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Sample records for agro-ecological zone grazing

  1. The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: The effect of agro-ecological zone, grazing management and age of cattle

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    C. Rubaire-Akiiki

    2004-03-01

    Full Text Available Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60% was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50% were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified.

  2. Oxisol (Ferralsol) Development In Two Agro-Ecological Zones of ...

    African Journals Online (AJOL)

    -ecological zone of Ghana. There is no documented information about these soils in the Moist Semi-Deciduous Forest (MSDF) agro-ecological zone of Ghana where climatic conditions conducive for Oxisol formation have been identified in ...

  3. Survey of smallholder beef cattle production systems in different agro-ecological zones of Cambodia.

    Science.gov (United States)

    Samkol, Pok; Sath, Keo; Patel, Mikaela; Windsor, Peter Andrew; Holtenius, Kjell

    2015-10-01

    A survey was conducted to better understand the contribution of farm productivity to rural household income and identify differences in production systems, feeding practices and development constraints to smallholder beef cattle producers in the four agro-ecological zones (AEZs) of Cambodia. A semi-structured questionnaire was used to interview 360 households in the four AEZs: I, the Great Lake Floodplain; II, the Mekong Floodplain; III, the Coastal and IV, the Plateau/Mountainous. In addition, samples of common nutritional resources used for cattle feed were collected for nutrient composition analysis, plus cattle were scored for body condition. Rice farming and cattle production were the most common sources of income in all AEZs. The average cattle herd size was 3.7 (SD = 2.4), but the majority of households raised 1-3 animals. The most common cattle management system was grazing with supplementation, mainly with rice straw and 'cut-and-carry' natural grasses fed during the wet season in all AEZs. The body condition score of all cattle types was 3.2 (SD = 0.8), except for cows in lactation that were 1.8. Major constraints to cattle production in AEZs I, II and III were lack of quality feed resources, capital for cattle production and concerns on breed quality, whereas in AEZ IV, diseases were identified as the main constraint. This survey confirms the importance of cattle to smallholders in the four AEZs. Interventions including farmer education to improve husbandry skills, increase the utilisation of forages and crop residues and address disease issues are necessary to enhance cattle production and rural livelihoods in Cambodia.

  4. Morphometric Traits of Muscovy Ducks from Two Agro Ecological Zones of Nigeria

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    Yakubu, A.

    2011-01-01

    Full Text Available Morphological variation between Muscovy ducks from the guinea savannah and rainforest zones of Nigeria was examined using multivariate discriminant analysis. Data comprised eight morphometric traits measured in a total of 435 adult ducks randomly selected in the two agro-ecological zones. Common descriptive statistics showed that ducks from the rainforest zone had higher (P< 0.05 body weight, foot length and thigh circumference, while their guinea savannah counterparts were longer (P< 0.05 in the neck. Stepwise discriminant analysis indicated that foot length, neck length, thigh circumference and body length were more effective in discriminating between the duck populations. The low Mahalanobis distance of 3.39, as revealed by the canonical discriminant analysis, is an indication of high gene flow between ducks from the two agro-ecological zones. The cluster analysis also revealed the homogeneity of the genetic identity of the duck populations. The present information will be the basis for further characterization, conservation and sustainable genetic improvement strategies for indigenous ducks.

  5. Ectoparasites of sheep in three agro-ecological zones in central Oromia, Ethiopia

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    Bersissa Kumsa

    2012-02-01

    Full Text Available A cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in sheep in three agro-ecological zones in central Oromia, Ethiopia, from October 2009 to April 2010. The study revealed that 637 (48.1% of the 1325 sheep examined were infested with one or more ectoparasites. The ectoparasites identified were Bovicola ovis (27.2%, Melophagus ovinus (16.4%, Ctenocephalides sp. (2.3%, Linognathus africanus (1.2%, Linognathus ovillus (0.3%, Sarcoptes sp. (1.2%, Amblyomma variegatum (4.4%, Rhipicephalus evertsi evertsi (1.9%, Rhipicephalus pravus (1.9%, Rhipicephalus (Boophilus decoloratus (1.1%, Rhipicephalus sanguineus (0.9%, Rhipicephalus praetextatus (1.1% and Hyalomma truncatum (1.6%. Statistically significant difference was observed in prevalence of B. ovis amongst study agroecological zones: highland 36.6%, midland 20.9% and lowland 14.0%. Significantly higher prevalence was recorded in highland agroecological zone. A significantly (OR = 0.041, p < 0.001 higher prevalence of M. ovinus in the highland (31.7% than in both the lowland (0% and midland (1.9% was observed. The risk of tick infestation in the lowland and midland was 9.883 times and 13.988 times higher than the risk in the highland, respectively. A significantly higher prevalence of Ctenocephalides species was encountered in both the lowland (OR = 4.738, p = 0.011 and midland (OR = 8.078, p = 0.000 than in the highland agro-ecological zone. However, a significant difference (p = 0.191 amongst agro-ecological zones was not found for the prevalence of Linognathus and Sarcoptes species. Statistically significant variation (p > 0.05 was never recorded in the prevalence of all the identified species of ectoparasites between male and female sheep hosts. However, a significantly (p = 0.006 higher prevalence of B. ovis was recorded between young and adult sheep. The risk of B. ovis infestation was 1.45 times higher in young than the adult sheep

  6. Ectoparasites of sheep in three agro-ecological zones in central Oromia, Ethiopia.

    Science.gov (United States)

    Kumsa, Bersissa; Beyecha, Kebede; Geloye, Mesula

    2012-10-23

    A cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in sheep in three agro-ecological zones in central Oromia, Ethiopia, from October 2009 to April 2010. The study revealed that 637 (48.1%) of the 1325 sheep examined were infested with one or more ectoparasites. The ectoparasites identified were Bovicola ovis (27.2%), Melophagus ovinus (16.4%), Ctenocephalides sp. (2.3%), Linognathus africanus (1.2%), Linognathus ovillus (0.3%), Sarcoptes sp. (1.2%), Amblyomma variegatum (4.4%), Rhipicephalus evertsi evertsi (1.9%), Rhipicephalus pravus (1.9%), Rhipicephalus (Boophilus) decoloratus (1.1%), Rhipicephalus sanguineus (0.9%), Rhipicephalus praetextatus (1.1%) and Hyalomma truncatum (1.6%). Statistically significant difference was observed in prevalence of B. ovis amongst study agroecological zones: highland 36.6%, midland 20.9% and lowland 14.0%. Significantly higher prevalence was recorded in highland agroecological zone. A significantly (OR = 0.041, p < 0.001) higher prevalence of M. ovinus in the highland (31.7%) than in both the lowland (0%) and midland (1.9%) was observed. The risk of tick infestation in the lowland and midland was 9.883 times and 13.988 times higher than the risk in the highland, respectively. A significantly higher prevalence of Ctenocephalides species was encountered in both the lowland (OR = 4.738, p = 0.011) and midland (OR = 8.078, p = 0.000) than in the highland agro-ecological zone. However, a significant difference (p = 0.191) amongst agro-ecological zones was not found for the prevalence of Linognathus and Sarcoptes species. Statistically significant variation (p > 0.05) was never recorded in the prevalence of all the identified species of ectoparasites between male and female sheep hosts. However, a significantly (p = 0.006) higher prevalence of B. ovis was recorded between young and adult sheep. The risk of B. ovis infestation was 1.45 times higher in young than the adult

  7. Developing an Agro-Ecological Zoning Model for Tumbleweed (Salsola kali, as Energy Crop in Drylands of Argentina

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    Falasca Silvia

    2016-12-01

    Full Text Available 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.

  8. Soil strength assessment using threshold probability approach on soils from three agro-ecological zones in Eritrea.

    NARCIS (Netherlands)

    Tekeste, M.A.; Habtzghi, D.H.; Stroosnijder, L.

    2007-01-01

    Soils in many agro-ecological zones in Eritrea, a country in sub-Saharan Africa, are low in productivity due to erosion, low organic matter and poor soil management. Recently, mechanised farming has been intensively practiced to increase agricultural food production. However, the use of heavy

  9. Multiclass Classification of Agro-Ecological Zones for Arabica Coffee: An Improved Understanding of the Impacts of Climate Change

    Science.gov (United States)

    Bunn, Christian; Läderach, Peter; Pérez Jimenez, Juan Guillermo; Montagnon, Christophe; Schilling, Timothy

    2015-01-01

    Cultivation of Coffea arabica is highly sensitive to and has been shown to be negatively impacted by progressive climatic changes. Previous research contributed little to support forward-looking adaptation. Agro-ecological zoning is a common tool to identify homologous environments and prioritize research. We demonstrate here a pragmatic approach to describe spatial changes in agro-climatic zones suitable for coffee under current and future climates. We defined agro-ecological zones suitable to produce arabica coffee by clustering geo-referenced coffee occurrence locations based on bio-climatic variables. We used random forest classification of climate data layers to model the spatial distribution of these agro-ecological zones. We used these zones to identify spatially explicit impact scenarios and to choose locations for the long-term evaluation of adaptation measures as climate changes. We found that in zones currently classified as hot and dry, climate change will impact arabica more than those that are better suited to it. Research in these zones should therefore focus on expanding arabica's environmental limits. Zones that currently have climates better suited for arabica will migrate upwards by about 500m in elevation. In these zones the up-slope migration will be gradual, but will likely have negative ecosystem impacts. Additionally, we identified locations that with high probability will not change their climatic characteristics and are suitable to evaluate C. arabica germplasm in the face of climate change. These locations should be used to investigate long term adaptation strategies to production systems. PMID:26505637

  10. Mineral composition ofTamarindus indicaLINN (tamarind) pulp and seeds from different agro-ecological zones of Uganda.

    Science.gov (United States)

    Okello, Jaspher; Okullo, John B L; Eilu, Gerald; Nyeko, Philip; Obua, Joseph

    2017-09-01

    Mineral composition of dry Tamarindus indica LINN pulp and seeds was evaluated on samples collected from three different agro-ecological zones of Uganda (Lake Victoria Crescent, and Eastern and West Nile). The objective of the study was to evaluate the mineral composition of T. indica pulp and seed samples from across Uganda's different agro-ecological zones and land use types. Separately grounded samples of T. indica pulp and seeds were analyzed for Zn, Fe, Mg, P, Na, K, and Ca. The univariate analysis of variance in the General Linear Model was used to compare differences in mineral composition. Treatment means were separated using Least Significant Difference (LSD) in Post Hoc Tests. The results showed that there were significant differences ( p  ≤ 0.005) in mineral composition levels of T. indica pulp and seed samples between the different agro-ecological zones with the exception of P and Na (for pulp). The T. indica pulp and seeds samples from the Lake Victoria Crescent zone and wild land use type had generally higher mineral levels than T. indica samples from other agro-ecological zones and different land use types. As mineral composition levels were generally higher in the seed than the pulp samples, consumption of T. indica seeds should be promoted. There is also need to conserve individual species both on-farm and in the wild population, but T. indica mineral concentrations (both pulp and seeds) were higher in the samples from the wild population, making them good for human and animal diets.

