livestock, and wood production as well as unique forest landscapes (as a proxy for aesthetic appreciation and habitats for unique animals and plants) and protection from dust storms. Irrigation is necessary for crop production in Xinjiang. The production of about 4.2 million tons of wheat and 500,000 tons of cotton requires more than 2 km3 of water each year. This is an important source of food and income for local residents, but the diverted water has negative and potentially costly impacts on downstream forests that potentially provide aesthetic services and protection from dust. Our analyses also show that cropland had increased by about 1.6 million ha from 1987 to 2010, while

  8. Plant-plant interactions in the restoration of Mediterranean drylands

    Science.gov (United States)

    Valdecantos, Alejandro; Fuentes, David; Smanis, Athanasios

    2014-05-01

    Plant-plant interactions are complex and dependent of both local abiotic features of the ecosystem and biotic relationships with other plants and animals. The net result of these interactions may be positive, negative or neutral resulting in facilitation, competition or neutralism, respectively (role of phylogeny). It has been proposed that competition is stronger between those individuals that share functional traits than between unrelated ones. The relative interaction effect of one plant on a neighbour may change in relation to resource availability - especially water in drylands. In addition, plants develop above and belowground biomass with time increasing the level and, eventually, changing the intensity and/or the direction of the interaction. In the framework of the restoration of degraded drylands, many studies have focused on the positive (nurse) effects of adult trees, shrubs and even grasses on artificially planted seedlings by improving the microclimate or providing protection against herbivores, but little is known about the interactions between seedlings of different life traits planted together under natural field conditions. In 2010 we established planting plots in two contrasted sites under semiarid Mediterranean climate and introduced one year old seedlings in different combinations of three species, two shrubs (Olea europaea and Pistacia lentiscus) and one grass (Stipa tenacissima). Half of the planting holes in each site were implemented with low-cost ecotechnological inputs to increase water availability by forcing runoff production and promoting deep infiltration (small plastic fabric + dry well). This resulted in four levels of abiotic stress. Biotic interactions were assessed by monitoring seedling survival and growth for three years after planting. The Relative Interaction Index (RII) of S. tenacissima on O. europaea was almost flat and close to 0 along the stress gradient since the beginning of the study suggesting limited interaction

  9. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

    Science.gov (United States)

    Rutherford, William A.; Painter, Thomas H.; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S.; Flagg, Cody; Reed, Sasha C.

    2017-01-01

    Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness—changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate. PMID:28281687

  10. Aeolian and fluvial processes in dryland regions: the need for integrated studies

    Science.gov (United States)

    Belnap, Jayne; Munson, Seth M.; Field, Jason P.

    2011-01-01

    Aeolian and fluvial processes play a fundamental role in dryland regions of the world and have important environmental and ecological consequences from local to global scales. Although both processes operate over similar spatial and temporal scales and are likely strongly coupled in many dryland systems, aeolian and fluvial processes have traditionally been studied separately, making it difficult to assess their relative importance in drylands, as well as their potential for synergistic interaction. Land degradation by accelerated wind and water erosion is a major problem throughout the world's drylands, and although recent studies suggest that these processes likely interact across broad spatial and temporal scales to amplify the transport of soil resources from and within drylands, many researchers and land managers continue to view them as separate and unrelated processes. Here, we illustrate how aeolian and fluvial sediment transport is coupled at multiple spatial and temporal scales and highlight the need for these interrelated processes to be studied from a more integrated perspective that crosses traditional disciplinary boundaries. Special attention is given to how the growing threat of climate change and land-use disturbance will influence linkages between aeolian and fluvial processes in the future. We also present emerging directions for interdisciplinary needs within the aeolian and fluvial research communities that call for better integration across a broad range of traditional disciplines such as ecology, biogeochemistry, agronomy, and soil conservation.

  11. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

    Science.gov (United States)

    Rutherford, William A.; Painter, Thomas H.; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S.; Flagg, Cody; Reed, Sasha C.

    2017-03-01

    Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness—changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate.

  12. Does an understanding of ecosystems responses to rainfall pulses improve predictions of responses of drylands to climate change?

    Science.gov (United States)

    Drylands will experience more intense and frequent droughts and floods. Ten-year field experiments manipulating the amount and variability of precipitation suggest that we cannot predict responses of drylands to climate change based on pulse experimentation. Long-term drought experiments showed no e...

  13. Organic farming at the farm level

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.; Madsen, Niels; Ørum, Jens Erik

    The purpose of this report is to present possible impacts of new technology and changes in legislation on the profitability of different types of organic farms. The aim is also to look at both the current and future trends in the organic area in Denmark. The farm level analyses are carried out...... as part of a larger project entitled “Economic analyses of the future development of organic farming – effects at the field, farm, sector and macroeconomic level”. The project links effects at the field-level with analyses at the farm level. These effects are then used in sector and macroeconomic analyses...

  14. Dynamic Hydrological Modeling in Drylands with TRMM Based Rainfall

    Directory of Open Access Journals (Sweden)

    Elena Tarnavsky

    2013-12-01

    Full Text Available This paper introduces and evaluates DryMOD, a dynamic water balance model of the key hydrological process in drylands that is based on free, public-domain datasets. The rainfall model of DryMOD makes optimal use of spatially disaggregated Tropical Rainfall Measuring Mission (TRMM datasets to simulate hourly rainfall intensities at a spatial resolution of 1-km. Regional-scale applications of the model in seasonal catchments in Tunisia and Senegal characterize runoff and soil moisture distribution and dynamics in response to varying rainfall data inputs and soil properties. The results highlight the need for hourly-based rainfall simulation and for correcting TRMM 3B42 rainfall intensities for the fractional cover of rainfall (FCR. Without FCR correction and disaggregation to 1 km, TRMM 3B42 based rainfall intensities are too low to generate surface runoff and to induce substantial changes to soil moisture storage. The outcomes from the sensitivity analysis show that topsoil porosity is the most important soil property for simulation of runoff and soil moisture. Thus, we demonstrate the benefit of hydrological investigations at a scale, for which reliable information on soil profile characteristics exists and which is sufficiently fine to account for the heterogeneities of these. Where such information is available, application of DryMOD can assist in the spatial and temporal planning of water harvesting according to runoff-generating areas and the runoff ratio, as well as in the optimization of agricultural activities based on realistic representation of soil moisture conditions.

  15. Fertility Island Formation and Evolution in Dryland Ecosystems

    Directory of Open Access Journals (Sweden)

    Luca Ridolfi

    2008-06-01

    Full Text Available Vast dryland regions around the world are affected by the encroachment of woody vegetation, with important environmental and economical implications. Grassland-to-shrubland conversions are often triggered by disturbance of grassland vegetation, and the consequent formation of barren areas prone to erosion-induced nutrient losses. Inhibition of encroachment by erosion-induced depletion of soil nutrients contributes to the emergence of highly heterogeneous landscapes with shrub-dominated fertility islands surrounded by nutrient-poor bare soil. Here, we develop a process-based simplistic model thataccounts for the two competing processes of resource depletion and shrub encroachment by a non-linear diffusion mechanism. The proposed model is able to generate stable vegetation patterns with the same statistical properties as those observed in areas with well-developed fertility islands. We also show how a subsequent disturbance of shrubland vegetation can shift the dynamics toward states with smaller vegetation biomass. The process of land degradation may then occur through a number of irreversible intermediate transitions associated with losses in ecosystem function.

  16. Rethinking the sustainability of Israel's irrigation practices in the Drylands.

    Science.gov (United States)

    Tal, Alon

    2016-03-01

    Broad utilization of drip irrigation technologies in Israel has contributed to the 1600 percent increase in the value of produce grown by local farmers over the past sixty-five years. The recycling of 86% of Israeli sewage now provides 50% of the country's irrigation water and is the second, idiosyncratic component in Israel's strategy to overcome water scarcity and maintain agriculture in a dryland region. The sustainability of these two practices is evaluated in light of decades of experience and ongoing research by the local scientific community. The review confirms the dramatic advantages of drip irrigation over time, relative to flood, furrow and sprinkler irrigation and its significance as a central component in agricultural production, especially under arid conditions. In contrast, empirical findings increasingly report damage to soil and to crops from salinization caused by irrigation with effluents. To be environmentally and agriculturally sustainable over time, wastewater reuse programs must ensure extremely high quality treated effluents and ultimately seek the desalinization of recycled sewage.

  17. Organic Farming in Austria

    OpenAIRE

    Vogl, C.R.; Heß, J

    1999-01-01

    During the present decade, Austria has experienced a dramatic increase in organic farming among those countries that comprise the European Union (EU). For example, in 1992, approximately 2,000 farms were practicing organic, ecological, or biodynamic farming methodes. By 1997 the number of certified organic farms plus those in transition from conventional farming had increased 10-fold to some 20,000 farms. This represents almost 9% of the total farms in Austria and an area of 345,375 ha, or 10...

  18. Hydrologic variability in dryland regions: impacts on ecosystem dynamics and food security.

    Science.gov (United States)

    D'Odorico, Paolo; Bhattachan, Abinash

    2012-11-19

    Research on ecosystem and societal response to global environmental change typically considers the effects of shifts in mean climate conditions. There is, however, some evidence of ongoing changes also in the variance of hydrologic and climate fluctuations. A relatively high interannual variability is a distinctive feature of the hydrologic regime of dryland regions, particularly at the desert margins. Hydrologic variability has an important impact on ecosystem dynamics, food security and societal reliance on ecosystem services in water-limited environments. Here, we investigate some of the current patterns of hydrologic variability in drylands around the world and review the major effects of hydrologic fluctuations on ecosystem resilience, maintenance of biodiversity and food security. We show that random hydrologic fluctuations may enhance the resilience of dryland ecosystems by obliterating bistable deterministic behaviours and threshold-like responses to external drivers. Moreover, by increasing biodiversity and the associated ecosystem redundancy, hydrologic variability can indirectly enhance post-disturbance recovery, i.e. ecosystem resilience.

  19. Biological soil crusts as an organizing principle in drylands: Chapter 1

    Science.gov (United States)

    Belnap, Jayne; Weber, Bettina; Büdel, Burkhard; Weber, Bettina; Buedel, Burkhard; Belnap, Jayne

    2016-01-01

    Biological soil crusts (biocrusts) have been present on Earth’s terrestrial surfaces for billions of years. They are a critical part of ecosystem processes in dryland regions, as they cover most of the soil surface and thus mediate almost all inputs and outputs from soils in these areas. There are many intriguing, but understudied, roles these communities may play in drylands. These include their function in nutrient capture and transformation, influence on the movement and distribution of nutrients and water within dryland soils, ability to structure vascular plant communities, role in creating biodiversity hotspots, and the possibility that they can be used as indicators of soil health. There are still many fascinating aspects of these communities that need study, and we hope that this chapter will facilitate such efforts.

  20. Pastoral mobility as a response to climate variability in African drylands

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    1999-01-01

    The article outlines aspects of ‘the new paradigm’ for dryland ecosystems and pastoral production systems. Rationality of pastoralism was claimed by parts of the research community for decades, but especially among policy and development planners pastoralism was perceived as an irrational...... and destructive production system. With the new paradigm a coherent theory is provided linking the dynamics of drylands with pastoral strategies. Consequences of the new paradigm are analysed from a theoretical point of view, emphasis is on implications for pastoral mobility with a focus on pastoral systems...... in West Africa. In an example from Ferlo, Senegal, different types of pastoral mobility are discussed with special focus on the importance of scale. It is concluded that pastoral mobility is a rational response to climate variability and unpredictability in African drylands....

  1. Quantifying influences of physiographic factors on temperate dryland vegetation, Northwest China

    Science.gov (United States)

    Du, Ziqiang; Zhang, Xiaoyu; Xu, Xiaoming; Zhang, Hong; Wu, Zhitao; Pang, Jing

    2017-01-01

    Variability in satellite measurements of terrestrial greenness in drylands is widely observed in land surface processes and global change studies. Yet the underlying causes differ and are not fully understood. Here, we used the GeogDetector model, a new spatial statistical approach, to examine the individual and combined influences of physiographic factors on dryland vegetation greenness changes, and to identify the most suitable characteristics of each principal factor for stimulating vegetation growth. Our results indicated that dryland greenness was predominantly affected by precipitation, soil type, vegetation type, and temperature, either separately or in concert. The interaction between pairs of physiographic factors enhanced the influence of any single factor and displayed significantly non-linear influences on vegetation greenness. Our results also implied that vegetation greenness could be promoted by adopting favorable ranges or types of major physiographical factors, thus beneficial for ecological conservation and restoration that aimed at mitigating environmental degradation. PMID:28067259

  2. Production of greenhouse-grown biocrust mosses and associated cyanobacteria to rehabilitate dryland soil function

    Science.gov (United States)

    Antoninka, Anita; Bowker, Matthew A.; Reed, Sasha C.; Doherty, Kyle

    2016-01-01

    Mosses are an often-overlooked component of dryland ecosystems, yet they are common members of biological soil crust communities (biocrusts) and provide key ecosystem services, including soil stabilization, water retention, carbon fixation, and housing of N2 fixing cyanobacteria. Mosses are able to survive long dry periods, respond rapidly to precipitation, and reproduce vegetatively. With these qualities, dryland mosses have the potential to be an excellent dryland restoration material. Unfortunately, dryland mosses are often slow growing in nature, and ex situ cultivation methods are needed to enhance their utility. Our goal was to determine how to rapidly produce, vegetatively, Syntrichia caninervis and S. ruralis, common and abundant moss species in drylands of North America and elsewhere, in a greenhouse. We manipulated the length of hydration on a weekly schedule (5, 4, 3, or 2 days continuous hydration per week), crossed with fertilization (once at the beginning, monthly, biweekly, or not at all). Moss biomass increased sixfold for both species in 4 months, an increase that would require years under dryland field conditions. Both moss species preferred short hydration and monthly fertilizer. Remarkably, we also unintentionally cultured a variety of other important biocrust organisms, including cyanobacteria and lichens. In only 6 months, we produced functionally mature biocrusts, as evidenced by high productivity and ecosystem-relevant levels of N2 fixation. Our results suggest that biocrust mosses might be the ideal candidate for biocrust cultivation for restoration purposes. With optimization, these methods are the first step in developing a moss-based biocrust rehabilitation technology.

  3. Assessing commercial livestock appropriation of the productive capacity of US drylands: A remote sensing approach

    Science.gov (United States)

    Washington-Allen, R. A.; Mitchell, J. E.; Oslen, H. E.

    2008-12-01

    The "State of Nation's Ecosystems" by the Heinz Institute and the recent "Millennium Ecosystem Assessment of Drylands" concluded that the amount of desertification and the extent to which human management actions contribute to this process is unknown at national to global spatial scales. This is primarily due to lack of studies at these large spatial scales and the temporal scales (> a 15-year time series of data) necessary to separate the effects of anthropogenic practices from climate change on Drylands. Consequently, this research seeks to develop procedures for determining 1) the area of Drylands within the United States where commercial grazing livestock occur or the livestock ecological footprint and 2) the impact of the footprint on the US's productive capacity. Our approach has been to develop a pilot geodatabase of year 2002 data that includes administrative boundaries, the Moderate Resolution Infrared Spectroradiometer's (MODIS) measures of gross and net primary productivity (GPP and NPP, respectively), US Department of Agriculture's National Agricultural Statistics Service's (USDA-NASS) county-level data on cattle, sheep, and goat inventories, transportation and power consumption networks, dryland extent, and land cover/land use. Secondly, the ratio of 1-km2 gridded mean annual potential evapotranspiration (MAPET) to mean annual precipitation (MAP) data were used to define the 50-year mean dryland extent in accordance with the United Nations Convention to Combat Desertification's definition of Drylands, the aridity index (AI) ≤ 0.65. Urban features, including transportation, power consumption, and land use/land cover, were subtracted from this dryland map to further refine it. The NASS tabular data was then related to the counties boundary map thus producing a county-level livestock number map that was then intersected with the dryland extent map to yield the US livestock ecological footprint. Lastly, this footprint map was then converted to a

  4. Biological Dimensions of Crack Morphology in Dryland Soils

    Science.gov (United States)

    DeCarlo, K. F.; Spiegel, M.; Caylor, K. K.

    2014-12-01

    Macropores and cracks have an integral role in soil hydrology, and the physicochemical factors that induce them have been the subject of much laboratory research. How these processes translate to field soils, however, is often obfuscated by the biological elements present that complicate its formation and dynamics. In this study, we investigated the biological influence of herbivores and vegetation on 3D crack morphology in a dryland swelling soil (black cotton/vertisol). Fieldwork was conducted at and near the Kenya Long-Term Exclosure Experiment (KLEE) plots in Mpala, central Kenya, where three different soil regions were identified: highly vegetated areas, animal trails, and termite mounds. Crack networks were physically characterized by pouring liquid resin into the soil and excavating them when dry, after which they were imaged and quantified using medical magnetic resonance imaging (MRI). Cracking intensity of each cast was corrected via soil moisture and bulk density measurements at 5 cm intervals over 30 cm. 3D characterization of the soil system shows that mechanical compaction is a major influence in the formation of extensive and deep cracks in animal trails, with megaherbivores (e.g. elephants) inducing the most extreme cracks. Bioturbation is seen as a major influence in the formation of shallower cracks in termite mounds, as termites loosen and aerate the soil and reduce the soil's cohesive properties. Highly vegetated soils show a large degree of variability: small, disconnected soil patches induced by vegetative cover and a larger root network results in smaller and shallower cracks, but full vegetative cover induces deep and irregular cracks, possibly due to diverted rainfall. Our results highlight the intricate connections between the biology and physics that dictate soil processes in a complex soil system at the field scale.

  5. Meta-Analyses of Biosolids Effect in Dryland Wheat Agroecosystems.

    Science.gov (United States)

    Barbarick, Kenneth; Ippolito, James; McDaniel, Jacob

    2017-03-01

    Land application to cropping systems is USEPA's preferred method of recycling biosolids. Determination of biosolids effect size through meta-analyses from two decades of field-location research at three sites should answer the question: Does 20 yr of biosolids application affect dryland wheat ( L.) grain production, grain nutrient concentrations, and soil elemental extractability compared with equivalent rates of commercial N fertilizer? At two sites, biennial biosolids application rates to a wheat-fallow (WF) rotation were up to 11.2 dry Mg ha and up to 112 kg commercial N fertilizer ha, whereas rates at the third location varied to match soil-test information. Crop rotations included WF and wheat-corn ( L.)-fallow. We completed meta-analyses of biosolids effects compared with N fertilizer on wheat yield, grain protein, grain total, and soil ammonium bicarbonate-diethylenetriaminepentaacetic acid (ABDTPA)-extractable P, Zn, Cu, Fe, and Ni concentrations at the aforementioned sites from 1993 through 2013. Results showed that biosolids produced greater grain P and Zn at one site. Biosolids rates at two sites resulted in greater grain Zn and ABDTPA P, Zn, Cu, and Fe. Meta-analyses tests for heterogeneity indicated that the variance for all sites and rates could be explained as consistent across treatments, whereas the test for the 20 yr showed that heterogeneity was large and other factors affected the variance (e.g., climatic variability between years). Meta-analysis showed the practical effect of biosolids over a 20-yr study and demonstrated that the primary biosolids effect was an improvement in Zn availability to wheat. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Desertification, salinization, and biotic homogenization in a dryland river ecosystem

    Science.gov (United States)

    Miyazono, S.; Patino, Reynaldo; Taylor, C.M.

    2015-01-01

    This study determined long-term changes in fish assemblages, river discharge, salinity, and local precipitation, and examined hydrological drivers of biotic homogenization in a dryland river ecosystem, the Trans-Pecos region of the Rio Grande/Rio Bravo del Norte (USA/Mexico). Historical (1977-1989) and current (2010-2011) fish assemblages were analyzed by rarefaction analysis (species richness), nonmetric multidimensional scaling (composition/variability), multiresponse permutation procedures (composition), and paired t-test (variability). Trends in hydrological conditions (1970s-2010s) were examined by Kendall tau and quantile regression, and associations between streamfiow and specific conductance (salinity) by generalized linear models. Since the 1970s, species richness and variability of fish assemblages decreased in the Rio Grande below the confluence with the Rio Conchos (Mexico), a major tributary, but not above it. There was increased representation of lower-flow/higher-salinity tolerant species, thus making fish communities below the confluence taxonomically and functionally more homogeneous to those above it. Unlike findings elsewhere, this biotic homogenization was due primarily to changes in the relative abundances of native species. While Rio Conchos discharge was > 2-fold higher than Rio Grande discharge above their confluence, Rio Conchos discharge decreased during the study period causing Rio Grande discharge below the confluence to also decrease. Rio Conchos salinity is lower than Rio Grande salinity above their confluence and, as Rio Conchos discharge decreased, it caused Rio Grande salinity below the confluence to increase (reduced dilution). Trends in discharge did not correspond to trends in precipitation except at extreme-high (90th quantile) levels. In conclusion, decreasing discharge from the Rio Conchos has led to decreasing flow and increasing salinity in the Rio Grande below the confluence. This spatially uneven desertification and

  7. Biotic degradation at night, abiotic degradation at day: positive feedbacks on litter decomposition in drylands.

    Science.gov (United States)

    Gliksman, Daniel; Rey, Ana; Seligmann, Ron; Dumbur, Rita; Sperling, Or; Navon, Yael; Haenel, Sabine; De Angelis, Paolo; Arnone, John A; Grünzweig, José M

    2017-04-01

    The arid and semi-arid drylands of the world are increasingly recognized for their role in the terrestrial net carbon dioxide (CO2 ) uptake, which depends largely on plant litter decomposition and the subsequent release of CO2 back to the atmosphere. Observed decomposition rates in drylands are higher than predictions by biogeochemical models, which are traditionally based on microbial (biotic) degradation enabled by precipitation as the main mechanism of litter decomposition. Consequently, recent research in drylands has focused on abiotic mechanisms, mainly photochemical and thermal degradation, but they only partly explain litter decomposition under dry conditions, suggesting the operation of an additional mechanism. Here we show that in the absence of precipitation, absorption of dew and water vapor by litter in the field enables microbial degradation at night. By experimentally manipulating solar irradiance and nighttime air humidity, we estimated that most of the litter CO2 efflux and decay occurring in the dry season was due to nighttime microbial degradation, with considerable additional contributions from photochemical and thermal degradation during the daytime. In a complementary study, at three sites across the Mediterranean Basin, litter CO2 efflux was largely explained by litter moisture driving microbial degradation and ultraviolet radiation driving photodegradation. We further observed mutual enhancement of microbial activity and photodegradation at a daily scale. Identifying the interplay of decay mechanisms enhances our understanding of carbon turnover in drylands, which should improve the predictions of the long-term trend of global carbon sequestration.

  8. Impacts of Global Change on Water Resources in Dryland East Asia

    Science.gov (United States)

    Ge Sun; Xiaoming Feng; Jingfeng Xiao; Alex Shiklomanov; Shengping Wang; Zhiqiang Zhang; Nan Lu; Shuai Wang; Liding Chen; Bojie Fu; Yaning Chen; Jiquan Chen

    2013-01-01

    The vast Dryland East Asia (DEA) area consists of several large geographic regions including the Qinghai-Tibet Plateau, Loess Plateau, and Mongolia Plateau. T he region is of great importance to the functioning of the earth system under a changing climate. In the past three decades, due to the unprecedented land use/land cover change, urbanization, industrialization...

  9. To tie or not to tie ridges for water conservation in Rift Valley drylands of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.; Stroosnijder, L.

    2012-01-01

    The Rift Valley drylands of Ethiopia are characterized by sandy loam soils that have poor fertility and unreliable rainfall conditions. The aim of this study was to examine the potential benefit of rainwater harvesting by tied-ridges and improved soil fertility on maize productivity through field ex

  10. Multi-element accumulation near Rumex crispus roots under wetland and dryland conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kissoon, La Toya T., E-mail: latoya.kissoon@ndsu.ed [Wet Ecosystem Research Group, Department of Biological Sciences, North Dakota State University, NDSU Department 2715, P.O. Box 6050 Fargo, ND 58108-6050 (United States); Jacob, Donna L.; Otte, Marinus L. [Wet Ecosystem Research Group, Department of Biological Sciences, North Dakota State University, NDSU Department 2715, P.O. Box 6050 Fargo, ND 58108-6050 (United States)

    2010-05-15

    Rumex crispus was grown under wet and dry conditions in two-chamber columns such that the roots were confined to one chamber by a 21 mum nylon mesh, thus creating a soil-root interface ('rhizoplane'). Element concentrations at 3 mm intervals below the 'rhizoplane' were measured. The hypothesis was that metals accumulate near plant roots more under wetland than dryland conditions. Patterns in element distribution were different between the treatments. Under dryland conditions Al, Ba, Cu, Cr, Fe, K, La, Mg, Na, Sr, V, Y and Zn accumulated in soil closest to the roots, above the 'rhizoplane' only. Under wetland conditions Al, Fe, Cr, K, V and Zn accumulated above as well as 3 mm below the 'rhizoplane' whereas La, Sr and Y accumulated 3 mm below the 'rhizoplane' only. Plants on average produced 1.5 times more biomass and element uptake was 2.5 times greater under wetland compared to dryland conditions. - Patterns of element accumulation near the roots of plants differ between dryland and wetland conditions.

  11. Predicting, Measuring, and Monitoring Aquatic Invertebrate Biodiversity on Dryland Military Bases

    Science.gov (United States)

    2016-12-15

    challenges for predicting how management decisions on military lands could affect landscape -scale patterns of aquatic invertebrate biodiversity. This...sites in dryland streams .............. 89 Figure 7.3 Pairwise correlations among all local and landscape distance metrics ....................... 94...Water Assessment Tool USDA: United States Department of Agriculture USGS: United States Geological Survey WSMR: White Sands Missile Range

  12. Sustainable semiarid dryland production in relation to tillage effects on Hydrology: 1983-2013

    Science.gov (United States)

    Semiarid dryland crop yields with no-till, NT, residue management are often greater than stubble-mulch tillage, SM, as a result of improved soil conditions or water conservation, but knowledge of long-term tillage effects on the comprehensive field hydrology and sustained crop production is needed. ...

  13. Assessing Vulnerability to Climate Change in Dryland Livelihood Systems: Conceptual Challenges and Interdisciplinary Solutions

    Directory of Open Access Journals (Sweden)

    Evan D. G. Fraser

    2011-09-01

    Full Text Available Over 40% of the earth's land surface are drylands that are home to approximately 2.5 billion people. Livelihood sustainability in drylands is threatened by a complex and interrelated range of social, economic, political, and environmental changes that present significant challenges to researchers, policy makers, and, above all, rural land users. Dynamic ecological and environmental change models suggest that climate change induced drought events may push dryland systems to cross biophysical thresholds, causing a long-term drop in agricultural productivity. Therefore, research is needed to explore how development strategies and other socioeconomic changes help livelihoods become more resilient and robust at a time of growing climatic risk and uncertainty. As a result, the overarching goal of this special feature is to conduct a structured comparison of how livelihood systems in different dryland regions are affected by drought, thereby making methodological, empirical, and theoretical contributions to our understanding of how these types of social-ecological systems may be vulnerable to climate change. In introducing these issues, the purpose of this editorial is to provide an overview of the two main intellectual challenges of this work, namely: (1 how to conceptualize vulnerability to climate change in coupled social-ecological systems; and (2 the methodological challenges of anticipating trends in vulnerability in dynamic environments.

  14. Milking drylands : gender networks, pastoral markets and food security in stateless Somalia

    NARCIS (Netherlands)

    Nori, M.

    2010-01-01

    The Milking Drylands research initiative addresses the critical issues of food security, market integration, gender roles and governance matters in a peculiar area of the world, the Somali ecosystem. The research aims at exploring interesting dynamics of ongoing social change, in order to stimulate

  15. Contributions of radiative factors to enhanced dryland warming over East Asia

    Science.gov (United States)

    Zhang, Yanting; Guan, Xiaodan; Yu, Haipeng; Xie, Yongkun; Jin, Hongchun

    2017-08-01

    Enhanced near-surface atmospheric warming has occurred over East Asia in recent decades, especially in drylands. Although local factors have been confirmed to provide considerable contributions to this warming, such factors have not been sufficiently analyzed. In this study, we extracted the radiatively forced temperature (RFT) associated with the built-up greenhouse gases, aerosol emission, and various other radiative forcing over East Asia and found a close relationship between RFT and CO2. In addition, using climate model experiments, we explored the responses of temperature changes to black carbon (BC), CO2, and SO4 and found that the enhanced dryland warming induced by CO2 had the largest magnitude and was strengthened by the warming effect of BC. Moreover, the sensitivity of daily maximum and minimum temperature changes to BC, CO2, and SO4 was examined. It showed asymmetric responses of daily maximum and minimum temperature to radiative factors, which led to an obvious change of diurnal temperature range (DTR), especially in drylands. The DTR's response to CO2 is the most significant. Therefore, CO2 not only plays a dominant role in enhanced warming but also greatly affects the decrease of DTR in drylands. However, the mechanisms of these radiative factors' effects in the process of DTR change are not clear and require more investigation.

  16. Using Remote Sensing, Geomorphology, and Soils to Map Episodic Streams in Drylands

    Science.gov (United States)

    Thibodeaux-Yost, S. N. S.

    2016-12-01

    Millions of acres of public land in the California deserts are currently being evaluated and permitted for the construction of large-scale renewable energy projects. The absence of a standard method for identifying episodic streams in arid and semi-arid (dryland) regions is a source of conflict between project developers and the government agencies responsible for conserving natural resources and permitting renewable energy projects. There is a need for a consistent, efficient, and cost-effective dryland stream delineation protocol that accurately reflects the extent and distribution of active watercourses. This thesis evaluates the stream delineation method and results used by the developer for the proposed Ridgecrest Solar Power Project on the El Paso Fan, Ridgecrest, Kern County, California. This evaluation is then compared and contrasted with results achieved using remote sensing, geomorphology, soils, and GIS analysis to identify stream presence on the site. This study's results identified 105 acres of watercourse, a value 10 times greater than that originally identified by the project developer. In addition, the applied methods provide an ecohydrologic base map to better inform project siting and potential project impact mitigation opportunities. This study concludes that remote sensing, geomorphology, and dryland soils can be used to accurately and efficiently identify episodic stream activity and the extent of watercourses in dryland environments.

  17. Defining a dryland grain sorghum production function for the Central Great Plains

    Science.gov (United States)

    Grain sorghum (Sorghum bicolor L. Moench) is a drought tolerant C4 species capable of making use of limited available water supplies and is suitable for dryland crop rotations in the central Great Plains. In order for farmers to assess the production risk encountered when utilizing sorghum in rotati...

  18. Desire for greener land : options for sustainable land management in drylands

    NARCIS (Netherlands)

    Schwilch, G.; Hessel, R.; Verzandvoort, S.J.E.

    2012-01-01

    Desire for Greener Land compiles options for Sustainable Land Management (SLM) in drylands. It is a result of the integrated research project DESIRE (Desertification Mitigation and Remediation of Land - A Global Approach for Local Solutions). Lasting five years (2007–2012) and funded within the EU’s

  19. Replacing fallow with forage triticale in dryland crop rotations increases profitability

    Science.gov (United States)

    A common dryland rotational cropping system in the semi-arid central Great Plains of the U.S. is wheat (Triticum aestivum L.)-corn (Zea mays L.)-fallow (WCF). However, the 12-month fallow period following corn production has been shown to be relatively inefficient in storing precipitation during the...

  20. Intensifying a semi-arid dryland crop rotation by replacing fallow with pea

    Science.gov (United States)

    Increasing dryland cropping system intensity in the semi-arid central Great Plains by reducing frequency of fallow can add diversity to cropping systems and decrease erosion potential. However elimination of the periodic fallow phase has been shown to reduce yields of subsequent crops in this region...

  1. To tie or not to tie ridges for water conservation in Rift Valley drylands of Ethiopia

    NARCIS (Netherlands)

    Temesgen, B.B.; Stroosnijder, L.

    2012-01-01

    The Rift Valley drylands of Ethiopia are characterized by sandy loam soils that have poor fertility and unreliable rainfall conditions. The aim of this study was to examine the potential benefit of rainwater harvesting by tied-ridges and improved soil fertility on maize productivity through field

  2. Legacy effects in linked ecological-soil-geomorphic systems of drylands

    Science.gov (United States)

    A legacy effect refers to the impact that previous conditions have on current processes or properties. Ecological legacies in drylands result from feedbacks among biotic, soil, and geomorphic processes that operate at multiple spatial and temporal scales. Legacy effects depend on (1) the magnitude o...

  3. Precipitation legacy effects on dryland ecosystem carbon fluxes: direction, magnitude and biogeochemical carryovers

    Science.gov (United States)

    The precipitation legacy effect, defined as the impact of historical precipitation (PPT) on extant ecosystem dynamics, has been recognized as an important driver in shaping the temporal variability of dryland aboveground net primary production (ANPP) and soil respiration. How the PPT legacy influenc...

  4. Life-cycle analysis of dryland greenhouse gases affected by cropping sequence and nitrogen fertilization

    Science.gov (United States)

    Little information is available about management practices effect on net global warming potential (GWP) and greenhouse gas intensity (GHGI) under dryland cropping systems. We evaluated the effects of cropping sequences (conventional till malt barley-fallow [CTB-F], no-till malt barley-pea [NTB-P], a...

  5. Tillage, cropping sequence, and nitrogen fertilization influence dryland soil nitrogen dynamics

    Science.gov (United States)

    Management practices are needed to reduce dryland N losses through N leaching and N2O emissions (a greenhouse gas) by increasing soil N storage and reducing N fertilization rate without influencing crop yields. The effects of tillage and cropping sequence combination and N fertilization rate were st...

  6. Organic farming at the farm level

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.; Madsen, Niels; Ørum, Jens Erik

    The purpose of this report is to present possible impacts of new technology and changes in legislation on the profitability of different types of organic farms. The aim is also to look at both the current and future trends in the organic area in Denmark. The farm level analyses are carried out...... as part of a larger project entitled “Economic analyses of the future development of organic farming – effects at the field, farm, sector and macroeconomic level”. The project links effects at the field-level with analyses at the farm level. These effects are then used in sector and macroeconomic analyses......, which are described in other reports from Food and Resource Economic Institute (Jacobsen, 2005 and Andersen et al., 2005). This gives coherent results from the field to the macroeconomic level regarding changes in technology and legislation....

  7. Values in Organic Farming

    DEFF Research Database (Denmark)

    Kjærgård, Bente; Pedersen, Kirsten Bransholm; Land, Birgit

    The study focuses on the recent debate about what is, or what constitutes, organic farming and what is the right path for organic farming in the future. The study is based on a critical discourse analysis of the controversy about suspending the private standard for organic farming adopted...

  8. Values in Organic Farming

    DEFF Research Database (Denmark)

    Kjærgård, Bente; Pedersen, Kirsten Bransholm; Land, Birgit

    The study focuses on the recent debate about what is, or what constitutes, organic farming and what is the right path for organic farming in the future. The study is based on a critical discourse analysis of the controversy about suspending the private standard for organic farming adopted...

  9. Climate and soil attributes determine plant species turnover in global drylands

    Science.gov (United States)

    Maestre, Fernando T.; Gotelli, Nicholas J.; Quero, José L.; Delgado-Baquerizo, Manuel; Bowker, Matthew A.; Eldridge, David J.; Ochoa, Victoria; Gozalo, Beatriz; Valencia, Enrique; Berdugo, Miguel; Escolar, Cristina; García-Gómez, Miguel; Escudero, Adrián; Prina, Aníbal; Alfonso, Graciela; Arredondo, Tulio; Bran, Donaldo; Cabrera, Omar; Cea, Alex; Chaieb, Mohamed; Contreras, Jorge; Derak, Mchich; Espinosa, Carlos I.; Florentino, Adriana; Gaitán, Juan; Muro, Victoria García; Ghiloufi, Wahida; Gómez-González, Susana; Gutiérrez, Julio R.; Hernández, Rosa M.; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Mau, Rebecca L.; Hughes, Frederic Mendes; Miriti, Maria; Monerris, Jorge; Muchane, Muchai; Naseri, Kamal; Pucheta, Eduardo; Ramírez-Collantes, David A.; Raveh, Eran; Romão, Roberto L.; Torres-Díaz, Cristian; Val, James; Veiga, José Pablo; Wang, Deli; Yuan, Xia; Zaady, Eli

    2015-01-01

    Aim Geographic, climatic, and soil factors are major drivers of plant beta diversity, but their importance for dryland plant communities is poorly known. This study aims to: i) characterize patterns of beta diversity in global drylands, ii) detect common environmental drivers of beta diversity, and iii) test for thresholds in environmental conditions driving potential shifts in plant species composition. Location 224 sites in diverse dryland plant communities from 22 geographical regions in six continents. Methods Beta diversity was quantified with four complementary measures: the percentage of singletons (species occurring at only one site), Whittake’s beta diversity (β(W)), a directional beta diversity metric based on the correlation in species occurrences among spatially contiguous sites (β(R2)), and a multivariate abundance-based metric (β(MV)). We used linear modelling to quantify the relationships between these metrics of beta diversity and geographic, climatic, and soil variables. Results Soil fertility and variability in temperature and rainfall, and to a lesser extent latitude, were the most important environmental predictors of beta diversity. Metrics related to species identity (percentage of singletons and β(W)) were most sensitive to soil fertility, whereas those metrics related to environmental gradients and abundance ((β(R2)) and β(MV)) were more associated with climate variability. Interactions among soil variables, climatic factors, and plant cover were not important determinants of beta diversity. Sites receiving less than 178 mm of annual rainfall differed sharply in species composition from more mesic sites (> 200 mm). Main conclusions Soil fertility and variability in temperature and rainfall are the most important environmental predictors of variation in plant beta diversity in global drylands. Our results suggest that those sites annually receiving ~ 178 mm of rainfall will be especially sensitive to future climate changes. These

  10. Can nitrogen fertilization aid restoration of mature tree productivity in degraded dryland riverine ecosystems?

    Science.gov (United States)

    Andersen, Douglas C.; Adair, Elizabeth Carol; Nelson, Sigfrid Mark; Binkley, Dan

    2014-01-01

    Restoration of riparian forest productivity lost as a consequence of flow regulation is a common management goal in dryland riverine ecosystems. In the northern hemisphere, dryland river floodplain trees often include one or another species of Populus, which are fast-growing, nutrient-demanding trees. Because the trees are phreatophytic in drylands, and have water needs met in whole or in part by a shallow water table, their productivity may be limited by nitrogen (N) availability, which commonly limits primary productivity in mesic environments. We added 20 g N m−2 in a 2-m radius around the base of mature Populus fremontii along each of a regulated and free-flowing river in semiarid northwest Colorado, USA (total n = 42) in order to test whether growth is constrained by low soil N. Twelve years after fertilization, we collected increment cores from these and matched unfertilized trees and compared radial growth ratios (growth in the 3-year post-fertilization period/growth in the 3-year pre-fertilization period) in paired t tests. We expected a higher mean ratio in the fertilized trees. No effect from fertilization was detected, nor was a trend evident on either river. An alternative test using analysis of covariance (ANCOVA) produced a similar result. Our results underscore the need for additional assessment of which and to what extent factors other than water control dryland riverine productivity. Positive confirmation of adequate soil nutrients at these and other dryland riparian sites would bolster the argument that flow management is necessary and sufficient to maximize productivity and enhance resilience in affected desert riverine forests.

  11. ECONOMIC IMPACTS OF DRYLAND SALINITY FOR GRAINS INDUSTRIES

    OpenAIRE

    2003-01-01

    This paper explores some possible economic impacts of worsening salinity severity and extent in the grains industry across Australia. It also looks at the potential to increase agricultural profits through remediation. The analysis is based on a spatial model of agricultural profits and salinity related crop/pasture yield losses. It is estimated that grains industry farming profits across Australia would rise by an upper limit $138 million per year were salinity costlessly removed from the la...

  12. Alley Farming in Thailand

    Directory of Open Access Journals (Sweden)

    Teerapol Silakul

    2010-08-01

    Full Text Available Poverty alleviation and environmental preservation are very important issues to many governments. Alley farming is beneficial to the environment because it conserves soil and sustains yields over time. Specifically, alley farming reduces soil erosion, which is a major problem in Thailand. Alley farming was conducted on a farmer’s field at Khaokwan Thong, a village in Uthaithani Province, Northern Thailand. We did a two-by-two factorial with and without alley farming, and with and without fertilizer. From this study, we observed that the two species used, Leucaena leucocephala and Acacia auriculiformis, grow well in Thailand, and that alley farming is suitable for Thailand. Few Thai farmers have heard about alley farming. However, it is nevertheless useful to know that there is potential for alley farming in Thailand using the two species. These plants, based upon the diameter and height measurements provided, grew well.

  13. Establishment of a constructed wetland in extreme dryland.

    Science.gov (United States)

    Tencer, Yoram; Idan, Gil; Strom, Marjorie; Nusinow, Uri; Banet, Dorit; Cohen, Eli; Schröder, Peter; Shelef, Oren; Rachmilevitch, Shimon; Soares, Ines; Gross, Amit; Golan-Goldhirsh, Avi

    2009-11-01

    of the system. The initial results of the monitoring are promising. In nearly all measurements, the system succeeded as expected to reduce levels of contaminants at least to the level acceptable for irrigating fruit trees and often to the level of unlimited irrigation. The introduction of the plants in the system and their physiological performance were evaluated and were found to correlate well to the quality of water in the various beds. It should be said at the outset that evaluation of the performance of a CW system is a long-term process. Thus, the main aim of this report is to present the problems, difficulties, preliminary results, and concepts concerned with the first stage of establishment of CW in an extremely dry region. The CW system was designed to dispose of municipal and agricultural wastes in a way that not merely reduces pollution, but adds to environmental quality by creating accessible parkland for local residents and tourists. Several factors affected the performance of the system at the initial stages of operation: ecological balance between microbes and plants, big seasonal variations, seepage and evaporation reduced the flow in the initial operation of the system. Despite the initial difficulties, the quality of water coming out the system is acceptable for irrigation. The CW can function well under extreme dryland conditions. The oxidation pond was the major source of evaporation and bad odors. Therefore, alternatives to the oxidation pond are needed. Cost effectiveness of the system still has to be evaluated systematically.

  14. Experimental warming in a dryland community reduced plant photosynthesis and soil CO2 efflux although the relationship between the fluxes remained unchanged

    Science.gov (United States)

    Wertin, Timothy M.; Belnap, Jayne; Reed, Sasha C.

    2016-01-01

    1.Drylands represent our planet's largest terrestrial biome and, due to their extensive area, maintain large stocks of carbon (C). Accordingly, understanding how dryland C cycling will respond to climate change is imperative for accurately forecasting global C cycling and future climate. However, it remains difficult to predict how increased temperature will affect dryland C cycling, as substantial uncertainties surround the potential responses of the two main C fluxes: plant photosynthesis and soil CO2 efflux. In addition to a need for an improved understanding of climate effects on individual dryland C fluxes, there is also notable uncertainty regarding how climate change may influence the relationship between these fluxes.

  15. Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Hasager, Charlotte Bay; Courtney, Michael

    2015-01-01

    The technology behind constructing wind farms offshore began to develop in 1991 when the Vindeby wind farm was installed off the Danish coast (11 Bonus 450 kW turbines). Resource assessment, grid connection, and wind farm operation are significant challenges for offshore wind power just...... as it is for the more traditional onshore wind power, which has been under development since the 1970s. However, offshore projects face extra technical challenges some of which requires in-depth scientific investigations. This article deals with some of the most outstanding challenges concerning the turbine structure...... concern are the problems associated with locating the turbines close together in a wind farm and the problems of placing several large wind farms in a confined area. The environmental impacts of offshore wind farms are also treated, but not the supply chain, that is, the harbors, the installation vessels...

  16. Boosting Farm Produce Supply

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the wake of escalating inflation,securing farm produce supply and stablizing grain prices could help to alleviate economic pressure The Chinese Government has pledged to secure a stable supply of farm produce.According to a document released after the annual Central Rural Work Conference held on December 22-23 in Beijing,preventing short supplies of farm produce and avoiding"ex-

  17. ABOUT SPONGE FARMING

    Directory of Open Access Journals (Sweden)

    Marijana Pećarević

    2005-04-01

    Full Text Available Sponges are the simplest multicellular animals. Farming of sponges is facilitated by their asexual reproduction and great ability of regeneration. Farming of filter-feeding sponges is environment friendly, and it can positively influence on environmental impact of other aquaculture activities. Natural populations of sponges in Mediterranean Sea are endangered by inappropriate overfishing. Farming of sponges is possible solution for regeneration and protection of natural populations.

  18. Legacy effects in linked ecological-soil-geomorphic systems of drylands

    Science.gov (United States)

    Monger, Curtis; Sala, Osvaldo E.; Duniway, Michael C.; Goldfus, Haim; Meir, Isaac A.; Poch, Rosa M.; Throop, Heather L.; Vivoni, Enrique R.

    2015-01-01

    A legacy effect refers to the impacts that previous conditions have on current processes or properties. Legacies have been recognized by many disciplines, from physiology and ecology to anthropology and geology. Within the context of climatic change, ecological legacies in drylands (eg vegetative patterns) result from feedbacks between biotic, soil, and geomorphic processes that operate at multiple spatial and temporal scales. Legacy effects depend on (1) the magnitude of the original phenomenon, (2) the time since the occurrence of the phenomenon, and (3) the sensitivity of the ecological–soil–geomorphic system to change. Here we present a conceptual framework for legacy effects at short-term (days to months), medium-term (years to decades), and long-term (centuries to millennia) timescales, which reveals the ubiquity of such effects in drylands across research disciplines.

  19. Farm Health and Safety

    Science.gov (United States)

    ... jobs in the United States. Farms have many health and safety hazards, including Chemicals and pesticides Machinery, ... equipment can also reduce accidents. Occupational Safety and Health Administration

  20. Phenological Response of an Arizona Dryland Forest to Short-Term Climatic Extremes

    Directory of Open Access Journals (Sweden)

    Jessica Walker

    2015-08-01

    Full Text Available Baseline information about dryland forest phenology is necessary to accurately anticipate future ecosystem shifts. The overarching goal of our study was to investigate the variability of vegetation phenology across a dryland forest landscape in response to climate alterations. We analyzed the influence of site characteristics and climatic conditions on the phenological patterns of an Arizona, USA, ponderosa pine (Pinus ponderosa forest during a five-year period (2005 to 2009 that encompassed extreme wet and dry precipitation regimes. We assembled 80 synthetic Landsat images by applying the spatial and temporal adaptive reflectance fusion method (STARFM to 500 m MODIS and 30 m Landsat-5 Thematic Mapper (TM data. We tested relationships between site characteristics and the timing of peak Normalized Difference Vegetation Index (NDVI to assess the effect of climatic stress on the green-up of individual pixels during or after the summer monsoon. Our results show that drought-induced stress led to a fragmented phenological response that was highly dependent on microsite parameters, as both the spatial autocorrelation of peak timing and the number of significant site variables increased during the drought year. Pixels at lower elevations and with higher proportions of herbaceous vegetation were more likely to exhibit dynamic responses to changes in precipitation conditions. Our study demonstrates the complexity of responses within dryland forest ecosystems and highlights the need for standardized monitoring of phenology trends in these areas. The spatial and temporal variability of phenological signals may provide a quantitative solution to the problem of how to evaluate dryland land surface trends across time.