  11. Investigating Strategies for Sustainable Vegetable Food Crop System in Three Agro Ecological Zones of the Humid Tropics Area of Cameroon

    OpenAIRE

    TATA NGOME, Precillia Ijang; AFARI-SEFA, Victor; NTSOMBOH-NTSEFONG, Godswill; OKOLLE, Justin; BILLA, Samuel Fru; MOMA, Crescence; ATEMKENG FONJI, Maureen; NGOME, Ajebesone Francis

    2018-01-01

    Vegetable cultivation remains an essential component of local people’s livelihoods. However, marked trend shifts in the varieties of vegetables due to large-scale commercial vegetable farming of exotic varieties in the broader market economy have resulted in the gradual disappearance of biodiversity involving vital species. The present study examined the situation of vegetable crop farming in three agro-ecological zones of Cameroon. Data were collected from a random sample of 235 respondents ...

  12. Ectoparasites of sheep in three agro-ecological zones in central Oromia, Ethiopia

    Directory of Open Access Journals (Sweden)

    Bersissa Kumsa

    2012-10-01

    Full Text Available A cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in sheep in three agro-ecological zones in central Oromia, Ethiopia, from October 2009 to April 2010. The study revealed that 637 (48.1% of the 1325 sheep examined were infested with one or more ectoparasites. The ectoparasites identified were Bovicola ovis (27.2%, Melophagus ovinus (16.4%, Ctenocephalides sp. (2.3%, Linognathus africanus (1.2%, Linognathus ovillus (0.3%, Sarcoptes sp. (1.2%, Amblyomma variegatum (4.4%, Rhipicephalus evertsi evertsi (1.9%, Rhipicephalus pravus (1.9%, Rhipicephalus (Boophilus decoloratus (1.1%, Rhipicephalus sanguineus (0.9%, Rhipicephalus praetextatus (1.1% and Hyalomma truncatum (1.6%. Statistically significant difference was observed in prevalence of B. ovis amongst study agroecological zones: highland 36.6%, midland 20.9% and lowland 14.0%. Significantly higher prevalence was recorded in highland agroecological zone. A significantly (OR = 0.041, p  0.05 was never recorded in the prevalence of all the identified species of ectoparasites between male and female sheep hosts. However, a significantly (p = 0.006 higher prevalence of B. ovis was recorded between young and adult sheep. The risk of B. ovis infestation was 1.45 times higher in young than the adult sheep. Furthermore, a significantly (p < 0.001 higher prevalence of M. ovinus, B. ovis and Sarcoptes sp. was found between sheep with poor and a good body condition. The ever increasing threat of ectoparasites on overall sheep productivity and tanning industry in Ethiopia warrants urgent control intervention. Further studies on the role of ectoparasites in transmission of diseases to sheep, zoonotic importance, comparative prevalence and load, and the importance of sheep as alternative hosts in different agroecological zones, breeds and management systems in Ethiopia are recommended so as to design applicable control programme in the country.

  13. Impacts of terracing on soil erosion control and crop yield in two agro-ecological zones of Rwanda

    Science.gov (United States)

    Rutebuka, Jules; Ryken, Nick; Uwimanzi, Aline; Nkundwakazi, Olive; Verdoodt, Ann

    2017-04-01

    Soil erosion remains a serious limiting factor to the agricultural production in Rwanda. Terracing has been widely adopted in many parts of the country in the past years, but its effectiveness is not yet known. Besides the standard radical (bench) terraces promoted by the government, also progressive terraces (with living hedges) become adopted mainly by the farmers. The aim of this study was to measure short-term (two consecutive rainy seasons 2016A and 2016B) run-off and soil losses for existing radical (RT) and progressive (PT) terraces versus non-protected (NP) fields using erosion plots installed in two agro-ecological zones, i.e. Buberuka highlands (site Tangata) and Eastern plateau (site Murehe) and determine their impacts on soil fertility and crop production. The erosion plot experiment started with a topsoil fertility assessment and during the experiment, maize was grown as farmer's cropping preference in the area. Runoff data were captured after each rainfall event and the collected water samples were dried to determine soil loss. Both erosion control measures reduced soil losses in Tangata, with effectiveness indices ranging from 43 to 100% when compared to the NP plots. RT showed the highest effectiveness, especially in season A. In Murehe, RT minimized runoff and soil losses in both seasons. Yet, the PT were largely inefficient, leading to soil losses exceeding those on the NP plots (ineffectiveness index of -78% and -65% in season A and B, respectively). Though topsoil fertility assessment in the erosion plots showed that the soil quality parameters were significantly higher in RT and NP plots compared to the PT plots on both sites, maize grain yield was not correlated with the physical effectiveness of the erosion control measures. Finally, the effectiveness of soil erosion control measures as well as their positive impacts on soil fertility and production differ not only by terracing type but also by agro-ecological zone and the management or

  14. THE EFFECT OF AGRO-ECOLOGICAL ZONES ON THE INCIDENCE AND DISTRIBUTION OF APHID VECTORS OF PEPPER VEINAL MOTTLE VIRUS, ON CULTIVATED PEPPER (CAPSICUM ANNUUM L. IN NIGERIA

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    A.A. FAJINMI

    2011-11-01

    Full Text Available The distribution of aphid vectors of Pepper veinal mottle virus (PVMV was studied on cultivated pepper between 2003 and 2005 in the major pepper producing areas of the six agro-ecological zones in Nigeria. The aphids were isolated, identified and their transmission ability determined. Population of aphid vectors increased progressively in all the agro-ecological zones from March at the onset of raining season reaching a peak in August and then declining from September at the on set of the dry season. The Humid forest and Derived Savanna agro-ecological zones recorded highest mean population of aphids / leaf and types of aphid’s species compared with other agro-ecological zones. Six species of aphid, Myzus persicae (Sulzer, Aphis gossipii (Glover, Aphis craccivora (Koch, Aphis spiraecola (Patch, Aphis fabae (Blanchard, and Rhopalosiphum maidis (Fitch, were identified on the pepper fields surveyed in all the agro-ecological zones. There was no significant difference in the occurrence of M. persicae, A. gossipii, A. craccivora, and R. maidis while A. spiraecola and A. fabae that varied in occurrence in all the zones. Ability to transmit PVMV to a healthy pepper plants varied in all the identified aphid species but R. maidis was not able to transmit PVMV from infected to a healthy pepper plant. A more sustainable approach to controlling pepper viruses is by targeting the aphid vectors and preventing the vectors from reaching the crops because the aphid vectors which are virus specific are the major means of transmitting virus to healthy plant.

  15. Fungal and bacterial metabolites of stored maize (Zea mays, L.) from five agro-ecological zones of Nigeria.

    Science.gov (United States)

    Adetunji, Modupeade; Atanda, Olusegun; Ezekiel, Chibundu N; Sulyok, Michael; Warth, Benedikt; Beltrán, Eduardo; Krska, Rudolf; Obadina, Olusegun; Bakare, Adegoke; Chilaka, Cynthia A

    2014-05-01

    Seventy composite samples of maize grains stored in five agro-ecological zones (AEZs) of Nigeria where maize is predominantly produced were evaluated for the presence of microbial metabolites with the LC-MS/MS technique. The possible relationships between the storage structures and levels of mycotoxin contamination were also evaluated. Sixty-two fungal and four bacterial metabolites were extracted from the grains, 54 of which have not been documented for maize in Nigeria. Aflatoxin B1 and fumonisin B1 were quantified in 67.1 and 92.9% of the grains, while 64.1 and 57.1% exceeded the European Union Commission maximum acceptable limit (MAL) for aflatoxin B1 and fumonisins, respectively. The concentration of deoxynivalenol was, however, below the MAL with occurrence levels of 100 and 10% for its masked metabolite, deoxynivalenol glucoside. The bacterial metabolites had low concentrations and were not a source of concern. The storage structures significantly correlated positively or negatively (p may therefore expose the population to mycotoxin contamination. There is need for an immediate action plan for mycotoxin mitigation in Nigeria, especially in the Derived Savannah zone, in view of the economic and public health importance of the toxins.

  16. Spatial distribution of Brucella antibodies with reference to indigenous cattle populations among contrasting agro-ecological zones of Uganda.

    Science.gov (United States)

    Kabi, Fredrick; Muwanika, Vincent; Masembe, Charles

    2015-09-01

    Indigenous cattle populations exhibit various degrees of agro-ecological fitness and provide desirable opportunities for investments to improve sustainable production for better rural small-scale farmers' incomes globally. However, they could be a source of infection to their attendants and other susceptible livestock if their brucellosis status remains unknown. This study investigated the spatial distribution of Brucella antibodies among indigenous cattle populations in Uganda. Sera from a total of 925 indigenous cattle (410 Ankole Bos taurus indicus, 50 Nganda and 465 East African Shorthorn Zebu (EASZ) - B. indicus) obtained randomly from 209 herds spread throughout Uganda were sequentially analysed for Brucella antibodies using the indirect (I) and competitive (C) enzyme linked Immuno-sorbent assays (ELISA). Recent incidences of abortion within the previous 12 months and routine hygienic practices during parturition were explored for public health risks. Brucella antibodies occurred in approximately 8.64% (80/925) and 28.70% (95% CI: 22.52, 34.89) of the sampled individual cattle and herds, respectively. Findings have shown that Ankole and EASZ cattle had similar seroprevalences. Indigenous cattle from the different study agro-ecological zones (AEZs) exhibited varying seroprevalences ranging from approximately 1.78% (95% CI: 0, 5.29) to 19.67% (95% CI: 8.99, 30.35) in the Lake Victoria Crescent (LVC) and North Eastern Drylands (NED) respectively. Significantly higher odds for Brucella antibodies occurred in the NED (OR: 3.40, 95% CI: 1.34, 8.57, p=0.01) inhabited by EASZ cattle compared to the KP (reference category) AEZ. Recent incidences of abortions within the previous 12 months were significantly (p<0.001) associated with seropositive herds. These findings add critical evidence to existing information on the widespread occurrence of brucellosis among indigenous cattle populations in Uganda and could guide allocation of meagre resources for awareness creation

  17. Rural poultry production in two agro-ecological zones of Uganda

    International Nuclear Information System (INIS)

    Illango, J.; Etoori, A.; Olupot, H.; Mabonga, J.

    2002-01-01

    A baseline study on rural poultry production, management and health was conducted in six selected villages in an agro-pastoral and montane zone of Uganda during the wet and dry season. In the 114 rural households visited, the farmers were interviewed by using a questionnaire. Poultry flocks were examined and samples were collected for laboratory investigations. A free-range management system with mixed poultry species was practiced by farmers in both zones. The major poultry flock parameters in the agro-pastoral and montane zone were, respectively, mean flock size of 22 (with a range of 3-65) and 17.5 (with a range of 6-60); mean hen:cock ratio of 2.6 to 1 and 4.8 to 1; mean egg production per hen per year of 8.8 and 11.5; mean hatchability of 70.8% and 85.7%; mean chick mortality of 39.6% and 28.6%. The flock ownership was single, mixed or shared among family households. Women were more involved in most of the activities regarding poultry management, although in both zones a division of labour existed within the household. Men predominantly made the decisions on sale, consumption and treatment of poultry. The most important health problems in the flocks in both zones in the two seasons were coughing, diarrhoea, fowl pox and internal parasites. It was concluded that the major constraints affecting rural poultry production in the two zones were diseases especially Newcastle disease and parasites, inadequate housing and poor feed supplementation especially in the dry season. Women had important responsibilities in rural poultry production in the two zones. The findings form the basis for an assessment of the effects of interventions on rural poultry production in the two zones. (author)

  18. Water Infiltration and Moisture in Soils under Conservation and Conventional Agriculture in Agro-Ecological Zone IIa, Zambia

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    Kjell B. Esser

    2017-06-01

    Full Text Available Conservation agriculture is often presented as being ‘climate smart’ due to anticipated increases in soil moisture. The extent of enhanced water availability in farmers’ fields is, however, poorly documented. This paper presents five data sets describing soil moisture in fields of small-scale conservation and conventional farmers in the Agro-ecological Zone IIa, Zambia. The data include (1 soil cover; (2 time required for visible soil surface saturation, ponding and initial runoff under artificial rainfall; (3 saturated water infiltration rates; (4 weekly soil moisture at six soil depths for two entire rain seasons; and (5 weekly rainfall in each field. Measurements were done for 15 pairs of comparable fields under conservation and conventional agriculture. Pairwise analysis showed significantly shorter time for surface saturation, ponding, and runoff in conservation fields compared to conventional fields. Saturated infiltration rates in riplines and basins of conservation fields were similar to rates in ploughed/hoed fields. Infiltration rates between riplines and between basins were 31–37% lower than those in ploughed/hoed fields. Soil moisture in riplines and basins of conservation fields was higher by an average factor of 1.08 down to 40 cm soil depth, whereas it was lower by an average factor of 0.89 between plant rows compared to fields under conventional tillage. Based on 34,000 soil moisture measurements from 0 to 60 cm depth over two seasons, soils in conservation fields contained a weighted average of 18.2% (vol. water compared to 19.9% (vol. in conventional fields (p < 0.05. The results indicate that small-scale adopters of conservation agriculture are less ‘climate smart’ than conventional farmers in terms of water infiltration and soil moisture.

  19. Development Of Regional Climate Mitigation Baseline For A DominantAgro-Ecological Zone Of Karnataka, India

    Energy Technology Data Exchange (ETDEWEB)

    Sudha, P.; Shubhashree, D.; Khan, H.; Hedge, G.T.; Murthy, I.K.; Shreedhara, V.; Ravindranath, N.H.

    2007-06-01

    Setting a baseline for carbon stock changes in forest andland use sector mitigation projects is an essential step for assessingadditionality of the project. There are two approaches for settingbaselines namely, project-specific and regional baseline. This paperpresents the methodology adopted for estimating the land available formitigation, for developing a regional baseline, transaction cost involvedand a comparison of project-specific and regional baseline. The studyshowed that it is possible to estimate the potential land and itssuitability for afforestation and reforestation mitigation projects,using existing maps and data, in the dry zone of Karnataka, southernIndia. The study adopted a three-step approach for developing a regionalbaseline, namely: i) identification of likely baseline options for landuse, ii) estimation of baseline rates of land-use change, and iii)quantification of baseline carbon profile over time. The analysis showedthat carbon stock estimates made for wastelands and fallow lands forproject-specific as well as the regional baseline are comparable. Theratio of wasteland Carbon stocks of a project to regional baseline is1.02, and that of fallow lands in the project to regional baseline is0.97. The cost of conducting field studies for determination of regionalbaseline is about a quarter of the cost of developing a project-specificbaseline on a per hectare basis. The study has shown the reliability,feasibility and cost-effectiveness of adopting regional baseline forforestry sectormitigation projects.

  20. Heavy metal pollutants in selected organs of African giant rats from three agro-ecological zones of Nigeria: evidence for their role as an environmental specimen bank.

    Science.gov (United States)

    Usende, Ifukibot Levi; Emikpe, Benjamin O; Olopade, James Olukayode

    2017-10-01

    An assessment of the concentration of heavy metals in the liver, brain, kidney, bone, and lungs of African giant rats (AGRs) from three agro-ecological zones of Nigeria having different industrial activities was carried out using atomic absorption spectrophotometer. Twenty adult AGRs from cities in mangrove/freshwater swamp, rainforest, and woodland/tall grass savanna agro-ecological zones of Nigeria were used for this study. AGRs were euthanized, carefully dissected, and the brains, liver, lungs, bone, and kidneys were harvested, digested, and analyzed for concentrations of vanadium (V), lead (Pb), cadmium (Cd), zinc (Zn), selenium (Se), copper (Cu), and iron (Fe). All data generated were evaluated for statistical significance using one-way ANOVA with Tukey's multiple post-test comparison. Results showed the major environmental heavy metal pollutants of the mangrove/freshwater swamp to be vanadium and selenium while those of woodland/tall grass savanna agro-ecological zones were lead, selenium, and zinc. The vanadium concentration was more than twofold higher in the observed tissues of AGR from the mangrove/freshwater swamp, and this may be related to increased exploitation of minerals and the activities of militants in pipeline vandalization in this zone. Interestingly, the highest concentration of this metal was seen in the lungs suggestive of a respiratory route of exposure. Among the potential adverse effects derived from exposure to metals, developmental toxicity is a serious risk. This type of investigation can assist in knowing the level of animal and human exposure to environmental pollutants both in highly industrialized and non-industrialized areas and is more ideal in environmental monitoring. This study therefore suggests AGR as model for ecotoxicological research and environmental specimen banks (ESBs) in this part of Africa.

  1. Yield, quality and nodulation studies of Kersting's groundnut (Macrotyloma geocarpum, (Harms) Merachal and Baudet) in the Coastal Savannah Agro-ecological zone of Ghana

    International Nuclear Information System (INIS)

    Adazebra, G. A.

    2013-07-01

    Two investigations were carried out in the field and laboratory to assess variation in yield and nodulation potential as well as differences in the types of Rhizobia nodulating some local accessions of Kersting's groundnut (Macrotyloma geocarpum Harms) Marechal and Baudet in the Coastal Savannah Agro-Ecological Zone of Ghana. The aim was to obtain information relevant to important yield and nodulation attributes of Kersting's groundnut under prevailing agro-ecological conditions and thereby determine the suitability or otherwise of growing the crop in the Coastal Savannah Agro-Ecological Zone. Ten local accessions of Kersting's groundnuts were obtained from the University for Development Studies (UDS) Nyankpala, Tamale in the Northern Region of Ghana and were evaluated under field conditions at Biotechnology and Nuclear Agriculture Research Institute (BNARI) research farms in the Greater Accra Region. Significant variations were found in most of quantitative characters that were measured for all the ten accessions. Yield studies conducted identified the Kersting's groundnut accession T8 to be the highest in both shoot dry matter production and grain yield per plot with values of 35.09 t ha -1 and 0.84 t ha -1 respectively. Nodulation studies also identified accessions T5 and T3 to be the best in %N content of roots and shoots with values of 1.43% and 3.05% respectively. The nitrogen yield was however, highest in Kersting's groundnut accession T7 for both roots and shoots with values of 12.29 kg ha -1 and 1,178 kg ha -1 respectively. Again, accession T7 was superior in the total plant nitrogen yield with a value of 1190 kg ha -1 . Correlation analysis revealed perfect association (r =1.0) between grain yield and dry seed and a nearly perfect association (r=0.99) between total plant nitrogen yield and nitrogen yield of shoots. Harvest index was highly positively correlated (r=0.72) with dry pod yield. Polymerase Chain Reaction (PCR) analysis was conducted for nine (9

  2. Geographical distribution of myrothecium leaf spot disease of momordica charantial L. caused by myrothecium roridum tode in agro-ecological zone of punjab, Pakistan

    International Nuclear Information System (INIS)

    Din, G. M.; Farooq, S.; Khan, S. N.; Imani, J.; Naz, S.

    2017-01-01

    A series of field surveys were carried out during July-October 2012-14 for the development of disease distribution map and updating the index of Myrothecium leaf spot of Momordica charantia (Bitter gourd) in Punjab province. A total of 29 districts were surveyed belonging to 9 sub agro ecological zones of Punjab. The index was calculated on the basis of incidence, prevalence and severity of the disease. The information from stakeholders was gathered through field scouting, formal and informal discussions. Data on socioeconomics was collected by a structured questionnaire. The symptomatic plants and soil specimens were collected form diseased field and transferred to lab for onward studies on host-pathogen characterization and management. Infection development on the plant was investigated on a (0-5) visual severity rating scale. Fungus was isolated, identified on morphological and molecular characteristics as Myrothecium roridum and cultures were deposited to First Fungal Culture Bank of Pakistan (Accession No. FCBP 1155) and Leibniz-institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Germany (Accession No. DSM 28971). Data gathered highlighted dominance of the disease in mixed cropping zone of Punjab province. Highest disease index (31%) was recorded in mixed cropping zone and lowest (3%) in D.G khan zone. However its severity may vary due to adopted cultural and chemical practices by individual farmers. The investigations strengthen the involvement of irrigation technique, soil type and cropping history in introduction and sporadic occurrence of the disease. (author)

  3. Factors influencing the prevalence and infestation levels of Varroa destructor in honeybee colonies in two highland agro-ecological zones of Uganda.