  1. Dryland anabranching river morphodynamics: Río Capilla, Salar de Uyuni, Bolivia

    Science.gov (United States)

    Li, Jiaguang; Bristow, Charlie S.; Luthi, Stefan M.; Donselaar, Marinus E.

    2015-12-01

    The dryland anabranching river Río Capilla is characterized by nonvegetated and vegetated reaches with prominent channel morphology. To identify the morphodynamics of such dryland anabranching systems and their controls, we investigated the Río Capilla of the southern Altiplano Plateau using high-resolution satellite imagery and field measurements. Comparison of high-resolution satellite data reveals that erosion exceeds deposition for the main channel, accompanied by changes in channel planform, such as meander and channel morphology. On-site surveys combined with high-precision GPS and high-resolution satellite imagery show that channels are characterized by shallowness and poor development of levees. The study area of the Río Capilla is divided into two zones of different slopes: zone 1 with a high slope and zone 2 with a low slope. Zone 1 has a relatively straight main channel with few anabranches and grass-covered banks that are stable despite the high gradient; whereas zone 2 is typified by more anabranches with nonvegetated banks, and the main channel experiences prominent bank accretion and erosion. Excavations show that point-bar deposits are fine-sand-dominated in two reaches and that river banks primarily consist of silt and clay. The limited vegetation cover and abundance of desiccation cracks and macropores make the river bank more erodible leading to pronounced lateral migration in this low-gradient dryland river system. Shallow channels and poor development of levees in combination with in-channel accretionary benches result in frequent overbank flooding, which results in a high density of crevasse splays over unconsolidated river banks and accretionary benches. Connection of headcuts and crevasse channels together with lateral migration and chute channels and reactivation of partially abandoned meanders produces an anabranching pattern in such dryland river systems.

  2. A model for simulating the deposition of water-lain sediments in dryland environments

    Directory of Open Access Journals (Sweden)

    M. A. Bunch

    2004-01-01

    Full Text Available A numerical process-imitating model, the Discrete Storm Event Sedimentation Simulator (DSESS, has been developed to represent the climatic and hydraulic conditions of drylands in modelling their geomorphological development and sedimentary facies distributions. The ultimate aim is to provide insights into the lateral variability of permeability in the Triassic Sandstone aquifers of the UK for the study of solute movement. DSESS employs discrete storm-flood automata, released across a cellular landscape, to model sediment transport: erosion, migration and deposition. Sediment classes with different grain sizes can be modelled. Empirical process-based equations are used to quantify the movement of the automata, their erosion potential, sediment-carrying capacity and interaction with the underlying sediments. The approach emphasises the sequence of dryland storm events and associated floods rather than their timing. Flood events are assumed to be discrete in time. Preliminary tests carried out with DSESS using simple systems and idealised initial conditions produce lithological and land surface features characteristic of dryland settings and indicate the potential of the model for large-scale, long-time modelling of sedimentary facies development. Markedly different results are observed across the range of tests carried out in response to the non-linear interactions between the different elements of the landscape and the floodwaters simulated with DSESS. Simulations show that sediment accumulations develop concave upward radial profiles, plano-convex cross-profiles and possess a general lateral grading of sediment with distance from source. The internal grain size architecture shows evidence of both persistent and rapidly changing flow conditions, with both lateral and longitudinal stepping of coarse bodies produced by ‘scour and fill’ events and random avulsions. Armoured layers form so that near-surface sediments have increased likelihood of

  3. A Correlational Analysis of Tethered Swimming, Swim Sprint Performance and Dry-land Power Assessments.

    Science.gov (United States)

    Loturco, I; Barbosa, A C; Nocentini, R K; Pereira, L A; Kobal, R; Kitamura, K; Abad, C C C; Figueiredo, P; Nakamura, F Y

    2016-03-01

    Swimmers are often tested on both dry-land and in swimming exercises. The aim of this study was to test the relationships between dry-land, tethered force-time curve parameters and swimming performances in distances up to 200 m. 10 young male high-level swimmers were assessed using the maximal isometric bench-press and quarter-squat, mean propulsive power in jump-squat, squat and countermovement jumps (dry-land assessments), peak force, average force, rate of force development (RFD) and impulse (tethered swimming) and swimming times. Pearson product-moment correlations were calculated among the variables. Peak force and average force were very largely correlated with the 50- and 100-m swimming performances (r=- 0.82 and -0.74, respectively). Average force was very-largely/largely correlated with the 50- and 100-m performances (r=- 0.85 and -0.67, respectively). RFD and impulse were very-largely correlated with the 50-m time (r=- 0.72 and -0.76, respectively). Tethered swimming parameters were largely correlated (r=0.65 to 0.72) with mean propulsive power in jump-squat, squat-jump and countermovement jumps. Finally, mean propulsive power in jump-squat was largely correlated (r=- 0.70) with 50-m performance. Due to the significant correlations between dry-land assessments and tethered/actual swimming, coaches are encouraged to implement strategies able to increase leg power in sprint swimmers.

  4. A model for simulating the deposition of water-lain sediments in dryland environments

    OpenAIRE

    M. A. Bunch; R. Mackay; Tellam, J. H.; Turner, P

    2004-01-01

    A numerical process-imitating model, the Discrete Storm Event Sedimentation Simulator (DSESS), has been developed to represent the climatic and hydraulic conditions of drylands in modelling their geomorphological development and sedimentary facies distributions. The ultimate aim is to provide insights into the lateral variability of permeability in the Triassic Sandstone aquifers of the UK for the study of solute movement. DSESS employs discrete storm-flood automata, released across...

  5. A model for simulating the deposition of water-lain sediments in dryland environments

    OpenAIRE

    M. A. Bunch; R. Mackay; Tellam, J. H.; Turner, P

    2004-01-01

    A numerical process-imitating model, the Discrete Storm Event Sedimentation Simulator (DSESS), has been developed to represent the climatic and hydraulic conditions of drylands in modelling their geomorphological development and sedimentary facies distributions. The ultimate aim is to provide insights into the lateral variability of permeability in the Triassic Sandstone aquifers of the UK for the study of solute movement. DSESS employs discrete storm-flood ...

  6. Climate change poised to threaten hydrologic connectivity and endemic fishes in dryland streams

    OpenAIRE

    Jaeger, Kristin L.; Julian D. Olden; Pelland, Noel A.

    2014-01-01

    We provide the first demonstration to our knowledge that projected changes in regional climate regimes will have significant consequences for patterns of intermittence and hydrologic connectivity in dryland streams of the American Southwest. By simulating fine-resolution streamflow responses to forecasted climate change, we simultaneously evaluate alterations in local flow continuity over time and network flow connectivity over space and relate how these changes may challenge the persistence ...

  7. Understanding the coupled natural and human systems in Dryland East Asia

    Science.gov (United States)

    Qi, Jiaguo; Chen, Jiquan; Wan, Shiqian; Ai, Likun

    2012-03-01

    Stressors including regional climate change, economic development effects upon land use and an increasing demand for food production have resulted in significant impacts on the dryland ecosystems in the East Asia (DEA) region. Ecosystem services, such as its provisional services in providing forage for grazing as well as its functional services in regulating water and carbon fluxes, have been significantly altered over the past three decades. Conversely, changes in the landscape, particularly land cover types, have also been blamed for intensified climatic events such as dust storms and severe and frequent droughts within the region. The interactive nature of climate, ecosystems and society is complex and not fully understood, making it difficult, if not impossible, to develop effective adaptation strategies for the region. A special synthesis workshop on ‘Dryland Ecosystems in East Asia: State, Changes, Knowledge Gaps, and Future’ was held from 18-20 July 2011 in Kaifeng, Henan Province, China, with the aim of identifying knowledge gaps, quantifying impacts and developing a future research agenda for the region. The specific objectives of this workshop were to answer some key socio-environmental questions, including the following. (1) What do we know about the drylands in DEA? (2) What are the knowledge gaps? (3) What are the solutions to these issues? This paper provides a synthesis of the workshop consensus and findings on the state of knowledge and challenges in addressing these science issues for the DEA region.

  8. Microseepage in drylands: Flux and implications in the global atmospheric source/sink budget of methane

    Science.gov (United States)

    Etiope, Giuseppe; Klusman, Ronald W.

    2010-07-01

    Drylands are considered a net sink for atmospheric methane and a main item of the global inventories of the greenhouse gas budget. It is outlined here, however, that a significant portion of drylands occur over sedimentary basins hosting natural gas and oil reservoirs, where gas migration to the surface takes place, producing positive fluxes of methane into the atmosphere. New field surveys, in different hydrocarbon-prone basins, confirm that microseepage, enhanced by faults and fractures in the rocks, overcomes the methanotrophic consumption occurring in dry soil throughout large areas, especially in the winter season. Fluxes of a few units to some tens of mg m - 2 day - 1 are frequent over oil-gas fields, whose global extent is estimated at 3.5-4.2 million km 2; higher fluxes (> 50 mg m - 2 day - 1 ) are primarily, but not exclusively, found in basins characterized by macro-seeps. Microseepage may however potentially exist over a wider area (˜ 8 million km 2, i.e. 15% of global drylands), including the Total Petroleum Systems, coal measures and portions of sedimentary basins that have experienced thermogenesis. Based on a relatively large and geographically dispersed data-set (563 measurements) from different hydrocarbon-prone basins in USA and Europe, upscaling suggests that global microseepage emission exceeding 10 Tg year - 1 is very likely. Microseepage is then only one component of a wider class of geological sources, including mud volcanoes, seeps, geothermal and marine seepage, which cannot be ignored in the atmospheric methane budget.

  9. Understanding the role of ecohydrological feedbacks in ecosystem state change in drylands

    Science.gov (United States)

    Turnbull, L.; Wilcox, B.P.; Belnap, J.; Ravi, S.; D'Odorico, P.; Childers, D.; Gwenzi, W.; Okin, G.; Wainwright, J.; Caylor, K.K.; Sankey, T.

    2012-01-01

    Ecohydrological feedbacks are likely to be critical for understanding the mechanisms by which changes in exogenous forces result in ecosystem state change. We propose that in drylands, the dynamics of ecosystem state change are determined by changes in the type (stabilizing vs amplifying) and strength of ecohydrological feedbacks following a change in exogenous forces. Using a selection of five case studies from drylands, we explore the characteristics of ecohydrological feedbacks and resulting dynamics of ecosystem state change. We surmise that stabilizing feedbacks are critical for the provision of plant-essential resources in drylands. Exogenous forces that break these stabilizing feedbacks can alter the state of the system, although such changes are potentially reversible if strong amplifying ecohydrological feedbacks do not develop. The case studies indicate that if amplifying ecohydrological feedbacks do develop, they are typically associated with abiotic processes such as runoff, erosion (by wind and water), and fire. These amplifying ecohydrological feedbacks progressively modify the system in ways that are long-lasting and possibly irreversible on human timescales.

  10. Changes to dryland rainfall result in rapid moss mortality and altered soil fertility

    Science.gov (United States)

    Reed, Sasha C.; Coe, Kirsten K.; Sparks, Jed P.; Housman, David C.; Zelikova, Tamara J.; Belnap, Jayne

    2012-01-01

    Arid and semi-arid ecosystems cover ~40% of Earth’s terrestrial surface, but we know little about how climate change will affect these widespread landscapes. Like many drylands, the Colorado Plateau in southwestern United States is predicted to experience elevated temperatures and alterations to the timing and amount of annual precipitation. We used a factorial warming and supplemental rainfall experiment on the Colorado Plateau to show that altered precipitation resulted in pronounced mortality of the widespread moss Syntrichia caninervis. Increased frequency of 1.2 mm summer rainfall events reduced moss cover from ~25% of total surface cover to soil fertility. Mosses are important members in many dryland ecosystems and the community changes observed here reveal how subtle modifications to climate can affect ecosystem structure and function on unexpectedly short timescales. Moreover, mortality resulted from increased precipitation through smaller, more frequent events, underscoring the importance of precipitation event size and timing, and highlighting our inadequate understanding of relationships between climate and ecosystem function in drylands.

  11. Climate change may restrict dryland forest regeneration in the 21st century

    Science.gov (United States)

    Petrie, M.D.; Bradford, John B.; Hubbard, R.M.; Lauenroth, W.K.; Andrews, Caitlin; Schlaepfer, D.R.

    2017-01-01

    The persistence and geographic expansion of dryland forests in the 21st century will be influenced by how climate change supports the demographic processes associated with tree regeneration. Yet, the way that climate change may alter regeneration is unclear. We developed a quantitative framework that estimates forest regeneration potential (RP) as a function of key environmental conditions for ponderosa pine, a key dryland forest species. We integrated meteorological data and climate projections for 47 ponderosa pine forest sites across the western United States, and evaluated RP using an ecosystem water balance model. Our primary goal was to contrast conditions supporting regeneration among historical, mid-21st century and late-21st century time frames. Future climatic conditions supported 50% higher RP in 2020–2059 relative to 1910–2014. As temperatures increased more substantially in 2060–2099, seedling survival decreased, RP declined by 50%, and the frequency of years with very low RP increased from 25% to 58%. Thus, climate change may initially support higher RP and increase the likelihood of successful regeneration events, yet will ultimately reduce average RP and the frequency of years with moderate climate support of regeneration. Our results suggest that climate change alone may begin to restrict the persistence and expansion of dryland forests by limiting seedling survival in the late 21st century.

  12. Functional diversity enhances the resistance of ecosystem multifunctionality to aridity in Mediterranean drylands.

    Science.gov (United States)

    Valencia, Enrique; Maestre, Fernando T; Le Bagousse-Pinguet, Yoann; Quero, José Luis; Tamme, Riin; Börger, Luca; García-Gómez, Miguel; Gross, Nicolas

    2015-04-01

    We used a functional trait-based approach to assess the impacts of aridity and shrub encroachment on the functional structure of Mediterranean dryland communities (functional diversity (FD) and community-weighted mean trait values (CWM)), and to evaluate how these functional attributes ultimately affect multifunctionality (i.e. the provision of several ecosystem functions simultaneously). Shrub encroachment (the increase in the abundance/cover of shrubs) is a major land cover change that is taking place in grasslands worldwide. Studies conducted on drylands have reported positive or negative impacts of shrub encroachment depending on the functions and the traits of the sprouting or nonsprouting shrub species considered. FD and CWM were equally important as drivers of multifunctionality responses to both aridity and shrub encroachment. Size traits (e.g. vegetative height or lateral spread) and leaf traits (e.g. specific leaf area and leaf dry matter content) captured the effect of shrub encroachment on multifunctionality with a relative high accuracy (r(2)  = 0.63). FD also improved the resistance of multifunctionality along the aridity gradient studied. Maintaining and enhancing FD in plant communities may help to buffer negative effects of ongoing global environmental change on dryland multifunctionality.

  13. Multi-element accumulation near Rumex crispus roots under wetland and dryland conditions.

    Science.gov (United States)

    Kissoon, La Toya T; Jacob, Donna L; Otte, Marinus L

    2010-05-01

    Rumex crispus was grown under wet and dry conditions in two-chamber columns such that the roots were confined to one chamber by a 21 mum nylon mesh, thus creating a soil-root interface ('rhizoplane'). Element concentrations at 3 mm intervals below the 'rhizoplane' were measured. The hypothesis was that metals accumulate near plant roots more under wetland than dryland conditions. Patterns in element distribution were different between the treatments. Under dryland conditions Al, Ba, Cu, Cr, Fe, K, La, Mg, Na, Sr, V, Y and Zn accumulated in soil closest to the roots, above the 'rhizoplane' only. Under wetland conditions Al, Fe, Cr, K, V and Zn accumulated above as well as 3 mm below the 'rhizoplane' whereas La, Sr and Y accumulated 3 mm below the 'rhizoplane' only. Plants on average produced 1.5 times more biomass and element uptake was 2.5 times greater under wetland compared to dryland conditions. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Challenges and Alternatives to Sustainable Management of Agriculture and Pastoral Ecosystems in Asian Drylands

    Science.gov (United States)

    Qi, J.

    2015-12-01

    There is no question that human must produce additional 70% food to feed the new 2.2 billion of people on the planet by 2050, but the question is where to grow the additional food. The demand for the additional food lies not only in producing the basic resources needed to sustain a healthy lifestyle, but also from a changing diet, especially in rapidly developing countries in the dryland regions around the world. It is forecast that this demand for meat will require an additional 0.2 billion tons per year by 2050, which is almost a doubling of present meat consumption. These new demands create mounting pressures on agriculture and pastoral ecosystems and the reported trajectory of warmer and drier climate in the future increases uncertainties in food security, adding further stresses to the already stressed nations in the Asian dryland belt. Different approaches are being either proposed or practiced in the region but the question is whether or not the current practices are sustainable or optimal in addressing the emerging issues. Given the complexity and interplay among the food, water and energy, what are alternatives to ensure a sustainable trajectory of regional development to meet the new food demand? This presentation reviews existing practices and proposes alternative solutions, by specifically examining the trade-offs between different ecosystem services that drylands in Asian may provide. Preliminary analysis suggested that the current trajectory of meat and milk production is likely not on a sustainable pathway.

  15. Mapping gains and losses in woody vegetation across global tropical drylands.

    Science.gov (United States)

    Tian, Feng; Brandt, Martin; Liu, Yi Y; Rasmussen, Kjeld; Fensholt, Rasmus

    2017-04-01

    Woody vegetation in global tropical drylands is of significant importance for both the interannual variability of the carbon cycle and local livelihoods. Satellite observations over the past decades provide a unique way to assess the vegetation long-term dynamics across biomes worldwide. Yet, the actual changes in the woody vegetation are always hidden by interannual fluctuations of the leaf density, because the most widely used remote sensing data are primarily related to the photosynthetically active vegetation components. Here, we quantify the temporal trends of the nonphotosynthetic woody components (i.e., stems and branches) in global tropical drylands during 2000-2012 using the vegetation optical depth (VOD), retrieved from passive microwave observations. This is achieved by a novel method focusing on the dry season period to minimize the influence of herbaceous vegetation and using MODerate resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data to remove the interannual fluctuations of the woody leaf component. We revealed significant trends (P vegetation not captured by traditional assessments. The method is validated using a unique record of ground measurements from the semiarid Sahel and shows a strong agreement between changes in VODwood and changes in ground observed woody cover (r(2)  = 0.78). Reliability of the obtained woody component trends is also supported by a review of relevant literatures for eight hot spot regions of change. The proposed approach is expected to contribute to an improved assessment of, for example, changes in dryland carbon pools.

  16. Using biogeochemical tracing and ecohydrological monitoring to increase understanding of water, sediment and carbon dynamics across dryland vegetation transitions

    Science.gov (United States)

    Puttock, Alan; Dungait, Jennifer; Macleod, Kit; Bol, Roland; Brazier, Richard

    2014-05-01

    Drylands worldwide have experienced rapid and extensive environmental change, which across large areas has been characterised by the encroachment of woody vegetation into grasslands. Woody encroachment leads to changes in the abiotic and biotic structure and function of dryland ecosystems and has been shown to result in accelerated soil erosion and loss of soil nutrients. The relationship between environmental change, soil erosion and the carbon cycle in dryland environments remains uncertain. Covering over 40 % of the terrestrial land surface, dryland environments are of significant global importance, both as a habitat and a soil carbon store. Thus, there is a clear need to further our understanding of dryland vegetation change and impacts on carbon dynamics. Here, grama grass to creosote shrub and grama grass to piñon-juniper woodland; two grass-to-woody ecotones that occur across large swathes of the semi-arid Southwestern United States are investigated. This study combines an ecohydrological monitoring framework with a multi-proxy biogeochemical approach using stable carbon isotope and n-alkane lipid biomarkers to trace the source of organic carbon. Results will be presented showing that following woody encroachment into grasslands, there is a transition to a more heterogeneous ecosystem structure and an increased hydrological connectivity. Consequentially, not only do drylands lose significantly more soil and organic carbon via accentuated fluvial erosion, but this includes significant amounts of legacy organic carbon which would previously have been stable under the previous grass cover. Results suggest that dryland soils may therefore, not act as a stable organic carbon pool and that accelerated fluvial erosion of carbon, driven by vegetation change, has important implications for the global carbon cycle.

  17. Migrant Farm Workers.

    Science.gov (United States)

    Slesinger, Doris P.; Pfeffer, Max J.

    This paper documents migrant farm workers as being among the most persistently underprivileged groups in American society. Migrant farm workers typically receive low wages from irregular employment and live in poverty with access to only substandard housing and inadequate health care. The lack of economic improvement stems from a number of…

  18. Not Your Family Farm

    Science.gov (United States)

    Tenopir, Carol; Baker, Gayle; Grogg, Jill E.

    2007-01-01

    The information industry continues to consolidate, just as agribusiness has consolidated and now dominates farming. Both the family farm and the small information company still exist but are becoming rarer in an age of mergers, acquisitions, and increased economies of scale. Small companies distinguish themselves by high quality, special themes,…

  19. 旱地作物需水量预报决策辅助系统%Decision Support System of Water Requirement Forecast for Dryland Crop

    Institute of Scientific and Technical Information of China (English)

    上官周平; 邵明安; 薛增召

    2001-01-01

    The decision support system of water requirement forecast for dryland crop is a systematic integrated intelligent computer software established by combining existing agronomy knowledge, model and expert experience with the artificial intelligent technology, on the foundation of Penman formula. This decision support system is a subsystem as "Expert system of water-saving agricultural of Northwestern area". It can give decision consulting for irrigation scheme for the management of winter wheat and summer corn in Middle of Shaanxi areas. And can led the water-saving farming to more scientific and more reasonable in this areas.%旱地作物需水量预报决策辅助系统是利用人工智能技术,在Penman公式的基础上结合现有西北旱区的农学知识、模型以及经验进行系统集成而建立的智能化计算机软件系统,该系统是西北地区节水农业专家系统的一个子系统。在生产实践中可为陕西关中地区的冬小麦、夏玉米的栽培作出灌溉方案的决策咨询。

  20. Impact of climate change on drylands with a focus on West Africa

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, A.J.; Verhagen, A.; Ruben, R. (eds.) [Impact of Climate Change on Drylands ICCD, Wageningen (Netherlands)

    2001-07-01

    The research effort started with a geographical inventory of all tropical and sub-tropical drylands to map the diversity in aridity, land degradation, population densities and urbanisation of the world's drylands, and to put the drylands of West Africa in perspective. It also guided a choice of in-depth study regions within West Africa. The scenario analysis shows a wide variety of outcomes, but with rather strong suggestions that most of dryland West Africa is expected to become a lot dryer. The consequences of these projections are an increase in high-risk environments for agriculture, including a southward shift of the and and semi-arid zones. Changes in rainfall distribution could mean an additional stress on agricultural production in these areas. Simulation studies clearly reveal a shift of the onset of the growing season and lower yield levels. To understand farmers' behaviour in West African drylands in preparing (Insuring) for dryer conditions and for agro-climatological droughts, in coping with droughts and adverse production conditions, and in adapting to changed conditions afterwards, we looked at their performance before, during and after drought years in the past identifying several adaptation strategies and policy recommendations. The conclusions are not very grim, contrary to the much-painted 'picture of doom' for Africa. West Africa's shock experience in the 1970s and 1980s did have the result that it became much better prepared for possible new drought shocks, and that its agricultural production performance in the 1990s (when rainfall became considerably better) improved. The future for the Sahel is not necessarily gloomy. However, system breakdown can occur during droughts. One may fear that in those situations religion will be used as a major catalyst for political support to exclusive claims (Islam versus Christianity and religious sub-groups versus sub-groups) and may result in massive violence and rapid deterioration

  1. Linkages between Land Surface Phenology Metrics and Natural and Anthropogenic Events in Drylands (Invited)

    Science.gov (United States)

    de Beurs, K.; Brown, M. E.; Ahram, A.; Walker, J.; Henebry, G. M.

    2013-12-01

    Tracking vegetation dynamics across landscapes using remote sensing, or 'land surface phenology,' is a key mechanism that allows us to understand ecosystem changes. Land surface phenology models rely on vegetation information from remote sensing, such as the datasets derived from the Advanced Very High Resolution Radiometer (AVHRR), the newer MODIS sensors on Aqua and Terra, and sometimes the higher spatial resolution Landsat data. Vegetation index data can aid in the assessment of variables such as the start of season, growing season length and overall growing season productivity. In this talk we use Landsat, MODIS and AVHRR data and derive growing season metrics based on land surface phenology models that couple vegetation indices with satellite derived accumulated growing degreeday and evapotranspiration estimates. We calculate the timing and the height of the peak of the growing season and discuss the linkage of these land surface phenology metrics with natural and anthropogenic changes on the ground in dryland ecosystems. First we will discuss how the land surface phenology metrics link with annual and interannual price fluctuations in 229 markets distributed over Africa. Our results show that there is a significant correlation between the peak height of the growing season and price increases for markets in countries such as Nigeria, Somalia and Niger. We then demonstrate how land surface phenology metrics can improve models of post-conflict resolution in global drylands. We link the Uppsala Conflict Data Program's dataset of political, economic and social factors involved in civil war termination with an NDVI derived phenology metric and the Palmer Drought Severity Index (PDSI). An analysis of 89 individual conflicts in 42 dryland countries (totaling 892 individual country-years of data between 1982 and 2005) revealed that, even accounting for economic and political factors, countries that have higher NDVI growth following conflict have a lower risk of

  2. Climate scenarios for semi-arid and sub-humid regions. A comparison of climate scenarios for the dryland regions, in West Africa from 1990 to 2050

    NARCIS (Netherlands)

    van den Born GJ; Schaeffer M; Leemans R; NOP

    2001-01-01

    The identification of climate scenarios for dryland areas in Sub-Saharan West Africa is part of a project to assess the impact of climate change on water availability, agriculture and food security in drylands (ICCD-project). The project is financed by Netherlands Research Programme on Global Air P

  3. Climate scenarios for semi-arid and sub-humid regions. A comparison of climate scenarios for the dryland regions, in West Africa from 1990 to 2050

    NARCIS (Netherlands)

    van den Born GJ; Schaeffer M; Leemans R; NOP

    2001-01-01

    The identification of climate scenarios for dryland areas in Sub-Saharan West Africa is part of a project to assess the impact of climate change on water availability, agriculture and food security in drylands (ICCD-project). The project is financed by Netherlands Research Programme on Global Air

  4. Observing farming systems

    DEFF Research Database (Denmark)

    Noe, Egon; Alrøe, Hugo Fjelsted

    2012-01-01

    In Denmark, agriculture is becoming increasingly specialised, and more and more actors are becoming involved in farm decision making. These trends are more or less pronounced in other European countries as well. We therefore find that to understand modern farming systems, we have to shift the focus...... of analysis from individual farmers to communication and social relations. This is where Luhmann’s social systems theory can offer new insights. Firstly, it can help observe and understand the operational closure and system logic of a farming system and how this closure is produced and reproduced. Secondly...

  5. Wind farm design optimization

    Energy Technology Data Exchange (ETDEWEB)

    Carreau, Michel; Morgenroth, Michael; Belashov, Oleg; Mdimagh, Asma; Hertz, Alain; Marcotte, Odile

    2010-09-15

    Innovative numerical computer tools have been developed to streamline the estimation, the design process and to optimize the Wind Farm Design with respect to the overall return on investment. The optimization engine can find the collector system layout automatically which provide a powerful tool to quickly study various alternative taking into account more precisely various constraints or factors that previously would have been too costly to analyze in details with precision. Our Wind Farm Tools have evolved through numerous projects and created value for our clients yielding Wind Farm projects with projected higher returns.

  6. Swimmer’s Shoulder in Athletes: Comparison between Efficacy of Aquatic versus Dry-land Concentric-Eccentric Exercises

    Directory of Open Access Journals (Sweden)

    P.K. Shah

    2016-05-01

    Full Text Available The purpose of the present study was to examine the level of pain gets reduced whether by dry-land based concentric-eccentric exercises or by the equivalent type of aquatic exercises in the elite swimmers complaining of chronic shoulder pain. Elite swimmers from India of both genders with an age group of 16-30 years were chosen having pain rated as ≤7 on visual analog scale with an exception of Bak’s Grade E provided with an absence of past shoulder surgeries and acute injuries. 46 of swimmer’s shoulder athletes were randomly divided in a group of two. 23 in each group were provided with respective sets of dry-land and aquatic concentric-eccentric exercises for 3 times/week for a period of 4 weeks. Outcome was measured using three parameters which included visual analog scale (VAS, 50m freestyle sprint and shoulder pain and disability index (SPADI scoring before and after the treatment in relation to freestyle and backstroke pattern of swimming. In results, the descriptive statistics of swimmers with aquatic and dry-land exercises; for VAS 0 sessions to the 12th session were measured. The swimmers with dry-land exercises had the higher mean values than the swimmers with aquatic exercises, showing statistically significant differences (p≤ 0.05-0.001. Whereas in case of before and after 50 metre sprint, no significant differences were there between these two sets of populations. In case of before and after SPADI scoring, swimmers with aquatic exercises had the lower mean values than those with the dry-land exercises, showing statistically significant differences (p ≤ 0.001. In conclusion, it may be stated that the aquatic concentric-eccentric exercises proved to be efficient for swimmers suffering from swimmer’s shoulder condition and early prognosis can be brought with aquatic rehabilitation as compared to the dry-land concentric-eccentric exercises.

  7. Rainfed farming systems

    National Research Council Canada - National Science Library

    Tow, P. G

    2011-01-01

    "While agriculturists need a good grasp of the many separate aspects of agriculture, it is essential that they also understand the functioning of farming systems as a whole and how they can be best managed...

  8. FarmStats_CNTYFARM

    Data.gov (United States)

    Vermont Center for Geographic Information — This datalayer contains Vermont agricultural data describing changes in farming activity (1860-1997), by county, extracted from U.S. Census of Agriculture. Initial...

  9. Agriculture: Organic Farming

    Science.gov (United States)

    Organic Farming - Organically grown food is food grown and processed using no synthetic fertilizers or pesticides. Pesticides derived from natural sources (such as biological pesticides) may be used in producing organically grown food.

  10. CONTRACT BROILER FARMING

    Directory of Open Access Journals (Sweden)

    Todsadee Areerat

    2012-01-01

    Full Text Available In Thailand, poultry sector is the main economic growth of livestock sector, especially broiler production. The rapid expansion in broiler production has been made possible by the increase in the number of commercial farms or contract farming. The objective of this research was to understand better how contract farming works, who gets involved and why and who benefits from the agreement. The study is based on the broiler file survey in Chiang Mai province of Thailand. As the results, contract farming looks quite attractive for farmers as well as for private companies but most of the farmers complained about long waiting until the delivery of the next cycle of chicks have started.

  11. Farming techniques for seaweeds

    OpenAIRE

    Castaños, M.; Buendia, R.

    1998-01-01

    Details are given of farming methods developed by the SEAFDEC Aquaculture Department for 3 different seaweeds: 1) Bottom line culture method for Kappaphycus; 2) Pond culture of Gracilaria; and, 3) Gracilariopsis bailinae, the new seaweed on the block.

  12. Vegetation and erosion: comments on the linking mechanisms from the perspective of the Australian drylands.

    Science.gov (United States)

    Dunkerley, D.

    2009-04-01

    John Thorne's wide-ranging research included an emphasis on the diverse roles of vegetation in modifying erosion processes under Mediterranean conditions, with primary field studies in Spain. Different global drylands reflect some differences in the nature or strength of the mechanisms linking vegetation and erosion. In Australia, low topographic gradients and plants adapted to water scarcity have facilitated the widespread development of contour-aligned vegetation groves. In these landscapes, the role of individual plants in modifying raindrop impact energy or overland flow erosivity is secondary to the community-level effects of the grove structures. Erosion in common rain events is limited to quite local redistribution of soil materials on metre scales. This highlights one of the unresolved issues that warrants more attention in drylands globally: under what range of rain events does the protective role of individual plants (or of groves) operate, and what is the threshold event size beyond which their effect is swamped by integrated overland flow arriving from upslope? In contrast with, for example, the well-understood role of bankfull flows in river architecture, general principles underlying dryland hillslope and channel responses to events of various magnitudes remain obscure. Clearly, however, there is no single role for plant cover; rather, that role varies with event magnitude and related properties such as the time since the last rain event. An important conclusion is therefore that context is important when evaluating the links between vegetation and erosion. The developing view of overland flow generally, but particularly relevant in drylands where plant cover is sparse, is that the connectedness of runoff flowpaths is a key parameter. It partly determines the extent to which the downslope movement of resources (soil, water, organic matter) is free or constrained, and this conception has the potential to support the formulation of some general models

  13. Landsat 8 and ICESat-2: Performance and potential synergies for quantifying dryland ecosystem vegetation cover and biomass

    Science.gov (United States)

    Glenn, Nancy F.; Neuenschwander, Amy; Vierling, Lee A.; Spaete, Lucas; Li, Aihua; Shinneman, Douglas; Pilliod, David; Arkle, Robert; McIlroy, Susan

    2016-01-01

    The Landsat 8 mission provides new opportunities for quantifying the distribution of above-ground carbon at moderate spatial resolution across the globe, and in particular drylands. Furthermore, coupled with structural information from space-based and airborne laser altimetry, Landsat 8 provides powerful capabilities for large-area, long-term studies that quantify temporal and spatial changes in above-ground biomass and cover. With the planned launch of ICESat-2 in 2017 and thus the potential to couple Landsat 8 and ICESat-2 data, we have unprecedented opportunities to address key challenges in drylands, including quantifying fuel loads, habitat quality, biodiversity, carbon cycling, and desertification.

  14. 山西旱地农业高效持续发展模式研究%Sustainable development models for dryland agriculture in Shanxi

    Institute of Scientific and Technical Information of China (English)

    李振吾; 籍增顺

    2001-01-01

    Dryland agriculture plays an important role in developing Shanxilocal economy. Three kinds of sustainable development models for dryland agriculture in Shanxi were established based on resource characteristics of dryland regions. (1) Cycling model of combining farming with raising animals: Land productivity increases by 49.7% compared with sole maize production system; Lamb gross weight with additive increase 11.3 kg after 115 days, 14% more than traditional management. Output of grass in slope is 12 000 kg/hm2~14 400 kg/hm2. (2) Model of sweet potato production-processing-raising animals: Sweet potato yield is more than 75 000 kg/ hm2, the cost of starch film is 27.9% lower than PVC film. Two kinds of sweet potato products with special taste has been produced, the value of starch noodles is 10 times as yaw sweet potato. (3) Eco-orchard with double-way controlling soil water: Compared with cleared orchard, soil water in 0 cm~60 cm depth in eco-orchard increases by 3.1%, organic matter content in 0 cm~40 cm soil profile increases by 0.17% and exchange potassium by 9.1 mg/100g soil. After 4-yr, the soil density decrease 0.20 g/cm3, the number of natural enemies increases by 3 times, pests decrease 95% and, fruit diseases decrease by 80%. Yield of first grade fruit was 27 000 kg/hm2, net income increased by 1 338 yuan/hm2.%经过4年攻关研究,建立起3套旱地农业高效持续发展模式:(1)种养结合良性循环模式。土地生产率较单作玉米高49.7%,绵羊当年育肥羔羊的屠宰率、净肉率分别较对照组高3.0%和1.4%。应用增肉剂羊只115d总增重11.3kg,较对照组日增重增加14.1%;改良草地产草量可达12000kg/hm2~14400 kg/hm2。(2)“甘薯-加工-养殖”产业化发展模式。在平常年份产鲜薯75 000 kg/hm2以上;生产的淀粉地膜,可降低覆膜成本27.9%。新研制的甘薯低糖脯有酸甜味型和怪味型两种,研制的即食粉丝,增值率在10倍左右。(3)旱

  15. Summary of Data Farming

    Directory of Open Access Journals (Sweden)

    Gary Horne

    2016-03-01

    Full Text Available Data Farming is a process that has been developed to support decision-makers by answering questions that are not currently addressed. Data farming uses an inter-disciplinary approach that includes modeling and simulation, high performance computing, and statistical analysis to examine questions of interest with a large number of alternatives. Data farming allows for the examination of uncertain events with numerous possible outcomes and provides the capability of executing enough experiments so that both overall and unexpected results may be captured and examined for insights. Harnessing the power of data farming to apply it to our questions is essential to providing support not currently available to decision-makers. This support is critically needed in answering questions inherent in the scenarios we expect to confront in the future as the challenges our forces face become more complex and uncertain. This article was created on the basis of work conducted by Task Group MSG-088 “Data Farming in Support of NATO”, which is being applied in MSG-124 “Developing Actionable Data Farming Decision Support for NATO” of the Science and Technology Organization, North Atlantic Treaty Organization (STO NATO.

  16. Modeling Soil Sodicity Problems under Dryland and Irrigated Conditions: Case Studies in Argentina and Colombia

    Science.gov (United States)

    Pla-Sentís, Ildefonso

    2014-05-01

    Salt-affected soils, both saline and sodic, my develop both under dryland and irrigated conditions, affecting negatively the physical and chemical soil properties, the crop production and the animal and human health.Among the development processes of salt-affected soils, the processes of sodification have been generally received less attention and is less understood than the development of saline soils. Although in both of them, hydrological processes are involved in their development, in the case of sodic soils we have to consider some additional chemical and physicochemical reactions, making more difficult their modeling and prediction. In this contribution we present two case studies: one related to the development of sodic soils in the lowlands of the Argentina Pampas, under dryland conditions and sub-humid temperate climate, with pastures for cattle production; the other deals with the development of sodic soils in the Colombia Cauca Valley, under irrigated conditions and tropical sub-humid climate, in lands used for sugarcane cropping dedicated to sugar and ethanol production. In both cases the development of sodicity in the surface soil is mainly related to the effects of the composition and level of groundwater, affected in the case of Argentina Pampas by the off-site changes in dryland use and management in the upper zones and by the drainage conditions in the lowlands, and in the case of the Cauca Valley, by the on-site irrigation and drainage management in lands with sugarcane. There is shown how the model SALSODIMAR, developed by the main author, based on the balance of water and soluble componentes of both the irrigation water and groundwater under different water and land management conditions, may be adapted for the diagnosis and prediction of both problems, and for the selection of alternatives for their management and amelioration.

  17. Modelling sediment export, retention and reservoir sedimentation in drylands with the WASA-SED model

    Directory of Open Access Journals (Sweden)

    E. N. Mueller

    2010-04-01

    Full Text Available Current soil erosion and reservoir sedimentation modelling at the meso-scale is still faced with intrinsic problems with regard to open scaling questions, data demand, computational efficiency and deficient implementations of retention and re-mobilisation processes for the river and reservoir networks. To overcome some limitations of current modelling approaches, the semi-process-based, spatially semi-distributed modelling framework WASA-SED (Vers. 1 was developed for water and sediment transport in large dryland catchments. The WASA-SED model simulates the runoff and erosion processes at the hillslope scale, the transport and retention processes of suspended and bedload fluxes in the river reaches and the retention and remobilisation processes of sediments in reservoirs. The modelling tool enables the evaluation of management options both for sustainable land-use change scenarios to reduce erosion in the headwater catchments as well as adequate reservoir management options to lessen sedimentation in large reservoirs and reservoir networks. The model concept, its spatial discretisation scheme and the numerical components of the hillslope, river and reservoir processes are described and a model application for the meso-scale dryland catchment Isábena in the Spanish Pre-Pyrenees (445 km2 is presented to demonstrate the capabilities, strengths and limits of the model framework. The example application showed that the model was able to reproduce runoff and sediment transport dynamics of highly erodible headwater badlands, the transient storage of sediments in the dryland river system, the bed elevation changes of the 93 hm3 Barasona reservoir due to sedimentation as well as the life expectancy of the reservoir under different management options.

  18. Increasing aridity reduces soil microbial diversity and abundance in global drylands.

    Science.gov (United States)

    Maestre, Fernando T; Delgado-Baquerizo, Manuel; Jeffries, Thomas C; Eldridge, David J; Ochoa, Victoria; Gozalo, Beatriz; Quero, José Luis; García-Gómez, Miguel; Gallardo, Antonio; Ulrich, Werner; Bowker, Matthew A; Arredondo, Tulio; Barraza-Zepeda, Claudia; Bran, Donaldo; Florentino, Adriana; Gaitán, Juan; Gutiérrez, Julio R; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Mau, Rebecca L; Miriti, Maria; Naseri, Kamal; Ospina, Abelardo; Stavi, Ilan; Wang, Deli; Woods, Natasha N; Yuan, Xia; Zaady, Eli; Singh, Brajesh K

    2015-12-22

    Soil bacteria and fungi play key roles in the functioning of terrestrial ecosystems, yet our understanding of their responses to climate change lags significantly behind that of other organisms. This gap in our understanding is particularly true for drylands, which occupy ∼41% of Earth´s surface, because no global, systematic assessments of the joint diversity of soil bacteria and fungi have been conducted in these environments to date. Here we present results from a study conducted across 80 dryland sites from all continents, except Antarctica, to assess how changes in aridity affect the composition, abundance, and diversity of soil bacteria and fungi. The diversity and abundance of soil bacteria and fungi was reduced as aridity increased. These results were largely driven by the negative impacts of aridity on soil organic carbon content, which positively affected the abundance and diversity of both bacteria and fungi. Aridity promoted shifts in the composition of soil bacteria, with increases in the relative abundance of Chloroflexi and α-Proteobacteria and decreases in Acidobacteria and Verrucomicrobia. Contrary to what has been reported by previous continental and global-scale studies, soil pH was not a major driver of bacterial diversity, and fungal communities were dominated by Ascomycota. Our results fill a critical gap in our understanding of soil microbial communities in terrestrial ecosystems. They suggest that changes in aridity, such as those predicted by climate-change models, may reduce microbial abundance and diversity, a response that will likely impact the provision of key ecosystem services by global drylands.

  19. Stressed deserts: A new vegetation/sediment-transport model for dryland environments

    Science.gov (United States)

    Mayaud, Jerome; Bailey, Richard; Wiggs, Giles

    2016-04-01

    In many drylands, vegetation is patchy and dynamic through time and space, with complex ecohydrological feedbacks and plant-plant interactions leading to the emergence of characteristic vegetation patterning. There is increasing evidence that information from the patterns themselves can be used as indicators of a dryland system's proximity to collapse. However, current models simulating the evolution of these vegetation patterns do not account for their effects on wind flow and on the entrainment, transport and redistribution of wind-blown material. Significant uncertainty therefore remains about how these vulnerable landscapes will react to increasing climate forcing and land-use pressure over the 21st century and beyond. We present the coupled Vegetation and Sediment TrAnsport model (ViSTA), a new, multi-scale cellular automaton model designed to simulate transport in vegetated dryland contexts. The model is parameterised using empirical data collected during a field campaign in Namibia that sought to investigate the impact of desert vegetation on wind speed and turbulence at the surface. A new turbulence-based model for aeolian transport is also used to drive the movement of sediment within ViSTA. We show that this coupled approach allows for realistic simulations of dynamics at both the bedform and landscape scale. It is especially important to understand the geomorphological responses of vegetated semi-arid landscapes to a variety of simulated stresses, since these regions are often heavily used for pastoralism, agriculture and habitation. In characterising possible transition scenarios between patterned and desert states, the ViSTA model therefore represents a powerful tool that has direct relevance to land management policies in highly vulnerable environments.

  20. Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change

    Science.gov (United States)

    McCluney, Kevin E.; Belnap, Jayne; Collins, Scott L.; González, Angélica L.; Hagen, Elizabeth M.; Holland, J. Nathaniel; Kotler, Burt P.; Maestre, Fernando T.; Smith, Stanley D.; Wolf, Blair O.

    2012-01-01

    Species interactions play key roles in linking the responses of populations, communities, and ecosystems to environmental change. For instance, species interactions are an important determinant of the complexity of changes in trophic biomass with variation in resources. Water resources are a major driver of terrestrial ecology and climate change is expected to greatly alter the distribution of this critical resource. While previous studies have documented strong effects of global environmental change on species interactions in general, responses can vary from region to region. Dryland ecosystems occupy more than one-third of the Earth's land mass, are greatly affected by changes in water availability, and are predicted to be hotspots of climate change. Thus, it is imperative to understand the effects of environmental change on these globally significant ecosystems. Here, we review studies of the responses of population-level plant-plant, plant-herbivore, and predator-prey interactions to changes in water availability in dryland environments in order to develop new hypotheses and predictions to guide future research. To help explain patterns of interaction outcomes, we developed a conceptual model that views interaction outcomes as shifting between (1) competition and facilitation (plant-plant), (2) herbivory, neutralism, or mutualism (plant-herbivore), or (3) neutralism and predation (predator-prey), as water availability crosses physiological, behavioural, or population-density thresholds. We link our conceptual model to hypothetical scenarios of current and future water availability to make testable predictions about the influence of changes in water availability on species interactions. We also examine potential implications of our conceptual model for the relative importance of top-down effects and the linearity of patterns of change in trophic biomass with changes in water availability. Finally, we highlight key research needs and some possible broader impacts

  1. Grazing and no-till cropping impacts on nitrogen retention in dryland agroecosystems.

    Science.gov (United States)

    Mobley, Megan L; McCulley, Rebecca L; Burke, Ingrid C; Peterson, Gary; Schimel, David S; Cole, C Vernon; Elliott, Edward T; Westfall, Dwayne G

    2014-11-01

    As the world's population increases, marginal lands such as drylands are likely to become more important for food production. One proven strategy for improving crop production in drylands involves shifting from conventional tillage to no-till to increase water use efficiency, especially when this shift is coupled with more intensive crop rotations. Practices such as no-till that reduce soil disturbance and increase crop residues may promote C and N storage in soil organic matter, thus promoting N retention and reducing N losses. By sampling soils 15 yr after a N tracer addition, this study compared long-term soil N retention across several agricultural management strategies in current and converted shortgrass steppe ecosystems: grazed and ungrazed native grassland, occasionally mowed planted perennial grassland, and three cropping intensities of no-till dryland cropping. We also examined effects of the environmental variables site location and topography on N retention. Overall, the long-term soil N retention of >18% in these managed semiarid ecosystems was high compared with published values for other cropped or grassland ecosystems. Cropping practices strongly influenced long-term N retention, with planted perennial grass systems retaining >90% of N in soil compared with 30% for croplands. Grazing management, topography, and site location had smaller effects on long-term N retention. Estimated 15-yr N losses were low for intact and cropped systems. This work suggests that semiarid perennial grass ecosystems are highly N retentive and that increased intensity of semiarid land management can increase the amount of protein harvested without increasing N losses. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. A model for simulating the deposition of water-lain sediments in dryland environments

    Science.gov (United States)

    Bunch, M. A.; Mackay, R.; Tellam, J. H.; Turner, P.

    A numerical process-imitating model, the Discrete Storm Event Sedimentation Simulator (DSESS), has been developed to represent the climatic and hydraulic conditions of drylands in modelling their geomorphological development and sedimentary facies distributions. The ultimate aim is to provide insights into the lateral variability of permeability in the Triassic Sandstone aquifers of the UK for the study of solute movement. DSESS employs discrete storm-flood automata, released across a cellular landscape, to model sediment transport: erosion, migration and deposition. Sediment classes with different grain sizes can be modelled. Empirical process-based equations are used to quantify the movement of the automata, their erosion potential, sediment-carrying capacity and interaction with the underlying sediments. The approach emphasises the sequence of dryland storm events and associated floods rather than their timing. Flood events are assumed to be discrete in time. Preliminary tests carried out with DSESS using simple systems and idealised initial conditions produce lithological and land surface features characteristic of dryland settings and indicate the potential of the model for large-scale, long-time modelling of sedimentary facies development. Markedly different results are observed across the range of tests carried out in response to the non-linear interactions between the different elements of the landscape and the floodwaters simulated with DSESS. Simulations show that sediment accumulations develop concave upward radial profiles, plano-convex cross-profiles and possess a general lateral grading of sediment with distance from source. The internal grain size architecture shows evidence of both persistent and rapidly changing flow conditions, with both lateral and longitudinal stepping of coarse bodies produced by ‘scour and fill’ events and random avulsions. Armoured layers form so that near-surface sediments have increased likelihood of preservation

  3. Surface-water dynamics and land use influence landscape connectivity across a major dryland region.

    Science.gov (United States)

    Bishop-Taylor, Robbi; Tulbure, Mirela G; Broich, Mark

    2017-01-24

    Landscape connectivity is important for the long-term persistence of species inhabiting dryland freshwater ecosystems, with spatiotemporal surface-water dynamics (e.g., flooding) maintaining connectivity by both creating temporary habitats and providing transient opportunities for dispersal. Improving our understanding of how landscape connectivity varies with respect to surface-water dynamics and land use is an important step to maintaining biodiversity in dynamic dryland environments. Using a newly available validated Landsat TM and ETM+ surface-water time series, we modelled landscape connectivity between dynamic surface-water habitats within Australia's 1 million km2 semi-arid Murray Darling Basin across a 25-year period (1987 to 2011). We identified key habitats that serve as well-connected 'hubs', or 'stepping-stones' that allow long-distance movements through surface-water habitat networks. We compared distributions of these habitats for short- and long-distance dispersal species during dry, average and wet seasons, and across land-use types. The distribution of stepping-stones and hubs varied both spatially and temporally, with temporal changes driven by drought and flooding dynamics. Conservation areas and natural environments contained higher than expected proportions of both stepping-stones and hubs throughout the time series; however, highly modified agricultural landscapes increased in importance during wet seasons. Irrigated landscapes contained particularly high proportions of well-connected hubs for long-distance dispersers, but remained relatively disconnected for less vagile organisms. The habitats identified by our study may serve as ideal high-priority targets for land-use specific management aimed at maintaining or improving dispersal between surface-water habitats, potentially providing benefits to biodiversity beyond the immediate site scale. Our results also highlight the importance of accounting for the influence of spatial and temporal

  4. An ecohydrological approach to predicting hillslope-scale vegetation patterns and dynamics in dryland ecosystems

    Science.gov (United States)

    Franz, Trenton; King, Elizabeth

    2015-04-01

    Drylands are an important ecosystem, as they cover over 40% of the Earth's land surface and are know to exhibit threshold behavior in response to climatic change and anthropogenic disturbance. Where dryland vegetation supports pastoralist livestock production, catastrophic ecological shifts present a grave concern because of the direct coupling between the livestock forage available and human livelihoods. In this research we investigate the spatiotemporal organization of grazing resources on hillslopes by developing a relatively simple spatially explicit daily stochastic ecohydrological 1-layer bucket model with dynamic vegetation and grazing components. The model, MVUA MINGI (Mosaic Vegetation Using Agent-based Modeling Incorporating Non-linear Grazing Impacts), was constructed using a 2-year observational study in central Kenya combining in-situ sensors with near surface hydrogeophysical surveys. The data were used to derive an empirical patch water balance of three representative patch types, bare soil, grass, and tree. Visual and hydrogeophysical observations indicated the system is dominated by Hortonian runoff, overland flow, and vertical infiltration of water into vegetation patches. The patch-based water balances were next incorporated into a Cellular Automata model allowing us to simulate a range of surface flowpath convergence states across the hillslope during a rain event. The model also allows the root to canopy radius of the tree patches to vary affecting the length scale of water competition. By changing the length scales of facilitation and competition, we find the model demonstrates a range of most efficient static vegetation patterns from random to highly organized. In order simulate the vegetation dynamics we incorporated continuous transition probabilities for each patch type based on the frequency and duration of drought and grazing intensity. The modeled vegetation dynamics indicate various stable states and the timescales between the state

  5. Adapting a regularized canopy reflectance model (REGFLEC) for the retrieval challenges of dryland agricultural systems

    KAUST Repository

    Houborg, Rasmus

    2016-08-20

    A regularized canopy reflectance model (REGFLEC) is applied over a dryland irrigated agricultural system in Saudi Arabia for the purpose of retrieving leaf area index (LAI) and leaf chlorophyll content (Chll). To improve the robustness of the retrieved properties, REGFLEC was modified to 1) correct for aerosol and adjacency effects, 2) consider foliar dust effects on modeled canopy reflectances, 3) include spectral information in the red-edge wavelength region, and 4) exploit empirical LAI estimates in the model inversion. Using multi-spectral RapidEye imagery allowed Chll to be retrieved with a Mean Absolute Deviation (MAD) of 7.9 μg cm− 2 (16%), based upon in-situ measurements conducted in fields of alfalfa, Rhodes grass and maize over the course of a growing season. LAI and Chll compensation effects on canopy reflectance were largely avoided by informing the inversion process with ancillary LAI inputs established empirically on the basis of a statistical machine learning technique. As a result, LAI was reproduced with good accuracy, with an overall MAD of 0.42 m2 m− 2 (12.5%). Results highlighted the considerable challenges associated with the translation of at-sensor radiance observations to surface bidirectional reflectances in dryland environments, where issues such as high aerosol loadings and large spatial gradients in surface reflectance from bright desert soils to dark vegetated fields are often present. Indeed, surface reflectances in the visible bands were reduced by up to 60% after correction for such adjacency effects. In addition, dust deposition on leaves required explicit modification of the reflectance sub-model to account for its influence. By implementing these model refinements, REGFLEC demonstrated its utility for within-field characterization of vegetation conditions over the challenging landscapes typical of dryland agricultural regions, offering a means through which improvements can be made in the management of these globally

  6. Impact of Climate Change on Drylands. Climate variability, livelihood strategies and policy options

    Energy Technology Data Exchange (ETDEWEB)

    Verhagen, A. [Plant Research International, Wageningen (Netherlands); Dietz, A.J. [Amsterdam Research Institute for Global Issues and Development Studies AGIDS, University of Amsterdam UvA, Amsterdam (Netherlands)

    2001-09-01

    The findings of the Impact of Climate Change on Drylands (ICCD) project were discussed during a workshop held on 26 and 27 April 2001. The aims of the workshop were to disseminate the findings of the ICCD project, create awareness of the possible effects of climate change and contribute to the dialogue on climate change research in West Africa. Both the workshop and the project were financed by the National Research Programme on Global Air Pollution and Climate Change (NRP), Centre Technique de Cooperation de Agricole et Rurale (CTA), Wageningen University (INREF), and Amsterdam Research Institute for Global Issues and Development Studies (AGIDS)

  7. Woody Plant Cover Dynamics in Sahelian Drylands from Earth Observation Based Seasonal Metrics

    Science.gov (United States)

    Brandt, M.; Hiernaux, P.; Fensholt, R.; Tagesson, T.; Rasmussen, K.; Mbow, C.

    2015-12-01

    Woody plants play an important role in drylands primary productivity and peoples' livelihood, however, due to their scattered appearance, quantifying and monitoring their abundance over a large area is challenging. From in situ measured woody cover we develop a phenology driven model to estimate the canopy cover of woody species in the Sahelian drylands. Annual maps are applied to monitor dynamics of woody populations in relation to climate and anthropogenic interference. The model estimates the total canopy cover of all woody phanerophytes and the concept is based on the significant difference in phenophases of dryland trees, shrubs and bushes as compared to that of the herbaceous plants. Whereas annual herbaceous are only green during the rainy season and senescence occurs shortly after flowering towards the last rains, most woody plants remain photosynthetically active over large parts of the year. We use Moderate Resolution Imaging Spectroradiometer (MODIS) and SPOT VEGETATION (VGT) seasonal metrics representing the dry season to reproduce in situ woody cover at 77 field sites (178 observations in 3x3 km plots between 2000 and 2014) in Niger, Mali and Senegal. The extrapolation to Sahel scale shows agreement between VGT and MODIS at an almost nine times higher woody cover than in the global tree cover product MOD44B which only captures trees of a certain minimum size. Trends over 15 years show that the pattern is closely related to population density and land cover/use. A negative woody cover change can be observed in densely populated areas, but a positive change is seen in sparsely populated regions. Whereas woody cover in cropland is generally stable, it is strongly positive in savannas and woodland. Discrepancies between the countries are huge and also deforestation can be observed at a more local scale. The method is applicable and derived woody cover maps of the Sahel are freely available. They represent an improvement of existing products and a

  8. Studies on the Effects of Climatic Factors on Dryland Wheat Grain Yield in Maragheh Region

    Directory of Open Access Journals (Sweden)

    V. Feiziasl

    2011-01-01

    Full Text Available Abstract In order to study the effects of climate variables on rainfed wheat grain yield, climate data and wheat yield for 10 years (1995-2005 collected from Dryland Agricultural Research Institute (DARI in Maragheh as the main station in cold and semi-cold areas. Collected data were analyzed by correlation coefficient, simple regression, stepwise regression and path analysis. The results showed that relationships between grain yield with average relative humidity and total rainfall of growing season was positive and significant at 5% and 1% probabilities, respectively. However, evaluation between grain yield with sunny hours and class A pan evaporation was negative and significant (p

  9. Stacked palimpsests vs. the needle in the haystack: the challenge of reconstructing palaeoenvironments in drylands

    Science.gov (United States)

    Fitzsimmons, Kathryn

    2016-04-01

    Drylands, incorporating the semi-arid desert margins vulnerable to desertification and drought, have overseen substantial climatic and environmental changes associated with the Quaternary. However, despite the extent of desert-marginal regions across the world, little is known about the nature and timing of environmental change in the past; likewise the trajectory for future change is uncertain. A major reason for our poor understanding of dryland palaeoenvironmets is likely to be a challenging combination of limited accessibility and the nature of archive preservation in these regions. Here I propose a conceptual framework for reconstructing palaeoenvironments in drylands, based on two respective endmembers in the spectrum of sediment availability. Environments with low sediment availability constitute landscapes containing stratigraphic layers within which successive climatic events may be superimposed, the material traces of which are partially destroyed or reworked. The metaphor of a "stacked palimpsest" is hereby invoked to describe this situation. At the opposite end of the spectrum, sediment-rich environments may result in semi-continuous deposits tens of metres thick and representing a relatively short period of time. This situation represents a challenge to extract the most valuable palaeoenvironmental evidence among the large quantities of sediment, becoming a veritable "needle in the haystack." I will enlarge on these two endmember concepts, using case studies from semi-arid Australia and the Eurasian loess belt to represent the "stacked palimpsest" and "needle in the haystack" metaphors respectively. Australian dryland landscapes are characterised by patchy, poorly preserved and spatially variable sedimentary deposits, and palaeoenvironmental records are consequently preserved over a large spatial and long temporal scale which can be viewed through the framework of the palimpsest model. By contrast, the thick Eurasian loess deposits which border the

  10. Cryptogamic covers control spectral vegetation indices and their seasonal variation in dryland systems

    Science.gov (United States)

    Rodriguez-Caballero, Emilio; Knerr, Tanja; Büdel, Burkhard; Hill, Joachim; Weber, Bettina

    2016-04-01

    Remote sensing data provide spatially continuous information on vegetation dynamics by means of long-term series of vegetation indices (VI). However, most of these indices show problematic results in drylands, as a consequence of the scarce vegetation cover and the strong effect of the open space between plants. Open soil between plants as well as rock surfaces in dryland ecosystems are often covered by complex communities of cyanobacteria, algae, lichens and mosses. These cryptogamic covers show a faster phenological response to water pulses than vascular vegetation, turning green almost immediately after the first rain following a dry period and modifying their spectral response. However, only few studies quantified the effects of cryptogamic covers on VI, and none of them considered them in the analysis of temporal series of satellite images, where differences in physiology and reflectance between cryptogamic covers and vascular vegetation interact. For this reason, we quantified how cryptogamic covers modify the Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI), based on field and lab spectral measurements. For two different biocrust-dominated ecosystems within the South African Karoo, we analyzed the effect of biocrusts on spectrally analyzed vegetation dynamics using multi-temporal series of VI obtained from LANDSAT and MODIS images . Cryptogamic covers exerted a considerable effect on both NDVI and EVI calculated from field and lab spectra. As previously described for vegetation, also increasing cryptogam cover caused an increase of both VI values, and this effect also became apparent at LANDSAT image scale. However, the response of VI extracted from LANDSAT images upon environmental factors differed between pixels dominated by cryptogams and vascular vegetation. Whereas vegetation showed the highest changes in VI values in response to water availability and temperature, cryptogamic covers, which are the main surface

  11. 旱地火龙果栽培技术%Dryland cultivation technique of pitaya

    Institute of Scientific and Technical Information of China (English)

    陈泉康

    2012-01-01

    介绍旱地种植火龙果的主要技术,包括采用单柱直立法种植、苗期管理、土肥管理与整形修剪、间隔种植与人工授粉、适时收获等栽培措施。%This paper introduced dryland cuhivation technique of pitaya, including using a single column vertical method for cultivation, seedling management, fertilizer management and pruning, planting spacer and artificial pollination, timely harvest.

  12. Mapping gains and losses in woody vegetation across global tropical drylands

    DEFF Research Database (Denmark)

    Tian, Feng; Brandt, Martin Stefan; Liu, Yi Y

    2017-01-01

    Woody vegetation in global tropical drylands is of significant importance for both the interannual variability of the carbon cycle and local livelihoods. Satellite observations over the past decades provide a unique way to assess the vegetation long-term dynamics across biomes worldwide. Yet...... in VODwood and changes in ground observed woody cover (r(2) = 0.78). Reliability of the obtained woody component trends is also supported by a review of relevant literatures for eight hot spot regions of change. The proposed approach is expected to contribute to an improved assessment of, for example...

  13. Certified safe farm: identifying and removing hazards on the farm.

    Science.gov (United States)

    Rautiainen, R H; Grafft, L J; Kline, A K; Madsen, M D; Lange, J L; Donham, K J

    2010-04-01

    This article describes the development of the Certified Safe Farm (CSF) on-farm safety review tools, characterizes the safety improvements among participating farms during the study period, and evaluates differences in background variables between low and high scoring farms. Average farm review scores on 185 study farms improved from 82 to 96 during the five-year study (0-100 scale, 85 required for CSF certification). A total of 1292 safety improvements were reported at an estimated cost of $650 per farm. A wide range of improvements were made, including adding 9 rollover protective structures (ROPS), 59 power take-off (PTO) master shields, and 207 slow-moving vehicle (SMV) emblems; improving lighting on 72 machines: placing 171 warning decals on machinery; shielding 77 moving parts; locking up 17 chemical storage areas, adding 83 lockout/tagout improvements; and making general housekeeping upgrades in 62 farm buildings. The local, trained farm reviewers and the CSF review process overall were well received by participating farmers. In addition to our earlier findings where higher farm review scores were associated with lower self-reported health outcome costs, we found that those with higher farm work hours, younger age, pork production in confinement, beef production, poultry production, and reported exposure to agrichemicals had higher farm review scores than those who did not have these characteristics. Overall, the farm review process functioned as expected. encouraging physical improvements in the farm environment, and contributing to the multi-faceted CSF intervention program.

  14. The impact of climate change on drylands. The case of West Africa

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, T. [AGIDS-CERES, Amsterdam (Netherlands); Verhagen, J. [AB-DLO, Wageningen (Netherlands)

    1999-07-01

    The world's drylands can be characterised as semi-arid and sub-humid areas, with average annual P/ETP between 0.20 and 0.75. Average rainfall conditions restrict rain-dependent agriculture to mainly sorghum, millet and marginal maize cultivation as food crops and groundnuts and cotton as crops for agro-industry and for export. Animal husbandry based on cattle, goats and sheep can also be adding to food supply and cash income. In general, rainfed agriculture gives relatively low crop yields per hectare. Yearly rainfall variation can be considerable. Rainfall unreliability results in relatively high risks of crop failure due to drought. In West Africa, UNESCO's map of the world distribution of and regions shows a band of semi-arid conditions from Dakar in Senegal, via Ouagadougou in Burkina Faso to Niamey in Niger and further to Kano in Nigeria, the Sahel proper. South of this zone there is a band of sub-humid conditions. UNESCO's aridity assessment was based on rainfall and evapotranspiration conditions for mostly 1930-1960. Combined with assessments of land degradation and population density it formed the basis for the ICCD typology of all drylands in the tropics and subtropics. 22 refs.

  15. Effects of Controlled Release Fertilizer on the Flag Leaves Senescence in Dry-land Wheat

    Directory of Open Access Journals (Sweden)

    Dandan Liu

    2013-05-01

    Full Text Available In order to select a reasonable controlled release fertilizer application method to slow down the senescence of flag leaf in dry-land wheat. The effects of controlled release fertilizer on soluble protein content, MDA content, the Catalase (CAT activity, the Superoxide Dismutase (SOD activity on the flag leaves senescence in dry-land wheat had been studied in the open field with the variety wheat Jimai22. The results indicated that, the combination application of controlled release fertilizer with conventional complex fertilizer on wheat was more conducive to the promotion of the soluble protein synthesis and it controlled the increasing of MDA content in flag leaf more effectively than the application of conventional complex fertilizer or controlled-release fertilizer alone on wheat. And it was more conductive to control or delay the process of flag leaf senescence with better maintenance of the SOD activity. The treatments in application of controlled release fertilization alone were conducive to these treatments with conventional complex fertilizer alone. Among these treatments, T6 was the best fertilization method with the lowest flag leaf senescence speed.

  16. Dryland Winter Wheat Yield, Grain Protein, and Soil Nitrogen Responses to Fertilizer and Biosolids Applications

    Directory of Open Access Journals (Sweden)

    Richard T. Koenig

    2011-01-01

    Full Text Available Applications of biosolids were compared to inorganic nitrogen (N fertilizer for two years at three locations in eastern Washington State, USA, with diverse rainfall and soft white, hard red, and hard white winter wheat (Triticum aestivum L. cultivars. High rates of inorganic N tended to reduce yields, while grain protein responses to N rate were positive and linear for all wheat market classes. Biosolids produced 0 to 1400 kg ha−1 (0 to 47% higher grain yields than inorganic N. Wheat may have responded positively to nutrients other than N in the biosolids or to a metered N supply that limited vegetative growth and the potential for moisture stress-induced reductions in grain yield in these dryland production systems. Grain protein content with biosolids was either equal to or below grain protein with inorganic N, likely due to dilution of grain N from the higher yields achieved with biosolids. Results indicate the potential to improve dryland winter wheat yields with biosolids compared to inorganic N alone, but perhaps not to increase grain protein concentration of hard wheat when biosolids are applied immediately before planting.

  17. Rainfall intensity switches ecohydrological runoff/runon redistribution patterns in dryland vegetation patches.

    Science.gov (United States)

    Magliano, Patricio N; Breshears, David D; Fernández, Roberto J; Jobbágy, Esteban G

    2015-12-01

    Effectively managing net primary productivity in drylands for grazing and other uses depends on understanding how limited rainfall input is redistributed by runoff and runon among vegetation patches, particularly for patches that contrast between lesser and greater amounts of vegetation cover. Due in part to data limitations, ecohydrologists generally have focused on rainfall event size to characterize water redistribution processes. Here we use soil moisture data from a semiarid woodland to highlight how, when event size is controlled and runoff and interception are negligible at the stand scale, rainfall intensity drives the relationship between water redistribution and canopy and soil patch attributes. Horizontal water redistribution variability increased with rainfall intensity and differed between patches with contrasting vegetation cover. Sparsely vegetated patches gained relatively more water during lower intensity events, whereas densely vegetated ones gained relatively more water during higher intensity events. Consequently, range managers need to account for the distribution of rainfall event intensity, as well as event size, to assess the consequences of climate variability and change on net primary productivity. More generally, our results suggest that rainfall intensity needs to be considered in addition to event size to understand vegetation patch dynamics in drylands.

  18. Dryland soil microbial communities display spatial biogeographic patterns associated with soil depth and soil parent material

    Science.gov (United States)

    Steven, Blaire; Gallegos-Graves, La Verne; Belnap, Jayne; Kuske, Cheryl R.

    2013-01-01

    Biological soil crusts (biocrusts) are common to drylands worldwide. We employed replicated, spatially nested sampling and 16S rRNA gene sequencing to describe the soil microbial communities in three soils derived from different parent material (sandstone, shale, and gypsum). For each soil type, two depths (biocrusts, 0–1 cm; below-crust soils, 2–5 cm) and two horizontal spatial scales (15 cm and 5 m) were sampled. In all three soils, Cyanobacteria and Proteobacteria demonstrated significantly higher relative abundance in the biocrusts, while Chloroflexi and Archaea were significantly enriched in the below-crust soils. Biomass and diversity of the communities in biocrusts or below-crust soils did not differ with soil type. However, biocrusts on gypsum soil harbored significantly larger populations of Actinobacteria and Proteobacteria and lower populations of Cyanobacteria. Numerically dominant operational taxonomic units (OTU; 97% sequence identity) in the biocrusts were conserved across the soil types, whereas two dominant OTUs in the below-crust sand and shale soils were not identified in the gypsum soil. The uniformity with which small-scale vertical community differences are maintained across larger horizontal spatial scales and soil types is a feature of dryland ecosystems that should be considered when designing management plans and determining the response of biocrusts to environmental disturbances.

  19. Phenology of Succession: Tracking the Recovery of Dryland Forests after Wildfire Events

    Science.gov (United States)

    Walker, J.; Brown, J. F.; Sankey, J. B.; Wallace, C.; Weltzin, J. F.

    2016-12-01

    The frequency, size, and intensity of forest wildfires in the U.S. Southwest have increased over the past 30 years. In the coming decades, burn effects and altered climatic conditions may increasingly divert vegetation recovery trajectories from pre-disturbance forested ecosystems toward grassland or shrub woodlands. Dryland herbaceous and woody vegetation species exhibit different phenological responses to precipitation, resulting in temporal and spatial shifts in landscape phenology patterns as the proportions of plant functional groups change over time. We have developed time series of Normalized Difference Vegetation Index (NDVI) and Soil-Adjusted Vegetation Index (SAVI) greenness measures derived from satellite imagery from 1984 - 2015 to record the phenological signatures that characterize recovery trajectories towards predominantly grassland, shrubland, or forest land cover types. We leveraged the data and computational resources available through the Google Earth Engine cloud-based platform to analyze time series of Landsat Thematic Mapper and Enhanced Thematic Mapper Plus imagery collected over maturing (40 years or more post-fire) dryland forests in Arizona and New Mexico, USA. These time series provided the basis for long-term comparisons of phenology behavior in different successional trajectories and enabled the assessment of climatic influence on the eventual outcomes.

  20. [Effects of organic fertilizer application rate on leaf photosynthetic characteristics and grain yield of dryland maize].

    Science.gov (United States)

    Wang, Xiao-Juan; Jia, Zhi-Kuan; Liang, Lian-You; Ding, Rui-Xia; Wang, Min; Li, Han

    2012-02-01

    A 4-year field experiment was conducted at the Heyang Research Station in Weibei dryland to study the effects of organic fertilizer application rate on the leaf photosynthetic characteristics and grain yield of dryland maize. Comparing with applying chemical fertilizer, applying organic fertilizer increased the leaf photosynthetic rate and stomatal conductance, but decreased the leaf intercellular CO2 concentration at each growth stage of maize significantly. With the increasing application rate of organic fertilizer, the leaf photosynthetic rate and stomatal conductance at each growth stage of maize had a gradual increase, while the leaf intercellular CO2 concentration had a gradual decrease. The leaf photosynthesis of maize at each growth stage was controlled by non-stomatal factors, and the application of organic fertilizer reduced the non-stomatal limitation on the photosynthesis performance significantly. The 4-year application of organic fertilizer improved soil nutrient status, and soil nutrients were no longer the main factors limiting the leaf photosynthetic rate and grain yield of maize.

  1. Contributions of Dryland Forest (Caatinga) to Species Composition, Richness and Diversity of Drosophilidae.

    Science.gov (United States)

    Oliveira, G F; Rohde, C; Garcia, A C L; Montes, M A; Valente, V L S

    2016-10-01

    In this study, semi-arid environments were tested to see if they support insect diversity. This was evaluated through the structure of the composition of assemblies of drosophilids in three conservation units placed in three different ecoregions in the dryland forests, Caatinga. This is a unique biome in northeast Brazil, comprising approximately 10% of the country. Species richness was investigated over 2 years during a prolonged drought, considered the worst affliction the Caatinga ecosystem had experienced in the last 50 years. Alpha diversity indices and the ecological similarity between the samples were calculated to determine how the environments drive the composition of Drosophilidae in such semi-arid places. A total of 7352 specimens were sampled. They were classified into 20 species belonging to four genera: Drosophila, Rhinoleucophenga, Scaptodrosophila, and Zaprionus. Drosophila nebulosa Sturtevant (44.5%) and Drosophila cardini Sturtevant (12.5%) were the most abundant species. The occurrences and abundances of all the species differed greatly between sites. These results and other ecological analyses indicate that although placed in the same biome, there are great variability in the drosophilid species and abundance among the three protected and conserved dryland environments.

  2. The visibility of using water boxes and mulch in dryland revegetation

    Science.gov (United States)

    Alhamad, Mohammad Noor; Alrababah, Mohammad; Athamneh, Hanaa

    2017-04-01

    Drylands cover more than 41% of the world's surface area and are homeland for about one-third of the world's population, 90% of them in developing countries. Land degradation in the drylands is hot environmental topic as it impacts environmental quality and jeopardizes food security in developing countries. The climate of Jordan varies from dry sub-humid Mediterranean in northwestern areas to desert conditions over a distance of 100 km, where more than 90 % of the county's area receives annual rainfall of less than 200 mm. In Jordan revegetation programs are rainfed; rainfall in Jordan is characterized by variable nature, thus, these programs faces a major challenge of the low survival rate of transplanted seedlings. The present study ought to explore the visibility of using water boxes and plastic mulch as an innovative approach to enhance seedling survival and establishment of four forest tress species ( Carob, Cupressus, Quercus, and Pinus). The experiment results showed that Cupressus, and Pinus seedlings expressed the highest survival rate of 88% and 84 % respectively, flowed by Crob (64%) and Querrcus (16%). The plastic mulch significantly enhanced the seedling survival rate b y40 % over the control while the water boxes resulted in an increase of 32 % over the control.

  3. Integrating knowledge exchange and the assessment of dryland management alternatives - A learning-centered participatory approach.

    Science.gov (United States)

    Bautista, Susana; Llovet, Joan; Ocampo-Melgar, Anahí; Vilagrosa, Alberto; Mayor, Ángeles G; Murias, Cristina; Vallejo, V Ramón; Orr, Barron J

    2017-06-15

    The adoption of sustainable land management strategies and practices that respond to current climate and human pressures requires both assessment tools that can lead to better informed decision-making and effective knowledge-exchange mechanisms that facilitate new learning and behavior change. We propose a learning-centered participatory approach that links land management assessment and knowledge exchange and integrates science-based data and stakeholder perspectives on both biophysical and socio-economic attributes. We outline a structured procedure for a transparent assessment of land management alternatives, tailored to dryland management, that is based on (1) principles of constructivism and social learning, (2) the participation of stakeholders throughout the whole assessment process, from design to implementation, and (3) the combination of site-specific indicators, identified by local stakeholders as relevant to their particular objectives and context conditions, and science-based indicators that represent ecosystem services of drylands worldwide. The proposed procedure follows a pattern of eliciting, challenging, and self-reviewing stakeholder perspectives that aims to facilitate learning. The difference between the initial baseline perspectives and the final self-reviewed stakeholder perspectives is used as a proxy of learning. We illustrate the potential of this methodology by its application to the assessment of land uses in a Mediterranean fire-prone area in East Spain. The approach may be applied to a variety of socio-ecological systems and decision-making and governance scales. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. The charcoal-degradation nexus: contested 'fuelscapes' in the sub-Saharan drylands of northern Kenya

    Science.gov (United States)

    Bergmann, Christoph; Petersen, Maike; Roden, Paul; Nüsser, Marcus

    2017-04-01

    Charcoal ranks amongst the most commercialized but least regulated commodities in sub-Saharan Africa. Despite its prevalence as an energy source for cooking and heating, localized environmental and livelihood impacts of charcoal production are poorly understood so far. The identified research deficit is amplified by widespread negative views of this activity as a poverty-driven cause of deforestation and land degradation. However, the charcoal-degradation nexus is apparently more complicated, not least because the extraction of biomass from already degraded woodlands can also be interpreted as an appropriate option under given management regimes. In order to better calibrate existing research agendas to site-specific geographies of charcoal production, we propose a re-conceptualization of such energy landscapes as 'fuelscapes' with complex material and social dimensions. The concept is tested with reference to a case study in Central Pokot, northern Kenya, where charcoal production only began in the early 1990's. Based on the assumption that the fine line between sustainable land management and degradation in dryland energy landscapes is not only highly variable but also increasingly contested, our study combines the knowledge input of different stakeholders with longitudinal time series of remote sensing data. Based on the results of our interdisciplinary analyses, we outline an integrated tool for the co-operative monitoring and management of prevailing degradation processes against the background of diversified livelihood activities in sub-Saharan drylands.

  5. Study on Water-Preserving Effects of Mulching for Dryland Winter Wheat in Loess Tableland

    Institute of Scientific and Technical Information of China (English)

    LIAO Yun-cheng; WEN Xiao-xia; HAN Si-ming; JIA Zhi-kuan

    2003-01-01

    Focused on the rainfall characteristics and the reality of agricultural production in the loess ta-bleland, and based on previous results, new patterns for dryland winter wheat production, in which the em-phasis was put on the film mulch with obvious water-preserving advantage, were designed to make effective useof rainfall. The results showed that the technique of the double mulch of film plus straw in summer fallow pe-riod can collect the rainfall in this period to the utmost extent and over 73.2 % of it can be stored in the soil,which is 108.4 mm more than that of conventional tillage. Furthermore, it can not only preserve water storedin soil in summer fallow, but also collect the rainfall in the growth period as much as possible by using thetechnique of making ridges plus film mulching and furrow sowing. So the patterns, which can greatly increaseboth the soil moisture and wheat yield, are the best choice for making full utilization of the rainfall and achie-ving a high and stable yield in the dryland wheat production of the loess tableland.

  6. Projecting avian response to linked changes in groundwater and riparian floodplain vegetation along a dryland river: a scenario analysis

    Science.gov (United States)

    Groundwater is a key driver of riparian condition on dryland rivers but is in high demand for municipal, industrial, and agricultural uses. Approaches are needed to guide decisions that balance human water needs while conserving riparian ecosystems. We developed a space-for-time substitution model ...

  7. A House Full of Trap Doors. Identifying barriers to resilient drylands in the toolbox of pastoral development

    Science.gov (United States)

    Krätli, Saverio; Kaufmann, Brigitte; Roba, Hassan; Hiernaux, Pierre; Li, Wenjun; Easdale, Marcos H.; Huelsebusch, Christian

    2016-04-01

    The theoretical understanding of drylands and pastoral systems has long undergone a U-turn from the initial perspective rooted in classical ecology. The shift has hinged on the way to represent asymmetric variability, from a disturbance in an ecosystem that naturally tends towards uniformity and stability, to a constitutive part of a dynamic ecosystem. Operationalising the new reversed perspective, including the need to update the methodological infrastructure to plan around drylands and pastoral development, remains a challenge. Underlying assumptions about stability and uniformity, that are a legacy of equilibrium thinking, remain embedded in the toolbox of pastoral development, starting from the technical language to talk about the subject. This effectively gets in the way of operationalizing state of the art understanding of pastoral systems and the drylands. Unless these barriers are identified, unpacked and managed, even the present calls for increasing the rigour and intensity of data collection - for example as part of the ongoing global process to revise and improve agricultural data - cannot deliver a realistic representation of pastoral systems in statistics and policy making. This contribution presents the case for understanding variability as an asset, and provides a range of examples of methodological barriers, including classifications of livestock systems, scale of observation, key parameters in animal production, indicators in the measurement of ecological efficiency, concepts of ecological fragility, natural resources, and pastoral risk. The need to update this legacy is a pressing challenge for policy makers concerned with both modernisation and resilience in the drylands.

  8. Armed conflict distribution in global drylands through the lens of a typology of socio-ecological vulnerability

    NARCIS (Netherlands)

    Sterzel, T.; Lüdeke, M.; Kok, M.; Soysa, De I.; Walther, C.; Sietz, D.; Lucas, P.; Janssen, P.

    2014-01-01

    Motivated by an inconclusive debate over implications of resource scarcity for violent conflict, and common reliance on national data and linear models, we investigate the relationship between socio-ecological vulnerability and armed conflict in global drylands on a subnational level. Our study eman

  9. Climate change predicted to negatively influence surface soil organic matter of dryland cropping systems in the Inland Pacific Northwest, USA

    Science.gov (United States)

    Soil organic matter (SOM) is a key indicator of agricultural productivity and overall soil health. Currently, dryland cropping systems of the inland Pacific Northwest (iPNW) span a large gradient in mean annual temperature (MAT) and precipitation (MAP).These climatic drivers are major determinants o...

  10. Climate change predicted to negatively influence surface soil health of dryland cropping systems in the Inland Pacific Northwest

    Science.gov (United States)

    Soil organic matter (SOM) is a key indicator of agricultural productivity and overall soil health. Currently, dryland cropping systems of the inland Pacific Northwest (iPNW) span a large gradient in mean annual temperature (MAT) and precipitation (MAP). These climatic drivers are major determinants ...

  11. Comparison of net global warming potential and greenhouse gas intensity affected by management practices in two dryland cropping sites

    Science.gov (United States)

    Little is known about the effect of management practices on net global warming potential (GWP) and greenhouse gas intensity (GHGI) that account for all sources and sinks of greenhouse gas (GHG) emissions in dryland cropping systems. The objective of this study was to compare the effect of a combinat...

  12. Dryland crop yields and soil organic matter as influenced by long-term tillage and cropping sequence

    Science.gov (United States)

    Long-term management practices are needed to sustain dryland crop yields and maintain soil organic matter in the northern Great Plains. We evaluated the 21-yr effects of no-till continuous spring wheat (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (...

  13. Long Island Solar Farm

    Energy Technology Data Exchange (ETDEWEB)

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  14. Wind Farm Recommendation Report

    Energy Technology Data Exchange (ETDEWEB)

    John Reisenauer

    2011-05-01

    On April 21, 2011, an Idaho National Laboratory (INL) Land Use Committee meeting was convened to develop a wind farm recommendation for the Executive Council and a list of proposed actions for proceeding with the recommendation. In terms of land use, the INL Land Use Committee unanimously agrees that Site 6 is the preferred location of the alternatives presented for an INL wind farm. However, further studies and resolution to questions raised (stated in this report) by the INL Land Use Committee are needed for the preferred location. Studies include, but are not limited to, wind viability (6 months), bats (2 years), and the visual impact of the wind farm. In addition, cultural resource surveys and consultation (1 month) and the National Environmental Policy Act process (9 to 12 months) need to be completed. Furthermore, there is no documented evidence of developers expressing interest in constructing a small wind farm on INL, nor a specific list of expectations or concessions for which a developer might expect INL to cover the cost. To date, INL assumes the National Environmental Policy Act activities will be paid for by the Department of Energy and INL (the environmental assessment has only received partial funding). However, other concessions also may be expected by developers such as roads, fencing, power line installation, tie-ins to substations, annual maintenance, snow removal, access control, down-time, and remediation. These types of concessions have not been documented, as a request, from a developer and INL has not identified the short and long-term cost liabilities for such concessions should a developer expect INL to cover these costs. INL has not identified a go-no-go funding level or the priority this Wind Farm Project might have with respect to other nuclear-related projects, should the wind farm remain an unfunded mandate. The Land Use Committee recommends Legal be consulted to determine what, if any, liabilities exist with the Wind Farm Project and

  15. Technologies in organic farming

    DEFF Research Database (Denmark)

    Lassen, Jesper

    2015-01-01

    (pollution) and consequences for human health. Broader ideas about ecosystems and the recycling of nutrients between the agricultural sector and the urban population are notably absent. On the basis of these findings the paper concludes by discussing the relationship between the consumers’ values that guide......In organic farming a dilemma is posed by the heavy reliance on nutrients from conventional livestock farming. For Danish organic plant producers the influx of conventional nutrients accounts for up to 70% of their nutrients. Facing this problem, Danish organic farmers’ organizations have decided...

  16. Drew Goodman, Earthbound Farm

    OpenAIRE

    Rabkin, Sarah

    2010-01-01

    Drew Goodman is CEO and co-founder, with his wife, Myra, of Earthbound Farm, based in San Juan Bautista, California. Two years after its 1984 inception on 2.5 Carmel Valley acres, Earthbound became the first successful purveyor of pre-washed salads bagged for retail sale. The company now produces more than 100 varieties of certified organic salads, fruits, and vegetables on a total of about 33,000 acres, with individual farms ranging from five to 680 acres in California, Arizona, Washington, ...

  17. Urban Farm Business Plan Handbook

    Science.gov (United States)

    The Urban Farm Business Plan Handbook (this document) provides guidance for developing a business plan for the startup and operation of an urban farm. It focuses on food and non-food related cultivated agriculture.

  18. Farm animal welfare

    DEFF Research Database (Denmark)

    Sandøe, Peter; Christiansen, Stine Billeschou; Appleby, M. C.

    2003-01-01

    An experimental survey was undertaken to explore the links between the characteristics of a moral issue, the degree of moral intensity/moral imperative associated with the issue (Jones, 1991), and people’s stated willingness to pay (wtp) for policy to address the issue. Two farm animal welfare...

  19. NORCOWE Reference Wind Farm

    DEFF Research Database (Denmark)

    Bak, Thomas; Graham, Angus

    2015-01-01

    Offshore wind farms are complex systems, influenced by both the environment (e.g. wind, waves, current and seabed) and the design characteristics of the equipment available for installation (e.g. turbine type, foundations, cabling and distance to shore). These aspects govern the capital and opera...

  20. FARM ANIMAL WELFARE ECONOMICS

    Directory of Open Access Journals (Sweden)

    L.T. CZISZTER

    2013-07-01

    Full Text Available This paper reviews the literature regarding the economics of the farm animal welfare. The following issues are addressed: productions costs and savings of the animal welfare regulations, benefits of improved animal welfare, and consumers’ willingness to pay for animal-friendly products.

  1. Farm animal welfare

    DEFF Research Database (Denmark)

    Sandøe, Peter; Christiansen, Stine Billeschou; Appleby, M. C.

    2003-01-01

    An experimental survey was undertaken to explore the links between the characteristics of a moral issue, the degree of moral intensity/moral imperative associated with the issue (Jones, 1991), and people’s stated willingness to pay (wtp) for policy to address the issue. Two farm animal welfare...

  2. Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

    Directory of Open Access Journals (Sweden)

    Anja Linstädter

    Full Text Available Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs. Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses and two-trait PFTs (e.g. perennial grasses performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may

  3. Are There Consistent Grazing Indicators in Drylands? Testing Plant Functional Types of Various Complexity in South Africa’s Grassland and Savanna Biomes

    Science.gov (United States)

    Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A.; Oomen, Roelof J.; du Preez, Chris C.; Ruppert, Jan C.; Ewert, Frank

    2014-01-01

    Despite our growing knowledge on plants’ functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa’s grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be

  4. Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

    Science.gov (United States)

    Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A; Oomen, Roelof J; du Preez, Chris C; Ruppert, Jan C; Ewert, Frank

    2014-01-01

    Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be useful

  5. Population pressure and farm fragmentation:

    African Journals Online (AJOL)

    user

    small but farms are further fragmented into diminutive size fields due to ... terms of household characteristics; land use and performance indicators; technology adoption .... 'best' unit of measurement of farm size, and size of enterprises within farms will ..... less common, accounting for 18 percent (3 percent) and 10 percent (7.

  6. Soil indicators to assess the effectiveness of restoration strategies in dryland ecosystems

    Science.gov (United States)

    Costantini, Edoardo; Branquinho, Cristina; Nunes, Alice; Schwilch, Gudrun; Stavi, Ilan; Valdecantos, Alejandro; Zucca, Claudio

    2016-04-01

    Soil indicators may be used for assessing both land suitability for restoration and the effectiveness of restoration strategies in restoring ecosystem functioning and services. In this review paper, several soil indicators, which can be used to assess the effectiveness of restoration strategies in dryland ecosystems at different spatial and temporal scales, are discussed. The selected indicators represent the different viewpoints of pedology, ecology, hydrology, and land management. The recovery of soil capacity to provide ecosystem services is primarily obtained by increasing soil rooting depth and volume, and augmenting water accessibility for vegetation. Soil characteristics can be used either as indicators of suitability, that is, inherently slow-changing soil qualities, or as indicators for modifications, namely dynamic, thus "manageable" soil qualities. Soil organic matter forms, as well as biochemistry, micro- and meso-biology, are among the most utilized dynamic indicators. On broader territorial scales, the Landscape Function Analysis uses a functional approach, where the effectiveness of restoration strategies is assessed by combining the analysis of spatial pattern of vegetation with qualitative soil indicators. For more holistic and comprehensive projects, effective strategies to combat desertification should integrate soil indicators with biophysical and socio-economic evaluation and include participatory approaches. The integrated assessment protocol of Sustainable Land Management developed by the World Overview of Conservation Approaches and Technologies network is thoroughly discussed. Two overall outcomes stem from the review: i) the success of restoration projects relies on a proper understanding of their ecology, namely the relationships between soil, plants, hydrology, climate, and land management at different scales, which is particularly complex due to the heterogeneous pattern of ecosystems functioning in drylands, and ii) the selection of

  7. Biological soil crusts emit large amounts of NO and HONO affecting the nitrogen cycle in drylands

    Science.gov (United States)

    Tamm, Alexandra; Wu, Dianming; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Steinkamp, Jörg; Meusel, Hannah; Elbert, Wolfgang; Behrendt, Thomas; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul J.; Su, Hang; Pöschl, Ulrich; Weber, Bettina

    2016-04-01

    Dryland systems currently cover ˜40% of the world's land surface and are still expanding as a consequence of human impact and global change. In contrast to that, information on their role in global biochemical processes is limited, probably induced by the presumption that their sparse vegetation cover plays a negligible role in global balances. However, spaces between the sparse shrubs are not bare, but soils are mostly covered by biological soil crusts (biocrusts). These biocrust communities belong to the oldest life forms, resulting from an assembly between soil particles and cyanobacteria, lichens, bryophytes, and algae plus heterotrophic organisms in varying proportions. Depending on the dominating organism group, cyanobacteria-, lichen-, and bryophyte-dominated biocrusts are distinguished. Besides their ability to restrict soil erosion they fix atmospheric carbon and nitrogen, and by doing this they serve as a nutrient source in strongly depleted dryland ecosystems. In this study we show that a fraction of the nitrogen fixed by biocrusts is metabolized and subsequently returned to the atmosphere in the form of nitric oxide (NO) and nitrous acid (HONO). These gases affect the radical formation and oxidizing capacity within the troposphere, thus being of particular interest to atmospheric chemistry. Laboratory measurements using dynamic chamber systems showed that dark cyanobacteria-dominated crusts emitted the largest amounts of NO and HONO, being ˜20 times higher than trace gas fluxes of nearby bare soil. We showed that these nitrogen emissions have a biogenic origin, as emissions of formerly strongly emitting samples almost completely ceased after sterilization. By combining laboratory, field, and satellite measurement data we made a best estimate of global annual emissions amounting to ˜1.1 Tg of NO-N and ˜0.6 Tg of HONO-N from biocrusts. This sum of 1.7 Tg of reactive nitrogen emissions equals ˜20% of the soil release under natural vegetation according

  8. Climate scenarios for semi-arid and sub-humid regions. A comparison of climate scenarios for the dryland regions, in West Africa from 1990 to 2050

    OpenAIRE

    van den Born GJ; Schaeffer M; Leemans R; NOP

    2001-01-01

    The identification of climate scenarios for dryland areas in Sub-Saharan West Africa is part of a project to assess the impact of climate change on water availability, agriculture and food security in drylands (ICCD-project). The project is financed by Netherlands Research Programme on Global Air Pollution and Climate Change (NRP) and part of theme 'Vulnerability of Natural and Social Systems for Climate'. The report describes the development and description of climate scenarios by ...

  9. Effect of inter-annual variability in pasture growth and irrigation response on farm productivity and profitability based on biophysical and farm systems modelling.

    Science.gov (United States)

    Vogeler, Iris; Mackay, Alec; Vibart, Ronaldo; Rendel, John; Beautrais, Josef; Dennis, Samuel

    2016-09-15

    Farm system and nutrient budget models are increasingly being used in analysis to inform on farm decision making and evaluate land use policy options at regional scales. These analyses are generally based on the use of average annual pasture yields. In New Zealand (NZ), like in many countries, there is considerable inter-annual variation in pasture growth rates, due to climate. In this study a modelling approach was used to (i) include inter-annual variability as an integral part of the analysis and (ii) test the approach in an economic analysis of irrigation in a case study within the Hawkes Bay Region of New Zealand. The Agricultural Production Systems Simulator (APSIM) was used to generate pasture dry matter yields (DMY) for 20 different years and under both dryland and irrigation. The generated DMY were linked to outputs from farm-scale modelling for both Sheep and Beef Systems (Farmaxx Pro) and Dairy Systems (Farmax® Dairy Pro) to calculate farm production over 20 different years. Variation in DMY and associated livestock production due to inter-annual variation in climate was large, with a coefficient of variations up to 20%. Irrigation decreased this inter-annual variation. On average irrigation, with unlimited available water, increased income by $831 to 1195/ha, but when irrigation was limited to 250mm/ha/year income only increased by $525 to 883/ha. Using pasture responses in individual years to capturing the inter-annual variation, rather than the pasture response averaged over 20years resulted in lower financial benefits. In the case study income from irrigation based on an average year were 10 to >20% higher compared with those obtained from individual years.

  10. A Framework for Identifying Selective Chemical Applications for IPM in Dryland Agriculture

    Science.gov (United States)

    Umina, Paul A.; Jenkins, Sommer; McColl, Stuart; Arthur, Aston; Hoffmann, Ary A.

    2015-01-01

    Shifts to Integrated Pest Management (IPM) in agriculture are assisted by the identification of chemical applications that provide effective control of pests relative to broad-spectrum pesticides but have fewer negative effects on natural enemy (beneficial) groups that assist in pest control. Here, we outline a framework for identifying such applications and apply this framework to field trials involving the crop establishment phase of Australian dryland cropping systems. Several chemicals, which are not presently available to farmers in Australia, were identified as providing moderate levels of pest control and seedling protection, with the potential to be less harmful to beneficial groups including predatory mites, predatory beetles and ants. This framework highlights the challenges involved in chemically controlling pests while maintaining non-target populations when pest species are present at damaging levels. PMID:26694469

  11. UNMANNED AERIAL VEHICLE (UAV) HYPERSPECTRAL REMOTE SENSING FOR DRYLAND VEGETATION MONITORING

    Energy Technology Data Exchange (ETDEWEB)

    Nancy F. Glenn; Jessica J. Mitchell; Matthew O. Anderson; Ryan C. Hruska

    2012-06-01

    UAV-based hyperspectral remote sensing capabilities developed by the Idaho National Lab and Idaho State University, Boise Center Aerospace Lab, were recently tested via demonstration flights that explored the influence of altitude on geometric error, image mosaicking, and dryland vegetation classification. The test flights successfully acquired usable flightline data capable of supporting classifiable composite images. Unsupervised classification results support vegetation management objectives that rely on mapping shrub cover and distribution patterns. Overall, supervised classifications performed poorly despite spectral separability in the image-derived endmember pixels. Future mapping efforts that leverage ground reference data, ultra-high spatial resolution photos and time series analysis should be able to effectively distinguish native grasses such as Sandberg bluegrass (Poa secunda), from invasives such as burr buttercup (Ranunculus testiculatus) and cheatgrass (Bromus tectorum).