    Science.gov (United States)

    Chemurot, Moses; Akol, Anne M; Masembe, Charles; de Smet, Lina; Descamps, Tine; de Graaf, Dirk C

    2016-04-01

    Varroa mites are ecto-parasites of honeybees and are a threat to the beekeeping industry. We identified the haplotype of Varroa mites and evaluated potential factors that influence their prevalence and infestation levels in the eastern and western highland agro-ecological zones of Uganda. This was done by collecting samples of adult worker bees between December 2014 and September 2015 in two sampling moments. Samples of bees were screened for Varroa using the ethanol wash method and the mites were identified by molecular techniques. All DNA sequences obtained from sampled mite populations in the two zones were 100 % identical to the Korean Haplotype (AF106899). Mean mite prevalence in the apiaries was 40 and 53 % for the western and eastern zones, respectively, during the first sampling. Over the second sampling, mean mite prevalence increased considerably in the western (59 %) but not in the eastern (51 %) zone. Factors that were associated with Varroa mite infestation levels include altitude, nature of apiary slope and apiary management practices during the first sampling. Our results further showed that Varroa mites were spreading from lower to higher elevations. Feral colonies were also infested with Varroa mites at infestation levels not significantly different from those in managed colonies. Colony productivity and strength were not correlated to mite infestation levels. We recommend a long-term Varroa mite monitoring strategy in areas of varying landscape and land use factors for a clear understanding of possible changes in mite infestation levels among African honeybees for informed decision making.

  4. Distribution of ticks infesting ruminants and risk factors associated with high tick prevalence in livestock farms in the semi-arid and arid agro-ecological zones of Pakistan.

    Science.gov (United States)

    Rehman, Abdul; Nijhof, Ard M; Sauter-Louis, Carola; Schauer, Birgit; Staubach, Christoph; Conraths, Franz J

    2017-04-19

    Tick infestation is the major problem for animal health that causes substantial economic losses, particularly in tropical and subtropical countries. To better understand the spatial distribution of tick species and risk factors associated with tick prevalence in livestock in Pakistan, ticks were counted and collected from 471 animals, including 179 cattle, 194 buffaloes, 80 goats and 18 sheep, on 108 livestock farms in nine districts, covering both semi-arid and arid agro-ecological zones. In total, 3,807 ticks representing four species were collected: Hyalomma anatolicum (n = 3,021), Rhipicephalus microplus (n = 715), Hyalomma dromedarii (n = 41) and Rhipicephalus turanicus (n = 30). The latter species is reported for the first time from the study area. Rhipicephalus microplus was the predominant species in the semi-arid zone, whereas H. anatolicum was the most abundant species in the arid zone. The overall proportion of tick-infested ruminants was 78.3% (369/471). It was highest in cattle (89.9%), followed by buffaloes (81.4%), goats (60.0%) and sheep (11.1%). The median tick burden significantly differed among animal species and was highest in cattle (median 58), followed by buffaloes (median 38), goats (median 19) and sheep (median 4.5). Female animals had significantly higher tick burdens than males and, in large ruminants, older animals carried more ticks than younger animals. The intensity of infestation was significantly lower in indigenous animals compared to exotic and crossbred cows. Analysis of questionnaire data revealed that the absence of rural poultry, not using any acaricides, traditional rural housing systems and grazing were potential risk factors associated with a higher tick prevalence in livestock farms. Absence of rural poultry, not performing acaricide treatments, traditional rural housing systems and grazing were important risk factors associated with higher tick prevalence in livestock farms. Age, gender, breed and animal

  5. Assessment of the Impacts of Climate Change on Maize Production in the Southern and Western Highlands Sub-agro Ecological Zones of Tanzania

    Directory of Open Access Journals (Sweden)

    Philbert M. Luhunga

    2017-08-01

    Full Text Available The Intergovernmental Panel on Climate Change (IPCC fourth assessment report confirmed that climate change is unequivocal. It is coming to us faster with larger impacts and bigger risks than even most climate scientists expected as recently as a few years ago. One particular worry is the disastrous consequence to agriculture and food security sectors in many parts of the world, particularly in developing countries. Adaptation is the only option to reduce the impacts of climate change. However, before planning adaptation policies or strategies to climate change, it is important to assess the impacts of climate change at regional and local scale to have scientific evidence that would guide the formulation of such policies or strategies. In this study the impacts of climate change on rain-fed maize (Zea Mays production in the southern and western highlands sub-agro ecological zones of Tanzania are evaluated. High resolution climate simulations from the Coordinated Regional Climate Downscaling Experiment_Regional Climate Models (CORDEX_RCMs were used as input into the Decision Support System for Agro-technological Transfer (DSSAT to simulate maize yield in the historical climate condition (1971–2000, present (2010–2039, mid (2040–2069, and end (2070–2099 centuries. Daily rainfall, solar radiations, minimum and maximum temperatures for the historical (1971–2000 climate condition and future climate projections (2010–2099 under two Representative Concentration Pathways (RCPs RCP4.5 and RCP 8.5 were used to drive DSSAT. The impacts of climate change were assessed by comparing the average maize yields in historical climate condition against the average of simulated maize yields in the present, mid and end centuries under RCP4.5 and RCP8.5. Results of future maize yields estimates from DSSAT driven by individual RCMs under both RCP scenarios (RCP 4.5 and RCP 8.5 differs from one RCM to another and from one scenario to another. This highlight

  6. Variations between post- and pre-harvest seasons in stunting, wasting, and Infant and Young Child Feeding (IYCF) practices among children 6-23 months of age in lowland and midland agro-ecological zones of rural Ethiopia.

    Science.gov (United States)

    Roba, Kedir Teji; O'Connor, Thomas Pacelli; Belachew, Tefera; O'Brien, Nora Mary

    2016-01-01

    Food availability and access are strongly affected by seasonality in Ethiopia. However, there are little data on seasonal variation in Infant and Young Child Feeding (IYCF) practices and malnutrition among 6-23 months old children in different agro-ecological zones of rural Ethiopia. Socio-demographic, anthropometry and IYCF indicators were assessed in post- and pre-harvest seasons among children aged 6-23 months of age randomly selected from rural villages of lowland and midland agro-ecological zones. Child stunting and underweight increased from prevalence of 39.8% and 26.9% in post-harvest to 46.0% and 31.8% in pre-harvest seasons, respectively. The biggest increase in prevalence of stunting and underweight between post- and pre-harvest seasons was noted in the midland zone. Wasting decreased from 11.6% post-harvest to 8.5% pre-harvest, with the biggest decline recorded in the lowland zone. Minimum meal frequency, minimum acceptable diet and poor dietary diversity increased considerably in pre-harvest compared to post-harvest season in the lowland zone. Feeding practices and maternal age were predictors of wasting, while women's dietary diversity and children age was predictor of child dietary diversity in both seasons. There is seasonal variation in malnutrition and IYCF practices among children 6-23 months of age with more pronounced effect in midland agro-ecological zone. A major contributing factor for child malnutrition may be poor feeding practices. Health information strategies focused on both IYCF practices and dietary diversity of mothers could be a sensible approach to reduce the burden of child malnutrition in rural Ethiopia.

  7. Vulnerability Assessment of the Livelihoods in Tanzania’s Semi-Arid Agro-Ecological Zone under Climate Change Scenarios

    Directory of Open Access Journals (Sweden)

    Msafiri Y. Mkonda

    2018-04-01

    Full Text Available Despite the established literature on the vulnerability to climate change in various parts of Tanzania, it is worthwhile to assess the extent of this vulnerability of the peoples’ livelihoods and predict its future outcome. This is particularly important in the vulnerable ecosystems, that is, the semi-arid zones of Tanzania where the people’s livelihoods are highly attached to the declining local condition. The present study aims to assess the livelihoods vulnerability in Kongwa District, the semi-arid zone of Central Tanzania. In doing so, a wide range of methods were employed during data collection and analyses including surveys, informative interviews, discussions and observation. The study sampled 400 (≤10% respondents during a survey. The Mann-Kendall Test with SPSS V20, Microsoft Excel and Theme content techniques were used for data analyses. The results indicate that climate stress has adversely impacted the quality of soil, vegetation, crop yields and intensified environmental degradation. Since most people depend upon the mentioned affected aspects, it is expected that also the level of livelihood vulnerability has elevated. Further, this situation has greatly contributed to increased poverty and thus, propagates the “tragedy of the common” to the available environmental resources. As a response to increased vulnerability, some farmers have abandoned thousands of hectares of agricultural farms that seemed to be less productive. Despite this, slight measures have been taken by both the government and other key stakeholders to limit vulnerability. The findings of this study provide a theoretical and practical basis for coordinating a sustainable man-environment relationship, ensuring the sustainability of the environment which is the major source of peoples’ livelihoods.

  8. Calibration of Daycent biogeochemical model for rice paddies in three agro-ecological zones in Peninsular India to optimize cropping practices and predict GHG emissions

    Science.gov (United States)

    Rajan, S.; Kritee, K.; Keough, C.; Parton, W. J.; Ogle, S. M.

    2014-12-01

    Rice is a staple for nearly half of the world population with irrigated and rainfed lowland rice accounting for about 80% of the worldwide harvested rice area. Increased atmospheric CO2 and rising temperatures are expected to adversely affect rice yields by the end of the 21st century. In addition, different crop management practices affect methane and nitrous oxide emissions from rice paddies antagonistically warranting a review of crop management practices such that farmers can adapt to the changing climate and also help mitigate climate change. The Daily DayCent is a biogeochemical model that operates on a daily time step, driven by four ecological drivers, i.e. climate, soil, vegetation, and management practices. The model is widely used to simulate daily fluxes of various gases, plant productivity, nutrient availability, and other ecosystem parameters in response to changes in land management and climate. We employed the DayCent model as a tool to optimize rice cropping practices in Peninsular India so as to develop a set of farming recommendations to ensure a triple win (i.e. higher yield, higher profit and lower GHG emissions). We applied the model to simulate both N2O and CH4 emissions, and crop yields from four rice paddies in three different agro-ecological zones under different management practices, and compared them with measured GHG and yield data from these plots. We found that, like all process based models, the biggest constraint in using the model was input data acquisition. Lack of accurate documentation of historic land use and management practices, missing historical daily weather data, and difficulty in obtaining digital records of soil and crop/vegetation parameters related to our experimental plots came in the way of our execution of this model. We will discuss utilization of estimates based on available literature, or knowledge-based values in lieu of missing measured parameters in our simulations with DayCent which could prove to be a

  9. The California Biomass Crop Adoption Model estimates biofuel feedstock crop production across diverse agro-ecological zones within the state, under different future climates

    Science.gov (United States)

    Kaffka, S.; Jenner, M.; Bucaram, S.; George, N.