  12. Coupled Human-Ecological Dynamics and Land Degradation in Global Drylands-A modelling approach (Invited)

    Science.gov (United States)

    Helldén, U.

    2009-12-01

    Drylands comprise one-third of the Earth’s land area. They pose research, management, and policy challenges impacting the livelihoods of 2.5 billion people. Desertification is said to affect some 10-20% of the drylands and is assumed to expand with climate change and population growth. Recent paradigms stress the importance of understanding linkages between human-ecological (H-E) systems in order to achieve sustainable management policies. Understanding coupled H-E systems is difficult at local levels. It represents an even greater challenge at regional scales to guide priorities and policy decisions at national and international levels. System dynamic modelling may help facilitating the probblem. Desertification and land degradation are often modelled and mathematically defined in terms of soil erosion. The soil erosion process is usually described as a function of vegetation ground cover, rainfall characteristics, topography, soil characteristics and land management. On-going research based on system dynamic modelling, focussing on elucidating the inherent complexity of H-E systems across multiple scales, enables an assessment of the relative roles that climate, policy, management, land condition, vulnerability and human adaptation may play in desertification and dryland development. An early approach (1995) to study desertification through an H-E coupled model considered desertification to be stress beyond resilience, i.e. irreversible, using a predator-prey system approach. As most predator-prey models, it was based on two linked differential equations describing the evolution of both a human population (predator) and natural resources (prey) in terms of gains, losses and interaction. A recent effort used a model approach to assess desertification risk through system stability condition analysis. It is based on the assumption that soil erosion and the soil sub-system play an overriding final role in the desertification processes. It is stressing the role and

  13. Wind Farms: Modeling and Control

    DEFF Research Database (Denmark)

    Soleimanzadeh, Maryam

    2012-01-01

    provides the state space form of the dynamic wind farm model. The model provides an approximation of the behavior of the flow in wind farms, and obtains the wind speed in the vicinity of each wind turbine. The control algorithms in this work are mostly on the basis of the developed wind farm model......The primary purpose of this work is to develop control algorithms for wind farms to optimize the power production and augment the lifetime of wind turbines in wind farms. In this regard, a dynamical model for wind farms was required to be the basis of the controller design. In the first stage......, a dynamical model has been developed for the wind flow in wind farms. The model is based on the spatial discretization of the linearized Navier-Stokes equation combined with the vortex cylinder theory. The spatial discretization of the model is performed using the Finite Difference Method (FDM), which...

  14. Cumulative drought and land-use impacts on perennial vegetation across a North American dryland region

    Science.gov (United States)

    Munson, Seth M.; Long, A. Lexine; Wallace, Cynthia; Webb, Robert H.

    2016-01-01

    Question The decline and loss of perennial vegetation in dryland ecosystems due to global change pressures can alter ecosystem properties and initiate land degradation processes. We tracked changes of perennial vegetation using remote sensing to address the question of how prolonged drought and land-use intensification have affected perennial vegetation cover across a desert region in the early 21st century? Location Mojave Desert, southeastern California, southern Nevada, southwestern Utah and northwestern Arizona, USA. Methods We coupled the Moderate-Resolution Imaging Spectroradiometer Enhanced Vegetation Index (MODIS-EVI) with ground-based measurements of perennial vegetation cover taken in about 2000 and about 2010. Using the difference between these years, we determined perennial vegetation changes in the early 21st century and related these shifts to climate, soil and landscape properties, and patterns of land use. Results We found a good fit between MODIS-EVI and perennial vegetation cover (2000: R2 = 0.83 and 2010: R2 = 0.74). The southwestern, far southeastern and central Mojave Desert had large declines in perennial vegetation cover in the early 21st century, while the northeastern and southeastern portions of the desert had increases. These changes were explained by 10-yr precipitation anomalies, particularly in the cool season and during extreme dry or wet years. Areas heavily impacted by visitor use or wildfire lost perennial vegetation cover, and vegetation in protected areas increased to a greater degree than in unprotected areas. Conclusions We find that we can extrapolate previously documented declines of perennial plant cover to an entire desert, and demonstrate that prolonged water shortages coupled with land-use intensification create identifiable patterns of vegetation change in dryland regions.

  15. Pulse-drought atop press-drought: unexpected plant responses and implications for dryland ecosystems

    Science.gov (United States)

    Hoover, David L; Duniway, Michael C.; Belnap, Jayne

    2015-01-01

    In drylands, climate change is predicted to cause chronic reductions in water availability (press-droughts) through reduced precipitation and increased temperatures as well as increase the frequency and intensity of short-term extreme droughts (pulse-droughts). These changes in precipitation patterns may have profound ecosystem effects, depending on the sensitivities of the dominant plant functional types (PFTs). Here we present the responses of four Colorado Plateau PFTs to an experimentally imposed, 4-year, press-drought during which a natural pulse-drought occurred. Our objectives were to (1) identify the drought sensitivities of the PFTs, (2) assess the additive effects of the press- and pulse-drought, and (3) examine the interactive effects of soils and drought. Our results revealed that the C3 grasses were the most sensitive PFT to drought, the C3shrubs were the most resistant, and the C4 grasses and shrubs had intermediate drought sensitivities. Although we expected the C3 grasses would have the greatest response to drought, the higher resistance of C3 shrubs relative to the C4 shrubs was contrary to our predictions based on the higher water use efficiency of C4 photosynthesis. Also, the additive effects of press- and pulse-droughts caused high morality in C3 grasses, which has large ecological and economic ramifications for this region. Furthermore, despite predictions based on the inverse texture hypothesis, we observed no interactive effects of soils with the drought treatment on cover or mortality. These results suggest that plant responses to droughts in drylands may differ from expectations and have large ecological effects if press- and pulse-droughts push species beyond physiological and mortality thresholds.

  16. Challenges in the participatory assessment of sustainable management practices in dryland ecosystems under regime shifts

    Science.gov (United States)

    Jucker Riva, Matteo; Schwilch, Gudrun; Liniger, Hanspeter

    2015-04-01

    Regime shifts, defined as a radical and persistent reconfiguration of an ecosystem following a disturbance, have been acknowledged by scientists as a very important aspect of the dynamic of ecosystems. However, their consideration in land management planning remains marginal and limited to specific processes and systems. Current research focuses on mathematical modeling and statistical analysis of spatio-temporal data for specific environmental variables. These methods do not fulfill the needs of land managers, who are confronted with a multitude of processes and pressure types and require clear and simple strategies to prevent regime shift or to increase the resilience of their environment. The EU-FP7 CASCADE project is looking at regime shifts of dryland ecosystems in southern Europe and specifically focuses on rangeland and forest systems which are prone to various land degradation threats. One of the aims of the project is to evaluate the impact of different management practices on the dynamic of the environment in a participatory manner, including a multi-stakeholder evaluation of the state of the environment and of the management potential. To achieve this objective we have organized several stakeholder meetings and we have compiled a review of management practices using the WOCAT methodology, which enables merging scientific and land users knowledge. We highlight here the main challenges we have encountered in applying the notion of regime shift to real world socio-ecological systems and in translating related concepts such as tipping points, stable states, hysteresis and resilience to land managers, using concrete examples from CASCADE study sites. Secondly, we explore the advantages of including land users' knowledge in the scientific understanding of regime shifts. Moreover, we discuss useful alternative concepts and lessons learnt that will allow us to build a participatory method for the assessment of resilient management practices in specific socio

  17. Climate and soil factors influencing seedling recruitment of plant species used for dryland restoration

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Erickson, Todd E.; Martini, Dylan C.; Dixon, Kingsley W.; Merritt, David J.

    2016-06-01

    Land degradation affects 10-20 % of drylands globally. Intensive land use and management, large-scale disturbances such as extractive operations, and global climate change, have contributed to degradation of these systems worldwide. Restoring these damaged environments is critical to improving ecosystem services and functions, conserve biodiversity, and contribute to climate resilience, food security, and landscape sustainability. Here, we present a case study on plant species of the mining intensive semi-arid Pilbara region in Western Australia that examines the effects of climate and soil factors on the restoration of drylands. We analysed the effects of a range of rainfall and temperature scenarios and the use of alternative soil materials on seedling recruitment of key native plant species from this area. Experimental studies were conducted in controlled environment facilities where conditions simulated those found in the Pilbara. Soil from topsoil (T) stockpiles and waste materials (W) from an active mine site were mixed at different proportions (100 % T, 100 % W, and two mixes of topsoil and waste at 50 : 50 and 25 : 75 ratios) and used as growth media. Our results showed that seedling recruitment was highly dependent on soil moisture and emergence was generally higher in the topsoil, which had the highest available water content. In general, responses to the climate scenarios differed significantly among the native species which suggest that future climate scenarios of increasing drought might affect not only seedling recruitment but also diversity and structure of native plant communities. The use of waste materials from mining operations as growth media could be an alternative to the limited topsoil. However, in the early stages of plant establishment successful seedling recruitment can be challenging in the absence of water. These limitations could be overcome by using soil amendments but the cost associated to these solutions at large landscape scales

  18. Salvadora persica agro-ecological suitability for oil production in Argentine dryland salinity.

    Science.gov (United States)

    Falasca, Silvia; Pitta-Alvarez, Sandra; del Fresno, Carolina Miranda

    2015-12-15

    One of the major causes of crop stress is soil or water salinity. Thus, selection of the best species for cultivation in semiarid and arid climates is fundamental. Salvadora persica is an evergreen perennial halophyte that can grow under extreme conditions, from very dry environments to highly saline soils. Based on international bibliography, the authors outlined an agro-ecological zoning model to determine the potential cultivation zones for S. persica in Argentina. This model may be applied to any part of the world, using the agro-ecological limits presented in this work. All the maps were developed by the implementation of a geographic information system (GIS) that can be updated by the further incorporation of complementary information, with the consequent improvement of the original database. The overlap of the agroclimatic suitability map on the drylands' saline soils and the drylands' alkaline soils maps, determined the agro-ecological zoning. Since some areas in the agro-ecological zoning can overlap with land that is already assigned for other uses, protected areas, current land use/cover of the different zones, and urban areas maps were incorporated into the GIS and subtracted by a mask. This resulted in the delimitation of "potential cultivation zoning", thus avoiding possible conflicts surrounding the use of land and making the agro-ecological zonation more efficient. There is a broad agro-ecological zone for cultivation of S. persica that extends from Northern Argentina to approximately 41° South latitude, under dry-subhumid to semiarid climates. Lands classified with different degrees of suitability in the potential cultivation zoning could be used for production of this species for energy purposes on lands that are either unsuitable for food production or currently assigned for other purposes. This paper represents pioneering work since there are no previous studies concerning the introduction of S. persica in Argentina.

  19. Effects of salinity on leaf breakdown: Dryland salinity versus salinity from a coalmine.

    Science.gov (United States)

    Sauer, Felix G; Bundschuh, Mirco; Zubrod, Jochen P; Schäfer, Ralf B; Thompson, Kristie; Kefford, Ben J

    2016-08-01

    Salinization of freshwater ecosystems as a result of human activities represents a global threat for ecosystems' integrity. Whether different sources of salinity with their differing ionic compositions lead to variable effects in ecosystem functioning is unknown. Therefore, the present study assessed the impact of dryland- (50μS/cm to 11,000μS/cm) and coalmine-induced (100μS/cm to 2400μS/cm) salinization on the leaf litter breakdown, with focus on microorganisms as main decomposer, in two catchments in New South Wales, Australia. The breakdown of Eucalyptus camaldulensis leaves decreased with increasing salinity by up to a factor of three. Coalmine salinity, which is characterised by a higher share of bicarbonates, had a slightly but consistently higher breakdown rate at a given salinity relative to dryland salinity, which is characterised by ionic proportions similar to sea water. Complementary laboratory experiments supported the stimulatory impact of sodium bicarbonates on leaf breakdown when compared to sodium chloride or artificial sea salt. Furthermore, microbial inoculum from a high salinity site (11,000μS/cm) yielded lower leaf breakdown at lower salinity relative to inoculum from a low salinity site (50μS/cm). Conversely, inoculum from the high salinity site was less sensitive towards increasing salinity levels relative to inoculum from the low salinity site. The effects of the different inoculum were the same regardless of salt source (sodium bicarbonate, sodium chloride and artificial sea salt). Finally, the microorganism-mediated leaf litter breakdown was most efficient at intermediate salinity levels (≈500μS/cm). The present study thus points to severe implications of increasing salinity intensities on the ecosystem function of leaf litter breakdown, while the underlying processes need further scrutiny.

  20. Soil indicators to assess the effectiveness of restoration strategies in dryland ecosystems

    Directory of Open Access Journals (Sweden)

    E. A. C. Costantini

    2015-12-01

    Full Text Available Soil indicators may be used for assessing both land suitability for restoration and the effectiveness of restoration strategies in restoring ecosystem functioning and services. In this review paper, several soil indicators, which can be used to assess the effectiveness of restoration strategies in dryland ecosystems at different spatial and temporal scales, are discussed. The selected indicators represent the different viewpoints of pedology, ecology, hydrology, and land management. The recovery of soil capacity to provide ecosystem services is primarily obtained by increasing soil rooting depth and volume, and augmenting water accessibility for vegetation. Soil characteristics can be used either as indicators of suitability, that is, inherently slow-changing soil qualities, or as indicators for modifications, namely dynamic, thus "manageable" soil qualities. Soil organic matter forms, as well as biochemistry, micro- and meso-biology, are among the most utilized dynamic indicators. On broader territorial scales, the Landscape Function Analysis uses a functional approach, where the effectiveness of restoration strategies is assessed by combining the analysis of spatial pattern of vegetation with qualitative soil indicators. For more holistic and comprehensive projects, effective strategies to combat desertification should integrate soil indicators with biophysical and socio-economic evaluation and include participatory approaches. The integrated assessment protocol of Sustainable Land Management developed by the World Overview of Conservation Approaches and Technologies network is thoroughly discussed. Two overall outcomes stem from the review: (i the success of restoration projects relies on a proper understanding of their ecology, namely the relationships between soil, plants, hydrology, climate, and land management at different scales, which is particularly complex due to the heterogeneous pattern of ecosystems functioning in drylands, and (ii

  1. Quantification of the Ecological Resilience of Drylands Using Digital Remote Sensing

    Directory of Open Access Journals (Sweden)

    Brien E. Norton

    2008-06-01

    Full Text Available Drylands cover 41% of the terrestrial surface and support > 36% of the world's population. However, the magnitude of dryland degradation is unknown at regional and global spatial scales and at 15-30-yr temporal scales. Historical archives of > 30 yr of Landsat satellite imagery exist and allow local to global monitoring and assessment of a landscape's natural resources in response to climatic events and human activities. Vegetation indices (VIs, i.e., proxies of vegetation characteristics such as phytomass, can be derived from the spectral properties of Landsat imagery. A dynamical systems analysis method called mean-variance analysis can be used to describe and quantify dynamic regimes of VI response to disturbance using characteristics of ecological resilience, particularly amplitude and malleability, from a change detection perspective. Amplitude is the magnitude of response of a VI to a disturbance; malleability is the degree of recovery of a resource after a disturbance. Spatially aggregate and spatially explicit (image differencing are methods whereby a VI image or statistic from one time period is subtracted from a VI image or statistic from another time period. To illustrate this method, we used a time series of Landsat imagery from 1972 to 1987 to measure the response of vegetation communities that are managed by subsistence agropastoral communities to the severe 1982-1984 El Niño-induced drought on the Bolivian Altiplano. We found that the entire landscape had decreased vegetation cover, increased variance (diagnostic of a regime shift, and thus, increased susceptibility to soil erosion during the drought. The wet meadow vegetation cover class had the lowest amplitude and thus the most resilience relative to other vegetation cover classes. This response identified the wet meadow as a key resource, as well as a harbinger of climate change for agropastoral communities in areas where drought is an endemic stressor.

  2. Regulations of evapotranspiration and ecosystem productivity from biophysical and human drivers in drylands Northern Eurasia

    Science.gov (United States)

    Chen, J.; Ouyang, Z.; John, R.; Henebry, G. M.; Xie, Y.; de Beurs, K.; Fan, Y.; Shao, C.; Qi, J.; Wu, J.; Liu, Y.

    2015-12-01

    The concept of coupled human and environmental systems (CHES) has been a dominant framework in the past decade for understanding the cohesive connections between natural and human systems. Here we focus on how socio-ecological services may be regulated by the regional and local water cycles and by ecosystem production in the drylands of Northern Asia (>40 degree N), which includes Inner Mongolia of China, Kazakhstan, Kyrgyzstan, Mongolia, Tajikistan, Turkmenistan, and Uzbekistan. Total precipitation and evapotranspiration are used as the primary drivers to explain ecosystem production (e.g., GPP) and indicators of social function and structure (e.g., GDP, population) using the data collected from 1980 through 2010 of these seven areas. We hypothesize that the changes in the regional and local water cycles in these contrasting regions and socioeconomic settings significantly affect CHES functioning. Institutional changes, including shifts in policy, can play a much stronger role than those caused by the physical changes in determining the relationships between water cycle and CHES functioning. The complex connections among the biophysical and socioeconomic variables are analyzed through structural equation modeling (SEM) at country and regional scales. The highest water use efficiency (GPP:PET=0.57) was found for Uzbekistan, which also had the highest GDP:GPP (0.66) among the seven areas. In contrast, Mongolia exhibited the lowest values during the study period despite its very high GPP:Population value (45.8). The low population in Mongolia appeared responsible for its rank within the dryland region. Regional institutional changes with global ramifications, such as the collapse of Soviet Union and China joining the World Trade Organization, appears to have affected the CHES of the study areas.

  3. Natural ecosystem mimicry in traditional dryland agroecosystems: Insights from an empirical and holistic approach.

    Science.gov (United States)

    Blanco, Julien; Michon, Geneviève; Carrière, Stéphanie M

    2017-08-30

    While the aim of Ecological Intensification is to enable the design of more sustainable and productive agricultural systems, it is not suited to dryland agroecosystems that are driven by non-equilibrium dynamics and intrinsic variability. Instead, a model based on mobility and variability management has been proposed for these agroecosystems. However, this model remains under-applied in southern Morocco where there have been few studies on the functioning of traditional agroecosystems. This paper focuses on an agroecosystem in the Moroccan Saharan fringe zone that combines agriculture and pastoralism in an acacia parkland. A grounded theory approach was used over a three-year investigation period (i) to highlight how agro-pastoral activities interface with environmental variability, and (ii) to analyze the formal and informal institutions that support these activities. Results show that farmers interface with rainfall variability through (i) an opportunistic agricultural calendar, (ii) a variation of cultivated areas, and (iii) crop diversification. Herders combine macro-mobility (nomads move over long distances to track rainfall) and micro-mobility (nomadic and sedentary herds are driven on a daily basis around settlements) to optimize the exploitation of ecological heterogeneity. During droughts, they also resort to State-subsidized forage supplies. Both cultivation and pastoral activities tend to interface with ecological dynamics and to mimic nature, resulting in a human-modified parkland that could be considered as a 'green agroecosystem'. The sustainability of natural resource use relies on flexible property rights, backed up by a social and cultural norm-based regulation system, that allow crop-livestock integration and landscape collective management. Despite encouraging results, the agroecosystem appears to be threatened by current agricultural policies, rural exodus and the lack of social recognition of nomadism. Nevertheless, because ecosystem mimicry of

  4. Pulse-drought atop press-drought: unexpected plant responses and implications for dryland ecosystems.

    Science.gov (United States)

    Hoover, David L; Duniway, Michael C; Belnap, Jayne

    2015-12-01

    In drylands, climate change is predicted to cause chronic reductions in water availability (press-droughts) through reduced precipitation and increased temperatures as well as increase the frequency and intensity of short-term extreme droughts (pulse-droughts). These changes in precipitation patterns may have profound ecosystem effects, depending on the sensitivities of the dominant plant functional types (PFTs). Here we present the responses of four Colorado Plateau PFTs to an experimentally imposed, 4-year, press-drought during which a natural pulse-drought occurred. Our objectives were to (1) identify the drought sensitivities of the PFTs, (2) assess the additive effects of the press- and pulse-drought, and (3) examine the interactive effects of soils and drought. Our results revealed that the C3 grasses were the most sensitive PFT to drought, the C3 shrubs were the most resistant, and the C4 grasses and shrubs had intermediate drought sensitivities. Although we expected the C3 grasses would have the greatest response to drought, the higher resistance of C3 shrubs relative to the C4 shrubs was contrary to our predictions based on the higher water use efficiency of C4 photosynthesis. Also, the additive effects of press- and pulse-droughts caused high morality in C3 grasses, which has large ecological and economic ramifications for this region. Furthermore, despite predictions based on the inverse texture hypothesis, we observed no interactive effects of soils with the drought treatment on cover or mortality. These results suggest that plant responses to droughts in drylands may differ from expectations and have large ecological effects if press- and pulse-droughts push species beyond physiological and mortality thresholds.

  5. Adaptive livelihood strategies for coping with water scarcity in the drylands of central Tanzania

    Science.gov (United States)

    Liwenga, Emma T.

    In this paper, it is argued that local knowledge for adapting to water scarcity is important for integrated resource management by taking into consideration both the natural and social constraints in a particular setting based on accumulated experience. The paper examines the relevance of local knowledge in sustaining agricultural production in the semiarid areas of central Tanzania. The paper specifically focuses on how water scarcity, as the major limiting factor, is addressed in the study area using local knowledge to sustain livelihoods of its people. The study was conducted in four villages; Mzula, Ilolo, Chanhumba and Ngahelezi, situation in Mvumi Division in Dodoma Region. The study mainly employed qualitative data collection techniques. Participatory methods provided a means of exploring perceptions and gaining deeper insights regarding natural resource utilization in terms of problems and opportunities. The main data sources drawn upon in this study were documentation, group interviews and field observations. Group interviews involved discussions with a group of 6-12 people selected on the basis of gender, age and socio-economic groups. Data analysis entailed structural and content analysis within the adaptive livelihood framework in relation to management of water scarcity using local knowledge. The findings confirm that rainfall is the main limiting factor for agricultural activities in the drylands of Central Tanzania. As such, local communities have developed, through time, indigenous knowledge to cope with such environments utilizing seasonality and diversity of landscapes. Use of this local knowledge is therefore effective in managing water scarcity by ensuring a continuous production of crops throughout the year. This practice implies increased food availability and accessibility through sales of such agricultural products. Local innovations for water management, such as cultivation in sandy rivers, appear to be very important means of accessing

  6. Effects of crop residue on soil and plant water evaporation in a dryland cotton system

    Science.gov (United States)

    Lascano, R. J.; Baumhardt, R. L.

    1996-03-01

    Dryland agricultural cropping systems emphasize sustaining crop yields with limited use of fertilizer while conserving both rain water and the soil. Conservation of these resources may be achieved with management systems that retain residues at the soil surface simultaneously modifying both its energy and water balance. A conservation practice used with cotton grown on erodible soils of the Texas High Plains is to plant cotton into chemically terminated wheat residues. In this study, the partitioning of daily and seasonal evapotranspiration ( E t) into soil and plant water evaporation was compared for a conventional and a terminated-wheat cotton crop using the numerical model ENWATBAL. The model was configured to account for the effects of residue on the radiative fluxes and by introducing an additional resistance to latent and sensible heat fluxes derived from measurements of wind speed and vapor conductance from a soil covered with wheat-stubble. Our results showed that seasonal E t was similar in both systems and that cumulative soil water evaporation was 50% of E t in conventional cotton and 31% of E t in the wheat-stubble cotton. Calculated values of E t were in agreement with measured values. The main benefit of the wheat residues was to suppress soil water evaporation by intercepting irradiance early in the growing season when the crop leaf area index (LAI) was low. In semiarid regions LAI of dryland cotton seldom exceeds 2 and residues can improve water conservation. Measured soil temperatures showed that early in the season residues reduced temperature at 0.1 m depth by as much as 5°C and that differences between systems diminished with depth and over time. Residues increased lint yield per unit of E t while not modifying seasonal E t and reducing cumulative soil water evaporation.

  7. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia

    Directory of Open Access Journals (Sweden)

    WAHYU ASTIKO

    2016-01-01

    Full Text Available Abstract. Astiko W, Fauzi MT, Sukartono. 2016. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia. Nusantara Bioscience 8: 66-70. Inoculation of arbuscular mycorrhizal fungi (AMF on maize in sandy soil is expected to have positive implications for the improvement of AMF population and nutrient uptake. However, how many increases in the AMF population and nutrient uptake in the second cycle of a certain cropping system commonly cultivated by the farmers after growing their corn crop have not been examined. Since different cropping systems would indicate different increases in the populations of AMF and nutrient uptake. This study aimed to determine the population AMF and nutrient uptake on the second cropping cycle of corn-based cropping systems which utilized indigenous mycorrhizal fungi on sandy soil in dryland area of North Lombok, West Nusa Tenggara, Indonesia. For that purpose, an experiment was conducted at the Akar-Akar Village in Bayan Sub-district of North Lombok, designed according to the Randomized Complete Block Design, with four replications and six treatments of cropping cycles (P0 = corn-soybean as a control, in which the corn plants were not inoculated with AMF; P1 = corn-soybean, P2 = corn-peanut, P3 = corn-upland rice, P4 = corn-sorghum, and P5 = corn-corn, in which the first cycle corn plants were inoculated with AMF. The results indicated that the mycorrhizal populations (spore number and infection percentage were highest in the second cycle sorghum, achieving 335% and 226% respectively, which were significantly higher than those in the control. Increased uptake of N, P, K and Ca the sorghum plants at 60 DAS of the second cropping cycle reached 200%; 550%; 120% and 490% higher than in the control. The soil used in this experiment is rough-textured (sandy loam, so it is relatively low in water holding capacity and high porosity.

  8. Using Stochastically Downscaled Climate Models and Multiproxy Lake Sediment Data to Connect Climatic Variations Over the Past 1000 Years and the History of Prehistoric Maize Farming in Utah

    Science.gov (United States)

    Thomson, M. J.; MacDonald, G. M.

    2015-12-01

    We are investigating the relationship between climatic variations over the past 1000 years and the history of prehistoric maize farming expansion and decline in the American Southwest, with a focus on Utah. We are examining both the downscaled climate models and high resolution analyses of lake cores and dendrochronological data matched with occupation information. We are testing the specific utility of stochastically downscaled general circulation models (viz. ECHO-G) to reconstruct local conditions for sites with documented prehistoric dryland farming through the so-called Medieval Climate Anomaly (MCA) and transition to the Little Ice Age (LIA). We are testing our model-based reconstructions with proxies of temperature and aridity from three subalpine lake sediment cores transecting Utah. We compare the patterns of climate change from the downscaled models and the paleoclimate records to a database of 837 radiocarbon dates over 169 locations of archaeological Native American maize-farmer site occupations in Utah.

  9. Wind farm production estimates

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Aagaard Madsen, Helge;

    2012-01-01

    on a 3GHz pc. The turbine controller is fully implemented. Initially, production estimates of a single turbine under free and wake conditions, respectively, are compared for (undis- turbed) mean wind speeds ranging from 3m/s to 25m/s. The undisturbed situation refers to a wind direction bin defined......In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind...... as 270◦ ±5◦, whereas the wake situation refers to the wind direction bin 319◦ ±5◦. In the latter case, the investigated turbine operated in the wake of 6 upstream turbines, with the mean wind direction being equal to the orientation of the wind turbine row. The production of the entire wind farm has been...

  10. Transgenic Farm Animals

    Science.gov (United States)

    Solomon, Morse B.; Eastridge, Janet S.; Paroczay, Ernest W.

    Conventional science to improve muscle and meat parameters has involved breeding strategies, such as selection of dominant traits or selection of preferred traits by cross breeding, and the use of endogenous and exogenous hormones. Improvements in the quality of food products that enter the market have largely been the result of postharvest intervention strategies. Biotechnology is a more extreme scientific method that offers the potential to improve the quality, yield, and safety of food products by direct genetic manipulation. In the December 13, 2007 issue of the Southeast Farm Press, an article by Roy Roberson pointed out that biotechnology is driving most segments of U.S. farm growth. He indicated that nationwide, the agriculture industry is booming and much of that growth is the result of biotechnology advancements.

  11. Particularities of farm accounting

    Directory of Open Access Journals (Sweden)

    Lapteș, R.

    2012-01-01

    Full Text Available Nowadays, agriculture has become one of the most important fields of activity, significant funds being allotted within the EU budget to finance the European agriculture. In this context, organising the accounting of economic entities which carry out their activity in the agricultural sector has acquired new meanings. The goal of the present study is to bring into the light the particularities of the farm accounting on two levels: on the one hand, from the perspective of the international accounting referential and, on the other hand, in compliance with the national accounting regulations. The most important conclusion of this work is that, in post-1990 Romania, no interest was further manifested for the refinement of aspects specific to farm accounting.

  12. Organic food and farming

    DEFF Research Database (Denmark)

    Kledal, Paul Rye

    The paper is based on research conducted for DARCOF II (Danish Research Centre for Organic Farming, www.darcof.dk). The aim of the research project is to analyze the future development of the Danish organic food sector through focusing on two agro-commodities: vegetables and pork. Emphasis...... is placed on identification of economic forces within the supply chains. The main conclusions of the paper – being the results from the organic vegetable chain – are that the rules and regulations, and the development of alternative transaction processes in organic food and farming have so far been founded...... conventional farmers – declining prices, concentration of production and shift in bargaining power to the retailers. Logically, this situation will lead eventually to increasing conflicts between organic values and their subordination to free market forces, i.e. conventionalization. In the same time retailers...

  13. Amy Courtney: Freewheelin' Farm

    OpenAIRE

    Rabkin, Sarah

    2010-01-01

    Shareholders in Freewheelin’ Farm’s community supported agriculture program enjoy an unusual perk: delivery by bicycle-drawn trailer. Freewheelin’ founder Amy Courtney, a 1997 graduate of UCSC’s Apprenticeship in Ecological Horticulture, strives to produce fresh, healthy food while minimizing her environmental footprint. Courtney started the farm in 2002 with almost no motorized vehicles, incorporating used equipment and recycled materials wherever possible in the farm’s operations. She and h...

  14. Wind farm production estimates

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Aagaard Madsen, Helge

    2012-01-01

    In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind the DWMm......In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind...... on a 3GHz pc. The turbine controller is fully implemented. Initially, production estimates of a single turbine under free and wake conditions, respectively, are compared for (undis- turbed) mean wind speeds ranging from 3m/s to 25m/s. The undisturbed situation refers to a wind direction bin defined...... as 270◦ ±5◦, whereas the wake situation refers to the wind direction bin 319◦ ±5◦. In the latter case, the investigated turbine operated in the wake of 6 upstream turbines, with the mean wind direction being equal to the orientation of the wind turbine row. The production of the entire wind farm has been...

  15. Modelling Farm Animal Welfare.

    Science.gov (United States)

    Collins, Lisa M; Part, Chérie E

    2013-05-16

    The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively) based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested.

  16. Modelling Farm Animal Welfare

    Directory of Open Access Journals (Sweden)

    Chérie E. Part

    2013-05-01

    Full Text Available The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested.

  17. The dangers of taking mud for granted: Lessons from Lower Old Red Sandstone dryland river systems of South Wales

    Science.gov (United States)

    Wright, V. Paul; Marriott, Susan B.

    2007-02-01

    Mudrocks are a prominent feature of many ancient dryland successions but they are not always a product of the settling out of suspension load. From studies of the late Silurian-early Devonian Old Red Sandstone mudrocks of South Wales it has been shown that many were not overbank sediments deposited from suspension on floodplains, but were emplaced as sand- and silt-sized aggregates transported as bed load and deposited in sinuous channels and as braid-bar complexes on multi-stage floodplains in dryland river systems. Using the Old Red Sandstone examples criteria are provided for the recognition of similar deposits in the sedimentary record. One important aspect of these mudrocks is that they can represent multiple recycling events and can constitute condensed deposits that may be characteristic of closed alluvial basins with periodically limited sediment supply.

  18. The Balance of N, P, and Manure Fertilizer Dosage on Growth and Yield of Peanuts in Alfisols Dryland

    Directory of Open Access Journals (Sweden)

    Suryono

    2015-01-01

    Full Text Available Peanuts cultivation in Alfisols dryland limited by low levels of soil fertility. An agricultural intensification that could be done is application of organic and inorganic fertilizer. This research aimed to study the balance of N, P, and manure fertilizer dosage on growth and yield of peanuts in alfisols dryland. The research was done in April 2014 - September 2014 in Sukosari, Jumantono, Karanganyar. This research was compiled using a Randomized Completely Block Design (RCBD factorial with three factors, there are dose of urea, SP-36 and cow manure fertilizer. The results showed that the dose combinations of urea, SP-36, and cow manure fertilizer have no interaction affected all of variable plant. The application of 300 kg ha-1 SP-36 fertilizer increased the number of pods and weight of pods, while the weight of 1000 seeds was improved by application of 150 kg ha-1 urea fertilizer.

  19. Studying Prehistoric Dryland Agricultural Systems in Central Arizona through Aerial LiDAR, Pedology, Hydrology, and Paleobotany

    OpenAIRE

    Michelle L. Wienhold; Richard Ciolek-Torello; Martin Gojda; Axel G Posluschny; Robert Wegener

    2014-01-01

    Statistical Research Inc. (SRI) conducted phased data recovery at two large dryland agricultural fields and associated Hohokam habitation sites along U.S. Highway 60 in central Arizona. The agricultural fields consisted of cross channel and contour rock alignments and rock piles covering many acres within and outside of a newly proposed highway right-of-way along Queen Creek. Nearby were small, seasonal habitation sites occupied between AD 400 and 1350. Aerial 3-Dimensional Laser Range ...

  20. Are large farms more efficient? Tenure security, farm size and farm efficiency: evidence from northeast China

    Science.gov (United States)

    Zhou, Yuepeng; Ma, Xianlei; Shi, Xiaoping

    2017-04-01

    How to increase production efficiency, guarantee grain security, and increase farmers' income using the limited farmland is a great challenge that China is facing. Although theory predicts that secure property rights and moderate scale management of farmland can increase land productivity, reduce farm-related costs, and raise farmer's income, empirical studies on the size and magnitude of these effects are scarce. A number of studies have examined the impacts of land tenure or farm size on productivity or efficiency, respectively. There are also a few studies linking farm size, land tenure and efficiency together. However, to our best knowledge, there are no studies considering tenure security and farm efficiency together for different farm scales in China. In addition, there is little study analyzing the profit frontier. In this study, we particularly focus on the impacts of land tenure security and farm size on farm profit efficiency, using farm level data collected from 23 villages, 811 households in Liaoning in 2015. 7 different farm scales have been identified to further represent small farms, median farms, moderate-scale farms, and large farms. Technical efficiency is analyzed with stochastic frontier production function. The profit efficiency is regressed on a set of explanatory variables which includes farm size dummies, land tenure security indexes, and household characteristics. We found that: 1) The technical efficiency scores for production efficiency (average score = 0.998) indicate that it is already very close to the production frontier, and thus there is little room to improve production efficiency. However, there is larger space to raise profit efficiency (average score = 0.768) by investing more on farm size expansion, seed, hired labor, pesticide, and irrigation. 2) Farms between 50-80 mu are most efficient from the viewpoint of profit efficiency. The so-called moderate-scale farms (100-150 mu) according to the governmental guideline show no

  1. Soil microbial communities drive the resistance of ecosystem multifunctionality to global change in drylands across the globe.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Eldridge, David J; Ochoa, Victoria; Gozalo, Beatriz; Singh, Brajesh K; Maestre, Fernando T

    2017-10-01

    The relationship between soil microbial communities and the resistance of multiple ecosystem functions linked to C, N and P cycling (multifunctionality resistance) to global change has never been assessed globally in natural ecosystems. We collected soils from 59 dryland ecosystems worldwide to investigate the importance of microbial communities as predictor of multifunctionality resistance to climate change and nitrogen fertilisation. Multifunctionality had a lower resistance to wetting-drying cycles than to warming or N deposition. Multifunctionality resistance was regulated by changes in microbial composition (relative abundance of phylotypes) but not by richness, total abundance of fungi and bacteria or the fungal: bacterial ratio. Our results suggest that positive effects of particular microbial taxa on multifunctionality resistance could potentially be controlled by altering soil pH. Together, our work demonstrates strong links between microbial community composition and multifunctionality resistance in dryland soils from six continents, and provides insights into the importance of microbial community composition for buffering effects of global change in drylands worldwide. © 2017 John Wiley & Sons Ltd/CNRS.

  2. Are the drylands in northern China sustainable? A perspective from ecological footprint dynamics from 1990 to 2010.

    Science.gov (United States)

    Li, Jingwei; Liu, Zhifeng; He, Chunyang; Tu, Wei; Sun, Zexiang

    2016-05-15

    The drylands in northern China (DNC), characterized by water scarcity, high climatic variability, and infertile soil, are crucial for China's sustainable development in the context of rapid urbanization. However, few studies have systematically investigated its sustainability. Our objective was to assess the sustainability of the DNC according to their ecological footprint (EF) dynamics from 1990 to 2010. We analyzed EF in the DNC at multiple scales ranging from the whole, to four dryland subtypes, to the drylands in each province. We found that the total EF in the DNC increased from 3.48 × 10(8) global hectares (gha) in 1990 to 1.26 × 10(9) gha in 2010, with a growth of 2.63 times, resulting in a more than 14 times increase of ecological deficit from 6.26 × 10(7) gha to 9.63 × 10(8)gha. In addition, the water withdrawal increased from 133.29 km(3) to 153.23 km(3) with a growth rate of 14.96%, while the Human Development Index grew from 0.62 to 0.79. We concluded that the DNC has already become unsustainable after the rapid increases of EF and water withdrawal from 1990 to 2010. We argue that effective management is needed to maintain and improve the environmental sustainability of the DNC. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Geomorphic and vegetation changes in a meandering dryland river regulated by a large dam, Sauce Grande River, Argentina

    Science.gov (United States)

    Casado, Ana; Peiry, Jean-Luc; Campo, Alicia M.

    2016-09-01

    This paper investigates post-dam geomorphic and vegetation changes in the Sauce Grande River, a meandering dryland river impounded by a large water-conservation dam. As the dam impounds a river section with scarce influence of tributaries, sources for fresh water and sediment downstream are limited. Changes were inspected based on (i) analysis of historical photographs/imagery spanning pre- (1961) and post-dam (1981, 2004) channel conditions for two river segments located above and below the dam, and (ii) field survey of present channel conditions for a set of eight reference reaches along the river segments. Whilst the unregulated river exhibited active lateral migration with consequent adjustments of the channel shape and size, the river section below the dam was characterized by (i) marked planform stability (93 to 97%), and by (ii) vegetation encroachment leading to alternating yet localized contraction of the channel width (up to 30%). The present river displays a moribund, stable channel where (i) redistribution of sediment along the river course no longer occurs and (ii) channel forms constitute a remnant of a fluvial environment created before closing the dam, under conditions of higher energy. In addition to providing new information on the complex geomorphic response of dryland rivers to impoundment, this paper represents the very first geomorphic assessment of the regulated Sauce Grande and therefore provides an important platform to underpin further research assessing the geomorphic state of this highly regulated dryland river.

  4. Fault Tolerant Wind Farm Control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2013-01-01

    with best at a wind turbine control level. However, some faults are better dealt with at the wind farm control level, if the wind turbine is located in a wind farm. In this paper a benchmark model for fault detection and isolation, and fault tolerant control of wind turbines implemented at the wind farm...... control level is presented. The benchmark model includes a small wind farm of nine wind turbines, based on simple models of the wind turbines as well as the wind and interactions between wind turbines in the wind farm. The model includes wind and power references scenarios as well as three relevant fault...... scenarios. This benchmark model is used in an international competition dealing with Wind Farm fault detection and isolation and fault tolerant control....

  5. Social Farming Rural Development Strategy

    Directory of Open Access Journals (Sweden)

    Adrian Gheorghe ZUGRAVU

    2013-12-01

    Full Text Available The paper follows two main objectives: to understand farmers’ perception and image of social services and to identify communication levers in order to improve the perceived image of social farming. Orientations in terms of communication are product-focused and aim at enhancing the reputation of social farming consequently with impact on rural development. This paper conducted a questionnaire survey of Romanian farmers’ perception toward social agricultural. The empirical study indicated that farmers shown different awareness to social farming.

  6. Understanding crop and farm management

    OpenAIRE

    Chongtham, Iman Raj

    2016-01-01

    Agriculture faces challenges in meeting rising demand for food, feed, fibre and fuel while coping with pressure from globalisation, limited natural resources and climate change. Farmers will choose management practices based on their goals and available resources and these practices will influence farm performance. The aim of this thesis was to understand farmers’ crop and farm management practices and their links to farm(er) characteristics, productivity, biodiversity, marketing channels and...

  7. Design and farm animal welfare.

    Science.gov (United States)

    Jackson, W T

    1976-07-24

    Farm animal welfare and the design of farm buildings and equipment are interrelated. The animals' requirements and preferences should first be estimated and ways in which this can be done are discussed, as are methods of assessment of their environment. Some examples of the influence which housing and equipment design can have are given. Attention is drawn to the difficulties inherent in the assessment of farm animal welfare and the postulation made that the veterinarian is well fitted to carry out such assessments.

  8. FarmVille For Dummies

    CERN Document Server

    Morales, Angela

    2011-01-01

    The only how-to, full-color book available on the game sensation FarmVille. With more than 80 million active players since the game?s release in 2009, there seems no end to the growing popularity of FarmVille. Whether accessed through the Facebook application or from the game?s Web site, this application is a worldwide phenomenon. Yet, there has been no beginner guide that offers an introduction to newcomers and updates to experienced players?until now. FarmVille For Dummies is aimed at getting novices acquainted with FarmVille rules and regulations, while more savvy players can sharpen their

  9. Immigrant Workers and Farm Performance

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Munch, Jakob R.; Seidelin, Claus Aastrup

    2013-01-01

    In many developed countries, the agricultural sector has experienced a significant inflow of immigrants. At the same time, agriculture is still in a process of structural transformation, resulting in fewer but larger and presumably more efficient farms. We exploit matched employer-employee data...... for Danish farms in 1980–2008 to analyze the micro-level relationship between these two developments. Farms employing immigrants tend to be both larger than and no less productive than other farms. Furthermore, an increased use of immigrants is associated with an improvement in job creation and revenue......, which at least partially seems to reflect a causal effect of immigrants....

  10. Spatial allocation of farming systems and farming indicators in Europe

    DEFF Research Database (Denmark)

    Kempen, Markus; Elbersen, Berien S.; Staritsky, Igor

    2011-01-01

    sample farms making it possible to aggregate farm types both to natural and to lower scale administrative regions. This spatial flexibility allows providing input data to economic or bio-physical models at their desired resolution. The allocation approach is implemented as a constrained optimization...

  11. Energy balance in IPM rice farms compared to conventional farms

    Directory of Open Access Journals (Sweden)

    Mehdi Fazeli

    2017-06-01

    Full Text Available Integrated Pest Management based on Farmer Field Schools (IPM/FFS is a program aimed to guide farmers toward managing agricultural pests in an environmentally responsible manner. This program has been in practice during the recent decade in the north of Iran. A study was conducted to evaluate the overall impacts of IPM/FFS program on energy balance and economic revenue of paddy (Oryza sativa L. farms compared with conventional farms (no IPM. The data of inputs, management practices, and output (yield of 238 paddy farms (135 IPM farms and 103 conventional farms located in a semi-Mediterranean climate were collected in 2010 and 2011. Total energy input, energy output, energy efficiency, and energy productivity were determined as indicators of energy balance. The total energy requirement for paddy production in IPM system was 48756 MJ ha−1, indicating that 8% more energy was used in IPM farms than that in conventional farms. It was noticed that IPM program in this region failed to reduce the consumption of chemical pesticides in paddy farms and the conventional system was more energy efficient than IPM system. Although paddy yield of the two systems was similar, the economic net return in IPM system was almost 20% higher than the conventional system due to the higher price of paddy produced in IPM system.

  12. Whole Farm Nutrient Balance Calculator for New York Dairy Farms

    Science.gov (United States)

    Soberon, Melanie A.; Ketterings, Quirine M.; Rasmussen, Caroline N.; Czymmek, Karl J.

    2013-01-01

    Nutrient loss and accumulation as well as associated environmental degradation have been a concern for animal agriculture for many decades. Federal and New York (NY) regulations apply to Concentrated Animal Feeding Operations and a comprehensive nutrient management plan (CNMP) is required for regulated farms. The whole farm nutrient mass balance…

  13. Whole Farm Nutrient Balance Calculator for New York Dairy Farms

    Science.gov (United States)

    Soberon, Melanie A.; Ketterings, Quirine M.; Rasmussen, Caroline N.; Czymmek, Karl J.

    2013-01-01

    Nutrient loss and accumulation as well as associated environmental degradation have been a concern for animal agriculture for many decades. Federal and New York (NY) regulations apply to Concentrated Animal Feeding Operations and a comprehensive nutrient management plan (CNMP) is required for regulated farms. The whole farm nutrient mass balance…

  14. Spatial allocation of farming systems and farming indicators in Europe

    NARCIS (Netherlands)

    Kempen, M.; Elbersen, B.S.; Staritsky, I.G.; Andersen, E.; Heckelei, T.

    2011-01-01

    In this article an approach to spatially allocate farm information to a specific environmental context is presented. At this moment the European wide farm information is only available at a rather aggregated administrative level. The suggested allocation approach adds a spatial dimension to all samp

  15. Developing ecological fingerprints for ecoclimatic zones in Australian drylands to inform land restoration

    Science.gov (United States)

    Muñoz-Rojas, Miriam; Escribano Velasco, Paula; Garcia, Monica

    2017-04-01

    With more than 25% of the global surface affected by land degradation processes, there is an urgent need to restore disturbed ecosystems worldwide. Increased arid conditions in projected scenarios of climate change need to be acknowledged in restoration programs; this is particularly critical in dryland ecosystems where significant changes are expected in their structure and functioning worldwide. Australia is the driest inhabited continent in the world with 70% of the country classified as arid or semi-arid (average annual rainfall of 250 mm or less). Moreover, Australia has undergone massive land-use changes in the last decades and the landscape is highly degraded and fragmented. These conditions position the country as one of the climate change vulnerable "hot spots" globally. In this research, we aim to evaluate a broad range of ecological indicators in natural Australian dryland ecosystems (both disturbed and undisturbed) that allow us to i) identify those areas most vulnerable to potential and environmental changes and ii) tracking the effectiveness of restoration practices. The most relevant indicators will be selected to inform decision-making in the design of management strategies to address the potential negative effects of climate change and further land degradation. These ecological indicators will be measured in 10 Australian ecoclimatic units that combine the main vegetation functional types and climate zones based on the aridity index as follows: hum¬mock grasslands in the hyper-arid zone; acacia shrublands, hummock grasslands and tussock grasslands in the arid zone; chenopod shrubs, hummock grasslands, mallee woodlands and tussock grasslands in the semi-arid zone and eucalyptus and acacia forest in the dry sub-humid zone. A set of fingerprints will be created to diagnose each ecoclimatic unit using a wide range of ecological indicators related with the ecosystem's composition, structure and function. We will combine novel technologies and

  16. Climate Change and Dryland Wheat Systems in the US Pacific Northwest

    Science.gov (United States)

    Stockle, C.; Karimi, T.; Huggins, D. R.; Nelson, R.