    2012-12-01

    Both regulators and businesses need realistic estimates for the potential production of biomass feedstocks for biofuels and bioproducts. This includes the need to understand how climate change will affect mid-tem and longer-term crop performance and relative advantage. The California Biomass Crop Adoption Model is a partial mathematical programming optimization model that estimates the profit level needed for new crop adoption, and the crop(s) displaced when a biomass feedstock crop is added to the state's diverse set of cropping systems, in diverse regions of the state. Both yield and crop price, as elements of profit, can be varied. Crop adoption is tested against current farmer preferences derived from analysis of 10 years crop production data for all crops produced in California, collected by the California Department of Pesticide Regulation. Analysis of this extensive data set resulted in 45 distinctive, representative farming systems distributed across the state's diverse agro-ecological regions. Estimated yields and water use are derived from field trials combined with crop simulation, reported elsewhere. Crop simulation is carried out under different weather and climate assumptions. Besides crop adoption and displacement, crop resource use is also accounted, derived from partial budgets used for each crop's cost of production. Systematically increasing biofuel crop price identified areas of the state where different types of crops were most likely to be adopted. Oilseed crops like canola that can be used for biodiesel production had the greatest potential to be grown in the Sacramento Valley and other northern regions, while sugar beets (for ethanol) had the greatest potential in the northern San Joaquin Valley region, and sweet sorghum in the southern San Joaquin Valley. Up to approximately 10% of existing annual cropland in California was available for new crop adoption. New crops are adopted if the entire cropping system becomes more profitable. In

  10. 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. Copyright © 2015 Elsevier

  11. Food Insecurity and Not Dietary Diversity Is a Predictor of Nutrition Status in Children within Semiarid Agro-Ecological Zones in Eastern Kenya

    Directory of Open Access Journals (Sweden)

    Zipporah N. Bukania

    2014-01-01

    Full Text Available Machakos and Makueni counties in Kenya are associated with historical land degradation, climate change, and food insecurity. Both counties lie in lower midland (LM lower humidity to semiarid (LM4, and semiarid (LM5 agroecological zones (AEZ. We assessed food security, dietary diversity, and nutritional status of children and women. Materials and Methods. A total of 277 woman-child pairs aged 15–46 years and 6–36 months respectively, were recruited from farmer households. Food security and dietary diversity were assessed using standard tools. Weight and height, or length in children, were used for computation of nutritional status. Findings. No significant difference (P>0.05 was observed in food security and dietary diversity score (DDS between LM4 and LM5. Stunting, wasting, and underweight levels among children in LM4 and LM5 were comparable as were BMI scores among women. However, significant associations (P=0.023 were found between severe food insecurity and nutritional status of children but not of their caregivers. Stunting was significantly higher in older children (>2 years and among children whose caregivers were older. Conclusion. Differences in AEZ may not affect dietary diversity and nutritional status of farmer households. Consequently use of DDS may lead to underestimation of food insecurity in semiarid settings.

  12. A soil-specific agro-ecological strategy for sustainable production in Argentina farm fields

    Science.gov (United States)

    Zamora, Martin; Barbera, Agustin; Castro-Franco, Mauricio; Hansson, Alejandro; Domenech, Marisa

    2017-04-01

    The continuous increment of frequencies and doses of pesticides, glyphosate and fertilizers, the deterioration of the structure, biotic balance and fertility of soils and the ground water pollution are characteristics of the current Argentinian agricultural model. In this context, agro-ecological innovations are needed to develop a real sustainable agriculture, enhancing the food supply. Precision agriculture technologies can strengthen the expansion of agro-ecological farming in experimental farm fields. The aim of this study was to propose a soil-specific agro-ecological strategy for sustainable production at field scale focused on the use of soil sensors and digital soil mapping techniques. This strategy has been developed in 15 hectares transition agro-ecological farm field, located at Barrow Experimental Station (Lat:-38.322844, Lon:-60.25572) Argentina. The strategy included five steps: (i) to measure apparent electrical conductivity (ECa) and elevation within agro-ecological farm field; (ii) to apply a clustering method using MULTISPATI-PCA algorithm to delimitate three soil-specific zones (Z1, Z2 and Z3); (iii) to determine three soil sampling points by zone, using conditioned Latin hypercube method, in addition to elevation and ECa as auxiliary information; (iv) to collect soil samples at 2-10 cm depth in each point and to determine in laboratory: total organic carbon content (TOC), cation-exchange capacity (CEC), pH and phosphorus availability (P-Bray). In addition, soil bulk density (SBD) was measured at 0-20 cm depth. Finally, (v) according to each soil-specific zone, a management strategy was recommended. Important differences in soil properties among zones could suggest that the strategy developed was able to apply an agro ecological soil-specific practice management. pH and P-Bray were significantly (panimal nutrition will include wheat husk, in order to achieve similar P levels among zones. The proposed strategy demonstrated that the agro-ecology

  13. Agro ecological zonification of the Putumayo Area

    International Nuclear Information System (INIS)

    Villaneda Vivas, E.

    1989-01-01

    The Agro ecological zonification of the Putumayo Area, defines and it quantifies reas according to environmental factors as climate, material parental and soil. In this work it is presented the astronomical localization, the geographical location and the detailed description of each of the agro ecological reas, that conform the Department. This zonification allowed through the delimitation of the different earth classes and of the quantification of the same ones, to extract fundamental information for the knowledge of the geography and for the planning of the agricultural and forest production in rational form. According to the study 85.8 percent of the lands corresponds to the warm thermal soil, 5.7 percent to the half soil, 7.2 percent to the cold and 1.3 percent to the very cold one and nival. As for the counties of humidity 91.6 percent presents humid climatic conditions and 8.4 percent it receives excessive humidity. The vocation of the lands of the Putumayo is however predominant forestall, some reas has possibilities of agricultural exploitation maintaining the vegetable covering. The reas of agricultural vocation has an extension of 43.250 there is equivalent to 1.7 percent of the department the forest areas have an extension of 2.445.250 there is. 27.4 percent presents an agricultural possibility and 30.7 percent they are areas of protection y/o reforestation

  14. Comportamento de vacas em lactação em pastagem manejada sob princípios agroecológicos Behavior of grazing lactating cows in agro-ecological managed pastures

    Directory of Open Access Journals (Sweden)

    Clair Jorge Olivo

    2006-12-01

    Full Text Available Este estudo foi realizado com o objetivo de estudar o comportamento de vacas holandesas em lactação durante o período hibernal em pastagem constituída de capim-elefante (Pennisetum purpureum Schum., aveia preta (Avena strigosa Schreb. e azevém (Lolium multiflorum Lam.. As avaliações foram feitas em três ciclos de pastejo, em 17/06, 04/08 e 16/09 de 2004. Em cada avaliação, utilizaram-se seis vacas entre o 2º e o 5º mês de lactação. O registro de dados foi realizado por dois observadores das 18 às 6h e das 8 às 16h, a cada 10 minutos. As características comportamentais observadas foram os tempos de pastejo em capim-elefante e em aveia + azevém, em pastejo total (pastejo de capim-elefante + aveia e azevém, em ruminação e ócio. Concomitantemente, avaliaram-se os dados da massa de forragem inicial, da qualidade da forragem ingerida e das condições ambientais. A maior intensidade de pastejo ocorreu após cada ordenha, verificando-se posteriormente um decréscimo, tanto durante o dia quanto à noite. Em média, o turno que os animais demandaram mais tempo de pastejo foi o diurno. O tempo destinado pelas vacas ao consumo de aveia e de azevém foi maior no período em que o capim-elefante apresentava menor porcentagem de lâminas foliares. O tempo de ócio diminuiu e o de ruminação aumentou no decorrer dos pastejos, como resultado do declínio na porcentagem de lâminas foliares e da elevação na porcentagem de colmos das espécies de ciclo hibernal. O capim-elefante foi pastejado em todas as avaliações. A presença de espécies de ciclos diferentes possibilitou aos animais equilibrarem a dieta volumosa.The objective of this trial was to study the behavior of lactating Holstein cows grazing pasture containing elephantgrass (Pennisetum purpureum Schum. and a mixture of black oat (Avena strigosa Schreb. plus ryegrass (Lolium multiflorum Lam.. Data from six early to mid lactating cows were collected every 10 minutes interval

  15. Farmers' awareness and perceived benefits of agro-ecological ...

    African Journals Online (AJOL)

    A transition towards intensification of smallholder banana systems requires that the full range of ecosystem services provided by AEI practices are recognized and valued by farmers. Therefore, empowering farmers with knowledge on their agro-ecological systems and locally adapting AEI practices is essential for realization ...

  16. Agro-ecological Differentials in Soybean Crop Evapotranspiration ...

    African Journals Online (AJOL)

    Agro-ecological Differentials in Soybean Crop Evapotranspiration and Implications for Adaptation to Climate Change. ... From this study it could be concluded that coping with climatic variations and future climate change will require complementary irrigation as well as improved crop management practices. Keywords: ...

  17. Agro-Ecología en los Andes Peruanos

    International Development Research Centre (IDRC) Digital Library (Canada)

    El reto. La pobreza en Perú es casi tres veces más extrema en las áreas rurales que en las urbanas, y es aún peor en la región andina. Con frecuencia, se promueve la agro-ecología como forma sustentable de aumentar el rendimiento general agrícola, reducir la pobreza, mitigar el cambio climático y mejorar la seguridad ...

  18. ANALYSIS OF AGRO-ECOLOGICAL SITUATION FOR IDENTIFICATION OF PROBLEMS BY PRA TECHNIQUES IN ADAPTIVE VILLAGE OF KRISHI VIGYAN KENDRA UNDER NEW ALLUVIA ZONE OF MURSHIDABAD DISTRICT OF WEST BENGAL

    Directory of Open Access Journals (Sweden)

    Abhishake Naskar

    2011-07-01

    Full Text Available Agro Ecosystem analysis using the Participatory Rural Appraisal (PRA techniques of an adaptive village (Jainpur of New Alluvial Zone of Murshidabad-Jiaganj block in Murshidabad district, West Bengal revealed that the village basically has rice and jute based farming system. The cropping intensity of the village is 233%. Out of 363 household 80% is engaged in Agriculture, Animal Husbandry and other allied activities. The land availability per household is 0.40 ha. The villagers are mostly scheduled caste. By snow ball technique major problems were identified .On the basis of bio-physical and socio-economic problems, thrust area were selected. Area specific On Farm Trials (OFT in farmers' were conducted on some researchable issues. Front Line Demonstration (FLD, training programme, health camp, awareness camp and other different extension activities were arranged to mitigate the problems.