    2015-12-01

    A regional assessment of historical and future yields, and components of the water, nitrogen, and carbon soil balance of dryland wheat-based cropping systems in the US Pacific Northwest is being conducted (Regional Approaches to Climate Change project funded by USDA-NIFA). All these elements intertwines and are important to understand the future of these systems in the region. A computer simulation methodology was used based on the CropSyst model and historic and projected daily weather data downscaled to a 4x4 km grid including 14 general circulation models (GCMs) and two representative concentration pathways of future atmospheric CO2 (RCP 4.5 and RCP 8.5). The study region was divided in 3 agro-ecological zones (AEZ) based on precipitation amount: low (460 mm/year), with a change from crop-fallow, to transition fallow (crop-crop-fallow) to annual cropping, respectively. Typical wheat-based rotations included winter wheat (WW)-Summer fallow (SF) for the low AEZ, WW-spring wheat (SW)-SF for the intermediate AEZ, and WW-SW-spring peas for the high AEZ, all under conventional and no tillage management. Alternative systems incorporating canola were also evaluated. Results suggest that, in most cases, these dryland systems may fare well in the future (31-year periods centered around 2030, 2050, and 2070), with potential gains in productivity. Also, a trend towards increased fallow in the intermediate AEZ appears possible for higher productivity, and the inclusion of less water demanding crops may help sustain cropping intensity. Uncertainties in these projections arise from large discrepancies among climate models regarding the warming rate, compounded by different possible future CO2 emission scenarios, the degree of change in frequency and severity of extreme events and associated potential damages to crop canopies due to cold weather and grain set reduction due to extreme heat events. Furthermore, there is little understanding of the impact of climate change on

  17. Mapping biological soil crusts for understanding their functional relevance in dryland ecosystems

    Science.gov (United States)

    Rodriguez-Caballero, E.; Escribano, P.; Chamizo, S.; Canton, Y.

    2012-04-01

    Biological soil crusts (BSCs) are considered a key element in the functioning of arid and semiarid ecosystems as they modify numerous soil surface properties involved in primary ecosystem processes such as hydrological and erosion processes, and nutrient cycling.. It is known that arid and semiarid ecosystems are conformed by a complex matrix of vegetated and open ground patches usually covered by BSCs. Geomorphic evolution of drylands depends on the individual response of patches and also on the interactions and feedback-processes among patches. These interactions are controlled by patch spatial distribution. On this account, to understand the role of BSCs in the system, it is necessary to introduce their effect at coarser scales, and to have accurate and spatially continuous information of BSC distribution. The inherent complexity and the spatial heterogeneity of drylands make field survey methods very limited for BSC mapping. Images reported by remote sensors are presented as a powerful tool for mapping BSC spatial distribution. Remote sensors provide synoptic and spatially continuous information of the territory. Different indices for mapping BSCs have been published. These indices are based on distinctive spectral characteristic of BSCs and differ in nature and objectives. The aim of this work was to analyze the feasibility of some of these indices in a semiarid area characterized by sparse vegetation cover usually mixed at subpixel level with elements characterized by very similar spectral response (bare soil, BSCs and dry vegetation). These indices were: i) CRCIA, index applied for mapping BSCs from hyperspectral images. ii) CI, index developed for mapping of cyanobacteria-dominated BSCs and iii) BSCI, index for mapping of lichen-dominated BSCs. The multispectral indices (CI and BSCI) classified as BSCs 50% of the pixels dominated by BSCs. The CRCIA hyperspectral index, showed better results than those obtained with multispectral indices. This index

  18. Livestock Farming Under Climate Change Conditions

    CSIR Research Space (South Africa)

    Koelle, B

    2016-12-01

    Full Text Available for livestock farming under changing environmental conditions. Farming with livestock can be challenging, especially when farming in arid areas. This handbook is primarily informed by the experience of farmers in the South African winter rainfall area....

  19. Strategy and risk in farming

    OpenAIRE

    Huirne, R.B.M.

    2002-01-01

    Issues that are relevant in current farm management are discussed. First, three basic farm management theories are presented: (1) decision-making theory; (1) system theory; and (3) theory of management by objectives. Next, two new developments are introduced, namely, strategic management and risk management.

  20. Intelligent control on wind farm

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2010-01-01

    with the wind farm makes the grid more vulnerable. The communication technologies have been considered as a solution to solve the problems according to the IEC 61400-25 series protocols. This paper presents the significance of communication technologies in wind farm system by the simulations on some practical...

  1. Grieving for the Family Farm.

    Science.gov (United States)

    Zeller, Simon H.

    1986-01-01

    Reviews impact of recent agricultural trends in South Dakota. Outlines Kubler-Ross' stages of grief/adaptation that farm families must negotiate as they cope with the trauma of the loss of their farms. Indicates service providers must overcome farmers' mistrust for human welfare services and reach out to this vulnerable population. (NEC)

  2. Food and farm products surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the radiological analyses performed on food and farm samples collected during 1994. The food and farm sampling design addresses the potential influence of Hanford Site releases. Details of the sampling design and radionuclides analyzed are included in this section.

  3. Offshore wind farms: Danish experiences

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, H.; Taylor, D.; Petersen, A. [Carl Bro Group, Edinburgh (United Kingdom)

    2000-07-01

    Denmark has extensive plans for offshore wind farms, and by 2030 parks to generate some 5,500 MW of power will be constructed. Out of this 4,000 MW will be offshore and to date 15 sites have been identified. Carl Bro Group are currently involved in the programme carrying out basic and detailed design, including EIA for 5 sites where construction is planned to take place before 2005. The first phase consists of the installation of 150MW wind farms. In Middelgrunden, off shore from Copenhagen, a scheme is well advanced to install 20 windmills generating approximately 40MW of power. This project is the largest offshore wind farm in the world and illustrates Denmark's commitment to sustainability. The paper gives an overview of the plans for offshore wind farms in Denmark and includes a detailed description of the farm at Middelgrunden, with emphasis on environmental, aesthetic, safety, design, construction and installation aspects. (Author)

  4. TOPFARM wind farm optimization tool

    DEFF Research Database (Denmark)

    Réthoré, Pierre-Elouan; Fuglsang, Peter; Larsen, Torben J.;

    the optimization problem includes elements as energy production, turbine degradation, operation and maintenance costs, electrical grid costs and foundation costs. The objective function is optimized using a dedicated multi fidelity approach with the locations of individual turbines in the wind farm spanning......A wind farm optimization framework is presented in detail and demonstrated on two test cases: 1) Middelgrunden and 2) Stags Holt/Coldham. A detailed flow model describing the instationary flow within a wind farm is used together with an aeroelastic model to determine production and fatigue loading...... of wind farm wind turbines. Based on generic load cases, the wind farm production and fatigue evaluations are subsequently condensed in a large pre-calculated database for rapid calculation of lifetime equivalent loads and energy production in the optimization loop.. The objective function defining...

  5. Characteristics of New Jersey Agritourism Farms

    OpenAIRE

    Schilling, Brian J.; Sullivan, Kevin P.

    2014-01-01

    Agritourism is an important alternative farm enterprise strategy in the U.S., especially for farms operating under urban influence. This paper develops a logit model to identify the characteristics of farms engaged in agritourism using 2007 Census of Agriculture respondent-level records. New Jersey, which ranks first nationally in the proportion of farm income derived from agritourism, provides the geographic context. We find that fruit/vegetable farms, rural residential/retirement farms, and...

  6. Dryland, calcareous soils store (and lose) significant quantities of near-surface organic carbon

    Science.gov (United States)

    Cunliffe, Andrew M.; Puttock, Alan K.; Turnbull, Laura; Wainwright, John; Brazier, Richard E.

    2016-04-01

    Semiarid ecosystems are susceptible to changes in dominant vegetation which may have significant implications for terrestrial carbon dynamics. The present study examines the distribution of organic carbon (OC) between particle size fractions in near-surface (0-0.05 m) soil and the water erosion-induced redistribution of particle-associated OC over a grass-shrub ecotone, in a semiarid landscape, subject to land degradation. Coarse (>2 mm) particles have comparable average OC concentrations to the fine (events was monitored over four annual monsoon seasons. Eroded sediment was significantly enriched in OC; enrichment increased significantly across the grass-shrub ecotone and appears to be an enduring phenomenon probably sustained through the dynamic replacement of preferentially removed organic matter. The average erosion-induced OC event yield increased sixfold across the ecotone from grass-dominated to shrub-dominated ecosystems, due to both greater erosion and greater OC enrichment. This erosional pathway is rarely considered when comparing the carbon budgets of grasslands and shrublands, yet this accelerated efflux of OC may be important for long-term carbon storage potentials of dryland ecosystems.

  7. 75 years of dryland science: Trends and gaps in arid ecology literature.

    Science.gov (United States)

    Greenville, Aaron C; Dickman, Chris R; Wardle, Glenda M

    2017-01-01

    Growth in the publication of scientific articles is occurring at an exponential rate, prompting a growing need to synthesise information in a timely manner to combat urgent environmental problems and guide future research. Here, we undertake a topic analysis of dryland literature over the last 75 years (8218 articles) to identify areas in arid ecology that are well studied and topics that are emerging. Four topics-wetlands, mammal ecology, litter decomposition and spatial modelling, were identified as 'hot topics' that showed higher than average growth in publications from 1940 to 2015. Five topics-remote sensing, climate, habitat and spatial, agriculture and soils-microbes, were identified as 'cold topics', with lower than average growth over the survey period, but higher than average numbers of publications. Topics in arid ecology clustered into seven broad groups on word-based similarity. These groups ranged from mammal ecology and population genetics, broad-scale management and ecosystem modelling, plant ecology, agriculture and ecophysiology, to populations and paleoclimate. These patterns may reflect trends in the field of ecology more broadly. We also identified two broad research gaps in arid ecology: population genetics, and habitat and spatial research. Collaborations between population genetics and ecologists and investigations of ecological processes across spatial scales would contribute profitably to the advancement of arid ecology and to ecology more broadly.

  8. Modeling ecohydrological dynamics of smallholder strategies for food production in dryland agricultural systems

    Science.gov (United States)

    Gower, Drew B.; Dell'Angelo, Jampel; McCord, Paul F.; Caylor, Kelly K.; Evans, Tom P.

    2016-11-01

    In dryland environments, characterized by low and frequently variable rainfall, smallholder farmers must take crop water sensitivity into account along with other characteristics like seed availability and market price when deciding what to plant. In this paper we use the results of surveys conducted among smallholders located near Mount Kenya to identify clusters of farmers devoting different fractions of their land to subsistence and market crops. Additionally, we explore the tradeoffs between water-insensitive but low-value subsistence crops and a water-sensitive but high-value market crop using a numerical model that simulates soil moisture dynamics and crop production over multiple growing seasons. The cluster analysis shows that most farmers prefer to plant either only subsistence crops or only market crops, with a minority choosing to plant substantial fractions of both. The model output suggests that the value a farmer places on a successful growing season, a measure of risk aversion, plays a large role in whether the farmer chooses a subsistence or market crop strategy. Furthermore, access to irrigation, makes market crops more appealing, even to very risk-averse farmers. We then conclude that the observed clustering may result from different levels of risk aversion and access to irrigation.

  9. Retrospective assessment of dryland soil stability in relation to grazing and climate change.

    Science.gov (United States)

    Washington-Allen, Robert A; West, Neil E; Ramsey, R Douglas; Phillips, Debra H; Shugart, Herman H

    2010-01-01

    Accelerated soil erosion is an aspect of dryland degradation that is affected by repeated intense drought events and land management activities such as commercial livestock grazing. A soil stability index (SSI) that detects the erosion status and susceptibility of a landscape at the pixel level, i.e., stable, erosional, or depositional pixels, was derived from the spectral properties of an archived time series (from 1972 to 1997) of Landsat satellite data of a commercial ranch in northeastern Utah. The SSI was retrospectively validated with contemporary field measures of soil organic matter and erosion status that was surveyed by US federal land management agencies. Catastrophe theory provided the conceptual framework for retrospective assessment of the impact of commercial grazing and soil water availability on the SSI. The overall SSI trend was from an eroding landscape in the early drier 1970s towards stable conditions in the wetter mid-1980s and late 1990s. The landscape catastrophically shifted towards an extreme eroding state that was coincident with the "The Great North American Drought of 1988". Periods of landscape stability and trajectories toward stability were coincident with extremely wet El Niño events. Commercial grazing had less correlation with soil stability than drought conditions. However, the landscape became more susceptible to erosion events under multiple droughts and grazing. Land managers now have nearly a year warning of El Niño and La Niña events and can adjust their management decisions according to predicted landscape erosion conditions.

  10. The performance of rotary power tiller using prototype rotary blades in dry-land field

    Directory of Open Access Journals (Sweden)

    Sirisak Chertkiattipol

    2008-11-01

    Full Text Available The effect of shape of prototype rotary blades on the performance of rotary power tiller was investigated in this study. Three sets of rotors, i.e. 14-blade rotor of the Japanese C-shape blade (4.5 cm tilling width of one blade; T1, 14-blade rotor of the prototype rotary blade no. 1 (4.5 cm tilling width of one blade; T2, and 10-blade rotor of the prototype rotary blade no. 2 (6.5 cm tilling width of one blade; T3 were used. The tests were conducted in a dry-land field of clay loam with soil moisture content of 16.04 % (d.b. and dry bulk density of 1.51 g/cm3 at different rotational speeds of 300, 350 and 400 rpm at one and two tilling passes. For all rotors, experimental results showed that the mean soil clod diameter decreased and soil inversion increased with increasing rotational speed of the rotor. The mean soil clod diameter decreased at pass 2. Soil inversion during pass 2 was higher than pass 1. However, the three sets of rotors showed no significant difference on mean soil clod diameter and soil inversion. The shape of blade prototype rotary blade no. 1 and the decreasing number of prototype rotary blade no. 2 did not affect the tillage performance as compared with the Japanese C-shaped blade.

  11. Identifying Categorical Land Use Transition and Land Degradation in Northwestern Drylands of Ethiopia

    Directory of Open Access Journals (Sweden)

    Worku Zewdie

    2016-05-01

    Full Text Available Land use transition in dryland ecosystems is one of the major driving forces to landscape change that directly impacts the welfare of humans. In this study, the support vector machine (SVM classification algorithm and cross tabulation matrix analysis are used to identify systematic and random processes of change. The magnitude and prevailing signals of land use transitions are assessed taking into account net change and swap change. Moreover, spatiotemporal patterns and the relationship of precipitation and the Normalized Difference Vegetation Index (NDVI are explored to evaluate landscape degradation. The assessment showed that 44% of net change and about 54% of total change occurred during the study period, with the latter being due to swap change. The conversion of over 39% of woodland to cropland accounts for the existence of the highest loss of valuable ecosystem of the region. The spatial relationship of NDVI and precipitation also showed R2 of below 0.5 over 55% of the landscape with no significant changes in the precipitation trend, thus representing an indicative symptom of land degradation. This in-depth analysis of random and systematic landscape change is crucial for designing policy intervention to halt woodland degradation in this fragile environment.

  12. Assessing woody vegetation trends in Sahelian drylands using MODIS based seasonal metrics

    DEFF Research Database (Denmark)

    Brandt, Martin Stefan; Hiernaux, Pierre; Rasmussen, Kjeld

    2016-01-01

    management of parkland trees by the farmers. Positive changes are observed in savannas (2.5 ± 5.4) and woodland areas (3.9 ± 7.3). The major pattern of woody cover change reveals strong increases in the sparsely populated Sahel zones of eastern Senegal, western Mali and central Chad, but a decreasing trend......Woody plants play a major role for the resilience of drylands and in peoples' livelihoods. However, due to their scattered distribution, quantifying and monitoring woody cover over space and time is challenging. We develop a phenology driven model and train/validate MODIS (MCD43A4, 500 m) derived...... metrics with 178 ground observations from Niger, Senegal and Mali to estimate woody cover trends from 2000 to 2014 over the entire Sahel. The annual woody cover estimation at 500 m scale is fairly accurate with an RMSE of 4.3 (woody cover %) and r2 = 0.74. Over the 15 year period we observed an average...

  13. Coupled hydrogeomorphic and woody-seedling responses to controlled flood releases in a dryland river

    Science.gov (United States)

    Wilcox, Andrew C.; Shafroth, Patrick B.

    2013-01-01

    Interactions among flow, geomorphic processes, and riparian vegetation can strongly influence both channel form and vegetation communities. To investigate such interactions, we took advantage of a series of dam-managed flood releases that were designed in part to maintain a native riparian woodland system on a sand-bed, dryland river, the Bill Williams River, Arizona, USA. Our resulting multiyear flow experiment examined differential mortality among native and nonnative riparian seedlings, associated flood hydraulics and geomorphic changes, and the temporal evolution of feedbacks among vegetation, channel form, and hydraulics. We found that floods produced geomorphic and vegetation responses that varied with distance downstream of a dam, with scour and associated seedling mortality closer to the dam and aggradation and burial-induced mortality in a downstream reach. We also observed significantly greater mortality among nonnative tamarisk (Tamarix) seedlings than among native willow (Salix gooddingii) seedlings, reflecting the greater first-year growth of willow relative to tamarisk. When vegetation was small early in our study period, the effects of vegetation on flood hydraulics and on mediating flood-induced channel change were minimal. Vegetation growth in subsequent years resulted in stronger feedbacks, such that vegetation's stabilizing effect on bars and its drag effect on flow progressively increased, muting the geomorphic effects of a larger flood release. These observations suggest that the effectiveness of floods in producing geomorphic and ecological changes varies not only as a function of flood magnitude and duration, but also of antecedent vegetation density and size.

  14. Rethinking the critical zone in drylands: It's the small things that count

    Science.gov (United States)

    Belnap, Jayne

    2016-04-01

    In most ecosystems, ecologists define the "critical zone" as the soil region where the majority of plant roots are concentrated. Thus, for instance, the critical zone in forested ecosystems is considered as the top several meters of soil. I propose a new way of thinking for deserts: that the critical zone is not where plant roots are found but is instead where the surface poikilohydric organisms are found: that is, just above, on, or within the top few centimeters of rock or soil surfaces. This extremely thin veneer of life is critical in almost every ecosystem process in deserts, including weathering, C and N cycles, dust capture, bio-availability of P and metals, decomposition, and soil stability. In addition, as these communities cover most soil and rock surfaces, they mediate almost all inputs (water, gases, and nutrients) and outputs (gases) to underlying strata. They also facilitate delivery of C and nutrients from the soil interspace to plants. The direct connection between lithic communities and soil surface BSC communities and the connection between BSCs living in the nutrient-rich soil surface zone and nearby vascular plants may be a critical process unique to dryland ecosystems.

  15. Drought hazard and desertification management in the drylands of Southern Africa.

    Science.gov (United States)

    Msangi, J P

    2004-12-01

    Droughts have been occurring persistently in southern African dryland regions for over a century. The impacts of droughts on people, their domesticated animals, wildlife, rangelands and cropped lands have been shown to be astronomical. If left alone the rangelands often recover after the calamity, however human occupation has led to irreversible damage. Even though some communities have evolved viable and sustainable coping mechanisms, recent times have seen weakened coping strategies leading to loss of life in most of the 10 countries in southern Africa. While land degradation has many inter-related causes and effects, drought-related effects have proven most difficult to manage and/or overcome. Drought-related land degradation or desertification poses a huge threat to sustainable land and resource management in the region. The paper examines appropriate drought mitigating initiatives, linking them to land tenure and land management practices. Numerous interventions targeted at reducing poverty and improvement in resource management have failed to achieve desired effects due to rigidity and imposition, and failure of the external interveners to recognise and incorporate indigenous peoples' preferences and coping strategies. Non-governmental organisations and authorities' willingness to institute drought and desertification combating measures are reviewed, highlighting the role that community action plays in reducing adverse effects in the region. Linkages to trade patterns that perpetuate poverty and unwise use of resources are discussed. Adopting 'people centred' mitigating measures is emphasised. Success rests with both the people in the 'south' and those in the 'north'. What is required is an informed global action.

  16. Wind Farm Control Survey

    DEFF Research Database (Denmark)

    Knudsen, Torben; Bak, Thomas; Svenstrup, Mikael

    2013-01-01

    This document is a delivery in the project NORCOWE. It is part of work package WP3.2.2. The main goal is to establish the present state-of-the-art for wind farm control for both research and practice. The main approach will be to study the literature. This will of cause be much more efficient...... for the research part than for the practice part. It is however not the intention to do company interviews or similar. This report is structured into a section for each WF control objective. These sections then includes the important control project issues: choice of input and output, control method, and modelling...... used for controller design and simulation respectively. A short section then discusses published literature from industry. Finally a conclusion is given discussing established results, open challenges and necessary research. An appendix present a method for optimising the energy in a one row wind...

  17. Biomass plantations - energy farming

    Energy Technology Data Exchange (ETDEWEB)

    Paul, S.

    1981-02-01

    Mounting oil import bills in India are restricting her development programmes by forcing the cutting down of the import of other essential items. But the countries of the tropics have abundant sunlight and vast tracts of arable wastelands. Energy farming is proposed in the shape of energy plantations through forestry or energy cropping through agricultural media, to provide power fuels for transport and the industries and also to provide fuelwoods for the domestic sector. Short rotation cultivation is discussed and results are given of two main species that are being tried, ipil-ipil and Casuarina. Evaluations are made on the use of various crops such as sugar cane, cassava and kenaf as fuel crops together with hydrocarbon plants and aquatic biomass. (Refs. 20)

  18. Global changes in dryland vegetation dynamics (1988–2008 assessed by satellite remote sensing: comparing a new passive microwave vegetation density record with reflective greenness data

    Directory of Open Access Journals (Sweden)

    N. Andela

    2013-10-01

    Full Text Available Drylands, covering nearly 30% of the global land surface, are characterized by high climate variability and sensitivity to land management. Here, two satellite-observed vegetation products were used to study the long-term (1988–2008 vegetation changes of global drylands: the widely used reflective-based Normalized Difference Vegetation Index (NDVI and the recently developed passive-microwave-based Vegetation Optical Depth (VOD. The NDVI is sensitive to the chlorophyll concentrations in the canopy and the canopy cover fraction, while the VOD is sensitive to vegetation water content of both leafy and woody components. Therefore it can be expected that using both products helps to better characterize vegetation dynamics, particularly over regions with mixed herbaceous and woody vegetation. Linear regression analysis was performed between antecedent precipitation and observed NDVI and VOD independently to distinguish the contribution of climatic and non-climatic drivers in vegetation variations. Where possible, the contributions of fire, grazing, agriculture and CO2 level to vegetation trends were assessed. The results suggest that NDVI is more sensitive to fluctuations in herbaceous vegetation, which primarily uses shallow soil water, whereas VOD is more sensitive to woody vegetation, which additionally can exploit deeper water stores. Globally, evidence is found for woody encroachment over drylands. In the arid drylands, woody encroachment appears to be at the expense of herbaceous vegetation and a global driver is interpreted. Trends in semi-arid drylands vary widely between regions, suggesting that local rather than global drivers caused most of the vegetation response. In savannas, besides precipitation, fire regime plays an important role in shaping trends. Our results demonstrate that NDVI and VOD provide complementary information and allow new insights into dryland vegetation dynamics.

  19. Progress towards the use of publicly available data networks to conduct cross-scale historical reconstructions of carbon dynamics in US Drylands

    Science.gov (United States)

    Washington-Allen, R. A.; Landolt, K.; Emanuel, R. E.; Therrell, M. D.; Nagle, N.; Grissino-Mayer, H. D.; Poulter, B.

    2016-12-01

    Emergent scale properties of water-limited or Dryland ecosystem's carbon flux are unknown at spatial scales from local to global and time scales of 10 - 1000 years or greater. The width of a tree ring is a metric of production that has been correlated with the amount of precipitation. This relationship has been used to reconstruct rainfall and fire histories in the Drylands of the southwestern US. The normalized difference vegetation index (NDVI) is globally measured by selected satellite sensors and is highly correlated with the fraction of solar radiation which is absorbed for photosynthesis by plants (FPAR), as well as with vegetation biomass, net primary productivity (NPP), and tree ring width. Publicly available web-based archives of free NDVI and tree ring data exist and have allowed historical temporal reconstructions of carbon dynamics for the past 300 to 500 years. Climate and tree ring databases have been used to spatially reconstruct drought dynamics for the last 500 years in the western US. In 2007, we hypothesized that NDVI and tree ring width could be used to spatially reconstruct carbon dynamics in US Drylands. In 2015, we succeeded with a 300-year historical spatial reconstruction of NPP in California using a Blue Oak tree ring chronology. Online eddy covariance flux tower measures of NPP are well correlated with satellite measures of NPP. This suggests that net ecosystem exchange (NEE = NPP - soil Respiration) could be historically reconstructed across Drylands. Ongoing research includes 1) scaling historical spatial reconstruction to US Drylands, 2) comparing the use of single versus multiple tree ring species (r2 = 68) and 3) use of the eddy flux tower network, remote sensing, and tree ring data to historically spatially reconstruct Dryland NEE.

  20. CDF II production farm project

    Energy Technology Data Exchange (ETDEWEB)

    Baranovski, A.; Benjamin, D.; Cooper, G.; Farrington, S.; Genser, K.; Hou, S.; Hsieh, T.; Kotwal, A.; Lipeles, E.; Murat, P.; Norman, M.; /Fermilab /Duke U. /Taiwan,

    2006-12-01

    We describe the architecture and discuss our operational experience in running the off-line reconstruction farm of the CDFII experiment. The Linux PC-based farm performs a wide set of tasks,ranging from producing calibrations and primary event reconstruction to large scale ntuple production.The farm control software uses a standard Condor toolkit and the data handling part is based on SAM (Sequential Access via Metadata)software.During its lifetime,the CDFII experiment will integrate a large amount of data (several petabytes)and the data processing chain is one of the key components of the successful physics program of the experiment.

  1. 旱地甘蔗品种展示示范总结%Demonstration of Sugarcane Varieties in Dryland

    Institute of Scientific and Technical Information of China (English)

    张永港; 王先; 李翠英; 肖培先; 杨新华; 李嫒甜; 钱文英

    2012-01-01

    According to new-plant demonstration, the result indicated that Dezhe 03-83, Yunzhe 03-103, Dezhe 06-24 were suitable to plant in dryland and Guangdong 60, Yunzhe 99-91, Liucheng 03-182 were suitable in fertile land. Guitang 21 were easily inverted resulting high content of reducing sugar and should be eliminated if seed supply were sufficient. Yunzhe 03-258 were not suitable to plant in dryland because of its low cane yield and low sugar content. Yunzhe 03-422, Dezhe 06-54, Yunrui 05-261 were not suitable to plant in dryland due to their irregularity in stalk diameter and low cane yield.%根据新植试验结果表明:德蔗03-83、云蔗03-103、德蔗06-24 3个品种较适合旱坡地种植;粤糖60号、云蔗99-91、柳城03-182适宜在水肥条件较好的蔗地种植;桂糖21号转化快、还原糖高,在种源充足的情况下建议淘汰;云蔗03-258产量、糖分低,鼠尾现象严重,不适宜旱坡地种植;云蔗03-422、德蔗06-54、云瑞05-261茎径不均匀,产量低,不适宜旱坡地种植.

  2. Climate change-induced vegetation shifts lead to more ecological droughts despite projected rainfall increases in many global temperate drylands

    Science.gov (United States)

    Tietjen, Britta; Schlaepfer, Daniel R.; Bradford, John B.; Laurenroth, William K.; Hall, Sonia A.; Duniway, Michael C.; Hochstrasser, Tamara; Jia, Gensuo; Munson, Seth M.; Pyke, David A.; Wilson, Scott D.

    2017-01-01

    Drylands occur world-wide and are particularly vulnerable to climate change since dryland ecosystems depend directly on soil water availability that may become increasingly limited as temperatures rise. Climate change will both directly impact soil water availability, and also change plant biomass, with resulting indirect feedbacks on soil moisture. Thus, the net impact of direct and indirect climate change effects on soil moisture requires better understanding.We used the ecohydrological simulation model SOILWAT at sites from temperate dryland ecosystems around the globe to disentangle the contributions of direct climate change effects and of additional indirect, climate change-induced changes in vegetation on soil water availability. We simulated current and future climate conditions projected by 16 GCMs under RCP 4.5 and RCP 8.5 for the end of the century. We determined shifts in water availability due to climate change alone and due to combined changes of climate and the growth form and biomass of vegetation.Vegetation change will mostly exacerbate low soil water availability in regions already expected to suffer from negative direct impacts of climate change (with the two RCP scenarios giving us qualitatively similar effects). By contrast, in regions that will likely experience increased water availability due to climate change alone, vegetation changes will counteract these increases due to increased water losses by interception. In only a small minority of locations, climate change induced vegetation changes may lead to a net increase in water availability. These results suggest that changes in vegetation in response to climate change may exacerbate drought conditions and may dampen the effects of increased precipitation, i.e. leading to more ecological droughts despite higher precipitation in some regions. Our results underscore the value of considering indirect effects of climate change on vegetation when assessing future soil moisture conditions in water

  3. What controls dryland soil stability? The surprising importance of biocrusts and their possible sensitivity to climate change

    Science.gov (United States)

    Bowker, M. A.; Belnap, J.; Maestre, F. T.; Chaudhary, V. B.

    2012-04-01

    In drylands of the world, wind and water erosion is controlled by the interplay of erosivity--the propensity of wind and water to move sediment--and erodibility--the mobility of soil particles. Land use can have several impacts on this interplay, particularly by increasing erodibility. Here we examine the system underlying dryland erodibility, which is determined by the interrelationships of inherent soil properties and dynamic biotic features, including plants and their root symbionts and soil biocrusts. We applied structural equation models to 7 datasets from drylands, mostly drawn from the Colorado Plateau of the United States but also from parts of Spain. The datasets spanned spatial resolutions of 25 cm2 up to 2 ha. Our models were able to explain 20-79% of the variation in soil aggregate stability (SAS), an attribute of erodibility. We found: 1. Dynamic biotic attributes tend to be more influential in determining SAS than inherent soil properties; 2. The magnitude of the effect of inherent soil properties on SAS? is remarkably stable among different datasets and scales; 3. Of the dynamic biotic attributes, biocrust abundance was the strongest predictor of SAS in 5 of the 6 datasets in which they were measured; 4. Plants may exert a strong positive effect on SAS, but this effect is highly variable among datasets. Because these dynamic biota are expected to respond to climate change, we can also expect climate change to affect soil erodibility. In a recent spatial modeling effort at the scale of the entire Colorado Plateau, we found that the most informative predictor of biocrust abundance was a negative effect of the ratio of summer to winter precipitation. Because climate projections suggest a decrease in cool season precipitation, and some suggest an increase in summer monsoonal precipitation (with much uncertainty) across the studied areas, the ratio of summer to winter precipitation is likely to increase, and soil erodibility may increase with it.

  4. Understanding Land System Change Through Scenario-Based Simulations: A Case Study from the Drylands in Northern China.

    Science.gov (United States)

    Liu, Zhifeng; Verburg, Peter H; Wu, Jianguo; He, Chunyang

    2017-03-01

    The drylands in northern China are expected to face dramatic land system change in the context of socioeconomic development and environmental conservation. Recent studies have addressed changes of land cover with socioeconomic development in the drylands in northern China. However, the changes in land use intensity and the potential role of environmental conservation measures have yet to be adequately examined. Given the importance of land management intensity to the ecological conditions and regional sustainability, our study projected land system change in Hohhot city in the drylands in northern China from 2013 to 2030. Here, land systems are defined as combinations of land cover and land use intensity. Using the CLUMondo model, we simulated land system change in Hohhot under three scenarios: a scenario following historical trends, a scenario with strong socioeconomic and land use planning, and a scenario focused on achieving environmental conservation targets. Our results showed that Hohhot is likely to experience agricultural intensification and urban growth under all three scenarios. The agricultural intensity and the urban growth rate were much higher under the historical trend scenario compared to those with more planning interventions. The dynamics of grasslands depend strongly on projections of livestock and other claims on land resources. In the historical trend scenario, intensively grazed grasslands increase whereas a large amount of the current area of grasslands with livestock converts to forest under the scenario with strong planning. Strong conversion from grasslands with livestock and extensive cropland to semi-natural grasslands was estimated under the conservation scenario. The findings provide an input into discussions about environmental management, planning and sustainable land system design for Hohhot.

  5. Understanding Land System Change Through Scenario-Based Simulations: A Case Study from the Drylands in Northern China

    Science.gov (United States)

    Liu, Zhifeng; Verburg, Peter H.; Wu, Jianguo; He, Chunyang

    2017-03-01

    The drylands in northern China are expected to face dramatic land system change in the context of socioeconomic development and environmental conservation. Recent studies have addressed changes of land cover with socioeconomic development in the drylands in northern China. However, the changes in land use intensity and the potential role of environmental conservation measures have yet to be adequately examined. Given the importance of land management intensity to the ecological conditions and regional sustainability, our study projected land system change in Hohhot city in the drylands in northern China from 2013 to 2030. Here, land systems are defined as combinations of land cover and land use intensity. Using the CLUMondo model, we simulated land system change in Hohhot under three scenarios: a scenario following historical trends, a scenario with strong socioeconomic and land use planning, and a scenario focused on achieving environmental conservation targets. Our results showed that Hohhot is likely to experience agricultural intensification and urban growth under all three scenarios. The agricultural intensity and the urban growth rate were much higher under the historical trend scenario compared to those with more planning interventions. The dynamics of grasslands depend strongly on projections of livestock and other claims on land resources. In the historical trend scenario, intensively grazed grasslands increase whereas a large amount of the current area of grasslands with livestock converts to forest under the scenario with strong planning. Strong conversion from grasslands with livestock and extensive cropland to semi-natural grasslands was estimated under the conservation scenario. The findings provide an input into discussions about environmental management, planning and sustainable land system design for Hohhot.

  6. Increased temperature and altered summer precipitation have differential effects on biological soil crusts in a dryland ecosystem

    Science.gov (United States)

    Johnson, Shannon L.; Kuske, Cheryl R.; Carney, Travis D.; Housman, David C.; Gallegos-Graves, La Verne; Belnap, Jayne

    2012-01-01

    Biological soil crusts (biocrusts) are common and ecologically important members of dryland ecosystems worldwide, where they stabilize soil surfaces and contribute newly fixed C and N to soils. To test the impacts of predicted climate change scenarios on biocrusts in a dryland ecosystem, the effects of a 2–3 °C increase in soil temperature and an increased frequency of smaller summer precipitation events were examined in a large, replicated field study conducted in the cold desert of the Colorado Plateau, USA. Surface soil biomass (DNA concentration), photosynthetically active cyanobacterial biomass (chlorophyll a concentration), cyanobacterial abundance (quantitative PCR assay), and bacterial community composition (16S rRNA gene sequencing) were monitored seasonally over 2 years. Soil microbial biomass and bacterial community composition were highly stratified between the 0–2 cm depth biocrusts and 5–10 cm depth soil beneath the biocrusts. The increase in temperature did not have a detectable effect on any of the measured parameters over 2 years. However, after the second summer of altered summer precipitation pattern, significant declines occurred in the surface soil biomass (avg. DNA concentration declined 38%), photosynthetic cyanobacterial biomass (avg. chlorophyll a concentration declined 78%), cyanobacterial abundance (avg. gene copies g−1 soil declined 95%), and proportion of Cyanobacteria in the biocrust bacterial community (avg. representation in sequence libraries declined 85%). Biocrusts are important contributors to soil stability, soil C and N stores, and plant performance, and the loss or reduction of biocrusts under an altered precipitation pattern associated with climate change could contribute significantly to lower soil fertility and increased erosion and dust production in dryland ecosystems at a regional scale.

  7. Swimmer’s Shoulder in Athletes: Comparison between Efficacy of Aquatic versus Dry-land Concentric-Eccentric Exercises

    OpenAIRE

    Shah, P.K.; Koley, S.

    2016-01-01

    The purpose of the present study was to examine the level of pain gets reduced whether by dry-land based concentric-eccentric exercises or by the equivalent type of aquatic exercises in the elite swimmers complaining of chronic shoulder pain. Elite swimmers from India of both genders with an age group of 16-30 years were chosen having pain rated as ≤7 on visual analog scale with an exception of Bak’s Grade E provided with an absence of past shoulder surgeries and acute injuries...

  8. Effects of in-water and dryland warm-ups on 50-meter freestyle performance in child swimmer

    OpenAIRE

    Kaya Fatih; Erzeybek Mustafa Said; Biçer Bilal; Meral Tuncay

    2017-01-01

    In this study, effectiveness of 3 warm-up (WU) modes on 50m free style on child swimmers has been evaluated. In repeated-measures counterbalanced design, 10 male swimmers of a local sports club (10-12 ages) have tried out 50m freestyle after each WU on different days. Each WU took 15 minutes and the intensity of WU has been checked over by Borg’s rating of perceived exertion (RPE) 15-point scale. a) no warm-up (NWU): the swimmers sat or laid down for 15 minutes, b) dryland warmup (DWU): conti...

  9. Alluvial flash-flood stratigraphy of a large dryland river: the Luni River, Thar Desert, Western India

    Science.gov (United States)

    Carling, Paul; Leclair, Suzanne; Robinson, Ruth

    2017-04-01

    Detailed descriptions of the fluvial architecture of large dryland rivers are few, which hinders the understanding of stratigraphic development in aggradational settings. The aim of this study was to obtain new generic insight of the fluvial dynamics and resultant stratigraphy of such a river. The novelty of this investigation is that an unusually extensive and deep section across a major active dryland river was logged and the dated stratigraphy related to the behaviour of the discharge regimen. The results should help improve understanding of the stratigraphic development in modern dryland rivers and in characterizing oil, gas and groundwater reservoirs in the dryland geological record more generally. The Luni River is the largest river in the Thar desert, India, but yet details of the channel stratigraphy are sparse. Discharges can reach 14,000 m3s-1 but the bed is dry most of the year. GPS positioning and mm-resolution surveys within a 700m long, 5m deep trench enabled logging and photography of the strata associations, dated using optically-stimulated luminescence (OSL). The deposits consist of planar, sandy, upper-stage plane bed lamination and low-angle stratification, sandwiching less-frequent dune trough cross-sets. Mud clasts are abundant at any elevation. Water-ripple cross-sets or silt-clay layers occur rarely, usually near the top of sections. Aeolian dune cross-sets also appear sparsely at higher elevations. Consequently, the majority of preserved strata are due to supercritical flows. Localized deep scour causes massive collapse and soft-sediment deformation. Scour holes are infilled by rapidly-deposited massive sands adjacent to older bedded-deposits. Within bedform phase diagrams, estimated hydraulic parameters indicate a dominance of the upper-stage plane bed state, but the presence of dune cross-sets is also related to the flood hydrograph. Repeated deep scour results in units of deposition of different OSL ages (50 to 500 years BP) found at

  10. Three-fold embeddedness of farm development

    NARCIS (Netherlands)

    Methorst, R.G.; Roep, D.; Verstegen, J.A.A.M.

    2016-01-01

    Farm development strategy is affected by, and affects, the biophysical and socio-economic context of the farm leading to agri-environmental challenges for farm development. For effective policies and support programmes it is important to understand the drivers for choices farm development. Three-fol

  11. Planning farm succession: how to be successful

    OpenAIRE

    Stephens, Mike

    2011-01-01

    Planning farm succession is really good farm planning in its broadest aspect. Unfortunately very few farmers and their families have devoted sufficient time to working out how the farm business will be transferred. After demonstrating the importance of the farm succession issue, this article goes on to explaining a method of successfully tackling the process.

  12. Organic Farming, Gender, and the Labor Process

    Science.gov (United States)

    Hall, Alan; Mogyorody, Veronika

    2007-01-01

    This paper seeks to explain variations in gender participation in farm production and decision-making through an analysis of organic farm types, sizes, and orientations. Based on both survey and case study data, the analysis shows that female farmers on vegetable farms and mixed livestock/cash crop farms are more likely to be involved in farm…

  13. 7 CFR 718.201 - Farm constitution.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Farm constitution. 718.201 Section 718.201 Agriculture... Reconstitution of Farms, Allotments, Quotas, and Bases § 718.201 Farm constitution. (a) In order to implement... this section. The constitution and identification of land as a farm for the first time and...

  14. Nature Quality in Organic Farming

    DEFF Research Database (Denmark)

    Tybirk, Knud; Alrøe, Hugo; Frederiksen, Pia

    2004-01-01

    Nature quality in relation to farming is a complex field. It involves different traditions and interests, different views of what nature is, and different ways of valuing nature. Furthermore there is a general lack of empirical data on many aspects of nature quality in the farmed landscape....... In this paper we discuss nature quality from the perspective of organic farming, which has its own values and goals in relation to nature – the Ecologist View of Nature. This is in contrast to the Culturist View characteristic of much conventional agriculture and the Naturalist View characteristic...... of the traditional biological approach to nature quality. This threefold distinction forms a framework for exploration of nature quality criteria in the farmed landscape. The traditional work on nature quality has mainly focused on biological interests based on a Naturalist View of Nature. In this paper we...

  15. Push-pull farming systems.

    Science.gov (United States)

    Pickett, John A; Woodcock, Christine M; Midega, Charles A O; Khan, Zeyaur R

    2014-04-01

    Farming systems for pest control, based on the stimulo-deterrent diversionary strategy or push-pull system, have become an important target for sustainable intensification of food production. A prominent example is push-pull developed in sub-Saharan Africa using a combination of companion plants delivering semiochemicals, as plant secondary metabolites, for smallholder farming cereal production, initially against lepidopterous stem borers. Opportunities are being developed for other regions and farming ecosystems. New semiochemical tools and delivery systems, including GM, are being incorporated to exploit further opportunities for mainstream arable farming systems. By delivering the push and pull effects as secondary metabolites, for example, (E)-4,8-dimethyl-1,3,7-nonatriene repelling pests and attracting beneficial insects, problems of high volatility and instability are overcome and compounds are produced when and where required.

  16. Green Care Farms

    Directory of Open Access Journals (Sweden)

    Simone R. de Bruin PhD

    2015-10-01

    Full Text Available Objective: To explore the value of day services at green care farms (GCFs in terms of social participation for people with dementia. Method: Semi-structured interviews were conducted with people with dementia who attended day services at a GCF (GCF group, n = 21, were on a waiting list (WL for day services at a GCF (WL group, n = 12, or attended day services in a regular day care facility (RDCF group, n = 17 and with their family caregivers. Results: People with dementia in the GCF and WL group were primarily males, with an average age of 71 and 76 years, respectively, who almost all had a spousal caregiver. People with dementia in the RDCF group were mostly females with an average age of 85 years, most of whom had a non-spousal caregiver. For both the GCF and RDCF groups, it was indicated that day services made people with dementia feel part of society. The most important domains of social participation addressed by RDCFs were social interactions and recreational activities. GCFs additionally addressed the domains “paid employment” and “volunteer work.” Conclusion: GCFs are valuable in terms of social participation for a particular group of people with dementia. Matching characteristics of adult day services (ADS centers to the preferences and capacities of people with dementia is of importance. Diversity in ADS centers is therefore desirable.

  17. Modelling and interpreting biologically crusted dryland soil sub-surface structure using automated micropenetrometry

    Science.gov (United States)

    Hoon, Stephen R.; Felde, Vincent J. M. N. L.; Drahorad, Sylvie L.; Felix-Henningsen, Peter

    2015-04-01

    Soil penetrometers are used routinely to determine the shear strength of soils and deformable sediments both at the surface and throughout a depth profile in disciplines as diverse as soil science, agriculture, geoengineering and alpine avalanche-safety (e.g. Grunwald et al. 2001, Van Herwijnen et al. 2009). Generically, penetrometers comprise two principal components: An advancing probe, and a transducer; the latter to measure the pressure or force required to cause the probe to penetrate or advance through the soil or sediment. The force transducer employed to determine the pressure can range, for example, from a simple mechanical spring gauge to an automatically data-logged electronic transducer. Automated computer control of the penetrometer step size and probe advance rate enables precise measurements to be made down to a resolution of 10's of microns, (e.g. the automated electronic micropenetrometer (EMP) described by Drahorad 2012). Here we discuss the determination, modelling and interpretation of biologically crusted dryland soil sub-surface structures using automated micropenetrometry. We outline a model enabling the interpretation of depth dependent penetration resistance (PR) profiles and their spatial differentials using the model equations, σ {}(z) ={}σ c0{}+Σ 1n[σ n{}(z){}+anz + bnz2] and dσ /dz = Σ 1n[dσ n(z) /dz{} {}+{}Frn(z)] where σ c0 and σ n are the plastic deformation stresses for the surface and nth soil structure (e.g. soil crust, layer, horizon or void) respectively, and Frn(z)dz is the frictional work done per unit volume by sliding the penetrometer rod an incremental distance, dz, through the nth layer. Both σ n(z) and Frn(z) are related to soil structure. They determine the form of σ {}(z){} measured by the EMP transducer. The model enables pores (regions of zero deformation stress) to be distinguished from changes in layer structure or probe friction. We have applied this method to both artificial calibration soils in the

  18. Long-term tillage and cropping sequence influence on dryland soil aggregate-carbon dynam

    Science.gov (United States)

    Sainju, U.; Tonthat, T.-C.; Jabro, J. D.

    2009-04-01

    Sequestration and transformation of soil C as a result of long-term management practices occur mainly in aggregates. This study evaluated the 21-yr effect of tillage and cropping sequence combinations on dryland soil C sequestration and transformation into various C fractions in aggregates at the 0-20 cm depth in eastern Montana, USA. Tillage and cropping sequences were no-tilled continuous spring wheat (NTCW), spring-tilled continuous spring wheat (STCW), fall- and spring-tilled continuous spring wheat (FSTCW), fall- and spring-tilled spring wheat-barley (1984-1999) followed by spring wheat-pea (2000-2004) (FSTW-B/P), and spring-tilled spring wheat-fallow (STW-F). Carbon fractions were soil organic C (SOC), particulate organic C (POC), microbial biomass C (MBC), and potential C mineralization (PCM). Total amount of crop biomass (stems + leaves) residue returned to soil from 1984 to 2004 was lower in STW-F than in other treatments. Aggregate proportion was greater in NTCW than in FSTCW in 4.75-2.00 mm aggregate-size class at 0-5 cm but was greater in STW-F than in STCW in 2.00-0.25 mm size class at 5-20 cm. The SOC and POC were greater in NTCW and STCW than in STW-F in all aggregate-size classes at 0-5 cm and greater in NTCW than in STW-F in 4.75-2.00 mm and STCW and FSTCW than in STW-F in all aggregate-size classes at 0-5 cm and greater in STCW than in NTCW, FSTCW, and STW-F in 4.75-2.00 mm size class at 5-20 cm. Similarly, MBC was greater in NTCW and STCW than in STW-F in STCW and FSTCW than in STW-F in 4.75-0.25 mm class size at 5-20 cm. No-till increased aggregate proportion and POC but reduced PCM and MBC compared with tilled practices in the continuous spring wheat system in 4.75-2.00 mm size class. Aggregate proportion was greater in 2.00-0.25 mm size class than in other aggregate-size classes. The SOC, POC, and PCM were greater in 4.75-2.00 mm than in <0.25 mm at 0-5 cm but MBC was greater in <0.25 mm than in 4.75-0.25 mm size class at both depths. Reduced

  19. Roy Fuentes: Fuentes Berry Farms

    OpenAIRE

    Rabkin, Sarah

    2010-01-01

    As president of Fuentes Berry Farms, Rogelio (Roy) Fuentes is one of many independent growers producing organic berries for Driscoll’s—a company that was initiated more than a century ago by two strawberry farmers on California’s Central Coast, and has since evolved into an international concern devoted to research, breeding, production, sales and distribution of conventionally and organically farmed strawberries, raspberries, blackberries and blueberries. Driscoll’s CEO Miles Reiter and his ...