  19. soil nutrients in agro-ecological zones of swaziland

    African Journals Online (AJOL)

    expected in some low-CBC soils in the hi ghveld. Hi ghveld soils contained significantly more occluded P but ... (1988) reported that, for beef cattle requirements, native forage was deficient in crude protein and. Mg contents ... Zn, Mn and M0 in the Usutu Forest of Swaziland. Ogwang (1988) analysed soil, forage and cattle ...

  20. Soil nutrients in agro-ecological zones of Swaziland | Haque ...

    African Journals Online (AJOL)

    Les contenus en cuivre et Zn étaient généralement élevés dans le bas veld, mais les différences n'étaient pas significatives. Comparés aux niveaux critiques, les contenus en Cu et Fe ont semblé adéquats, mais le Zn et Mn étaient déficients aux certaines sites. Mots Clés: Ions échangeables, maïs, micronutriments, fractions ...

  1. Current anthropogenic pressures on agro-ecological protected coastal wetlands.

    Science.gov (United States)

    Pascual-Aguilar, Juan; Andreu, Vicente; Gimeno-García, Eugenia; Picó, Yolanda

    2015-01-15

    Coastal wetlands are areas that suffer from great pressure. Much of it is due to the rapid development of the surrounding artificial landscapes, where socio-economic factors lead to alterations in the nearby environment, affecting the quality of natural and agricultural systems. This work analyses interconnections among landscapes under the hypothesis that urban-artificial impacts could be detected on soils and waters of an agro-ecological protected area, L'Albufera de Valencia Natural Park, located in the vicinity of the City of Valencia, Spain. The methodological framework developed addresses two types of anthropogenic pressure: (1) direct, due to artificialisation of soil covers that cause soil sealing, and (2) indirect, which are related to water flows coming from urban populations through sewage and irrigation systems and which, ultimately, will be identified by the presence of emerging pharmaceutical contaminants in waters of the protected area. For soil sealing, a methodology based on temporal comparison of two digital layers for the years 1991 and 2011, applying Geographical Information Systems and landscapes metrics, was applied. To determine presence of emerging contaminants, 21 water samples within the Natural Park were analysed applying liquid chromatography tandem mass spectrometry for the detection of 17 pharmaceutical compounds. Results showed that both processes are present in the Natural Park, with a clear geographical pattern. Soil sealing and presence of pharmaceuticals are more intensive in the northern part of the study area. This is related to population density (detection of pharmaceuticals) and land cover conversion from agricultural and natural surfaces to artificial ones (soil sealing). Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The Structure of Backyard Poultry in the Sivas Agro-Ecological Sub-Regions

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    Hasan Eleroğlu

    2015-02-01

    Full Text Available In this research, Sivas province divided into four agro-ecological zones (I, II, III and IV in terms of climate, land form, soil type and land cover. The face-to-face interviews were conducted with a total of 663 families in the 85 villages in order to determine the general structure of backyard poultry in the Sivas. Although women are determined as the primary factor at the rate of 65.6% in feeding-watering, they have a role in the product sales only 34.0% while man have 57.8%. The hens of agro–ecological zones are grouped as white, brown, black, and mixed according to feather colour and the average values of regions are calculated as 3.40, 4.78, 4.25, and 3.85 units/farm, respectively. Significant differences were found between regions in terms of the number of mixed coloured and brown coloured hens. Live weight and egg production were not affected by regional differences and mean live weight and egg weight was founded as 2.17 kg and 58.45 g, respectively. Egg production in the regions I, II, III and IV were determined as 82.35, 89.32, 64.13, and 78.66 units/year, respectively. There was no difference among the regions. It was determined that round type drinkers were used at the rate of 43.3%. Widely used cereal in feeding of chickens is wheat (89.9% followed by mixed feed (5.3%. The 41.24% of total eggs produced is consumed in the farm, 23.20% are served, and 33.57% are sold. Education and health studies to be conducted in the local backyard poultry will help in the short term to the achievement of the organic standards.

  3. Re-classification of agro-ecological regions of Zimbabwe in ...

    African Journals Online (AJOL)

    This study re-classifies the agro-ecological regions (natural regions) of Zimbabwe using soil data, mean-annual rainfall and length of growing season. Rainfall data from selected meteorological stations covered the period 1972- 2006. Soil data were obtained from the soil map of Zimbabwe, while length of growing seasons ...

  4. An agro-ecological framework for integrated nutrient management, with special reference to Kenya

    NARCIS (Netherlands)

    Smaling, E.M.A.

    1993-01-01

    This thesis provides a framework for integrated nutrient management in agricultural land use systems, with particular reference to its impact on productivity, fertilizer use efficiency, and sustainability in well-delimited tracts of land (agro-ecological units), characterized by a specific

  5. Grazing management that regenerates ecosystem function and ...

    African Journals Online (AJOL)

    Adopting a systems view and regenerative philosophy can indicate how to regenerate ecosystem function on commercial-scale agro-ecological landscapes. Adaptive multi-paddock grazing management is an example of an approach for grazinglands. Leading conservation farmers have achieved superior results in ...

  6. Harmonization of rules for VCU testing of maize in comparable agro ecological regions

    Directory of Open Access Journals (Sweden)

    van Waes J.

    2004-01-01

    variety with the same reliability as at national level. For the future variety testing should be realized on the basis of comparable agro-ecological regions with the same crop husbandry and use of the crop. These regions must be clearly defined so that the release of varieties corresponds to the high demands for harvest security and good conservation possibilities of the harvested material. The most important criteria for evaluation should be: harvest security, disease resistance, yield and quality. The basis for a good success for international cooperation is a good knowledge of the national systems: searching for similarities and finding a solution for differences. Once a variety on a catalogue in one European country, the breeding company tries to sell the variety in the whole agro-ecological for which the variety is adapted. Therefore it is important that in the surrounding zones, where the variety is tested, the same criteria are valid. In this presentation we will give a proposal for harmonization and international cooperation for controlling the VCU- value of new maize varieties.

  7. Studies on Biodiversity Diagnosis of Vineyard Farms at the Agro-Ecological Infrastructure Level

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    Liliana Lucia Tomoiagă

    2016-11-01

    Based on the results obtained from the studied vineyards, during 2015, the agro-ecological infrastructure or AEI percent based on the actual area occupied varies between 7% and 35%. Evaluation of the implementation AEI during 2015 in wine-growing farms in Romania showed that the amount of semi-natural elements is not sufficient to stop the loss of biodiversity and their quality needs to be favored also.

  8. Studies on Biodiversity Diagnosis of Vineyard Farms at the Agro-Ecological Infrastructure Level

    OpenAIRE

    Liliana Lucia Tomoiagă; Ligia Ficiu; Gabriel Tabaranu; Cosmina Argatu; Gabi Zaldea; Diana Vizitiu

    2016-01-01

    In Romania, the vine farms are currently spread on approximately 180.000 ha, therefore an important part of biodiversity, functional or planned is present. To avoid a biodiversity decline it is necessary for the vineyards to have a clear evidence of the state of their biodiversity. Based on the results obtained from the studied vineyards, during 2015, the agro-ecological infrastructure or AEI percent based on the actual area occupied varies between 7% and 35%. Evaluation of the implementat...

  9. Household Food Insecurity along an Agro-Ecological Gradient Influences Children's Nutritional Status in South Africa.

    Science.gov (United States)

    Chakona, Gamuchirai; Shackleton, Charlie M

    2017-01-01

    The burden of food insecurity and malnutrition is a severe problem experienced by many poor households and children under the age of five are at high risk. The objective of the study was to examine household food insecurity, dietary diversity, and child nutritional status in relation to local context which influences access to and ability to grow food in South Africa and explore the links and associations between these and household socio-economic status. Using a 48-h dietary recall method, we interviewed 554 women from randomly selected households along a rural-urban continuum in three towns situated along an agro-ecological gradient. The Household Dietary Diversity Scores (HDDS) and the Household Food Insecurity Access Scale (HFIAS) tools were used to measure household dietary diversity and food insecurity, respectively. Anthropometric measurements with 216 children (2-5 years) from the sampled households were conducted using height-for-age and mid-upper arm circumference (MUAC) as indicators of stunting and wasting, respectively. The key findings were that mean HDDS declined with decreasing agro-ecological potential from the wettest site (8.44 ± 1.72) to the other two drier sites (7.83 ± 1.59 and 7.76 ± 1.63). The mean HFIAS followed the opposite trend. Stunted growth was the dominant form of malnutrition detected in 35% of children and 18% of children were wasted. Child wasting was greatest at the site with lowest agro-ecological potential. Children from households with low HDDS had large MUAC which showed an inverse association among HDDS and obesity. Areas with agro-ecological potential had lower prevalence of food insecurity and wasting in children. Agro-ecological potential has significant influence on children's nutritional status, which is also related to household food security and socio-economic status. Dependence on food purchasing and any limitations in households' income, access to land and food, can result in different forms of

  10. Meat production in sheep hybrids in agro-ecological feeding and growing system

    Directory of Open Access Journals (Sweden)

    Maria Sauer

    2014-10-01

    Full Text Available Research points out the effect of feeding young hybrid sheep (Black-faced German x Ţurcană in the conditions of permanent hill grasslands with two technological systems of improving grasslands: the conventional chemical (NPK fertilisation system and the agro-ecological organic fertilisation (sheep folding and over-sowing system. Studies show that the changes in the floristic structure of the grasslands have influenced both fodder yield and quality and meat production and quality. Meat production depending on experimental factors ranged between 189 and 393 kg/ha in the grasslands improved conventionally and between 191 and 461 kg/ha in the grasslands fertilised organically.

  11. Impacts of Agro-Ecological Practices on Soil Losses and Cash Crop Yield

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    Daniela De Benedetto

    2017-12-01

    Full Text Available The aim of this study was to determine the impact of agro-ecological practices on soil losses, by assessing experimental field topography changes and cauliflower crop yield after an artificial extreme rainfall event. Data were collected in an innovative experimental device in which different combined agronomic strategies were tested such as hydraulic arrangement, crop rotations and agro-ecological service crops (ASC introduction. The collection of elevation data was carried out in kinematic way before rainfall, and in punctual surveys to evaluate the effects of artificial event on this parameter. Non-parametric tests were performed to evaluate differences between samples. High-resolution digital elevation models were generated from independent data using kriging, and elevation difference maps were produced. The results indicated that the data before and after the artificial rainfall were statistically different. The raised strips suffered soil loss showing that the strip with permanent intercropping was higher than that in the absence of ASC. A significant rise of elevation was registered in the furrowed strips after rainfall, and deposition of soil occurred at the lowest areas of the experimental field. Moreover, the study showed a relationship between cash crop yield and elevation: the areas with lower elevation (higher flooding were characterized by the lowest yield.