  20. Hydroclimatic dynamics in southwestern Romania drylands over the past 50 years

    Science.gov (United States)

    Prăvălie, Remus; Zaharia, Liliana; Bandoc, Georgeta; Petrişor, Alexandru I.; ionuş, Oana; Mitof, Iulian

    2016-08-01

    The present paper examines hydroclimatic dynamics in southwestern Romania drylands, which is one of the country's most heavily affected regions by climate change. The analysis focuses on two of the region's representative catchments (Drincea and Desnatui), covers the past five decades (1961-2009), and is based on climate data (mean monthly and annual climatic water balance values - CWB, expressed in mm) and hydrological data (mean monthly and annual streamflow rate values - SFR, expressed in m3/s). The data were provided by five regional weather stations, i.e., by five gauging stations located within the two catchments. The analysis was conducted on three temporal scales (annual, seasonal and monthly), and used statistical methods, such as Mann-Kendall test/Sen's slope method for trend analysis, and Spearman/Student test for the statistical association between climatic and hydrological parameters. The results indicated an overall increase in climatic water deficit, with direct effects on streamflow reduction. Statistically significant trends (climatic water deficit increase and streamflow decrease) were identified especially in spring (with maximum rate values of (-1.66 mm/yr)/(-81.3 mm/49 yrs), for the CWB, and (-0.02 m3/s/yr)/(-0.9 m3/s/49 yrs), for the SFR). In some cases (mainly in the autumn months) it was found that, while climatic water deficit has decreased, the streamflow rate has increased. Statistical correlations revealed the relationship between the considered hydroclimatic parameters, with a particularly high statistical significance in spring and summer. Weak and inverse correlations between climatic and hydrological parameters can be explained by the role of other factors controlling the streamflow, both natural (soil and lithology) and anthropogenic (wetland drainage, water body conversion, dam and reservoirs building).

  1. Land Degradation States and Trends in the Northwestern Maghreb Drylands, 1998–2008

    Directory of Open Access Journals (Sweden)

    Gabriel del Barrio

    2016-07-01

    Full Text Available States of ecological maturity and temporal trends of drylands in Morocco, Algeria and Tunisia north of 28°N are reported for 1998–2008. The input data were Normalized Difference Vegetation Index databases and corresponding climate fields, at a spatial resolution of 1 km and a temporal resolution of one month. States convey opposing dynamics of human exploitation and ecological succession. They were identified synchronically for the full period by comparing each location to all other locations in the study area under equivalent aridity. Rain Use Efficiency (RUE at two temporal scales was used to estimate proxies for biomass and turnover rate. Biomass trends were determined for every location by stepwise regression using time and aridity as predictors. This enabled human-induced degradation to be separated from simple responses to interannual climate variation. Some relevant findings include large areas of degraded land, albeit improving over time or fluctuating with climate, but rarely degrading further; smaller, but significant areas of mature and reference vegetation in most climate zones; very low overall active degradation rates throughout the area during the decade observed; biomass accumulation over time exceeding depletion in most zones; and negative feedback between land states and trends suggesting overall landscape persistence. Semiarid zones were found to be the most vulnerable. Those results can be disaggregated by country or province. The combination with existing land cover maps and national forest inventories leads to the information required by the two progress indicators associated with the United Nations Convention to Combat Desertification strategic objective to improve the conditions of ecosystems and with the Sustainable Development Goal Target 15.3 to achieve land degradation neutrality. Beyond that, the results are also useful as a basis for land management and restoration.

  2. Evaluation of multiple satellite evaporation products in two dryland regions using GRACE

    KAUST Repository

    Lopez, Oliver

    2015-12-01

    Remote sensing has become a valuable tool for monitoring the water cycle variables in areas that lack the availability of ground-based measurements. Integrating multiple remote sensing-based estimates of evaporation, precipitation, and the terrestrial water storage changes with local measurements of streamflow into a consistent estimate of the regional water budget is a challenge, due to the scale mismatch among the retrieved variables. Evapotranspiration, including soil evaporation, interception losses and canopy transpiration, has received special focus in a number of recent studies that aim to provide global or regional estimates of evaporation at regular time intervals using a variety of remote sensing input. In arid and semi-arid regions, modeling of evaporation is particularly challenging due to the relatively high role of the soil evaporation component in these regions and the variable nature of rainfall events that drive the evaporation process. In this study, we explore the hydrological consistency of remote sensing products in terms of water budget closure and the correlation among spatial patterns of precipitation (P), evaporation (E) and terrestrial water storage, using P-E as a surrogate of water storage changes, with special attention to the evaporation component. The analysis is undertaken within two dryland regions that have presented recent significant changes in climatology (Murray-Darling Basin in Australia) and water storage (the Saq aquifer in northern Saudi Arabia). Water storage changes were derived from the Gravity Recovery and Climate Experiment (GRACE) spherical harmonic (SH) coefficients. Six remote sensing-based evaporation estimates were subtracted from the Global Precipitation Climatology Project (GPCP)-based precipitation estimates and were compared with GRACE-derived water storage changes. Our results suggest that it is not possible to close the water balance by using satellite data alone, even when adopting a spherical harmonic

  3. Revisiting classic water erosion models in drylands: The strong impact of biological soil crusts

    Science.gov (United States)

    Bowker, M.A.; Belnap, J.; Bala, Chaudhary V.; Johnson, N.C.

    2008-01-01

    Soil erosion and subsequent degradation has been a contributor to societal collapse in the past and is one of the major expressions of desertification in arid regions. The revised universal soil loss equation (RUSLE) models soil lost to water erosion as a function of climate erosivity (the degree to which rainfall can result in erosion), topography, soil erodibility, and land use/management. The soil erodibility factor (K) is primarily based upon inherent soil properties (those which change slowly or not at all) such as soil texture and organic matter content, while the cover/management factor (C) is based on several parameters including biological soil crust (BSC) cover. We examined the effect of two more precise indicators of BSC development, chlorophyll a and exopolysaccharides (EPS), upon soil stability, which is closely inversely related to soil loss in an erosion event. To examine the relative influence of these elements of the C factor to the K factor, we conducted our investigation across eight strongly differing soils in the 0.8 million ha Grand Staircase-Escalante National Monument. We found that within every soil group, chlorophyll a was a moderate to excellent predictor of soil stability (R2 = 0.21-0.75), and consistently better than EPS. Using a simple structural equation model, we explained over half of the variance in soil stability and determined that the direct effect of chlorophyll a was 3?? more important than soil group in determining soil stability. Our results suggest that, holding the intensity of erosive forces constant, the acceleration or reduction of soil erosion in arid landscapes will primarily be an outcome of management practices. This is because the factor which is most influential to soil erosion, BSC development, is also among the most manageable, implying that water erosion in drylands has a solution. ?? 2008 Elsevier Ltd.

  4. Ecological strategies predict associations between aquatic and genetic connectivity for dryland amphibians.

    Science.gov (United States)

    Mims, Meryl C; Phillipsen, Ivan C; Lytle, David A; Kirk, Emily E Hartfield; Olden, Julian D

    2015-05-01

    The study of how population genetic structure is shaped by attributes of the environment is a central scientific pursuit in ecology and conservation. But limited resources may prohibit landscape genetics studies for many threatened species, particularly given the pace of current environmental change. Understanding the extent to which species' ecological strategies--their life histories, biology, and behavior-predict patterns and drivers of population connectivity is a critical step in evaluating the potential of multi-taxa inference in landscape genetics. We present results of a landscape genetic study of three dryland amphibians: the canyon treefrog (Hyla arenicolor), red-spotted toad (Anaxyrus punctatus), and Mexican spadefoot (Spea multiplicata). These species characterize a range of ecological strategies, driven primarily by different water dependencies, enabling amphibian survival in arid and semiarid environments. We examined a suite of hypothesized relationships between genetic connectivity and landscape connectivity across species. We found a positive relationship between population differentiation and water dependency, e.g., longer larval development periods and site fidelity for reliable water sources. We also found that aquatic connectivity is important for all species, particularly when considered with topography (slope). The effect of spatial scale varied by species, with canyon treefrogs and Mexican spadefoots characterized by relatively consistent results at different scales in contrast to the stark differences in results for red-spotted toads at different scales. Using ecological information to predict relationships between genetic and landscape connectivity is a promising approach for multi-taxa inference and may help inform conservation efforts where single-species genetic studies are not possible.

  5. Adapting forest to climate change in drylands: the Portuguese case-study

    Science.gov (United States)

    Branquinho, Cristina; Príncipe, Adriana; Nunes, Alice; Kobel, Melanie; Soares, Cristina; Vizinho, André; Serrano, Helena Cristina; Pinho, Pedro

    2017-04-01

    The recent expansion of the semiarid climate to all the region of the south of Portugal and the growing impact of climate change demands local adaptation. The growth of the native forest represents a strategy at the ecosystem level to adapt to climate change since it increases resilience and increases also de delivery of ecosystem services such as the increment of organic matter in the soil, carbon and nitrogen, biodiversity, water infiltration, etc. Moreover, decreases susceptibility to desertification. For that reason, large areas have been reforested in the south of Portugal with the native species holm oak and cork oak but with a low rate of effectiveness. Our goal in this work is to show how the cost-benefit relation of the actions intended to expand the forest of the Portuguese semiarid can be lowered by taking into account the microclimatic conditions and high spatial resolution management. The potential of forest regeneration was modelled at the local and regional level in the semiarid area using information concerning the Potential Solar Radiation. This model gives us the rate of native forest regeneration after a disturbance with high spatial resolution. Based on this model the territory was classified in: i) easy regeneration areas; ii) areas with the need of assisted reforestation, using methods that increase water and soil conservation; iii) areas of difficult reforestation because of the costs. Additionally, a summary of the success of reforestations was made in the historical semiarid since the 60s based on the evaluation of a series of case studies, where we quantified the ecosystem services currently delivered by the reforested ecosystems. We will discuss and propose a strategy for forests to adapt to climate change scenario in dryland Portugal. Acknowledgement: Programa Adapt: financed by EEA Grants and Fundo Português de Carbono and by FCT-MEC project PTDC/AAG-GLO/0045/2014.

  6. Hydroclimatic dynamics in southwestern Romania drylands over the past 50 years

    Indian Academy of Sciences (India)

    Remus Pravalie; Liliana Zaharia; Georgeta Bandoc; Alexandru I Petrisor; Oana Ionus; Iulian Mitof

    2016-08-01

    The present paper examines hydroclimatic dynamics in southwestern Romania drylands, which is one of the country’s most heavily affected regions by climate change. The analysis focuses on two of the region’s representative catchments (Drincea and Desnatui), covers the past five decades (1961–2009), and is basedon climate data (mean monthly and annual climatic water balance values – CWB, expressed in mm) and hydrological data (mean monthly and annual streamflow rate values – SFR, expressed in m$^3$/s). The data were provided by five regional weather stations, i.e., by five gauging stations located within the two catchments. The analysis was conducted on three temporal scales (annual, seasonal and monthly), and used statistical methods, such as Mann–Kendall test/Sen’s slope method for trend analysis, and Spearman/Student test for the statistical association between climatic and hydrological parameters. The results indicated an overall increase in climatic water deficit, with direct effects on streamflow reduction.Statistically significant trends (climatic water deficit increase and streamflow decrease) were identified especially in spring (with maximum rate values of (−1.66 mm/yr)/(−81.3 mm/49 yrs), for the CWB, and (−0.02 m$^3$/s/yr)/(−0.9 m$^3$/s/49 yrs), for the SFR). In some cases (mainly in the autumn months) it was found that, while climatic water deficit has decreased, the streamflow rate has increased. Statistical correlations revealed the relationship between the considered hydroclimatic parameters, with a particularly high statistical significance in spring and summer. Weak and inverse correlations between climatic and hydrological parameters can be explained by the role of other factors controlling the streamflow,both natural (soil and lithology) and anthropogenic (wetland drainage, water body conversion, dam and reservoirs building).

  7. Dryland soil chemical properties and crop yields affected by long-term tillage and cropping sequence.

    Science.gov (United States)

    Sainju, Upendra M; Allen, Brett L; Caesar-TonThat, Thecan; Lenssen, Andrew W

    2015-01-01

    Information on the effect of long-term management on soil nutrients and chemical properties is scanty. We examined the 30-year effect of tillage frequency and cropping sequence combination on dryland soil Olsen-P, K, Ca, Mg, Na, SO4-S, and Zn concentrations, pH, electrical conductivity (EC), and cation exchange capacity (CEC) at the 0-120 cm depth and annualized crop yield in the northern Great Plains, USA. Treatments were no-till continuous spring wheat (Triticum aestivum L.) (NTCW), spring till continuous spring wheat (STCW), fall and spring till continuous spring wheat (FSTCW), fall and spring till spring wheat-barley (Hordeum vulgare L., 1984-1999) followed by spring wheat-pea (Pisum sativum L., 2000-2013) (FSTW-B/P), and spring till spring wheat-fallow (STW-F, traditional system). At 0-7.5 cm, P, K, Zn, Na, and CEC were 23-60% were greater, but pH, buffer pH, and Ca were 6-31% lower in NTCW, STCW, and FSTW-B/P than STW-F. At 7.5-15 cm, K was 23-52% greater, but pH, buffer pH, and Mg were 3-21% lower in NTCW, STCW, FSTCW, FSTW-B/P than STW-F. At 60-120 cm, soil chemical properties varied with treatments. Annualized crop yield was 23-30% lower in STW-F than the other treatments. Continuous N fertilization probably reduced soil pH, Ca, and Mg, but greater crop residue returned to the soil increased P, K, Na, Zn, and CEC in NTCW and STCW compared to STW-F. Reduced tillage with continuous cropping may be adopted for maintaining long-term soil fertility and crop yields compared with the traditional system.

  8. Whole Farm Management to Reduce Nutrient Losses From Dairy Farms: A Simulation Study

    NARCIS (Netherlands)

    Rotz, C.A.; Oenema, J.; Keulen, van H.

    2006-01-01

    Whole-farm simulation provides a tool for evaluating long-term impacts of nutrient conservation technologies and strategies on dairy farms. A farm simulation model was verified to predict the production and nutrient flows of the De Marke experimental dairy farm in the Netherlands. On this farm,

  9. Ships as future floating farm systems?

    Science.gov (United States)

    Moustafa, Khaled

    2016-09-29

    Environmental and agriculture challenges such as severe drought, desertification, sprawling cities and shrinking arable lands in large regions in the world compel us to think about alternative and sustainable farming systems. Ongoing projects to build floating cities in the sea suggest that building specific ships for farming purposes (as farming ships or farming boats) would also be attainable to introduce new farming surfaces and boost food production worldwide to cope with food insecurity issues.

  10. Data Farming in Support of NATO

    Science.gov (United States)

    2014-03-01

    Farming into Decision Support System 5-29 Figure 6-1 The Credo of a Data Farmer and the Realms of Data Farming 6-2 Figure 6-2 Data Farming is Question...Figure 6-1: The Credo of a Data Farmer and the Realms of Data Farming. All 6 realms are covered by a sub-working group of MSG-088 Data Farming. As Figure

  11. Farm Biogas Handbook; Gaardsbiogashandbok

    Energy Technology Data Exchange (ETDEWEB)

    Christensson, Kjell; Bjoernsson, Lovisa; Dahlgren, Stefan; Eriksson, Peter; Lantz, Mikael; Lindstroem, Johanna; Mickelaaker, Maria

    2009-04-15

    A very large share of the total raw material potential for biogas production will be found within the agriculture. The raw material potential of manure in Sweden amounts to 4 - 6 TWh. Within the agriculture there is moreover a big potential in the form of residues from plant cultivation and non-food crops (approximately 7 TWh) that can to be used for biogas production. The potential for biogas production from only residues and manure is around 8-10 TWh. An increased biogas production within the agriculture would give significant environmental effects. Among other things manure, that today is leaking methane gas to the atmosphere, can be fermented, and trough this process the methane losses will be reduced. When the produced biogas replaces fossil fuel, an overall environmental effect will be reached, that is highly significant. This manual deals with biogas plants for agriculture and such plants that do not have extensive transports of different raw materials, as manure, wastes etc. One of the starting points for this manual's set-up is a course plan that Biogas Syd made for the courses they give to farmers, advisors and others. The manual illustrates important aspects in planning and construction of biogas plants, from raw material and technology to dimensioning of plant, use of biogas and planning of local gas grids. We also think it is important to illustrate the legislation that encompasses construction work and operation of a biogas plant. Investment costs are also illustrated, but the book does not give any extensive economic calculations, since we believe that such calculations need their own manual in the form of calculation examples, based on various conditions. The final section is called 'Biogas on farm - from idea to reality' where the entire process from analysis and pre-planning to monitoring and control of plant during operation is briefly described

  12. Urban Land-Cover Change and Its Impact on the Ecosystem Carbon Storage in a Dryland City

    Directory of Open Access Journals (Sweden)

    Yan Yan

    2015-12-01

    Full Text Available Lack of research into the complexity in urban land conversion, and paucity of observational data of soil organic carbon (SOC beneath impervious surface area (ISA limit our understanding of the urbanization effects on carbon (C pools in dryland cities. Employing Landsat TM images acquired in 1990 and 2010, a hybrid classification method consisting of Linear Spectral Mixture Analysis and decision tree classification was applied to retrieve the land cover (water, ISA, greenspace, cropland, and remnant desert of the largest dryland city in China—Urumqi. Based on vegetation carbon (VEGC and SOC density data determined through field observations and literature reviews, we developed Urumqi’s C pool maps in 1990 and 2010, and assessed the urbanization impacts on ecosystem C. Our results showed that ISA tripled from 1990 to 2010 displacing remnant desert and cropland. The urban landscape, especially the greenspaces, became obviously fragmented. In 2010, more than 95% of the urban ecosystem C was SOC, 48% of which under the ISA. The city lost 19% of C stock from 1990 to 2010. About 82% of the ecosystem C loss was caused by the conversion of remnant desert and cropland into ISA, mainly in the northern city.

  13. Riparian plant composition along hydrologic gradients in a dryland river basin and implications for a warming climate

    Science.gov (United States)

    Reynolds, Lindsay; Shafroth, Patrick B.

    2017-01-01

    Droughts in dryland regions on all continents are expected to increase in severity and duration under future climate projections. In dryland regions, it is likely that minimum streamflow will decrease with some perennial streams shifting to intermittent flow under climate-driven changes in precipitation and runoff and increases in temperature. Decreasing base flow and shifting flow regimes from perennial to intermittent could have significant implications for stream-dependent biota, including riparian vegetation. In this study, we asked, how do riparian plant communities vary along wet-to-dry hydrologic gradients on small (first–third order) streams? We collected data on geomorphic, hydrologic, and plant community characteristics on 54 stream sites ranging in hydrology from intermittent to perennial flow across the Upper Colorado River Basin (284,898 km2). We found that plant communities varied along hydrologic gradients from high to low elevation between streams, and perennial to intermittent flow. We identified indicator species associated with different hydrologic conditions and suggest how plant communities may shift under warmer, drier conditions. Our results indicate that species richness and cover of total, perennial, wetland, and native plant groups will decrease while annual plants will increase under drying conditions. Understanding how plant communities respond to regional drivers such as hydroclimate requires broad-scale approaches such as sampling across whole river basins. With increasingly arid conditions in many regions of the globe, understanding plant community shifts is key to understanding the future of riparian ecosystems.

  14. Climatic and Socioeconomic Determinants of the Supply and Demand of Net Primary Production in sub-Saharan Drylands

    Science.gov (United States)

    Abdi, A.

    2015-12-01

    Around two-thirds of Africa's inhabitants live in drylands and rely on multifaceted livelihoods involving rain-fed agriculture, cash crops, pastoralism, and livestock production. A large portion of dryland sub-Saharan Africa is under the influence of global climatic teleconnections that produces variability in the Earth's climate. Areas where the vegetation has a strong response to climatic variability clearly exhibit the relationship between human well-being and the climate system. We define NPP supply as the annual amount of carbon that plants remove from the atmosphere through photosynthesis and store as biomass, and NPP demand is the annual amount of carbon required for food, feed and fuel and it drives land use changes such as the expansion of cropland, wood fuel extraction and pasture creation. In this poster, we present preliminary evidence to show that global climatic teleconnections regulate the NPP supply in Africa, while NPP demand increase as a function of demographic growth. Our results point to a scenario whereby the demand for NPP could outpace available supply. Increased climatic variability and extreme events could potentialy tilt this balance further by reducing NPP supply through intense droughts and floods.

  15. Effect of farming practices and farm history on incidence of coconut ...

    African Journals Online (AJOL)

    Effect of farming practices and farm history on incidence of coconut lethal yellowing in Mozambique. ... African Crop Science Journal ... to investigate the impact of farming practices and related history, on the CLYD incidence in Mozambique.

  16. Environmental factors affecting the accuracy of surface fluxes from a two-source model in Mediterranean drylands: Upscaling instantaneous to daytime estimates

    DEFF Research Database (Denmark)

    Morillas, Laura; Villagarcia, Luis; Domingo, Francisco;

    2014-01-01

    The temperature-based two-source model (TSM) of Norman et al. (1995) has not been properly evaluated under the water stress conditions that are typical in natural Mediterranean drylands. In such areas, the asynchrony between precipitation and energy supply strongly reduces evapotranspiration, E (...

  17. Global warming likely reduces crop yield and water availability of the dryland cropping systems in the U.S. central Great Plains

    Science.gov (United States)

    We investigated impacts of GCM-projected climate change on dryland crop rotations of wheat-fallow and wheat-corn-fallow in the Central Great Plains (Akron in Colorado, USA) using the CERES 4.0 crop modules in RZWQM2. The climate change scenarios for CO2, temperature, and precipitation were produced ...

  18. Revisiting the paper “Using radiometric surface temperature for surface energy flux estimation in Mediterranean drylands from a two-source perspective”

    DEFF Research Database (Denmark)

    Kustas, William P.; Nieto, Hector; Morillas, Laura

    2016-01-01

    The recent paper by Morillas et al. [Morillas, L. et al. Using radiometric surface temperature for surface energy flux estimation in Mediterranean drylands from a two-source perspective, Remote Sens. Environ. 136, 234–246, 2013] evaluates the two-source model (TSM) of Norman et al. (1995) with re...

  19. CleverFarm final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-09-15

    Wind turbine technology has ventured in recent years from prototypes and first deployments towards large power plant scale projects. With this, also the ownership structure of wind farms changed: from single farmers to cooperatives, and to large multi-national developers specialised in building and running wind power projects. At the same time, the best sites for wind energy were already taken, leading to more remote sites and offshore sites being developed. Both these developments lead to an increased wish for remote monitoring of turbines. Ideally, the turbine would know on its own accord when it would need maintenance, and call the maintenance crew autonomously. The crew then would have all the information they need to have before they go out to the turbine and do the necessary tasks. Having knowledge of the type of fault that has happened would help the maintenance crew to deal with it efficiently. This also could mean to wait until the next scheduled maintenance is due. The potential savings for this alone are considerable, if you think of the plans for offshore wind farms tens of kilometres from the coast, where access would probably be by helicopter. The idea behind this project was to take the existing techniques developed for optimising and enhancing the performance of wind farms, integrate them into one system and implement the system at a number of wind farms. The techniques include remote measuring of the status and production of the wind farm, short-term prediction of the expected wind speeds at and power output from the wind farm, models for wake calculations, remote control of wind farm production and so on. (au)

  20. CleverFarm final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-09-15

    Wind turbine technology has ventured in recent years from prototypes and first deployments towards large power plant scale projects. With this, also the ownership structure of wind farms changed: from single farmers to cooperatives, and to large multi-national developers specialised in building and running wind power projects. At the same time, the best sites for wind energy were already taken, leading to more remote sites and offshore sites being developed. Both these developments lead to an increased wish for remote monitoring of turbines. Ideally, the turbine would know on its own accord when it would need maintenance, and call the maintenance crew autonomously. The crew then would have all the information they need to have before they go out to the turbine and do the necessary tasks. Having knowledge of the type of fault that has happened would help the maintenance crew to deal with it efficiently. This also could mean to wait until the next scheduled maintenance is due. The potential savings for this alone are considerable, if you think of the plans for offshore wind farms tens of kilometres from the coast, where access would probably be by helicopter. The idea behind this project was to take the existing techniques developed for optimising and enhancing the performance of wind farms, integrate them into one system and implement the system at a number of wind farms. The techniques include remote measuring of the status and production of the wind farm, short-term prediction of the expected wind speeds at and power output from the wind farm, models for wake calculations, remote control of wind farm production and so on. (au)

  1. Diagnosis of GLDAS LSM based aridity index and dryland identification for socioeconomic aspect of water resources management

    Science.gov (United States)

    Ghazanfari, S.; Pande, S.; Hashemy, M.; Naseri M., M.

    2012-04-01

    Water resources scarcity plays an important role in socioeconomic aspect of livelihood pattern in dryland areas. Hydrological perspective of aridity is required for social and economic coping Strategies. Identification of dryland areas is crucial to guide policy aimed at intervening in water stressed areas and addressing its perennial livelihood or food insecurity. Yet, prevailing aridity indices are beset with methodological limitations that restrict their use in delineating drylands and, might be insuffient for decision making frameworks. Palmer's Drought Severity index (PDSI) reports relative soil moisture deviations from long term means, which does not allow cross comparisons, while UNEP's aridity index, the ratio of annual evaporative demand to rainfall supply, ignores site specific soil and vegetation characteristics that are needed for appropriate water balance assessment. We propose to refine UNEP's aridity index by accounting for site specific soil and vegetation to partition precipitation into competing demands of evaporation and runoff. We create three aridity indices at a 1 x 1 degree spatial resolution based on 3 decades of soil moisture time series from three GLDAS Land Surface Models (LSM's): VIC, MOSAIC and NOAH. We compare each LSM model aridity map with the UNEP aridity map which was created based on LSM data forcing. Our approach is to extract the first Eigen function from Empirical Orthogonal Function (EOF) analysis that represents the dominant spatial template of soil moisture conditions of the three LSM's. Frequency of non-exceedence of this dominant soil moisture mode for a location by all other locations is used as our proposed aridity index. The EOF analysis reveals that the first Eigen function explains, respectively, 33%, 43% and 47% of the VIC, NOAH and MOSAIC models. The temporal coefficients associated with the first OF (Orthogonal Function) for all three LSMS clearly show seasonality with a discrete jump in trend around the year 1999

  2. TOPFARM wind farm optimization tool

    Energy Technology Data Exchange (ETDEWEB)

    Rethore, P.-E.; Fuglsang, P.; Larsen, Torben J.; Buhl, T.; Larsen, Gunner C.

    2011-02-15

    A wind farm optimization framework is presented in detail and demonstrated on two test cases: 1) Middelgrunden and 2) Stags Holt/Coldham. A detailed flow model describing the instationary flow within a wind farm is used together with an aeroelastic model to determine production and fatigue loading of wind farm wind turbines. Based on generic load cases, the wind farm production and fatigue evaluations are subsequently condensed in a large pre-calculated database for rapid calculation of lifetime equivalent loads and energy production in the optimization loop. The objective function defining the optimization problem includes elements as energy production, turbine degradation, operation and maintenance costs, electrical grid costs and foundation costs. The objective function is optimized using a dedicated multi fidelity approach with the locations of individual turbines in the wind farm spanning the design space. The results are over all satisfying and are giving some interesting insights on the pros and cons of the design choices. They show in particular that the inclusion of the fatigue loads costs give rise to some additional details in comparison with pure power based optimization. The Middelgrunden test case resulted in an improvement of the financial balance of 2.1 M Euro originating from a very large increase in the energy production value of 9.3 M Euro mainly counterbalanced by increased electrical grid costs. The Stags Holt/Coldham test case resulted in an improvement of the financial balance of 3.1 M Euro. (Author)

  3. Strengthening Voices: How patoralist communities and local government are shaping strategies for adaptive environmental management and poverty reduction in Tanzania's drylands

    Energy Technology Data Exchange (ETDEWEB)

    Jode, Helen de; Hesse, Ced

    2011-06-15

    Across Tanzania, climate change is being felt in the changing patterns and intensity of rainfall, and in the growing unpredictability of the seasons. The drylands are being increasingly affected, and there is an urgent need to strengthen institutional capacity and good governance for drylands planning. Pastoralism provides over 90% of the meat and milk products consumed nationally in Tanzania. The pastoralist production system successfully exploits and adapts to the disequilibrium in the dryland ecosystems, but pastoralist voices are frequently excluded from the decision-making and management of dryland resources. The marginalisation of pastoralists is resulting in falling production levels. Since 2007, IIED, the Kimmage Development Studies Centre and the Tanzania Natural Resource Forum have been undertaking a project with their partners with the specific goal of generating more informed and equitable discussion and debate on pastoralism. Using local government reform processes, the 'Strengthening Voices' project works at the community, local government and national levels - addressing the lack of knowledge and power imbalances within all three. The central pillar of the project is a training course on the economic and ecological processes at the heart of pastoral systems — clarifying the rationale that underpins livelihood strategies. National politicians, local district officials and community participants have all benefited from the training. At the end of its 1st three-year phase good progress has been made in designing and implementing tools and approaches that promote citizen access to decision-making. With their new evidence, training and advocacy skills, people are now better able to inform policy of the economic and environmental benefits of dryland livelihood systems. This booklet and accompanying DVD explain the background to the project, its achievements, and how it plans to build on its successes to roll out the project to other districts in Tanzania

  4. Global changes in dryland vegetation dynamics (1988–2008 assessed by satellite remote sensing: combining a new passive microwave vegetation density record with reflective greenness data

    Directory of Open Access Journals (Sweden)

    N. Andela

    2013-05-01

    Full Text Available Drylands, covering nearly 30% of the global land surface, are characterized by high climate variability and sensitivity to land management. Here, two satellite observed vegetation products were used to study the long-term (1988–2008 vegetation changes of global drylands: the widely used reflective-based Normalized Difference Vegetation Index (NDVI and the recently developed passive-microwave-based Vegetation Optical Depth (VOD. The NDVI is sensitive to the chlorophyll concentrations in the canopy and the canopy cover fraction, while the VOD is sensitive to vegetation water content of both leafy and woody components. Therefore it can be expected that using both products helps to better characterize vegetation dynamics, particularly over regions with mixed herbaceous and woody vegetation. Linear regression analysis was performed between antecedent precipitation and observed NDVI and VOD independently to distinguish the contribution of climatic and non-climatic drivers in vegetation variations. Where possible, the contributions of fire, grazing, agriculture and CO2 level to vegetation trends were assessed. The results suggest that NDVI is more sensitive to fluctuations in herbaceous vegetation, which primarily use shallow soil water whereas VOD is more sensitive to woody vegetation, which additionally can exploit deeper water stores. Globally, evidence is found for woody encroachment over drylands. In the arid drylands, woody encroachment seems to be at the expense of herbaceous vegetation and a global driver is interpreted. Trends in semi-arid drylands vary widely between regions, suggesting that local rather than global drivers caused most of the vegetation response. In savannas, besides precipitation, fire regime plays an important role in shaping trends. Our results demonstrate that NDVI and VOD provide complementary information, bringing new insights on vegetation dynamics.

  5. Vegetation change in dryland environments: understanding changes in fluvial fluxes via changes in hydrological connectivity

    Science.gov (United States)

    Puttock, A.; Brazier, R. E.; Dungait, J. A. J.; Bol, R.; Macleod, C. J. A.

    2012-04-01

    Dryland environments are estimated to cover around 40% of the global land surface (Okin et al, 2009) and are home to approximately 2.5 billion people (Reynolds et al. 2007). Many of these areas have recently experienced extensive land degradation. One such area and the focus of this project is the semi-arid US Southwest, where degradation over the past 150 years has been characterised by the invasion of woody vegetation into grasslands. The transition from grass to woody vegetation results in a change in ecosystem structure and function (Turnbull et al, 2008). Structural change is typically characterised by an increased heterogeneity of soil and vegetation resources, associated with reduced vegetation coverage. Functional change is characterised by an increased vulnerability to soil erosion and the potential loss of key nutrients to adjacent fluvial systems. Such loss of resources may impact heavily upon the amount of carbon that is sequestered by these environments and the amount of carbon that is lost as the land becomes more degraded. Therefore, understanding these vegetation transitions is significant for sustainable land use and global biogeochemical cycling. Connectivity is a key concept in understanding the hydrological response to this vegetation change, with reduced vegetation coverage in woody environments being associated with longer and more connected overland flow pathways. This increase in hydrological connectivity results in an accentuated rainfall-runoff response and increased fluvial fluxes of eroded sediment and associated soil organic carbon and other nutrients. This project uses an ecohydrological approach, characterising ecological structure and monitoring natural rainfall-runoff events over bounded plots with different vegetation covering the transitions from C4 pure-grass (Bouteloua eriopoda) to C3 creosote (Larrea tridentate) shrubland and C3 piñon-juniper (Pinus edulis-Juniperus monosperma) mixed stand woodland. Data collected quantifies

  6. Aerodynamic roughness length estimation with lidar and imaging spectroscopy in a shrub-dominated dryland

    Science.gov (United States)

    Li, Aihua; Zhao, Wenguang; Mitchell, Jessica J; Glenn, Nancy F; Germino, Matthew; Sankey, Joel B.; Allen, Richard G

    2017-01-01

    The aerodynamic roughness length (Z0 m) serves an important role in the flux exchange between the land surface and atmosphere. In this study, airborne lidar (ALS), terrestrial lidar (TLS), and imaging spectroscopy data were integrated to develop and test two approaches to estimate Z0 m over a shrub dominated dryland study area in south-central Idaho, USA. Sensitivity of the two parameterization methods to estimate Z0 m was analyzed. The comparison of eddy covariance-derived Z0 m and remote sensing-derived Z0 m showed that the accuracy of the estimated Z0 m heavily depends on the estimation model and the representation of shrub (e.g., Artemisia tridentata subsp. wyomingensis) height in the models. The geometrical method (RA1994) led to 9 percent (~0.5 cm) and 25% (~1.1 cm) errors at site 1 and site 2, respectively, which performed better than the height variability-based method (MR1994) with bias error of 20 percent and 48 percent at site 1 and site 2, respectively. The RA1994 model resulted in a larger range of Z0 m than the MR1994 method. We also found that the mean, median and 75th percentiles of heights (H75) from ALS provides the best Z0 m estimates in the MR1994 model, while the mean, median, and MLD (Median Absolute Deviation from Median Height), as well as AAD (Mean Absolute Deviation from Mean Height) heights from ALS provides the best Z0 m estimates in the RA1994 model. In addition, the fractional cover of shrub and grass, distinguished with ALS and imaging spectroscopy data, provided the opportunity to estimate the frontal area index at the pixel-level to assess the influence of grass and shrub on Z0m estimates in the RA1994 method. Results indicate that grass had little effect on Z0 m in the RA1994 method. The Z0 m estimations were tightly coupled with vegetation height and its local variance for the shrubs. Overall, the results demonstrate that the use of height and fractional cover from remote sensing data are promising

  7. Alignment between values of dryland pastoralists and conservation needs for small mammals.

    Science.gov (United States)

    Addison, Jane; Pavey, Chris R

    2017-04-01

    Policies for conservation outside protected areas, such as those designed to address the decline in Australian mammals, will not result in net improvements unless they address barriers to proenvironmental behavior. We used a mixed-methods approach to explore potential value-action gaps (disconnects between values and subsequent action) for small mammal conservation behaviors among pastoralists in dryland Australia. Using semistructured surveys and open-ended interviews (n = 43), we explored values toward small mammals; uptake of a range of current and intended actions that may provide benefit to small mammals; and potential perceived barriers to their uptake. Pastoralists assigned great conservation value to small mammals; over 80% (n = 36) agreed to strongly agreed that small mammals on their property were important. These values did not translate into stated willingness to engage in voluntary cessation of wild-dog control (r(2) = 0.187, p = 0.142, n = 43). However, assigning great conservation value to small mammals was strongly related to stated voluntary willingness to engage in the proenvironmental behavior most likely to result in benefits to small mammals: cat and fox control (r(2) = 0.558, p = 0.000, n = 43). There was no significant difference between stated voluntarily and incentivized willingness to engage in cat and fox control (p = 0.862, n = 43). The high levels of willingness to engage in voluntary cat and fox control highlight a potential entry point for addressing Australia's mammal declines because the engagement of pastoralists in conservation programs targeting cat and fox control is unlikely to be prevented by attitudinal constraints. Qualitative data suggest there is likely a subpopulation of pastoralists who value small mammals but do not wish to engage in formal conservation programs due to relational barriers with potential implementers. A long-term commitment to engagement with pastoralists by implementers will thus be necessary for

  8. Farm animal proteomics - A review

    DEFF Research Database (Denmark)

    Bendixen, Emøke; Danielsen, Marianne; Hollung, Kristin

    2011-01-01

    in large-scale operations, with the aim to obtain animal products for human consumption. Hence, understanding the biological traits that impact yield and quality of these products is the specific aim of much biological experimentation. However, most of the data gathered from experiments on e.g. swine......In agricultural sciences as in all other areas of life science, the implementation of proteomics and other post-genomic tools is an important step towards more detailed understanding of the complex biological systems that control physiology and pathology of living beings. Farm animals are raised...... and cattle are relevant not only for farm animal sciences, but also for adding to our understanding of complex biological mechanisms of health and disease in humans. The aim of this review is to present an overview of the specific topics of interest within farm animal proteomics, and to highlight some...

  9. Challenges in wind farm optimization

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.

    for the wind turbine modeling, where aeroelastic models are required, and for the wind farm flow field description, where in-stationary flow field modeling is needed to capture the complicated mixture of atmospheric boundary layer (ABL) flows and upstream emitted meandering wind turbine wakes, which together...... dictates the fatigue loading of the individual wind turbines. Within an optimization context, the basic challenge in describing the in-stationary wind farm flow field is computational speed. The Dynamic Wake Meandering (DWM) model includes the basic features of a CFD Large Eddy Simulation approach...

  10. Social-insect fungus farming

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Boomsma, Jacobus Jan

    2006-01-01

    Which social insects rear their own food? Growing fungi for food has evolved twice in social insects: once in new-world ants about 50 million years ago; and once in old-world termites between 24 and 34 million years ago [1] and [2] . The termites domesticated a single fungal lineage - the extant...... the farming insects with most of their food ( Figure 1 ). No secondary reversals to the ancestral life style are known in either group, which suggests that the transitions to farming were as drastically innovative and irreversible as when humans made this step about 10,000 years ago....

  11. Succession Planning in Australian Farming

    Directory of Open Access Journals (Sweden)

    John Hicks

    2012-11-01

    Full Text Available The theme of this paper is that succession planning in Australian farming is under-developed.It may be linked to economic and social change which suggests that farmers need to adapt togenerational change but this is being resisted or ignored. The implications of this are the slowdecline of family farming, a poor transfer of skills and knowledge to subsequent generationsof farmers in some parts of the agricultural sector and the potential for an extension of thefinancial services industry to develop a more effective raft of succession planning measuresto mitigate the effects of a traditional approach to succession in agriculture.

  12. To what extent does organic farming rely on nutrient inflows from conventional farming?

    Science.gov (United States)

    Nowak, Benjamin; Nesme, Thomas; David, Christophe; Pellerin, Sylvain

    2013-12-01

    Organic farming is increasingly recognized as a prototype for sustainable agriculture. Its guidelines ban the use of artificial fertilizers. However, organic farms may import nutrients from conventional farming through material exchanges. In this study, we aimed at estimating the magnitude of these flows through the quantification of nitrogen, phosphorus and potassium inflows from conventional farming to organic farming. Material inflows and outflows were collected for two cropping years on 63 farms. The farms were located in three French agricultural districts distributed over a gradient of farming activity defined by both the stocking rate and the ratio of the farm area under arable crops. Our results showed that on average, inflows from conventional farming were 23%, 73% and 53% for nitrogen, phosphorus and potassium, respectively. These inflows were strongly determined by the farm production systems. However, for farms similar in terms of production systems, the inflows also depended on the local context, such as the proximity of organic livestock farms: the reliance of organic farming on conventional farming was lower in mixed than in specialized districts. These results highlight the necessity to quantify the contribution of nutrient inflows from conventional farming when assessing organic farming and development scenarios.

  13. Assessing farm animal welfare without visiting the farm

    DEFF Research Database (Denmark)

    Sørensen, Jan Tind; Houe, Hans; Sandøe, Peter;

    Animal welfare is typically assessed on farms by external observers making systematic observations of animals and/or the environment. External observers are costly, and efforts to minimize the time spent by external observers are giving rise to a delicate discussion of priorities of costs, validi...

  14. Attitude and acceptance of offshore wind farms

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Möller, B.

    2011-01-01

    Generally people are more positive towards offshore wind farms compared to on-land wind farms. However, the attitudes are commonly assumed to be independent of experience with wind farms. Important relations between attitude and experience might therefore be disregarded. The present paper gives...... a novel contribution to this field. First of all, we give a thorough review of the studies that have analysed the relation between experience with wind turbines and attitude. In addition, we supplement the review by analysing the effect of travel distance to the nearest offshore wind farm and the wind...... farms attributes on attitude towards offshore wind farms. The results point towards that the travel time and the attributes of the nearest offshore wind farm influence the attitude significantly. Travel time has mixed effects on the attitude, whilst offshore wind farms with many turbines generate more...

  15. Determinants of farm diversification in the Netherlands

    NARCIS (Netherlands)

    Meraner, M.; Heijman, W.J.M.; Kuhlman, J.W.; Finger, R.

    2015-01-01

    Farm diversification has been prominently supported by agricultural policy makers aiming to support rural development. To increase the understanding of determinants influencing diversification and hence to increase the efficiency of policies aiming to support farm diversification this paper presents

  16. Wakes in large offshore wind farms

    DEFF Research Database (Denmark)

    Berthelmie, Rebecca J.; Frandsen, Sten Tronæs; Rathmann, Ole

    2008-01-01

    Power losses due to wind turbine wakes are of the order of 10 and 20% of total power output in large wind farms. The focus of this research carried out within the EC funded UPWIND project is wind speed and turbulence modelling for large wind farms/wind turbines in complex terrain and offshore...... is for five turbines in flat terrain. Finally a complex terrain wind farm will be modelled and compared with observations. For offshore wind farms, the focus is on cases at the Horns Rev wind farm which indicate wind farm models require modification to reduce under-prediction of wake losses while CFD models...... in order to optimise wind farm layouts to reduce wake losses and loads. For complex terrain, a set of three evaluations is underway. The first is a model comparison for a Gaussian Hill where CFD models and wind farm models are being compared for the case of one hilltop wind turbine. The next case...

  17. Entomology: A Bee Farming a Fungus.

    Science.gov (United States)

    Oldroyd, Benjamin P; Aanen, Duur K

    2015-11-16

    Farming is done not only by humans, but also by some ant, beetle and termite species. With the discovery of a stingless bee farming a fungus that provides benefits to its larvae, bees can be added to this list.

  18. Organic farming improves pollination success in strawberries.

    Science.gov (United States)

    Andersson, Georg K S; Rundlöf, Maj; Smith, Henrik G

    2012-01-01

    Pollination of insect pollinated crops has been found to be correlated to pollinator abundance and diversity. Since organic farming has the potential to mitigate negative effects of agricultural intensification on biodiversity, it may also benefit crop pollination, but direct evidence of this is scant. We evaluated the effect of organic farming on pollination of strawberry plants focusing on (1) if pollination success was higher on organic farms compared to conventional farms, and (2) if there was a time lag from conversion to organic farming until an effect was manifested. We found that pollination success and the proportion of fully pollinated berries were higher on organic compared to conventional farms and this difference was already evident 2-4 years after conversion to organic farming. Our results suggest that conversion to organic farming may rapidly increase pollination success and hence benefit the ecosystem service of crop pollination regarding both yield quantity and quality.

  19. Organic farming improves pollination success in strawberries.

    Directory of Open Access Journals (Sweden)

    Georg K S Andersson

    Full Text Available Pollination of insect pollinated crops has been found to be correlated to pollinator abundance and diversity. Since organic farming has the potential to mitigate negative effects of agricultural intensification on biodiversity, it may also benefit crop pollination, but direct evidence of this is scant. We evaluated the effect of organic farming on pollination of strawberry plants focusing on (1 if pollination success was higher on organic farms compared to conventional farms, and (2 if there was a time lag from conversion to organic farming until an effect was manifested. We found that pollination success and the proportion of fully pollinated berries were higher on organic compared to conventional farms and this difference was already evident 2-4 years after conversion to organic farming. Our results suggest that conversion to organic farming may rapidly increase pollination success and hence benefit the ecosystem service of crop pollination regarding both yield quantity and quality.

  20. Biogas and Bioethanol Production in Organic Farming

    DEFF Research Database (Denmark)

    Oleskowicz-Popiel, Piotr

    The thesis consists of two parts. First one is an introduction providing background information on organic farming, ethanol and anaerobic digestion processes, and concept of on‐farm bioenergy production. Second part consists of 8 papers....

  1. 7 CFR 761.103 - Farm assessment.

    Science.gov (United States)

    2010-01-01

    ... Agency assesses each farming operation to determine the applicant's financial condition, organizational structure, management strengths and weaknesses, appropriate levels of Agency oversight, credit counseling... assessment must evaluate, at a minimum, the: (1) Farm organization and key personnel qualifications; (2) Type...

  2. Keeping Noise Down on the Farm

    Science.gov (United States)

    ... Do > Keeping Noise Down on the Farm Keeping Noise Down on the Farm SHARE Some people may ... risks permanent hearing damage. Take steps to reduce noise from machinery. Keep machinery running smoothly by replacing ...

  3. Flexible Exchange of Farming Device Data

    DEFF Research Database (Denmark)

    Iftikhar, Nadeem; Pedersen, Torben Bach

    2011-01-01

    A new trend in the farming business is to replace conventional farming devices with computerized farming devices. Accordingly, numerous computer-based farming devices for logging, processing and exchanging data have recently been installed on moving farm machinery such as tractors. The exchange...... of data generally takes place between the devices and farming systems, mostly installed at the premises of farmers, contractors, advisory services etc. In most cases, data exchange is based on farming data exchange standards and is bi-directional. Bi-directional data exchange allows different devices...... and systems to exchange data based on a predefined set of rules. In consequence, many hand-coded data exchange solutions have been developed in the farming business. Although efforts regarding incorporating data exchange standards have been made, their actual usage so far has been limited, due to the fact...