  12. Agro-ecology and irrigation technology : comparative research on farmer-managed irrigation systems in the Mid-hills of Nepal

    NARCIS (Netherlands)

    Parajuli, U.N.

    1999-01-01

    Design and management of irrigation infrastructure in farmer managed irrigation systems (FMISs) are strongly influenced by social and agro-ecological conditions of an area. This thesis analyzes the elements of social and agro-ecological conditions in FMISs in the mid-hills of Nepal and

  13. Identification and characterization of agro-ecological infrastructures by remote sensing

    Science.gov (United States)

    Ducrot, D.; Duthoit, S.; d'Abzac, A.; Marais-Sicre, C.; Chéret, V.; Sausse, C.

    2015-10-01

    Agro-Ecological Infrastructures (AEIs) include many semi-natural habitats (hedgerows, grass strips, grasslands, thickets…) and play a key role in biodiversity preservation, water quality and erosion control. Indirect biodiversity indicators based on AEISs are used in many national and European public policies to analyze ecological processes. The identification of these landscape features is difficult and expensive and limits their use. Remote sensing has a great potential to solve this problem. In this study, we propose an operational tool for the identification and characterization of AEISs. The method is based on segmentation, contextual classification and fusion of temporal classifications. Experiments were carried out on various temporal and spatial resolution satellite data (20-m, 10-m, 5-m, 2.5-m, 50-cm), on three French regions southwest landscape (hilly, plain, wooded, cultivated), north (open-field) and Brittany (farmland closed by hedges). The results give a good idea of the potential of remote sensing image processing methods to map fine agro-ecological objects. At 20-m spatial resolution, only larger hedgerows and riparian forests are apparent. Classification results show that 10-m resolution is well suited for agricultural and AEIs applications, most hedges, forest edges, thickets can be detected. Results highlight the multi-temporal data importance. The future Sentinel satellites with a very high temporal resolution and a 10-m spatial resolution should be an answer to AEIs detection. 2.50-m resolution is more precise with more details. But treatments are more complicated. At 50-cm resolution, accuracy level of details is even higher; this amplifies the difficulties previously reported. The results obtained allow calculation of statistics and metrics describing landscape structures.

  14. Delineation Lithuanian agricultural land for agro-ecological suitability for farming using soil and terrain criteria

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    Jarasiunas Gintaras

    2017-03-01

    Full Text Available The aim of investigation is to analyse and classify the state of agricultural land affected by naturalbiophysical, that is, soil and terrain-slope, handicaps on its overall agro-ecological suitability for agricultural use. For the classification of land for suitability with respect to sustainable use and efficient protection, the following actual criteria were selected: soil texture, soil drainage and terrainslope. For identifying the relatively homogeneous areas, the Ward hierarchical cluster method was used. According to our estimates, Lithuanian agricultural land with unfavourable soil texture, poorly soil drainage and steep slopes covers an area of 33.59, 4.76 and 1.03% of total agricultural area, respectively. On the basis of functional classification of state of agro-ecological conditions of Lithuania, two orders of suitability (S-suitable, N-not suitable and five land suitability classes were identified and delineated: S1 (highly suitable included 10 district municipalities, S2 (moderately suitable included 12 district municipalities, S3 (marginally suitable included 15 district municipalities, N1 (currently not suitable included 10 district municipalities and N2 (permanently not suitable included 4 district municipalities. S3 occupies the largest (29.80% share of the Lithuanian territory and N2 the least (5.66%. The land suitable for agriculture means with suitability classes S1, S2 and S3 was found on an area of 2,960,562 ha, which is 81.6% of the total land. In addition, soil texture was the most important factor causing differences in the classes of suitability. On the basis of natural limiting factors from an agronomic and eco-environmental perspective, the optimal sustainable development in agrosphere and a balanced-practical concept of land management and proper land use policy is presented. It is a reasonable base for agroecological regionalisation of Lithuania.

  15. Assessing farmers' interest in agroforestry in two contrasting agro-ecological zones of Rwanda

    NARCIS (Netherlands)

    Bucagu, C.; Vanlauwe, B.; Wijk, van M.T.; Giller, K.E.

    2013-01-01

    Uptake and management of agroforestry technologies differs among farms in Rwanda and needs to be documented as a basis for shaping future research and development programs. The objective of this study was to investigate current agroforestry practices, farmers’ preferences, tree management and

  16. Ectoparasites of small ruminants in three selected agro-ecological sites of Tigray Region, Ethiopia.

    Science.gov (United States)

    Mulugeta, Y; Yacob, Hailu T; Ashenafi, Hagos

    2010-08-01

    A study on ectoparasites of small ruminants in three selected agro-ecological sites of Tigray Region, Ethiopia disclosed an overall prevalence of 55.5% and 58% in each examined 750 sheep and goats, respectively. In the sheep population, Melophagus ovinus (19.1%), tick infestations (16%), Damalinia ovis (15.3%), Linognathus africanus (11.5%), and Ctenocephalides felis (9%) were the major ectoparasites. The major ectoparasites identified in goats were tick infestations (29.7%), L. africanus (27.9%), Sarcoptes scabiei var. caprae (12.5%), C. felis (11.1%), and Demodex caprae (6.8%). In sheep, there was a statistically significant difference (P ovinus, L. africanus, and ticks between midland and highland. In goats, the risk of Sarcoptes scabiei var. caprae infestation in midland (odds ratio (OR) = 17.2, P < 0.001) and lowland (OR = 5.2, P < 0.001) was 17.2 times and 5.2 times, respectively, higher than the highland. Favorable climatic conditions, backward level of management, poor level of consciousness and awareness of farmers, and weak animal health extension services are believed to have contributed for widespread distribution and occurrences of ectoparasites. The growing threat of ectoparasites to small ruminant production and the tanning industry needs well-coordinated and urgent control intervention.

  17. Household Food Insecurity along an Agro-Ecological Gradient Influences Children’s Nutritional Status in South Africa

    Directory of Open Access Journals (Sweden)

    Gamuchirai Chakona

    2018-01-01

    Full Text Available The burden of food insecurity and malnutrition is a severe problem experienced by many poor households and children under the age of five are at high risk. The objective of the study was to examine household food insecurity, dietary diversity, and child nutritional status in relation to local context which influences access to and ability to grow food in South Africa and explore the links and associations between these and household socio-economic status. Using a 48-h dietary recall method, we interviewed 554 women from randomly selected households along a rural–urban continuum in three towns situated along an agro-ecological gradient. The Household Dietary Diversity Scores (HDDS and the Household Food Insecurity Access Scale (HFIAS tools were used to measure household dietary diversity and food insecurity, respectively. Anthropometric measurements with 216 children (2–5 years from the sampled households were conducted using height-for-age and mid-upper arm circumference (MUAC as indicators of stunting and wasting, respectively. The key findings were that mean HDDS declined with decreasing agro-ecological potential from the wettest site (8.44 ± 1.72 to the other two drier sites (7.83 ± 1.59 and 7.76 ± 1.63. The mean HFIAS followed the opposite trend. Stunted growth was the dominant form of malnutrition detected in 35% of children and 18% of children were wasted. Child wasting was greatest at the site with lowest agro-ecological potential. Children from households with low HDDS had large MUAC which showed an inverse association among HDDS and obesity. Areas with agro-ecological potential had lower prevalence of food insecurity and wasting in children. Agro-ecological potential has significant influence on children’s nutritional status, which is also related to household food security and socio-economic status. Dependence on food purchasing and any limitations in households’ income, access to land and food, can result in

  18. Household Food Insecurity along an Agro-Ecological Gradient Influences Children’s Nutritional Status in South Africa

    Science.gov (United States)

    Chakona, Gamuchirai; Shackleton, Charlie M.

    2018-01-01

    The burden of food insecurity and malnutrition is a severe problem experienced by many poor households and children under the age of five are at high risk. The objective of the study was to examine household food insecurity, dietary diversity, and child nutritional status in relation to local context which influences access to and ability to grow food in South Africa and explore the links and associations between these and household socio-economic status. Using a 48-h dietary recall method, we interviewed 554 women from randomly selected households along a rural–urban continuum in three towns situated along an agro-ecological gradient. The Household Dietary Diversity Scores (HDDS) and the Household Food Insecurity Access Scale (HFIAS) tools were used to measure household dietary diversity and food insecurity, respectively. Anthropometric measurements with 216 children (2–5 years) from the sampled households were conducted using height-for-age and mid-upper arm circumference (MUAC) as indicators of stunting and wasting, respectively. The key findings were that mean HDDS declined with decreasing agro-ecological potential from the wettest site (8.44 ± 1.72) to the other two drier sites (7.83 ± 1.59 and 7.76 ± 1.63). The mean HFIAS followed the opposite trend. Stunted growth was the dominant form of malnutrition detected in 35% of children and 18% of children were wasted. Child wasting was greatest at the site with lowest agro-ecological potential. Children from households with low HDDS had large MUAC which showed an inverse association among HDDS and obesity. Areas with agro-ecological potential had lower prevalence of food insecurity and wasting in children. Agro-ecological potential has significant influence on children’s nutritional status, which is also related to household food security and socio-economic status. Dependence on food purchasing and any limitations in households’ income, access to land and food, can result in different forms

  19. Agro-ecological potential of the cup plant (Silphium perfoliatum L.) from a biodiversity perspective

    Science.gov (United States)

    Schrader, Stefan; Schorpp, Quentin; Lena Müller, Anna; Dauber, Jens

    2017-04-01

    The cup plant (Silphium perfoliatum L.) is an alternative bioenergy crop that may contribute to a more environmentally friendly production of renewable resources. The potential benefits of the cup plant are the perennial cultivation without tillage and its flowering-characteristics. Hence it can be hypothesized that beneficial organisms are promoted which in turn improves the provision of ecosystem services like soil fertility and pollination. To date biomass production in Germany is based mainly on cropping systems like intensive maize cultivation that bear a risk for biodiversity and ecosystem services. The importance to counteract this development increases considering the large land requirements for significant generation of energy from biomass. To what extent cropping of the cup plant meets the expectations of a sustainable biomass production was investigated within a comprehensive assessment of soil fauna communities (earthworms, collembolans, nematodes) including their functional groups as well as pollinating insects (bees and hoverflies) including the quantification of pollen and nectar in cup-plant cultivation systems with a crop management close to agricultural practice. From the results it became obvious that the cup plant as a bioenergy crop has got the necessary potential to mitigate the negative development of biodiversity and ecosystem services, especially in regions with a large share of maize monocultures. This agro-ecological potential can only be reached if certain agronomic requirements are met, i.e. a late harvest and cultivation periods of at least five years. Under these conditions the landscape context has to be considered. Semi-natural habitats in the surrounding landscape are required for nesting and larval development of wild pollinator groups. The development of biological functions in soil is tied to the land use history i.e. previous land use: Positive developments are expected for conversion of intensively managed crop fields to the