  4. Problems associated with shellfish farming.

    Science.gov (United States)

    Chinabut, S; Somsiri, T; Limsuwan, C; Lewis, S

    2006-08-01

    Shellfish culture is a major sector of aquaculture production worldwide, and zoonoses and drug residues associated with shellfish farm practice are of concern to public health. This paper focuses on three of the most important shellfish species: molluscs, crabs and shrimp. Although many diseases can affect shellfish, they do not appear to be transmittable to humans. Rather, the main hazards are associated with the methods used to farm the different species. The risk to human health from shellfish most commonly relates to contamination by biotoxins produced by marine algae. Another well-recognised problem associated with shellfish culture is the contamination of shellfish with domestic sewage that contains human pathogenic bacteria and viruses, which causes diseases such as typhoid fever and hepatitis. In shrimp farming, the main potential food safety hazards are zoonoses, chemical contamination and veterinary drug residues. Untreated effluent from shrimp farms is a major concern to the environmental sector as it is known to promote plankton blooms if directly discharged into natural water sources.

  5. Consumer perceptions of farmed fish

    NARCIS (Netherlands)

    Reinders, Machiel J.; Banović, Marija; Guerrero, Lluis; Krystallis, Athanasios

    2016-01-01

    Purpose – The purpose of this paper is to investigate possible cross-cultural consumer segments
    in the EU aquaculture market and provide direction and focus for marketing strategies for farmed
    fish products.
    Design/methodology/approach – Selected psychographic constructs (i.e. category i

  6. The Roots of "Animal Farm".

    Science.gov (United States)

    Schaefer, Barbara E.

    The presentation of the book "Animal Farm" by George Orwell to sophomores at East Orange Catholic High School, New Jersey, as a "political document" is discussed. Through research, panel discussions and voluntary comments, the students studied the book in depth comparing it to the power struggle between Stalin and Trotsky in…

  7. Consumer perceptions of farmed fish

    NARCIS (Netherlands)

    Reinders, Machiel J.; Banović, Marija; Guerrero, Lluis; Krystallis, Athanasios

    2016-01-01

    Purpose – The purpose of this paper is to investigate possible cross-cultural consumer segments
    in the EU aquaculture market and provide direction and focus for marketing strategies for farmed
    fish products.
    Design/methodology/approach – Selected psychographic constructs (i.e. category

  8. Imagining the ideal dairy farm.

    Science.gov (United States)

    Cardoso, Clarissa S; Hötzel, Maria José; Weary, Daniel M; Robbins, Jesse A; von Keyserlingk, Marina A G

    2016-02-01

    Practices in agriculture can have negative effects on the environment, rural communities, food safety, and animal welfare. Although disagreements are possible about specific issues and potential solutions, it is widely recognized that public input is needed in the development of socially sustainable agriculture systems. The aim of this study was to assess the views of people not affiliated with the dairy industry on what they perceived to be the ideal dairy farm and their associated reasons. Through an online survey, participants were invited to respond to the following open-ended question: "What do you consider to be an ideal dairy farm and why are these characteristics important to you?" Although participants referenced social, economic, and ecological aspects of dairy farming, animal welfare was the primary issue raised. Concern was expressed directly about the quality of life for the animals, and the indirect effect of animal welfare on milk quality. Thus participants appeared to hold an ethic for dairy farming that included concern for the animal, as well as economic, social, and environmental aspects of the dairy system.

  9. Farm and Ranch Financial Statements

    OpenAIRE

    Israelsen, Clark; Feuz, Dillon

    2014-01-01

    This fact sheet is a brief overview of the financial statements and budgeting tools that are likely a part of most farm financial record keeping systems. Links are provided for additional detail on any one financial report or topic. A brief description of a Balance Sheet, a Profit Loss Statement or Income Statement, Statement of Cash Flows and Enterprise Analysis is included.

  10. Farm size and growth in field crop and dairy farms in France, Hungary and Slovenia

    Directory of Open Access Journals (Sweden)

    Z. Bakucs

    2013-09-01

    Full Text Available The aim of this article is to investigate the relationship between size and farm growth. The existing theories of the association between size and farm growth give mixed results by countries and over time. This paper pursues a twofold objective: on one hand, to test the validity of Gibrat’s Law for French, Hungarian and Slovenian specialized dairy and crop farms during the pre- and post-accession period to the European Union membership. Dairy and crops farms are prevailing in the farming structure of these countries. Using Farm Accountancy Data Network datasets makes it necessary to avoid biases due to heterogeneous structures across the farming systems. Thus we use quantile regressions to control for farm size related heterogeneity in the samples. On the other hand, the main novelty of this paper is the comparative analysis of the relationship between farm size and farm growth between transition Hungarian and Slovenian and non-transition French farming sectors, characterized by rather different farm structures. The results reject the validity of Gibrat’s Law for crop farms in Hungary and to a lesser extent in France, and for French and Slovenian dairy farms. We provide evidence that smaller farms grew faster than larger ones over the studied period 2001-2007 for France, 2001-2008 for Hungary, and 2004-2008 for Slovenia. Conversely, the results for Slovenia suggest that the rate of growth of crop farms in terms of its land is independent from its size.

  11. Whole farm management to reduce nutrient losses from dairy farms: a simulation study

    NARCIS (Netherlands)

    Rotz, C.A.; Oenema, J.; Keulen, van H.

    2003-01-01

    Whole farm simulation provides a tool for evaluating the impact of nutrient conservation technologies and strategies on dairy farms. A farm simulation model was verified by simulating the production and nutrient flows of the De Marke experimental dairy farm in the Netherlands. Technology such as a

  12. Farm population of the United States: 1986.

    Science.gov (United States)

    Deare, D; Kalbacher, J Z

    1987-11-01

    This report presents annual estimates of selected social and economic characteristics of the farm population in 1986. Also included are fertility characteristics from the June 1986 Current Population Survey (CPS) and data from the March 1986 CPS supplement. The Census Bureau and the Economic Research Service of the Department of Agriculture prepared the farm population estimates for 1986 from CPS data. Highlights of the data follow. 1) About 5,226,000 persons lived on farms in rural areas of the US in 1986. About 1 of 46 persons, or 2.2% of the nation's population, had a farm residence in 1986, compared to 30.2% in 1920. The farm population consists of persons living on farms in rural areas of the country; it does not include residents of the small number of farms in urban areas. 2) No statistically significant change in the number of farm residents occurred between 1985 and 1986. 3) Half of all farm residents now live in the Midwest. The Southern farm population has rapidly declined to just 29% of the national total; its 11% loss over the last year made it the only 1 of the 4 geographic regions to experience a significant change in number of farm residents. 4) About 1/4 (1.3 million) of the farm population live in metropolitan areas, while 3/4 live in non metropolitan areas. 5) In 1986, 97% of farm residents were white, 2% black, and 2% hispanic. 6) The median age of rural farm residents was 37 years in 1986, which is significantly higher than the median of 31.6 years for the non-farm production. There were 110 men/100 women living on farms in 1986, compared with just 93 men/100 women in the nonfarm population. 7) About 69% of farm residents 15+ were married and living with a spouse, compared with 56% of nonfarm residents. 8) About 87% of farm households were made up of families; the comparable proportion of nonfarm families was 72%. The average size of the farm family is 3.18 members compared to 3.21 members/nonfarm family. 9) The number of children born to ever

  13. Making Investments in Dryland Development Work: Participatory Scenario Planning in the Makanya Catchment, Tanzania

    Directory of Open Access Journals (Sweden)

    Elin I. Enfors

    2008-12-01

    Full Text Available The agro-ecosystems of semi-arid and dry sub-humid SSA are inherently dynamic. At this point in time they are also experiencing a series of complex social-ecological changes that make their future even more uncertain. To ensure that development investments made today in the small-scale farming systems that dominate these regions make sense also in a long-term perspective they should benefit the local communities over a range of potential futures. We applied a participatory scenario planning approach to a smallholder farming community in semi-arid Tanzania, exploring four alternative development trajectories for the area, to increase the robustness of current investments in small-scale water system technologies. We found that water system technologies will be important across a number of possible futures, but that the most relevant target of these innovations, e.g., staple- versus cash-crop production, or individual- versus community-managed systems, differs. We argue that building capacity for experimentation among farmers is key to upgrading their farming systems, as this will generate benefits over a range of alternative futures. Furthermore, we found it to be essential across a range of scenarios to analyze the system-level impact of proposed interventions for successful investments in water system technologies. We conclude that although the method presents some challenges, participatory scenario planning is a useful tool for integrating research and development projects in the larger context, asit increases the understanding of events and processes that may either challenge the project or provide opportunities for it.

  14. Reliability evaluation for offshore wind farms

    DEFF Research Database (Denmark)

    Zhao, Menghua; Blåbjerg, Frede; Chen, Zhe

    2005-01-01

    In this paper, a new reliability index - Loss Of Generation Ratio Probability (LOGRP) is proposed for evaluating the reliability of an electrical system for offshore wind farms, which emphasizes the design of wind farms rather than the adequacy for specific load demand. A practical method...... to calculate LOGRP of offshore wind farms is proposed and evaluated....

  15. Fish benefits from offshore wind farm development

    DEFF Research Database (Denmark)

    Leonhard, Simon B.; Stenberg, Claus; Støttrup, Josianne

    2013-01-01

    The studies up until 2006 showed few effects on the fish fauna that could be attributed to the establishment and operation of the wind farms. Fish abundance and diversity were not higher inside the wind farms than in the areas outside the wind farms. One obvious reason for this could be that the ...

  16. Roundfish monitoring Princess amalia Wind Farm

    NARCIS (Netherlands)

    Hal, van R.

    2013-01-01

    This report describes the results of field work in the Princess Amalia Wind Farm (in Dutch: Prinses Amaliawindpark, or PAWP). It is to realize the requirements of the Monitoring and Evaluation Program, which is part of the Wbr-permit of the wind farm. The objective is to determine if the wind farm f

  17. Farming in the city of Nairobi

    NARCIS (Netherlands)

    Foeken, D.W.J.; Mboganie-Mwangi, A.

    1998-01-01

    This paper describes urban farming in Nairobi, Kenya: its magnitude and characteristics, its importance for those involved, the constraints faced by urban farmers, the impact of urban farming on the environment, the legal and institutional setting, and the prospects for urban farming. The paper is b

  18. Do farm audits improve milk quality?

    NARCIS (Netherlands)

    Flores-Miyamoto, A.; Reij, M.W.; Velthuis, A.G.J.

    2014-01-01

    Milk quality is assessed using bulk milk analysis and by farm audits in the Netherlands. However, the extent of the effect that dairy farm audits have on milk quality is unknown. Data from over 13,000 audits performed on 12,855 dairy farms from February 2006 to April 2008 were merged with laboratory

  19. Missouri Small Farm Family Program. Revised.

    Science.gov (United States)

    Enlow, George; And Others

    Records maintained by rural extension designees on the Missouri Small Farm Family Program, (initiated in 1972 by the cooperative extension service to help low income farm families learn to use available resources to improve their quality of life) provided data re: family characteristics, farm improvement progress, and improvement in the quality of…

  20. Capital adjustment patterns on Dutch pig farms

    NARCIS (Netherlands)

    Gardebroek, C.

    2004-01-01

    This paper develops a generalised adjustment cost framework that explicitly accounts for zero investments on Dutch pig farms. A farm-specific flexible adjustment cost function is used to account for differences in adjustment costs between farms. Using the Generalised Method of Moments the Euler equa

  1. Effects of rainfall intensity and intermittency on woody vegetation cover and deep soil moisture in dryland ecosystems

    Science.gov (United States)

    Zhang, Ding-Hai; Li, Xin-Rong; Zhang, Feng; Zhang, Zhi-Shan; Chen, Yong-Le

    2016-12-01

    Identifying the relationship between the stochastic daily rainfall regime and the dynamics of plants and soil moisture is fundamental for the sustainable management of dryland ecosystems in a context of global climate change. An eco-hydrological model that couples the dynamics of woody vegetation cover and deep soil moisture (typically with a depth interval of 30-150 cm) was used to investigate the effect of stochastic intensity and the intermittency of precipitation on soil moisture in this deep interval, which affects woody vegetation cover. Our results suggest that the precipitation intensity and intermittency play an important role in the dynamics of wood vegetation cover and deep soil moisture. In arid and semiarid regions, as the annual precipitation increased, the rate of woody vegetation cover increased as a power-law function, and the deep soil moisture increased exponentially. For a given annual rainfall, there were positive correlations between the rainfall intensity (or rainfall intermittency) and both the woody vegetation cover and deep soil moisture. The positive correlations between wood vegetation cover and both rainfall intensity and intermittency may decrease with increases in the precipitation intensity or precipitation intermittency. The positive correlations between deep soil moisture and both rainfall intensity and rainfall intermittency increase as the precipitation intensity or precipitation intermittency increases. Moreover, these positive correlations may increase with increases in the mean annual rainfall. Our results emphasize the importance of daily precipitation variations in controlling the responses of woody vegetation cover and deep soil moisture to climate variations in arid and semiarid regions. Our model can aid the understanding of rainfall processes and indicates that increases in rainfall intensity or rainfall intermittency may lead to an increase in woody vegetation cover and deep soil moisture given an invariable annual

  2. Quantifying drylands' drought resistance and recovery: the importance of drought intensity, dominant life history and grazing regime.

    Science.gov (United States)

    Ruppert, Jan C; Harmoney, Keith; Henkin, Zalmen; Snyman, Hennie A; Sternberg, Marcelo; Willms, Walter; Linstädter, Anja

    2015-03-01

    Projected global change will increase the level of land-use and environmental stressors such as drought and grazing, particularly in drylands. Still, combined effects of drought and grazing on plant production are poorly understood, thus hampering adequate projections and development of mitigation strategies. We used a large, cross-continental database consisting of 174 long-term datasets from >30 dryland regions to quantify ecosystem responses to drought and grazing with the ultimate goal to increase functional understanding in these responses. Two key aspects of ecosystem stability, resistance to and recovery after a drought, were evaluated based on standardized and normalized aboveground net primary production (ANPP) data. Drought intensity was quantified using the standardized precipitation index. We tested effects of drought intensity, grazing regime (grazed, ungrazed), biome (grassland, shrubland, savanna) or dominant life history (annual, perennial) of the herbaceous layer to assess the relative importance of these factors for ecosystem stability, and to identify predictable relationships between drought intensity and ecosystem resistance and recovery. We found that both components of ecosystem stability were better explained by dominant herbaceous life history than by biome. Increasing drought intensity (quasi-) linearly reduced ecosystem resistance. Even though annual and perennial systems showed the same response rate to increasing drought intensity, they differed in their general magnitude of resistance, with annual systems being ca. 27% less resistant. In contrast, systems with an herbaceous layer dominated by annuals had substantially higher postdrought recovery, particularly when grazed. Combined effects of drought and grazing were not merely additive but modulated by dominant life history of the herbaceous layer. To the best of our knowledge, our study established the first predictive, cross-continental model between drought intensity and drought

  3. Integrated approaches to restore gullies in land prone to soil piping: innovations from the drylands of northern Ethiopia

    Science.gov (United States)

    Frankl, Amaury; Deckers, Jozef; Moulaert, Lys; Van Damme, Alexander; Haile, Mitiku; Poesen, Jean; Nyssen, Jan

    2014-05-01

    Multiple on-site and off-site effects of gully erosion threaten sustainable development, which is especially evident in dryland environments. To control soil erosion by gullying, various soil and water conservation measures have been developed, of which check dams are the most common. Where soil piping occurs, soil and water conservation measures have limited effect on gully stabilization, and check dams easily collapse. Therefore, new integrated approaches are needed to control gully erosion induced by soil piping. Here, a subsurface geomembrane dam is proposed as an innovative measure to reduce subsurface flow in soil pipes near gullies. Application of such a dam in Northern Ethiopia, resulted in a decrease of gully erosion rates in Vertisols, and a rising water table in the intergully areas near the gully channel. The consequence of this effect for agriculture near gully channels is the reduction of soil desiccation and hence, increased crop yields in the intergully areas near the gully channels. With the gully filling and stabilizing, runoff water could be diverted into adjacent land, offering additional benefits to the local communities. Here, the runoff diversion was done into a vegetation protection site, in order to enhances biomass production, especially tree growth. Moreover, a water collection pound was created to make water available in the prolonged dry season. These interventions support additional economical activities such as beekeeping and the establishment of a tree nursery. With the multiple on-site and off-site benefits of the integrated approach, local communities have a better guarantee of investment return and livelihood improvement, increasing their support to gully rehabilitation schemes. Keywords: Crop, Subsurface dam, Soil and water conservation, Tree growth, Vertisol, Dryland.

  4. Farm Typology in the Berambadi Watershed (India: Farming Systems Are Determined by Farm Size and Access to Groundwater

    Directory of Open Access Journals (Sweden)

    Marion Robert

    2017-01-01

    Full Text Available Farmers’ production decisions and agricultural practices directly and indirectly influence the quantity and quality of natural resources, some being depleted common resources such as groundwater. Representing farming systems while accounting for their flexibility is needed to evaluate targeted, regional water management policies. Farmers’ decisions regarding investing in irrigation and adopting cropping systems are inherently dynamic and must adapt to changes in climate and agronomic, economic and social, and institutional, conditions. To represent this diversity, we developed a typology of Indian farmers from a survey of 684 farms in Berambadi, an agricultural watershed in southern India (state of Karnataka. The survey provided information on farm structure, the cropping system and farm practices, water management for irrigation, and economic performances of the farm. Descriptive statistics and multivariate analysis (Multiple Correspondence Analysis and Agglomerative Hierarchical Clustering were used to analyze relationships between observed factors and establish the farm typology. We identified three main types of farms: (1 large diversified and productivist farms; (2 small and marginal rainfed farms, and (3 small irrigated marketing farms. This typology represents the heterogeneity of farms in the Berambadi watershed.

  5. 12 CFR 619.9140 - Farm Credit bank(s).

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Farm Credit bank(s). 619.9140 Section 619.9140 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9140 Farm Credit bank(s). Except as otherwise defined, the term Farm Credit bank(s) includes Farm Credit...

  6. Empirical Analysis of Farm Credit Risk under the Structure Model

    Science.gov (United States)

    Yan, Yan

    2009-01-01

    The study measures farm credit risk by using farm records collected by Farm Business Farm Management (FBFM) during the period 1995-2004. The study addresses the following questions: (1) whether farm's financial position is fully described by the structure model, (2) what are the determinants of farm capital structure under the structure model, (3)…

  7. Empirical Analysis of Farm Credit Risk under the Structure Model

    Science.gov (United States)

    Yan, Yan

    2009-01-01

    The study measures farm credit risk by using farm records collected by Farm Business Farm Management (FBFM) during the period 1995-2004. The study addresses the following questions: (1) whether farm's financial position is fully described by the structure model, (2) what are the determinants of farm capital structure under the structure model, (3)…

  8. Health effects of agrochemicals among farm workers in commercial farms of Kwekwe district, Zimbabwe

    OpenAIRE

    Magauzi, Regis; Mabaera, Bigboy; Rusakaniko, Simbarashe; Chimusoro, Anderson; Ndlovu, Nqobile; Tshimanga, Mufuta; Shambira, Gerald; Chadambuka, Addmore; Gombe, Notion

    2011-01-01

    Introduction Farm workers are at a very high risk of occupational diseases due to exposure to pesticides resulting from inadequate education, training and safety systems. The farm worker spends a lot of time exposed to these harmful agrochemicals. Numerous acute cases with symptoms typical of agrochemical exposure were reported from the commercial farms. We assessed the health effects of agrochemicals in farm workers in commercial farms of Kwekwe District (Zimbabwe), in 2006. Methods An analy...

  9. 50 CFR 14.23 - Live farm-raised fish and farm-raised fish eggs.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Live farm-raised fish and farm-raised fish eggs. 14.23 Section 14.23 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF... Exportation at Designated Ports § 14.23 Live farm-raised fish and farm-raised fish eggs. Live farm-raised...

  10. Stability analysis of offshore wind farm and marine current farm

    Science.gov (United States)

    Shawon, Mohammad Hasanuzzaman

    Renewable energy has been playing an important role to meet power demand and 'Green Energy' market is getting bigger platform all over the world in the last few years. Due to massive increase in the prices of fossil fuels along with global warming issues, energy harvesting from renewable energy sources has received considerable interest, nowadays, where extensive researches are going on to ensure optimum use of renewable sources. In order to meet the increasing demand of electricity and power, integration of renewable energy is getting highest priorities around the world. Wind is one of the most top growing renewable energy resources and wind power market penetration is expected to reach 3.35 percent by 2013 from its present market of about 240 GW. A wind energy system is the most environmental friendly, cost effective and safe among all renewable energy resources available. Another promising form of renewable energy is ocean energy which covers 70 % of the earth. Ocean energy can be tapped from waves, tides and thermal elements. Offshore Wind farm (OWF) has already become very popular for large scale wind power integration with the onshore grid. Recently, marine current farm (MCF) is also showing good potential to become mainstream energy sources and already successfully commissioned in United Kingdom. However, squirrel cage induction generator (SCIG) has the stability problem similar to synchronous generator especially during fault location to restore the electromagnetic torque. Series dynamic braking resistor (SDBR) has been known as a useful mean to stabilize fixed speed wind generator system. On the other hand, doubly fed induction generator (DFIG) has the capability of coupling the control of active and reactive power and to provide necessary reactive power demand during grid fault conditions. Series dynamic braking resistor (SDBR) can also be employed with DFIG to limit the rotor over current. An integration of wind and tidal energy represents a new

  11. Farm woodlands for the future. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, P.J.; Brierley, E.D.R.; Morris, J. [eds.] [Cranfield University, Silsoe (United Kingdom). Institute of Water and Environment; Evans, J. [Imperial College, London (United Kingdom). T.H. Huxley School

    1999-07-01

    This book contains the papers presented at the conference on 'Farm Woodlands for the Future' held at Cranfield University on 8-10 September 1999. Topics covered include the socio-economic role of farm woodlands; the value of farm woodlands for shelter, biodiversity and landscape enhancement; the economic value of of farm woodlands; the value of agroforestry, poplar and short rotation coppice; and the promotion of farm woodlands. Of the eighteen papers published in this book, one is abstracted here.

  12. Establishing a benchmarking for fish farming

    DEFF Research Database (Denmark)

    Lasner, Tobias; Brinker, Alexander; Nielsen, Rasmus

    2016-01-01

    The promotion of Blue Growth in aquaculture requires an understanding of the economic drivers influencing the sector at farm level, but the collection of reliable and comparable data at this level is time-consuming and expensive. This study suggests an alternative strategy for qualitative sampling...... German farms profit from local market prices and advanced farm management. Danish farms using recirculating techniques remain competitive thanks to enhanced productivity and economy of scale. However, small traditional farms in Germany and Denmark may struggle to stay competitive in the long term....... Organic farms in both countries face challenges of high feed costs and comparatively low productivity with mixed success. Using edible protein energy return on investment (epEROI) as an indicator of ecological sustainability, all surveyed farms compared very favourably with the terrestrial systems...

  13. Key Succes Factors for Organic Farming Development

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Ramdhani

    2012-07-01

    Full Text Available The aim of this research is to determine the weight from determinant factors in developing organic farming in Garut District, West Java, Indonesia. Determinant factor in the research are determined based on judgment from the respondent. Determinant factors in developing farming are classified by some aspects such as technology, social and politic, economic and environment. The weight of each factor is counted by using weight method based on Analytic Hierarchy Process (AHP Model. The result of synthesis shows that respondents prefer organic farming method than conventional method. However, to implement organic farming extensively needs program or policy support from stakeholders on sub-criteria who tend to make organic farming better. The programs including orientation on quantity improvement in organic farming yield, provision of equipments, and raw materials, farmer’s performance, financial support, provision of market, and decreasing organic farming business risk.

  14. Leverages for on-farm innovation from farm typologies? An illustration for family-based dairy farms in north-west Michoacán, Mexico

    NARCIS (Netherlands)

    Cortez Arriola, J.; Rossing, W.A.H.; Amendola Massiotti, R.D.; Scholberg, J.M.S.; Groot, J.C.J.; Tittonell, P.A.

    2015-01-01

    Knowledge on farm diversity provides insight into differences among farms, enables scaling from individual farm to farm population level and vice versa, and has been used in the definition of recommendation domains for introduction of novel technologies. Farm diversity can be broadly described in te

  15. Leverages for on-farm innovation from farm typologies? An illustration for family-based dairy farms in north-west Michoacán, Mexico

    NARCIS (Netherlands)

    Cortez Arriola, J.; Rossing, W.A.H.; Amendola Massiotti, R.D.; Scholberg, J.M.S.; Groot, J.C.J.; Tittonell, P.A.

    2015-01-01

    Knowledge on farm diversity provides insight into differences among farms, enables scaling from individual farm to farm population level and vice versa, and has been used in the definition of recommendation domains for introduction of novel technologies. Farm diversity can be broadly described in te

  16. Floating VAWT wind farm concepts

    OpenAIRE

    Schmidt Paulsen, Uwe; Friis Pedersen, Troels; Vita, Luca

    2008-01-01

    The report contains proposals and descriptions of VAWTs of 200kW, 1MW, 5MW and 25MW sizes in terms of dimensions, weights, loads, and power production. Additionally a proposal of the use of each of these sizes in a concept description for a 100MW wind farm. Manufacture, transportation, installation, maintenance and operation of VAWTs are considered briefly. A summary on advantages and disadvantages of floating VAWTs is given.

  17. Grid Integration of Wind Farms

    Science.gov (United States)

    Giæver Tande, John Olav

    2003-07-01

    This article gives an overview of grid integration of wind farms with respect to impact on voltage quality and power system stability. The recommended procedure for assessing the impact of wind turbines on voltage quality in distribution grids is presented. The procedure uses the power quality characteristic data of wind turbines to determine the impact on slow voltage variations, flicker, voltage dips and harmonics. The detailed assessment allows for substantially more wind power in distribution grids compared with previously used rule-of-thumb guidelines. Power system stability is a concern in conjunction with large wind farms or very weak grids. Assessment requires the use of power system simulation tools, and wind farm models for inclusion in such tools are presently being developed. A fixed-speed wind turbine model is described. The model may be considered a good starting point for development of more advanced models, hereunder the concept of variable-speed wind turbines with a doubly fed induction generator is briefly explained. The use of dynamic wind farm models as part of power system simulation tools allows for detailed studies and development of innovative grid integration techniques. It is demonstrated that the use of reactive compensation may relax the short-term voltage stability limit and allow integration of significantly more wind power, and that application of automatic generation control technology may be an efficient means to circumvent thermal transmission capacity constraints. The continuous development of analysis tools and technology for cost-effective and secure grid integration is an important aid to ensure the increasing use of wind energy. A key factor for success, however, is the communication of results and gained experience, and in this regard it is hoped that this article may contribute.

  18. The CDF Central Analysis Farm

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.H.; /MIT; Neubauer, M.; /UC, San Diego; Sfiligoi, I.; /Frascati; Weems, L.; /Fermilab; Wurthwein, F.; /UC, San Diego

    2004-01-01

    With Run II of the Fermilab Tevatron well underway, many computing challenges inherent to analyzing large volumes of data produced in particle physics research need to be met. We present the computing model within CDF designed to address the physics needs of the collaboration. Particular emphasis is placed on current development of a large O(1000) processor PC cluster at Fermilab serving as the Central Analysis Farm for CDF. Future plans leading toward distributed computing and GRID within CDF are also discussed.

  19. Branchburg Solar Farm and Carport

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, John [Township of Branchburg, NJ (United States)

    2013-10-23

    To meet the goal of becoming a model of green, clean, and efficient consumer of energy, the Township of Branchburg will install of a 250kw solar farm to provide energy for the Township of Branchburg Municipal Building, a 50kw Solar carport to provide power to the Municipal Annex, purchase 3 plug in hybrid-electric vehicles, and install 3 dual-head charging stations.

  20. Farm cooperation to improve sustainability.

    Science.gov (United States)

    Andersson, Hans; Larsén, Karin; Lagerkvist, Carl-Johan; Andersson, Chrisitian; Blad, Fredrik; Samuelsson, Johan; Skargren, Per

    2005-06-01

    In this paper, it is demonstrated that partnership arrangements between farmers might be a way to secure the economic viability of their farms as well as to increase profitability. The article discusses empirical analyses of three different forms of collaboration, with an emphasis on the environmental improvements associated with collaboration. Collaboration between a dairy farm and a crop farm is analyzed in the first case. The results show that potential gains from improved diversification and crop rotation are substantial, and even larger when the collaboration also involves machinery. The second analysis considers external integration between farrowing and finishing-pig operations. Gains from collaboration originate from biological and technical factors, such as improved growth rate of the pigs and better utilization of buildings. Finally, an evaluation of a group of collaborating crop farmers is performed. In this case, the benefits that arise are mainly due to reduced machinery costs and/or gains due to other factors, such as improved crop rotation and managerial/marketing strategies.

  1. Quality of life and sleep quality are similarly improved after aquatic or dry-land aerobic training in patients with type 2 diabetes: A randomized clinical trial.

    Science.gov (United States)

    S Delevatti, Rodrigo; Schuch, Felipe Barreto; Kanitz, Ana Carolina; Alberton, Cristine L; Marson, Elisa Corrêa; Lisboa, Salime Chedid; Pinho, Carolina Dertzbocher Feil; Bregagnol, Luciana Peruchena; Becker, Maríndia Teixeira; Kruel, Luiz Fernando M

    2017-09-06

    To compare the effects of two aerobic training models in water and on dry-land on quality of life, depressive symptoms and sleep quality in patients with type 2 diabetes. Randomized clinical trial. Thirty-five patients with type 2 diabetes were randomly assigned to aquatic aerobic training group (n=17) or dry-land aerobic training group (n=18). Exercise training length was of 12 weeks, performed in three weekly sessions (45min/session), with intensity progressing from 85% to 100% of heart rate of anaerobic threshold during interventions. All outcomes were evaluated at baseline and 12 weeks later. In per protocol analysis, physical and psychological domains of quality of life improved in both groups (pquality of life and sleep quality improved in both groups (paquatic environment provides similar effects to aerobic training in a dry-land environment on quality of life, depressive symptoms and sleep quality in patients with type 2 diabetes. Clinical trial reg. no. NCT01956357, clinicaltrials.gov. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. Effect of Covering and Fertilizer in Leisure Period on Wintering Wheat Growth under Dryland Condition%休闲期施肥覆盖对旱地小麦越冬期幼苗生长的影响

    Institute of Scientific and Technical Information of China (English)

    任爱霞; 孙敏; 赵维峰; 邓妍; 邓联峰; 高志强

    2011-01-01

    采用大田试验研究了休闲期不同施肥、不同覆盖对旱地小麦越冬期0~20 cm土壤蓄水量、农艺性状、倒二叶POD和SOD活性、MDA含量的影响,从而通过改革耕作技术,达到形成冬前壮苗的目的.结果表明:休闲期施农家肥可增加旱地小麦越冬期0~20 cm土壤蓄水量,可增加越冬期分蘖数、单株干重,显著增加倒二叶的POD、SOD活性,显著降低MDA含量.无论施农家肥与否,0~20 cm土壤蓄水量、单株干重、POD和SOD活性均以渗水地膜覆盖最高,不覆盖显著最低,液态地膜居中,且渗水地膜处理较液态地膜和不覆盖处理可显著增加0~20 cm土壤蓄水量和单株干重;MDA含量以不覆盖最高,液态地膜覆盖居中,渗水地膜覆盖条件处理最低.可见,旱地小麦采用休闲期施农家肥+渗水地膜覆盖的栽培措施有利于提高土壤蓄水量,促进旱地小麦生长.%Field test was carried out to study the effect of different covering and fertilizer in leisure period on soil water storage at the depth of 0-20 cm,on plant growth, and on the activities of POD and SOD, and MDA content in wheat leaves in under dryland condition, thus through the farming technique reformation to form strong wheat before wintering . The results showed that soil water storage at the depth of 0 - 20 cm, tiller numbers and dry weight in plant, POD and SOD activity were increased, and MDA content was decreased under the treatment of the farmyard fertilizer. The results also indicated that the soil water storage at the depth of 0~20 cm, tiller numbers and dry weight in plant, POD and SOD activity were the highest under the treatment of water permeability plastic film mulching (PM), and the lowest under the treatment without covering(CK) among the three treatments. The soil water storage at the depth of 0 - 20 cm and dry weight in plant were significantly increased under the treatment of PM. MDA content was the highest under the treatment of CK

  3. Livestock systems and farming styles in Eastern Italian Alps: an on-farm survey

    Directory of Open Access Journals (Sweden)

    Maurizio Ramanzin

    2010-01-01

    Full Text Available This research aimed to study the relationships between livestock systems, landscape maintenance and farming styles in the Belluno Province, a mountainous area of the Eastern Italian Alps. A total of 65 farms were sampled on the basis of livestock category farmed and herd size. Farms were visited to collect information on technical and productive aspects, on landscape features of land managed, which was identified by aerial photographs and digitised in a GIS environment, and on the farmers’ background, attitudes and approach to farming. Six different livestock systems were identified: intensive beef cattle (2 farms; extensive beef cattle (12 farms; large sheep/goat farms (9 farms; small sheep/goat farms (6 farms; intensive dairy cattle (14 farms and extensive dairy cattle (22 farms. The intensive systems had larger herds, modern structures and equipment, and were strongly production oriented, whereas the extensive systems had smaller herds and productivity, with often traditional or obsolete structures and equipment, but showed a tendency to diversify production by means of on-farm cheese making and/or mixed farming of different livestock categories. The ability to maintain meadows and pastures was greater for the extensive systems, especially in steep areas, while the annual nitrogen output, estimated as kg N/ha, was lower. Data on the farmers’ background and attitudes were analysed with a non-hierarchical cluster procedure that clustered the farmers into 4 farming styles widely different in motivations to farming, innovative capability, and ability to diversify income sources and ensure farm economic viability. The farming styles were distributed across all livestock systems, indicating the lack of a linkage between the assignment of a farm to a livestock system and the way the farm is managed. This study demonstrates that in mountain areas variability of livestock systems may be high, and that they differ not only in production practices

  4. A conceptual framework for dryland aeolian sediment transport along the grassland-forest continuum: Effects of woody plant canopy cover and disturbance

    Science.gov (United States)

    Breshears, David D.; Whicker, Jeffrey J.; Zou, Chris B.; Field, Jason P.; Allen, Craig D.

    2009-04-01

    Aeolian processes are of particular importance in dryland ecosystems where ground cover is inherently sparse because of limited precipitation. Dryland ecosystems include grassland, shrubland, savanna, woodland, and forest, and can be viewed collectively as a continuum of woody plant cover spanning from grasslands with no woody plant cover up to forests with nearly complete woody plant cover. Along this continuum, the spacing and shape of woody plants determine the spatial density of roughness elements, which directly affects aeolian sediment transport. Despite the extensiveness of dryland ecosystems, studies of aeolian sediment transport have generally focused on agricultural fields, deserts, or highly disturbed sites where rates of transport are likely to be greatest. Until recently, few measurements have been made of aeolian sediment transport over multiple wind events and across a variety of types of dryland ecosystems. To evaluate potential trends in aeolian sediment transport as a function of woody plant cover, estimates of aeolian sediment transport from recently published studies, in concert with rates from four additional locations (two grassland and two woodland sites), are reported here. The synthesis of these reports leads to the development of a new conceptual framework for aeolian sediment transport in dryland ecosystems along the grassland-forest continuum. The findings suggest that: (1) for relatively undisturbed ecosystems, shrublands have inherently greater aeolian sediment transport because of wake interference flow associated with intermediate levels of density and spacing of woody plants; and (2) for disturbed ecosystems, the upper bound for aeolian sediment transport decreases as a function of increasing amounts of woody plant cover because of the effects of the height and density of the canopy on airflow patterns and ground cover associated with woody plant cover. Consequently, aeolian sediment transport following disturbance spans the largest

  5. Low soil moisture during hot periods drives apparent negative temperature sensitivity of soil respiration in a dryland ecosystem: A multi-model comparison

    Science.gov (United States)

    Tucker, Colin; Reed, Sasha C.

    2016-01-01

    Arid and semiarid ecosystems (drylands) may dominate the trajectory of biosphere-to-atmosphere carbon (C) flux over the coming century. Accordingly, understanding dryland CO2 efflux controls is important for understanding C cycling at the global-scale: key unknowns regarding how temperature and moisture interact to regulate dryland C cycling remain. Further, the patchiness of dryland vegetation can create ‘islands of fertility’, with spatially heterogeneous rates of soil respiration (Rs). At our study site in southeastern Utah, USA we added or removed litter (0 to 650% of control) in paired plots that were either associated with a shrub or with interspaces between vascular plants. We measured Rs, soil temperature, and water content (θ) on eight sampling dates between October 2013 and November 2014. Rs was highest following monsoon rains in late summer when soil temperature was ~30°C. During mid-summer, Rs was low, associated with high soil temperatures (>40°C), resulting in an apparent negative temperature sensitivity of Rs at high temperatures, and positive temperature sensitivity at low-moderate temperatures. We used Bayesian statistical methods to compare multiple competing models capturing a wide range of hypothesized relationships between temperature, moisture, and Rs. The best fit model indicates apparent negative temperature sensitivity of soil respiration at high temperatures reflects the control of soil moisture – not high temperatures – in limiting Rs. The modeled Q10 ranged from 2.7 at 5°C to 1.4 at 45°C. Litter addition had no effect on temperature sensitivity or reference respiration (Rref = Rs at 20°C and optimum moisture) beneath shrubs, and little effect on Rref in interspaces, yet Rref was 1.5 times higher beneath shrubs than in interspaces. Together, these results suggest reduced Rs often observed at high temperatures in drylands is dominated by the control of moisture, and that variable litter inputs – at least over the short

  6. Restoration of degraded drylands in northern Chile: The need of local stakeholders' participation to prevent and combat desertification

    Science.gov (United States)

    Jorquera-Jaramillo, Carmen; Yáñez-Acevedo, Marcia; Gutiérrez, Julio R.; Cortés-Bugueño, José Luis; Pastén-Marambio, Víctor; Barraza-Cepeda, Claudia

    2015-04-01

    Desertification is one of the main factors determining poverty, long-term socio-economic problems, natural resources depletion and disturbances in rural communities living at the Coquimbo Region drylands (North-Central Chile). The Chilean State, along with private initiatives, have invested 473.6 Million dollars (1976 to 2008) to recover degraded areas through afforestation and soil management of 1,373,758 hectares. However, there is no information about the impact of the practices and changes experienced by the local stakeholders. Therefore, there is a need for a comprehensive evaluation considering both socioeconomic and biophysical aspects. To this end, a Protocol on Integrated Assessment (IAPro, PRACTICE project) was applied in two rural communities, involving communal afforested sites and their adjacent degraded drylands: El Sauce (ES, Limarí province) and Las Cañas (LC, Choapa province), Coquimbo Region. Participatory afforestation and soil conservation projects were implemented at both sites by the Chilean National Forestry Service (CONAF) in agreement with each local community (Jiménez y Tapia Agricultural Community at ES and Las Cañas de Choapa Peasant's Community at LC). The protocol involved 7 steps: (1) Stakeholder platform identification and engagement; (2) Baseline assessment and selection of site-specific indicators; (3) Integration and weighting of common and site-specific indicators; (4) Data collection; (5) Integrating and perspectives on a MCDA (Multi-Criteria Decision Analysis); (6) Collective Integrated assessment and knowledge sharing; (7) Dissemination. Interviews involved local and institutional stakeholders related to both sites' implementation, administration and/or local impacts. For the ES site, 5 actions were defined and assessed: No action (control); fences; mechanic and biological practices (soil stabilization, runoff control on slopes); runoff control in micro-basins, gullies and ravines; and footpath for educational and

  7. Farming in an Agriburban Ecovillage Development

    Directory of Open Access Journals (Sweden)

    Lenore Newman

    2014-12-01

    Full Text Available A growing desire for local food systems has increased interest in peri-urban farming, leading to the rise of agriburban landscapes, in which a desire to farm or to be near farmland is a contributing factor to development patterns. Interviews and site visits to the Yarrow Ecovillage near Vancouver, Canada, outline an example of a development that allows new farmers access to land in a setting with few tensions between farming and non-farming residents in a zone on the edge of a protected agricultural region. Although there are limitations to replication of this model, we suggest that intentional settlements with an agricultural element on the rural/urban fringe could buffer traditional tensions between farm usage and residential usage, while allowing small-scale farmers a place to farm in areas with prohibitively high land values.

  8. An Overview of Offshore Wind Farm Design

    DEFF Research Database (Denmark)

    Giebel, Gregor; Hasager, Charlotte Bay

    2016-01-01

    For offshore wind energy to be viable, the design of wind turbines is not the only important factor—rather, the design of wind farms is also crucial. The current chapter discusses the challenges of designing an optimum wind farm and identifies the various factors that need to be considered. Lastly......, the chapter presents the novel EERA-DTOC tool for designing offshore wind farm clusters....

  9. Farming in the city of Nairobi

    OpenAIRE

    Foeken, D.W.J.; Mboganie-Mwangi, A.

    1998-01-01

    This paper describes urban farming in Nairobi, Kenya: its magnitude and characteristics, its importance for those involved, the constraints faced by urban farmers, the impact of urban farming on the environment, the legal and institutional setting, and the prospects for urban farming. The paper is based on four studies carried out in Nairobi by Diana Lee-Smith et al. (1984-1985), Donald Freeman (1987), Alice Mboganie Mwangi (1994), and Pascale Dennery (1994)

  10. Developmental Tendency of Dry Land Farming Technologies

    Institute of Scientific and Technical Information of China (English)

    SHAN Lun

    2002-01-01

    The developmental tendency of dry land farming technologies in the semiarid area of China were reviewed based on the overview of recent progress in dry land farming researches from China and oversea. It was emphasized that conservation tillage, limited irrigation, genetic modification and chemical control are the important aspects for the dry land farming research and development of the future. In addition, some considerations and suggestions on above-mentioned aspects were proposed in this paper.

  11. Organic Farming Worldwide 2007: Overview & Main Statistics

    OpenAIRE

    Yussefi, Minou; Willer, Helga

    2007-01-01

    The Foundation Ecology & Agriculture SOEL and the Research Institute of Organic Agriculture FiBL have collected data about organic farming worldwide every year since 1999. Since the publication of the 2003 results, IFOAM has collaborated in the project. In an annual yearbook, the data are published together with articles from experts on the development of organic farming in the continents and on other issues related to the global development of organic farming. This chapter summarizes the ...

  12. Provenance discrimination and Source-to-Sink studies from a dryland fluvial regime:An example from Kachchh, western India

    Institute of Scientific and Technical Information of China (English)

    S. P. PRIZOMWALA; Nilesh BHATT; N. BASAVAIAH

    2014-01-01

    Tracing the sediment delivery from its source terrain to its ultimate sink envisage multiple factors that play a vital role in understanding present day erosional engine. To accomplish this, it is significant to distinguish the variable end-members contributing to the basin. The findings from the study of dryland coastal fluvial regime in Kachchh (Western India), which is one of the end members contributing to the Gulf of Kachchh coast (partial sink) and finally to the Arabian Sea (ultimate sink) have been presented here. Multi-proxy sediment provenance proxies such as grain-size, clay minerals, geochemistry and magnetic minerals have been employed to evaluate the provenance discriminating characteristics of the Kachchh dryland fluvial system and factors influencing them. The results of different proxies indicate that the provenance signatures of uplands are quite characteristic with magnetic susceptibility (χ) values of<20 × 10-7 m3 kg-1 and smectite (S)/kaolinite (K) ratio between 0.26 and 0.49. The middle reaches show marked increase in magnetic mineral concentration withχvalues (140 × 10-7 m3 kg-1) and S/K ratio (4.92), while the estuarine tract shows χ values (80 × 10-7m3 kg-1), S/K ratio (1.90) and, characteristic heavy minerals (i.e. mica minerals), probably reflect the interplay between land and sea oscillations. Major sources of sediments within catchment scale were identified, viz., upland sedimentary rocks (Juran and Bhuj Formation sandstone-shale) and middle reaches volcanic (Deccan Trap Formation basalt) rocks. The present study draw cautions in provenance of sediment discrimination in areas influenced by Deccan basalt that has the overwhelming sediment delivery and a comparatively subdued effects of other provenance signatures. The studied proxies of mineralogy of clays, magnetic minerals and geochemistry of heavy and major elements serve as the potential for fingerprint of sediment source regions and hence behold a strong position in source to

  13. The impact of livestock grazing on plant diversity: an analysis across dryland ecosystems and scales in southern Africa.

    Science.gov (United States)

    Hanke, Wiebke; Böhner, Jürgen; Dreber, Niels; Jürgens, Norbert; Schmiedel, Ute; Wesuls, Dirk; Dengler, Jürgen

    2014-07-01

    A general understanding of grazing effects on plant diversity in drylands is still missing, despite an extensive theoretical background. Cross-biome syntheses are hindered by the fact that the outcomes of disturbance studies are strongly affected by the choice of diversity measures, and the spatial and temporal scales of measurements. The aim of this study is to overcome these weaknesses by applying a wide range of diversity measures to a data set derived from identical sampling in three distinct ecosystems. We analyzed three fence-line contrasts (heavier vs. lighter grazing intensity), representing different degrees of aridity (from arid to semiarid) and precipitation regimes (summer rain vs. winter rain) in southern Africa. We tested the impact of grazing intensity on multiple aspects of plant diversity (species and functional group level, richness and evenness components, alpha and beta diversity, and composition) at two spatial scales, and for both 5-yr means and interannual variability. Heavier grazing reduced total plant cover and substantially altered the species and functional composition at all sites. However, a significant decrease in species alpha diversity was detected at only one of the three sites. By contrast, alpha diversity of plant functional groups responded consistently across ecosystems and scales, with a significant decrease at heavier grazing intensity. The cover-based measures of functional group diversity responded more sensitively and more consistently than functional group richness. Beta diversity of species and functional types increased under heavier grazing, showing that at larger scales, the heterogeneity of the community composition and the functional structure were increased. Heavier grazing mostly increased interannual variability of alpha diversity, while effects on beta diversity and cover were inconsistent. Our results suggest that species diversity alone may not adequately reflect the shifts in vegetation structure that occur

  14. Dryland Flood-Irrigation and its Impact on CO2 Production and the Accumulation of Pedogenic Carbonate in West Texas

    Science.gov (United States)

    Ortiz, A. C.; Jin, L.

    2016-12-01

    Agricultural fields in drylands are intensively irrigated. Indeed, pecan orchards at the El Paso, TX region are flooded with over one meter of water per growing season. The waters are usually oversaturated in calcite (CaCO3) and continuous evapotranspiration drives CaCO3 precipitation, releasing CO2. As such, the loading of CaCO3 through flood irrigation in drylands impacts Ca and C cycles greatly. We characterized soil, soil gas and soil water samples to quantify rates of pedogenic carbonate accumulation and CO2 release, identify the sources of C and Ca in pedogenic carbonates, and investigate kinetic and environmental controls of CaCO3 formation. Simple calculations show that up to 112000kg/km2/yr of Ca is loaded onto the fields by irrigation, evidenced by high water-soluble and acid-leachable Ca in soils, especially in clayey soils. We used 87Sr/86Sr ratios to quantify the relative importance of different Ca end-members including flood irrigation. Data show that water-soluble soil leachates have similar 87Sr/86Sr ratios as irrigation waters at depth, but lighter signatures at surface, probably due dust and fertilizer inputs. We measured daily soil-atmosphere CO2 efflux, δ13CCO2 and concentrations of CO2 gas samples at different soil depths between two irrigation events and at two sites with sandy versus clayey soils. These data help determine if sources of soil CO2 change with depth, irrigation event and if CO2 transport is controlled by texture. Correlations of δ13CCO2 and soil CO2 concentrations indicate mixing of organically respired, atmospheric and CaCO3-derived CO2. We found co-variation of δ13CCO2 and soil CO2 with time, where soil CO2 became heavier in carbon isotopes and more abundant in concentrations, illustrating shifts from soil respired CO2, characterized by lighter C, to increased proportions of CaCO3-derived CO2 with heavier C. Efflux data show peak values as soils dried, indicating supersaturation of soil waters and precipitation of pedogenic

  15. Mutually supportive use of stable isotope and gas chromatography techniques to understand ecohydrological interactions in dryland environments

    Science.gov (United States)

    Puttock, A.; Brazier, R. E.; Dungait, J. A. J.; Bol, R.; Dixon, E. R.; Macleod, C. J. A.

    2012-04-01

    Many drylands globally are experiencing extensive vegetation change. In the semi-arid Southwestern United States, this change is characterised by the encroachment of woody vegetation into environments previously dominated by grassland (Van Auken. 2009). The transition from grass to woody vegetation results in a change in ecosystem structure and function (Turnbull et al. 2008). Structural change is typically characterised by an increased heterogeneity of soil and vegetation resources, associated with reduced vegetation coverage and an increased vulnerability to soil erosion and the potential loss of key nutrients to adjacent fluvial systems. This project uses an ecohydrological approach, monitoring natural rainfall-runoff events and resulting water and sediment fluxes over six bounded plots with different vegetation coverage at the Sevilleta National Wildlife Refuge, New Mexico, USA. The experiment takes advantage of a shift in the photosynthetic pathway of dominant vegetation from C3 piñon-juniper (Pinus edulis-Juniperus monosperma) mixed stand through a C4 pure-grass (Bouteloua eriopoda) to C3 shrub (Larrea tridentate). This allows for the utilisation of natural abundance tracing techniques, specifically stable 13C isotope and gas chromatography lipid biomarker analyses. Results collected during the 2010 and 2011 monsoon seasons will be presented, using biogeochemical signatures, to trace and partition fluvial soil organic matter and carbon fluxes during runoff generating rainfall events. Results show that biogeochemical signatures specific to individual plant species can be used to define the provenance of carbon, quantifying whether more Pinus edulis-Juniperus monosperma derived carbon is mobilised from the upland plots, or whether more Larrea tridentata carbon is lost when compared to bouteloa eripoda losses in the lowlands. Results also show that biogeochemical signatures vary with event characteristics, raising the possibility of using these tracing

  16. Landsat and GRACE observations of arid wetland dynamics in a dryland river system under multi-decadal hydroclimatic extremes

    Science.gov (United States)

    Xie, Zunyi; Huete, Alfredo; Ma, Xuanlong; Restrepo-Coupe, Natalia; Devadas, Rakhesh; Clarke, Kenneth; Lewis, Megan

    2016-12-01

    complex dryland river systems. The protracted Millennium Drought from 2001 to 2009 resulted in long-term absence of major flood events, which substantially suppressed wetland vegetation growth. However, the 2010-11 La Niña induced flooding events led to an exceptionally large resurgence of vegetation, with a mean vegetation growth extent anomaly exceeding the historical average (1988-2011) by more than 1.5 standard deviations, suggesting a significant resilience of arid wetland ecosystems to climate variability. This study showed the ecological functioning of arid wetlands is particularly sensitive to large-scale hydrological fluctuations and extreme drought conditions, and vulnerable to future altered water regimes due to climate change. The methods developed herein can be applied to arid wetlands located in other dryland river systems across the globe.

  17. Afvloeiing uit en aanpassing in de landbouw 1968 [Mobility in farming, parttime farming 1968

    NARCIS (Netherlands)

    Weerdenburg, L.

    2007-01-01

    Farm and personnel / successor / attitude to change in modern times / contacts with immigrants / status of farmers / attitude to the farmer's work / motivations to leave farming / work type preferences / expectations for the future / attitude to reconstruction / re-allocations / cooperation / biogra

  18. Afvloeiing uit en aanpassing in de landbouw 1968 [Mobility in farming, parttime farming 1968

    NARCIS (Netherlands)

    Weerdenburg, L.

    1968-01-01

    Farm and personnel / successor / attitude to change in modern times / contacts with immigrants / status of farmers / attitude to the farmer's work / motivations to leave farming / work type preferences / expectations for the future / attitude to reconstruction / re-allocations / cooperation / biogra

  19. Roads used on farm owned by Open Space Institute and leased to Roxbury Farm.

    Data.gov (United States)

    National Park Service, Department of the Interior — This line file represents the major roads used to access Roxbury Farm and the farm fields. This shapefile is part of a project called Biological Surveys at the...

  20. Framework of Multi-objective Wind Farm Controller Applicable to Real Wind Farms

    DEFF Research Database (Denmark)

    Kazda, Jonas; Gögmen, Tuhfe; Giebel, Gregor;

    2016-01-01

    Optimal wind farm control can mitigate adverse wake effects that can potentially cause up to 40% power loss and 80% increased fatigue loads in wind farms. The aim of this work is to outline a methodological framework of an optimal wind farm controller, which provides improved solutions to critical......-objective optimal wind farm controller is outlined with the following key characteristics. Available control objectives are (i) to maximize the total wind farm power output or (ii) to follow a specified power reference for the wind farm’s total power output while reducing the fatigue loads of the wind turbines...... areas of optimal wind farm control research. The basis of this framework is a review of optimal wind farm control methodologies, which is presented first. It is observed that there is, at present, mainly a need for more advanced wind farm operation models. Thereafter the framework of a multi...

  1. Afvloeiing uit en aanpassing in de landbouw 1968 [Mobility in farming, parttime farming 1968

    NARCIS (Netherlands)

    Weerdenburg, L.

    2007-01-01

    Farm and personnel / successor / attitude to change in modern times / contacts with immigrants / status of farmers / attitude to the farmer's work / motivations to leave farming / work type preferences / expectations for the future / attitude to reconstruction / re-allocations / cooperation /

  2. Harmonic Aspects of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz Hubert; Bak, Claus Leth; Hjerrild, Jesper

    2010-01-01

    This paper presents the aim, the work and the findings of a PhD project entitled "Harmonics in Large Offshore Wind Farms". It focuses on the importance of harmonic analysis in order to obtain a better performance of future wind farms. The topic is investigated by the PhD project at Aalborg...... of offshore wind farm (OWF) systems....... University (AAU) and DONG Energy. The objective of the project is to improve and understand the nature of harmonic emission and propagation in wind farms (WFs), based on available information, measurement data and simulation tools. The aim of the project is to obtain validated models and analysis methods...

  3. Biofilm responses to marine fish farm wastes

    Energy Technology Data Exchange (ETDEWEB)

    Sanz-Lazaro, Carlos, E-mail: carsanz@um.es [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100 Murcia (Spain); Navarrete-Mier, Francisco; Marin, Arnaldo [Departamento de Ecologia e Hidrologia, Facultad de Biologia, Universidad de Murcia, 30100 Murcia (Spain)

    2011-03-15

    The changes in the biofilm community due to organic matter enrichment, eutrophication and metal contamination derived from fish farming were studied. The biofilm biomass, polysaccharide content, trophic niche and element accumulation were quantified along an environmental gradient of fish farm wastes in two seasons. Biofilm structure and trophic diversity was influenced by seasonality as well as by the fish farm waste load. Fish farming enhanced the accumulation of organic carbon, nutrients, selenium and metals by the biofilm community. The accumulation pattern of these elements was similar regardless of the structure and trophic niche of the community. This suggests that the biofilm communities can be considered a reliable tool for assessing dissolved aquaculture wastes. Due to the ubiquity of biofilms and its wide range of consumers, its role as a sink of dissolved wastes may have important implications for the transfer of aquaculture wastes to higher trophic levels in coastal systems. - Research highlights: > Biofilms can act as a trophic pathway of fish farm dissolved wastes. > Biofilms are reliable tools for monitoring fish farm dissolved wastes. > The influence of the fish farm dissolved wastes can be detected 120-350 m from farm. - Under the influence of fish farming biofilm accumulates organic carbon, nutrients, selenium and metals, regardless of the structure and trophic niche of the community.

  4. 12 CFR 619.9145 - Farm Credit Bank.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Farm Credit Bank. 619.9145 Section 619.9145 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9145 Farm Credit Bank. The term Farm Credit Bank refers to a bank resulting from the mandatory merger of the Federal...

  5. 12 CFR 619.9146 - Farm Credit institutions.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Farm Credit institutions. 619.9146 Section 619.9146 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9146 Farm Credit institutions. Except as otherwise defined, the term Farm Credit institutions refers to all...

  6. Incidence of unintentional injuries in farming based on one year of weekly registration in Danish farms

    DEFF Research Database (Denmark)

    Rasmussen, K; Carstensen, O; Lauritsen, Jens

    2000-01-01

    In Denmark, farming ranks as the industry with the highest incidence rate of fatal injuries. For nonfatal injuries, insufficient registration practices prevent valid comparisons between occupations. This study examines the occurrence of farm accidents and injuries, as well as work-specific factors......, via weekly registration in a representative sample of 393 farms in one county during 1 year....

  7. Exploring the role of farm animals in providing care at care farms

    NARCIS (Netherlands)

    Hassink, Jan; Bruin, de Simone R.; Berget, Bente; Elings, Marjolein

    2017-01-01

    We explore the role of farm animals in providing care to different types of participants at care farms (e.g., youngsters with behavioural problems, people with severe mental problems and people with dementia). Care farms provide alternative and promising settings where people can interact with

  8. CleverFarm - A superSCADA system for wind farms

    DEFF Research Database (Denmark)

    Juhl, A.; Hansen, K.G.; Giebhardt, J.;

    2004-01-01

    The CleverFarm project started out to build an integrated monitoring system for wind farms, where all information would be available and could be used across the wind farm for maintenance and component health assessments. This would enable wind farmoperators to prioritise their efforts, since the...

  9. Farming with care: the evolution of care farming in the Netherlands

    NARCIS (Netherlands)

    Hassink, J.; Hulsink, W.; Grin, J.

    2014-01-01

    The aim of this paper is to describe and understand the evolution of the care farming sector in one of its pioneering countries, the Netherlands. Care farms combine agricultural production with health and social services. Care farming is a phenomenon that faces specific challenges associated with co

  10. A Wind Farm Electrical Systems Evaluation with EeFarm-II

    NARCIS (Netherlands)

    Pierik, J.; Axelsson, U.; Eriksson, E.; Salomonsson, D.; Bauer, P.; Czech, B.

    2010-01-01

    EeFarm-II is used to evaluate 13 different electrical systems for a 200 MW wind farm with a 100 km connection to shore. The evaluation is based on component manufacturer data of 2009. AC systems are compared to systems with DC connections inside the wind farm and DC connection to shore. Two options

  11. Farm growth and exit: consequences of EU dairy policy reform for Dutch dairy farming

    NARCIS (Netherlands)

    Peerlings, J.H.M.; Ooms, D.L.

    2008-01-01

    The purpose of this paper is to analyse farm growth and exit and its interaction in Dutch dairy farming as consequences of the 2003 CAP reform and 2008 CAP Health Check. Results indicate that the decision to exit dairy farming is largely determined by household characteristics as age and the size of

  12. Farming with care: the evolution of care farming in the Netherlands

    NARCIS (Netherlands)

    Hassink, J.; Hulsink, W.; Grin, J.

    2014-01-01

    The aim of this paper is to describe and understand the evolution of the care farming sector in one of its pioneering countries, the Netherlands. Care farms combine agricultural production with health and social services. Care farming is a phenomenon that faces specific challenges associated with

  13. Comparative analysis as a management tool for broiler breeder farms: simulated individual farm analysis (IFAS)

    NARCIS (Netherlands)

    Yassin, H.; Velthuis, A.G.J.; Giesen, G.W.J.; Oude Lansink, A.G.J.M.

    2012-01-01

    The objective of this study was to develop a management information system to evaluate the tactical management of a breeder flock using individual farm analysis with a deterministic simulation model (IFAS). Individual farm analysis is a method that evaluates the performance of individual farms by

  14. Whole-Farm Evaluation of Phosphorus Crystallization as a Dairy Farm BMP

    Science.gov (United States)

    A recently proven method for precipitating significant phosphorus from dairy lagoons was incorporated to the Integrated Farm System Model. A whole-farm analysis of this BMP, including environmental and economical effects, were evaluated for an organic dairy farm in Washington. The BMP provides a non...

  15. Improving Environmental Management on Small-scale Farms: Perspectives of Extension Educators and Horse Farm Operators

    Science.gov (United States)

    Rebecca, Perry-Hill; Linda, Prokopy

    2015-01-01

    Although the number of small-scale farms is increasing in North America and Europe, few studies have been conducted to better understand environmental management in this sector. We investigate this issue by examining environmental management on horse farms from both the perspective of the "expert" extension educator and horse farm operator. We conducted a Delphi survey and follow-up interviews with extension educators in Indiana and Kentucky. We also conducted interviews and farm assessments with 15 horse farm operators in the two states. Our results suggest a disconnection between the perceptions of extension educators and horse farm operators. Extension educators believed that operators of small horse farms are unfamiliar with conservation practices and their environmental benefits and they found it difficult to target outreach to this audience. In the interviews with horse farm operators, we found that the majority were somewhat familiar with conservation practices like rotational grazing, soil testing, heavy use area protection, and manure composting. It was not common, however, for practices to be implemented to generally recognized standards. The horse farm respondents perceived these practices as interrelated parts of a system of farm management that has developed over time to best deal with the physical features of the property, needs of the horses, and available resources. Because conservation practices must be incorporated into a complex farm management system, traditional models of extension (i.e., diffusion of innovations) may be inappropriate for promoting better environmental management on horse farms.

  16. Reading the Farm-Training Agricultural Professionals in Whole Farm Analysis for Sustainable Agriculture

    Science.gov (United States)

    Mallory, Ellen; White, Charles; Morris, Thomas; Kiernan, Nancy Ellen

    2011-01-01

    Reading the Farm is a 2- to 3-day professional development program that brings together agricultural service providers from a range of agencies, with various expertise and levels of experience, to explore whole-farm systems and sustainability through in-depth study of two case-study farms. Over 90% of past participants reported that the program…

  17. Flow adjustment inside large finite-size wind farms approaching the infinite wind farm regime

    Science.gov (United States)

    Wu, Ka Ling; Porté-Agel, Fernando

    2017-04-01

    Due to the increasing number and the growing size of wind farms, the distance among them continues to decrease. Thus, it is necessary to understand how these large finite-size wind farms and their wakes could interfere the atmospheric boundary layer (ABL) dynamics and adjacent wind farms. Fully-developed flow inside wind farms has been extensively studied through numerical simulations of infinite wind farms. The transportation of momentum and energy is only vertical and the advection of them is neglected in these infinite wind farms. However, less attention has been paid to examine the length of wind farms required to reach such asymptotic regime and the ABL dynamics in the leading and trailing edges of the large finite-size wind farms. Large eddy simulations are performed in this study to investigate the flow adjustment inside large finite-size wind farms in conventionally-neutral boundary layer with the effect of Coriolis force and free-atmosphere stratification from 1 to 5 K/km. For the large finite-size wind farms considered in the present work, when the potential temperature lapse rate is 5 K/km, the wind farms exceed the height of the ABL by two orders of magnitude for the incoming flow inside the farms to approach the fully-developed regime. An entrance fetch of approximately 40 times of the ABL height is also required for such flow adjustment. At the fully-developed flow regime of the large finite-size wind farms, the flow characteristics match those of infinite wind farms even though they have different adjustment length scales. The role of advection at the entrance and exit regions of the large finite-size wind farms is also examined. The interaction between the internal boundary layer developed above the large finite-size wind farms and the ABL under different potential temperature lapse rates are compared. It is shown that the potential temperature lapse rate plays a role in whether the flow inside the large finite-size wind farms adjusts to the fully

  18. Energy use in pig farming

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-02-15

    This guide presents benchmark data on 'typical' and 'good practice' levels of energy consumption for pig farms in the UK. Benchmarks are valuable because they allow producers to compare their performance with other similar businesses. In addition, they also provide two other useful functions: They allow routine assessments to be made that show progress against a benchmark. Such appraisals are not restricted to year-on-year evaluations as they can be carried out quarterly, monthly or even weekly to track progress on a more frequent basis Opportunity assessments can be carried out. For example, if a facility is to be modified or upgraded, the effect of the change can be determined. Throughout this guide, the benchmarks and information are based on methods and techniques that minimise energy consumption whilst maintaining pig performance at an economically acceptable level. Pig farming in the UK is a complex and diverse business with a variety of facilities being used for each stage of production. Therefore, in order to give realistic guidelines, production has been broken down into several key areas to illustrate typical performance benchmarks. These production areas are: farrowing accommodation; weaning accommodation; finisher accommodation; feeding system; and waste handling. The guide has a detailed breakdown with graphs and data analysis.

  19. Off-farm work decisions on Dutch cash crop farms and the 1992 and Agenda 2000 CAP reforms

    NARCIS (Netherlands)

    Woldehanna, T.; Oude Lansink, A.G.J.M.; Peerlings, J.H.M.

    2000-01-01

    A double hurdle model of off-farm work participation and off-farm labour income was derived and estimated consistent with a farm household model. It was found that rationing and unexpected transaction costs inhibit farm households from participating in off-farm work. The 1992 and the Agenda 2000 CAP

  20. 29 CFR 500.41 - Farm labor contractor is responsible for actions of his farm labor contractor employee.

    Science.gov (United States)

    2010-07-01

    ..., prior to such employee's engagement in any activity enumerated in section 3(6) of the Act. A farm labor... farm labor contractor employee. 500.41 Section 500.41 Labor Regulations Relating to Labor (Continued... PROTECTION Registration of Farm Labor Contractors and Employees of Farm Labor Contractors Engaged in Farm...

  1. Developing an Agro-Ecological Zoning Model for Tumbleweed (Salsola kali), as Energy Crop in Drylands of Argentina

    Science.gov (United States)

    Falasca, Silvia; Pitta-Alvarez, Sandra; Ulberich, Ana

    2016-12-01

    Salsola kali is considered extremely valuable as an energy crop worldwide because it adapts easily to environments with strong abiotic stresses (hydric, saline and alkaline) and produces large amounts of biomass in drylands. This species is categorized as an important weed in Argentina. The aim of this work was to design an agro-ecological zoning model for tumbleweed in Argentina, employing a Geography Information System. Based on the bioclimatic requirements for the species and the climatic data for Argentina (1981-2010 period), an agro-climatic suitability map was drawn. This map was superimposed on the saline and alkaline soil maps delineated by the Food and Agriculture Organization for dry climates, generating the agro-ecological zoning on a scale of 1 : 500 000. This zoning revealed very suitable and suitable cultivation areas on halomorphic soils. The potential growing areas extend from N of the Salta province (approximately 22° S) to the Santa Cruz province (50° S). The use of tumbleweed on halomorphic soils under semi-arid to arid conditions, for the dual purpose of forage use and source of lignocellulosic material for bioenergy, could improve agricultural productivity in these lands. Furthermore, it could also contribute to their environmental sustainability, since the species can be used to reclaim saline soils over the years. Based on international bibliography, the authors outlined an agro-ecological zoning model. This model may be applied to any part of the world, using the agro-ecological limits presented here.

  2. Effects of in-water and dryland warm-ups on 50-meter freestyle performance in child swimmer

    Directory of Open Access Journals (Sweden)

    Kaya Fatih

    2017-01-01

    Full Text Available In this study, effectiveness of 3 warm-up (WU modes on 50m free style on child swimmers has been evaluated. In repeated-measures counterbalanced design, 10 male swimmers of a local sports club (10-12 ages have tried out 50m freestyle after each WU on different days. Each WU took 15 minutes and the intensity of WU has been checked over by Borg’s rating of perceived exertion (RPE 15-point scale. a no warm-up (NWU: the swimmers sat or laid down for 15 minutes, b dryland warmup (DWU: continuous rope-jumping at RPE 12 for 5 minutes, 2 sets 10x15s calisthenics with 15s breathing spaces and continuous ropejumping at RPE 14 for 5 minutes, c in-water warm up (SWU: continuous freestyle swimming at RPE 12 for 5 minutes, freestyle swimming with 8x15m maximum performance with 30s breathing spaces and continuous freestyle swimming at RPE 14 for 5 minutes. RPE, stroke count and heart rate (HR have been evaluated together with the best time in swimming performance. Compared with NWU swimming time post DWU was faster, however the fastest swimming time was achieved post SWU. After NWU swimming RPE was significantly higher. Significant difference could not be found in terms of HR and stroke count. Consequently, SWU is better for swimming performance and DWU can be used when swimming pool is not available.

  3. Changing Forestry Policy by Integrating Water Aspects into Forest/Vegetation Restoration in Dryland Areas in China

    Institute of Scientific and Technical Information of China (English)

    WANG Yanhui; Mike Bonell; Karl-Heinz Feger; YU Pengtao; XIONG Wei; XU Lihong

    2012-01-01

    Restoration forestry (forest rehabilitation) or re-vegetation is one effective measure to solve environmental problems, notably soil erosion. It may be further stimulated by the Clean Development Mechanism for carbon sequestration. However, there is an intensive and on-going debate about the adverse effects arising from afforestation in dryland areas, such as soil drying up which may cause further damage to the success of forest restoration, and the water yield reduction from watershed which may harm the regional development. On other hand, some preliminary studies showed a possibility that these adverse effects may be diminished more or less by properly designing the system structure and spatial distribution of forest/vegetation in a watershed. However, it is urgent to develop an evidence-based and sustainable new forestry policy for harmonizing forest-water interrelation. As a leading country in afforestation, China is beginning to develop a more trans-disciplinary and cross-sectoral forestry policy for harmonizing forestry development with water management. The main points of the changing new forestry policy should include: (1) Establishing a regional development strategy focusing on harmonized forest-water relations; (2) Taking forest-water interactions as an important part of evaluation; (3) Reducing the 'eco-water' quota of forests through technical advancement; (4) Developing and extending water-adaptive forest management practices; (S) Strengthening forest ecohydrological research and decision support ability.

  4. Mixed cropping of annual feed legumes with barley improves feed quantity and crude protein content under dry-land conditions

    Directory of Open Access Journals (Sweden)

    Khoshnood Alizadeh

    2013-01-01

    Full Text Available The objective of this research is to determine a suitable mixture of annual feed legumes and barley as a winter crop under dry-land conditions. Seeds of Hungarian vetch (cv. 2670, smooth vetch (cv. Maragheh, and local varieties of grass pea and field pea were mixed with barley (cv. Abidar in a 1:1 ratio and were tested, along with related monoculture. All legumes in the mixture survived winter while legumes alone, except Hungarian vetch, did not survive in the cold areas. The maximum fresh and dry forage yields (56 and 15 ton ha-1 respectively were obtained from a mixture of smooth vetch and barley in provinces with mild winter and more than 400 mm of rainfall. The mixture of barley and smooth vetch resulted in the highest mean crude protein content (17%. Autumn seeding of smooth vetch and barley in a 1:1 ratio produced more than 2 ton ha-1 of dry biomass with good quality in all studied areas and thus could serve as an alternative cropping system after wheat/barley in cold and semi-cold dry land.

  5. Dryland biological soil crust cyanobacteria show unexpected decreases in abundance under long-term elevated CO2.

    Science.gov (United States)

    Steven, Blaire; Gallegos-Graves, La Verne; Yeager, Chris M; Belnap, Jayne; Evans, R David; Kuske, Cheryl R

    2012-12-01

    Biological soil crusts (biocrusts) cover soil surfaces in many drylands globally. The impacts of 10 years of elevated atmospheric CO2 on the cyanobacteria in biocrusts of an arid shrubland were examined at a large manipulated experiment in Nevada, USA. Cyanobacteria-specific quantitative PCR surveys of cyanobacteria small-subunit (SSU) rRNA genes suggested a reduction in biocrust cyanobacterial biomass in the elevated CO2 treatment relative to the ambient controls. Additionally, SSU rRNA gene libraries and shotgun metagenomes showed reduced representation of cyanobacteria in the total microbial community. Taxonomic composition of the cyanobacteria was similar under ambient and elevated CO2 conditions, indicating the decline was manifest across multiple cyanobacterial lineages. Recruitment of cyanobacteria sequences from replicate shotgun metagenomes to cyanobacterial genomes representing major biocrust orders also suggested decreased abundance of cyanobacteria sequences across the majority of genomes tested. Functional assignment of cyanobacteria-related shotgun metagenome sequences indicated that four subsystem categories, three related to oxidative stress, were differentially abundant in relation to the elevated CO2 treatment. Taken together, these results suggest that elevated CO2 affected a generalized decrease in cyanobacteria in the biocrusts and may have favoured cyanobacteria with altered gene inventories for coping with oxidative stress.

  6. Dryland biological soil crust cyanobacteria show unexpected decreases in abundance under long-term elevated CO2

    Science.gov (United States)

    Steven, Blaire; Gallegos-Graves, La Verne; Yeager, Chris M.; Belnap, Jayne; Evans, R. David; Kuske, Cheryl R.

    2012-01-01

    Biological soil crusts (biocrusts) cover soil surfaces in many drylands globally. The impacts of 10 years of elevated atmospheric CO2 on the cyanobacteria in biocrusts of an arid shrubland were examined at a large manipulated experiment in Nevada, USA. Cyanobacteria-specific quantitative PCR surveys of cyanobacteria small-subunit (SSU) rRNA genes suggested a reduction in biocrust cyanobacterial biomass in the elevated CO2 treatment relative to the ambient controls. Additionally, SSU rRNA gene libraries and shotgun metagenomes showed reduced representation of cyanobacteria in the total microbial community. Taxonomic composition of the cyanobacteria was similar under ambient and elevated CO2 conditions, indicating the decline was manifest across multiple cyanobacterial lineages. Recruitment of cyanobacteria sequences from replicate shotgun metagenomes to cyanobacterial genomes representing major biocrust orders also suggested decreased abundance of cyanobacteria sequences across the majority of genomes tested. Functional assignment of cyanobacteria-related shotgun metagenome sequences indicated that four subsystem categories, three related to oxidative stress, were differentially abundant in relation to the elevated CO2 treatment. Taken together, these results suggest that elevated CO2 affected a generalized decrease in cyanobacteria in the biocrusts and may have favoured cyanobacteria with altered gene inventories for coping with oxidative stress.

  7. Biological soil crusts: An organizing principle in dryland ecosystems (aka: the role of biocrusts in arid land hydrology)

    Science.gov (United States)

    Chamizo, Sonia; Belnap, Jayne; Elridge, David J; Issa, Oumarou M

    2016-01-01

    Biocrusts exert a strong influence on hydrological processes in drylands by modifying numerous soil properties that affect water retention and movement in soils. Yet, their role in these processes is not clearly understood due to the large number of factors that act simultaneously and can mask the biocrust effect. The influence of biocrusts on soil hydrology depends on biocrust intrinsic characteristics such as cover, composition, and external morphology, which differ greatly among climate regimes, but also on external factors as soil type, topography and vegetation distribution patterns, as well as interactions among these factors. This chapter reviews the most recent literature published on the role of biocrusts in infiltration and runoff, soil moisture, evaporation and non-rainfall water inputs (fog, dew, water absorption), in an attempt to elucidate the key factors that explain how biocrusts affect land hydrology. In addition to the crust type and site characteristics, recent studies point to the crucial importance of the type of rainfall and the spatial scale at which biocrust effects are analyzed to understand their role in hydrological processes. Future studies need to consider the temporal and spatial scale investigated to obtain more accurate generalizations on the role of biocrusts in land hydrology.

  8. family farming; quantification; RENAF (registration of family farming; Argentina.

    Directory of Open Access Journals (Sweden)

    Mabel Manzanal

    2015-04-01

    Full Text Available As part of an ongoing research project, this paper discusses public policies that link family farming (FF and food security and sovereignty (FSS which have been promoted in Argentina since 2010.The objective of this research is to contribute to knowledge about developmental and territorial issues, based on the study of experiences located in the provinces of Buenos Aires and Misiones.The article contextualizes and analyzes the emergence of FF and FSS policies, as well as the differences in the ways in which they were managed and implemented in the cases selected. All of this raises the following questions: what role is assigned to FF in rural development policy? What conception of "food sovereignty" lies behind these policies? 

  9. Analysis of organic farming practices amongst crop farmers in Delta ...

    African Journals Online (AJOL)

    Dr. atoma & Family

    The farming practice is eco-friendly and works in agreement with nature. ... Lampkin (1990), said that organic farming systems rely on crop rotation, crop residues, .... The study revealed high-level awareness of organic farming practices but ...

  10. Growing Wheat. People on the Farm.

    Science.gov (United States)

    Department of Agriculture, Washington, DC. Office of Governmental and Public Affairs.

    This booklet, one in a series about life on modern farms, describes the daily life of the Don Riffel family, wheat farmers in Kansas. Beginning with early morning, the booklet traces the family's activities through a typical harvesting day in July, while explaining how a wheat farm is run. The booklet also briefly describes the wheat growing…

  11. The Challenge of Research on Farm Women.

    Science.gov (United States)

    Elbert, Sarah

    1981-01-01

    Researchers studying farm women must ask if successful integration of family and farm systems in the late 20th century involves feminism and, if so, what form of feminism. Available from: Rural Sociological Society, 325 Morgan Hall, University of Tennessee, Knoxville, TN 37916. (NEC)

  12. Computerized management support for swine breeding farms.

    NARCIS (Netherlands)

    Huirne, R.B.M.

    1990-01-01

    1. INTRODUCTIONThe investigations described in this thesis have been directed towards computerized management support for swine breeding farms, focused on sow productivity and profitability. The study is composed of three basic parts: (1) basic description and definition of farm man

  13. Farming of Freshwater Rainbow Trout in Denmark

    DEFF Research Database (Denmark)

    Jokumsen, Alfred; Svendsen, Lars Moeslund

    Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark......Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark...

  14. Bringing the Classroom to the Farm.

    Science.gov (United States)

    Peters, Robert R.; And Others

    1986-01-01

    Describes a study conducted to determine if extension agents could expand their audience through a series of statewide on-farm meetings. The study also sought to determine if the on-farm approach would result in adoption of recommended mastitis control practices. Results are presented and discussed. (CT)

  15. Leptospirosis in a Dutch catfish farm

    NARCIS (Netherlands)

    Kolwijck, E.; Dofferhoff, A.S.M.; Leur, J. van der; Meis, J.F.G.M.

    2011-01-01

    A 51-year-old farm worker presented with jaundice and fever. There had been a rat infestation around the farm ponds and in the shed. He was admitted to our hospital with acute renal and liver failure, thrombocytopenia and rhabdomyolysis. Because of the clinical clues, leptospirosis was suspected and

  16. Prevention of farm injuries in Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Kurt; Carstensen, Ole; Lauritsen, Jens

    2003-01-01

    This study examined the effects of a 4-year randomized intervention program that combined a safety audit with safety behavior training in the prevention of farm injuries.......This study examined the effects of a 4-year randomized intervention program that combined a safety audit with safety behavior training in the prevention of farm injuries....

  17. Farmers’ perception of opportunities for farm development

    NARCIS (Netherlands)

    Methorst, Ron

    2016-01-01

    Differences in the perception of opportunities for farm development is researched in this thesis in relation to differences in the embedding of the farm in the socio-material context. This study contributes to a Sociology of Entrepreneurship in focusing on the decision-maker specific aspects using t

  18. 7 CFR 795.16 - Custom farming.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Custom farming. 795.16 Section 795.16 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE... pesticides, and harvesting for hire with remuneration on a unit of work basis, except that, for the purpose...

  19. Evaluating the Sustainable Intensification of arable farms.

    Science.gov (United States)

    Gadanakis, Yiorgos; Bennett, Richard; Park, Julian; Areal, Francisco Jose

    2015-03-01

    Sustainable Intensification (SI) of agriculture has recently received widespread political attention, in both the UK and internationally. The concept recognises the need to simultaneously raise yields, increase input use efficiency and reduce the negative environmental impacts of farming systems to secure future food production and to sustainably use the limited resources for agriculture. The objective of this paper is to outline a policy-making tool to assess SI at a farm level. Based on the method introduced by Kuosmanen and Kortelainen (2005), we use an adapted Data Envelopment Analysis (DEA) to consider the substitution possibilities between economic value and environmental pressures generated by farming systems in an aggregated index of Eco-Efficiency. Farm level data, specifically General Cropping Farms (GCFs) from the East Anglian River Basin Catchment (EARBC), UK were used as the basis for this analysis. The assignment of weights to environmental pressures through linear programming techniques, when optimising the relative Eco-Efficiency score, allows the identification of appropriate production technologies and practices (integrating pest management, conservation farming, precision agriculture, etc.) for each farm and therefore indicates specific improvements that can be undertaken towards SI. Results are used to suggest strategies for the integration of farming practices and environmental policies in the framework of SI of agriculture. Paths for improving the index of Eco-Efficiency and therefore reducing environmental pressures are also outlined.

  20. Organic food and farming research in Finland

    OpenAIRE

    Nykänen, Arja

    2006-01-01

    In Finland we have a tendency of increasing activities in organic food and farming research during last five years. Most of the organic food and farming research i Finland is carried out at the MTT Agrifood Research Finland. The rest is done at the universities and other institutes.

  1. SUSTAINABILITY OF FARMING ENTERPRISE - UNDERSTANDING, GOVERNANCE, EVALUATION

    Directory of Open Access Journals (Sweden)

    H. Bachev

    2016-02-01

    Full Text Available This article gives answers to following important questions: "what is sustainability of farming enterprises" such as individual and family farms, agri-firms of different types, agri-cooperatives, etc.", "what are the mechanisms and modes of governance of sustainability of farming enterprises", and "how to evaluate the sustainability level of farming enterprise and efficiency of its governance". First, evolution of the "concept" of sustainability of farming enterprise is discussed and more adequately defined as ability of a particular enterprise to maintain its managerial, economic, social and ecological functions in a long term. Second, institutional, market, private, public and hybrid mechanisms and modes of governance of farming enterprise's sustainability are specified. Third, a specific for the conditions of East-European agriculture framework for assessing sustainability level of farming enterprise and efficiency of its governance is suggested. Ultimate goal is to assist farming enterprises' management and strategy formation as well as improvement of public policies and forms of public intervention in agrarian sector.

  2. Wakes in large offshore wind farms

    DEFF Research Database (Denmark)

    Berthelmie, Rebecca J.; Frandsen, Sten Tronæs; Rathmann, Ole

    2008-01-01

    Power losses due to wind turbine wakes are of the order of 10 and 20% of total power output in large wind farms. The focus of this research carried out within the EC funded UPWIND project is wind speed and turbulence modelling for large wind farms/wind turbines in complex terrain and offshore in ...

  3. A reference architecture for Farm Software Ecosystems

    NARCIS (Netherlands)

    Kruize, J.W.; Wolfert, J.; Scholten, H.; Verdouw, C.N.; Kassahun, A.; Beulens, A.J.M.

    2016-01-01

    Smart farming is a management style that includes smart monitoring, planning and control of agricultural processes. This management style requires the use of a wide variety of software and hardware systems from multiple vendors. Adoption of smart farming is hampered because of a poor interoperabi

  4. Breeding for behavioural change in farm animals

    DEFF Research Database (Denmark)

    D'Eath, R.B.; Conington, J.; Lawrence, A.B.

    2010-01-01

    In farm animal breeding, behavioural traits are rarely included in selection programmes despite their potential to improve animal production and welfare. Breeding goals have been broadened beyond production traits in most farm animal species to include health and functional traits, and opportunit...

  5. The Challenge of Research on Farm Women.

    Science.gov (United States)

    Elbert, Sarah

    1981-01-01

    Researchers studying farm women must ask if successful integration of family and farm systems in the late 20th century involves feminism and, if so, what form of feminism. Available from: Rural Sociological Society, 325 Morgan Hall, University of Tennessee, Knoxville, TN 37916. (NEC)

  6. Buffalo farms: same product, different strategies

    Directory of Open Access Journals (Sweden)

    E. Turri

    2010-02-01

    Full Text Available The aim of our paper is to investigate relationships between socio-demographic variables and access to rural development policy to sustain buffalo farm activity. An empirical analysis is applied, concerning buffalo farms of region Lazio, in Italy. Results confirms the hypothesis of strict interaction between access to policy and the explicative variables.

  7. Factors influencing the process of farm liquidation

    Directory of Open Access Journals (Sweden)

    Michał Dudek

    2010-01-01

    Full Text Available In the paper the logit analysis was used in order to define the factors influencing farm liquidation. The prevalence of this phenomenon and its regional differences were analysed. Significant and negative impact of the number of people in a family farm and the number of machinery and technical equipment, as well as the positive impact of the farmer’ age are reported.

  8. The Freedoms and Capabilities of Farm Animals

    DEFF Research Database (Denmark)

    Cabaret, Jacques; Chylinski, Caroline; Vaarst, Mette

    2014-01-01

    Organic farming promotes animal husbandry practices that consider the welfare of the animals on the farm. The concept of animal welfare and the standards that should encompass this concept have in many cases been largely generalised in practice, which leaves relevant aspects of animal freedom or ...

  9. Farming of Freshwater Rainbow Trout in Denmark

    DEFF Research Database (Denmark)

    Jokumsen, Alfred; Svendsen, Lars Moeslund

    Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark......Textbook on Farming of Freshwater Rainbow Trout in Denmark. Danish edition with the title: Opdræt af regnbueørred i Danmark...

  10. Benchmarking the environmental performances of farms

    NARCIS (Netherlands)

    Snoo, de G.R.

    2006-01-01

    Background, Aim and Scope The usual route for improvement of agricultural practice towards sustainability runs via labelling schemes for products or farm practices. In most approaches requirements are set in absolute terms, disregarding the variation in environmental performance of farms. Another ap

  11. Water Availability for Winter Wheat Affected by Summer Fallow Tillage Practices in Slope Dryland

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-bin; YANG Bo; Roger Hartmann; Donald Gabriels; CAI Dian-xiong; JIN Ke; WU Hui-jun; BAI Zhan-guo; ZHANG Can-jun; YAO Yu-qing; LU Jun-jie; WANG Yu-hong

    2003-01-01

    The tillage experiments for winter wheat were conducted on the slope farmland in Luoyang,Henan Province in the semihumid to arid loess plateau areas of North China. Different tillage methods inclu-ding reduced tillage (RT), no-till (NT), 2 crops/year (2C), subsoiling(SS), and conventional tillage (CT)were compared to determine the effects of tillage methods on soil water conservation, water availability, andwheat yields in a search for better farming systems in the areas. The NT and SS showed good effects on waterconservation. The soil water storage increased 12 - 33 mm with NT and 9 - 24 mm with SS at the end of sum-mer fallow periods. The soil evaporation with NT and SS decreased 7 - 8 mm and 34 - 36 mm during the fallowperiods of 1999 and 2001, respectively. Evapotranspiration (ET) with NT and SS increased about 47 mm dur-ing wheat growth periods of 2000 to 2001. Treatment RT and 2C had low water storage and high water lossesduring the fallow periods. The winter wheat yields with conservation tillage practices were improved in the 2ndyear, increased by 3, 5 and 8 % with RT, NT and SS, respectively, compared with CT. The highest wheatyields were obtained with subsoiling, and the maximum economic benefits from no-till. All conservation tillagepractices provided great benefits to saving energy and labors, reducing operation inputs, and increasing eco-nomic returns. No-till and subsoiling have shown promise in increasing water storage, reducing water loss, en-hancing water availability, and saving energy, as well as increasing wheat yield.

  12. Biogas and bioethanol production in organic farming

    Energy Technology Data Exchange (ETDEWEB)

    Oleskowicz-Popiel, P.

    2010-08-15

    The consumer demand for environmentally friendly, chemical free and healthy products, as well as concern regarding industrial agriculture's effect on the environment has led to a significant growth of organic farming. On the other hand, organic farmers are becoming interested in direct on-farm energy production which would lead them to independency from fossil fuels and decrease the greenhouse gas emissions from the farm. In the presented work, the idea of biogas and bioenergy production at the organic farm is investigated. This thesis is devoted to evaluate such a possibility, starting from the characterization of raw materials, through optimizing new processes and solutions and finally evaluating the whole on-farm biorefinery concept with the help of a simulation software. (LN)

  13. INL Wind Farm Project Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Gary Siefert

    2009-07-01

    The INL Wind Farm project proposes to install a 20 MW to 40 MW wind farm on government property, consisting of approximately ten to twenty full-sized (80-meter hub height) towers with 2 MW turbines, and access roads. This includes identifying the optimal turbine locations, building access roads, and pouring the tower foundations in preparation for turbine installation. The project successfully identified a location on INL lands with commercially viable wind resources (i.e., greater than 11 mph sustained winds) for a 20 to 40 MW wind farm. Additionally, the proposed Wind Farm was evaluated against other General Plant Projects, General Purpose Capital Equipment projects, and Line Item Construction Projects at the INL to show the relative importance of the proposed Wind Farm project.

  14. Exploring the multifunctional role of farming systems

    DEFF Research Database (Denmark)

    Hermansen, John Erik; Noe, Egon; Halberg, Niels

    2006-01-01

    Public expectations of farming practices are changing from a demand for environmentally "sustainable farming practices" to farming making an "enhanced contribution to the development of the rural areas", the so-called multifunctionality. Based on our research model of including farmers...... in the development of eco-friendly farming systems, we propose that the achievement of these changed expectations could be facilitated through an appropriate research and development initiative in several European regions. Key elements in such a project sould include: (i) the establishment of platforms for dialogue...... makers and administrators, grassroots movements and research staff. It is expected that such a coordinated research initiative can revitalize the contribution of farming to rural development and yield important insight to be used by the individual farmer in coping with future challenges....

  15. CREDIT LEVEL INFLUENCING FACTORS AT HUNGARIAN FARMS

    Directory of Open Access Journals (Sweden)

    Toth Jozsef

    2012-12-01

    Full Text Available In this paper we estimate the impact of different factors on creditability of agricultural farms. According to the literature the collateral (tangible assets, the farm size, productivity, and subsidies should have significant effects on farm loans. We use data from the Hungarian Farm Accountancy Data Network to test our two hypotheses and theoretical assumptions for the period 2001-2010. Because of using panel data, we do our estimations using fixed effects econometrics model to test our assumptions. The results indicate that the chosen factors have significant influence on total liabilities and short- and long-term loans as well. With specially interest of subsidies the growing level of supports decrease the need of other financial tools. At output factors (inclusive farm size have significant and positive effect, same as collateral (tangible assets.

  16. Growing Up on an Appalachian Farm.

    Science.gov (United States)

    Holston, Ezra C; Callen, Bonnie

    2017-01-01

    Background Research on centenarians to date has focused on areas with a high population of centenarians. However, there is limited literature on centenarians' perspectives about growing up on farms from the heartland of Appalachia in Eastern Tennessee. Purpose This qualitative descriptive study was designed to characterize the role of a farming childhood by exploring the viewpoints of community-dwelling centenarians who grew up on farms in south central Appalachia. Methods A qualitative descriptive design was used with a convenience sample ( n = 16). Cognitive status was determined with the Short Portable Mental Status Questionnaire. Demographic data were collected. Interviews were transcribed and analyzed with the Neuendorf method of content analysis. Results Main emerging themes were the farm, the family, and the environment. Conclusion The farm was at the center of these centenarians' childhood, influencing their family, community relations, and social interactions, which provided lessons that they utilized throughout their long lives.

  17. Correlates of psychosomatic stress symptoms among farm women: a research note on farm and family functioning.

    Science.gov (United States)

    Berkowitz, A D; Perkins, H W

    1985-01-01

    The relationship between self-reported psychosomatic stress symptoms and dimensions of family and farm functioning were examined in a sample of New York State dairy farm wives (N = 126). The farm women completed a questionnaire assessing home and farm task loads, farm complexity, intrapersonal role conflict, interpersonal role conflict, husband support, and marital satisfaction. The psychosomatic stress symptoms included nervousness, restlessness, insomnia, shortness-of-breath, and fainting. In general, stress symptoms showed little relationship to task loads, farm complexity, and intrapersonal role conflict. Much stronger relationships were found for interpersonal role conflict, husband support, and marital satisfaction. Thus, these findings point to the greater importance of family relationships in preventing or buffering stress in comparison with simple role-related task expectations of farm systems.

  18. A Wind Farm Electrical Systems Evaluation with EeFarm-II

    Directory of Open Access Journals (Sweden)

    Jan Pierik

    2010-03-01

    Full Text Available EeFarm-II is used to evaluate 13 different electrical systems for a 200 MW wind farm with a 100 km connection to shore. The evaluation is based on component manufacturer data of 2009. AC systems are compared to systems with DC connections inside the wind farm and DC connection to shore. Two options have the best performance for this wind farm size and distance: the AC system and the system with a DC connection to shore. EeFarm-II is a user friendly computer program for wind farm electrical and economic evaluation. It has been built as a Simulink Library in the graphical interface of Matlab-Simulink. EeFarm-II contains models of wind turbines, generators, transformers, AC cables, inductors, nodes, splitters, PWM converters, thyristor converters, DC cables, choppers and statcoms.

  19. FARM OPERATIONS FACING DEVELOPMENT: RESULTS FROM THE CENSUS LONGITUDINAL FILE

    OpenAIRE

    Hoppe, Robert A.; Korb, Penelope J.

    2001-01-01

    This paper examines farms in areas undergoing development, using a longitudinal file constructed by linking several agricultural censuses. Individual farms are followed over the 1982-97 period. Survival, exit, and entrance rates are presented for three types of farms: recreational, adaptive, and traditional. The three types of farms are located where one would expect. Traditional farms are concentrated in nonmetropolitan (nonmetro) counties, while adaptive farms are concentrated in metro core...

  20. The sociocultural sustainability of livestock farming: an inquiry into social perceptions of dairy farming.

    Science.gov (United States)

    Boogaard, B K; Oosting, S J; Bock, B B; Wiskerke, J S C

    2011-08-01

    Over the past 50 years, the scale and intensity of livestock farming have increased significantly. At the same time, Western societies have become more urbanised and fewer people have close relatives involved in farming. As a result, most citizens have little knowledge or direct experience of what farming entails. In addition, more people are expressing concerns over issues such as farm animal welfare. This has led to increasing public demand for more sustainable ways of livestock farming. To date, little research has been carried out on the social pillar of sustainable livestock farming. The aim of this study is to provide insights into the sociocultural sustainability of livestock farming systems. This study reviews the key findings of earlier published interdisciplinary research about the social perceptions of dairy farming in the Netherlands and Norway (Boogaard et al., 2006, 2008, 2010a and 2010b) and synthesises the implications for sociocultural sustainability of livestock farming. This study argues that the (sociocultural) sustainable development of livestock farming is not an objective concept, but that it is socially and culturally constructed by people in specific contexts. It explains the social pillar of the economics/ecological/social model sustainability in terms of the fields of tensions that exist between modernity, traditions and naturality - 'the MTN knot' - each of which has positive and negative faces. All three angles of vision can be seen in people's attitudes to dairy farming, but the weight given to each differs between individuals and cultures. Hence, sociocultural sustainability is context dependent and needs to be evaluated according to its local meaning. Moreover, sociocultural sustainability is about people's perceptions of livestock farming. Lay people might perceive livestock farming differently and ascribe different meanings to it than experts do, but their 'reality' is just as real. Finally, this study calls for an ongoing