  20. An Integrative Database System of Agro-Ecology for the Black Soil Region of China

    Directory of Open Access Journals (Sweden)

    Cuiping Ge

    2007-12-01

    Full Text Available The comprehensive database system of the Northeast agro-ecology of black soil (CSDB_BL is user-friendly software designed to store and manage large amounts of data on agriculture. The data was collected in an efficient and systematic way by long-term experiments and observations of black land and statistics information. It is based on the ORACLE database management system and the interface is written in PB language. The database has the following main facilities:(1 runs on Windows platforms; (2 facilitates data entry from *.dbf to ORACLE or creates ORACLE tables directly; (3has a metadata facility that describes the methods used in the laboratory or in the observations; (4 data can be transferred to an expert system for simulation analysis and estimates made by Visual C++ and Visual Basic; (5 can be connected with GIS, so it is easy to analyze changes in land use ; and (6 allows metadata and data entity to be shared on the internet. The following datasets are included in CSDB_BL: long-term experiments and observations of water, soil, climate, biology, special research projects, and a natural resource survey of Hailun County in the 1980s; images from remote sensing, graphs of vectors and grids, and statistics from Northeast of China. CSDB_BL can be used in the research and evaluation of agricultural sustainability nationally, regionally, or locally. Also, it can be used as a tool to assist the government in planning for agricultural development. Expert systems connected with CSDB_BL can give farmers directions for farm planting management.

  1. Persistence of highly pathogenic avian influenza H5N1 virus defined by agro-ecological niche.

    Science.gov (United States)

    Hogerwerf, Lenny; Wallace, Rob G; Ottaviani, Daniela; Slingenbergh, Jan; Prosser, Diann; Bergmann, Luc; Gilbert, Marius

    2010-06-01

    The highly pathogenic avian influenza (HPAI) H5N1 virus has spread across Eurasia and into Africa. Its persistence in a number of countries continues to disrupt poultry production, impairs smallholder livelihoods, and raises the risk a genotype adapted to human-to-human transmission may emerge. While previous studies identified domestic duck reservoirs as a primary risk factor associated with HPAI H5N1 persistence in poultry in Southeast Asia, little is known of such factors in countries with different agro-ecological conditions, and no study has investigated the impact of such conditions on HPAI H5N1 epidemiology at the global scale. This study explores the patterns of HPAI H5N1 persistence worldwide, and for China, Indonesia, and India includes individual provinces that have reported HPAI H5N1 presence during the 2004-2008 period. Multivariate analysis of a set of 14 agricultural, environmental, climatic, and socio-economic factors demonstrates in quantitative terms that a combination of six variables discriminates the areas with human cases and persistence: agricultural population density, duck density, duck by chicken density, chicken density, the product of agricultural population density and chicken output/input ratio, and purchasing power per capita. The analysis identifies five agro-ecological clusters, or niches, representing varying degrees of disease persistence. The agro-ecological distances of all study areas to the medoid of the niche with the greatest number of human cases are used to map HPAI H5N1 risk globally. The results indicate that few countries remain where HPAI H5N1 would likely persist should it be introduced.

  2. Persistence of highly pathogenic avian influenza H5N1 virus defined by agro-ecological niche

    Science.gov (United States)

    Hogerwerf, Lenny; Wallace, Rob G.; Ottaviani, Daniela; Slingenbergh, Jan; Prosser, Diann; Bergmann, Luc; Gilbert, Marius

    2010-01-01

    The highly pathogenic avian influenza (HPAI) H5N1 virus has spread across Eurasia and into Africa. Its persistence in a number of countries continues to disrupt poultry production, impairs smallholder livelihoods, and raises the risk a genotype adapted to human-to-human transmission may emerge. While previous studies identified domestic duck reservoirs as a primary risk factor associated with HPAI H5N1 persistence in poultry in Southeast Asia, little is known of such factors in countries with different agro-ecological conditions, and no study has investigated the impact of such conditions on HPAI H5N1 epidemiology at the global scale. This study explores the patterns of HPAI H5N1 persistence worldwide, and for China, Indonesia, and India includes individual provinces that have reported HPAI H5N1 presence during the 2004–2008 period. Multivariate analysis of a set of 14 agricultural, environmental, climatic, and socio-economic factors demonstrates in quantitative terms that a combination of six variables discriminates the areas with human cases and persistence: agricultural population density, duck density, duck by chicken density, chicken density, the product of agricultural population density and chicken output/input ratio, and purchasing power per capita. The analysis identifies five agro-ecological clusters, or niches, representing varying degrees of disease persistence. The agro-ecological distances of all study areas to the medoid of the niche with the greatest number of human cases are used to map HPAI H5N1 risk globally. The results indicate that few countries remain where HPAI H5N1 would likely persist should it be introduced.

  3. Research on the integration of teaching content of core courses in Agro-ecological environmental specialties of higher vocational colleges

    Science.gov (United States)

    Chen, Juan; Ma, Guosheng

    2018-02-01

    Curriculum is the means to cultivate higher vocational talents. On the basis of analyzing the core curriculum problems of curriculum reform and Agro-ecological environmental specialties in higher vocational colleges, this paper puts forward the optimization and integration measures of 6 core courses, including “Eco-environment Repair Technology”, “Agro-environmental Management Plan”, “Environmental Engineering Design”, “Environmental Pest Management Technology”, “Agro-chemical Pollution Control Technology”, “Agro-environmental Testing and Analysis”. It integrates the vocational qualification certificate education and professional induction certificate training items, and enhances the adaptability, skills and professionalism of professional core curriculum.

  4. SDS-PAGE For Glutenins Protein of Some Durum Wheat Cultivars coming from Different Agro-Ecological Areas

    Directory of Open Access Journals (Sweden)

    Ahmed Salih Khalaf

    Full Text Available Ten durum wheat cultivars of different agro-ecological resources were involved, and subjected to electrophoresis for their glutenin subunits. Glutenin subunits resolution and coding based on relative mobility. Cultivars shown differences in migration patterns and categorized into different groups in accordance to possessing a particular subunits. Caronia and Haurani were similar as they possess subunits 6 + 15, while ACSAD 65, Simeto, and Waha possess subunits 7 + 8; but Korifla and Gidara 2 and Creso possess subunits 6 + 8 with an additional subunit 20 for the Creso. Lastly, Cham 5 and Om rabi 5 possess subunits 20.

  5. History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting

    Directory of Open Access Journals (Sweden)

    Utzinger Jürg

    2008-10-01

    Full Text Available Abstract Background Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. Methods The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007 in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. Results One case of P. vivax was detected among the 363 schoolchildren examined (0.28%. The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%. Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. Conclusion The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against

  6. Agro-ecology, household economics and malaria in Uganda: empirical correlations between agricultural and health outcomes.

    Science.gov (United States)

    Wielgosz, Benjamin; Kato, Edward; Ringler, Claudia

    2014-07-03

    This paper establishes empirical evidence relating the agriculture and health sectors in Uganda. The analysis explores linkages between agricultural management, malaria and implications for improving community health outcomes in rural Uganda. The goal of this exploratory work is to expand the evidence-base for collaboration between the agricultural and health sectors in Uganda. The paper presents an analysis of data from the 2006 Uganda National Household Survey using a parametric multivariate Two-Limit Tobit model to identify correlations between agro-ecological variables including geographically joined daily seasonal precipitation records and household level malaria risk. The analysis of agricultural and environmental factors as they affect household malaria rates, disaggregated by age-group, is inspired by a complimentary review of existing agricultural malaria literature indicating a gap in evidence with respect to agricultural management as a form of malaria vector management. Crop choices and agricultural management practices may contribute to vector control through the simultaneous effects of reducing malaria transmission, improving housing and nutrition through income gains, and reducing insecticide resistance in both malaria vectors and agricultural pests. The econometric results show the existence of statistically significant correlations between crops, such as sweet potatoes/yams, beans, millet and sorghum, with household malaria risk. Local environmental factors are also influential- daily maximum temperature is negatively correlated with malaria, while daily minimum temperature is positively correlated with malaria, confirming trends in the broader literature are applicable to the Ugandan context. Although not necessarily causative, the findings provide sufficient evidence to warrant purposefully designed work to test for agriculture health causation in vector management. A key constraint to modeling the agricultural basis of malaria transmission is

  7. Detection and spatial distribution of multiple-contaminants in agro-ecological Mediterranean wetlands (Marjal de Pego-Oliva, Spain)

    Science.gov (United States)

    Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Gimeno-García, Eugenia; Picó, Yolanda; Masia, Ana

    2015-04-01

    Socio economic activities are more and more producing amounts (in quantity and quality) of non desirable chemical substances (contaminants) that can be found in open air environments. As many of these products persist and may also circulate among environmental compartments, the cumulative incidence of such multiple contaminants combination may be a cause of treat that should not exists taking only in consideration concentrations of each contaminant individually because the number and the type of compounds are not known, as well as their cumulative and interaction effects. Thus prior to any further work analyzing the environmental risk of multiple contaminants their identification and level of concentration is required. In this work the potential presence of multiple contaminants of anthropogenic origin in a protected agro-ecological Mediterranean wetland is studied: the Pego-Oliva Marsh Natural Park (Valencian Community, Spain), which is characterized by a long history of human pressures, such as marsh transformation for agricultural uses. Two major groups of relevant pollutants have been targeted according o two distinct environmental matrices: seven heavy metals in soils (Cd, Co, Cr, Cu, Ni, Pb and Zn) and fourteen emerging contaminants /drugs of abuse in surface waters of the natural lagoon, rivers and artificial irrigation networks (6-ACMOR, AMP, BECG, COC, ECGME, HER, KET, MAMP, MDA, MDMA, MET, MOR, THC, THC-COOH). The wetland was divided in nine representative zones with different types of land cover and land use. For soils, 24 samples were collected and for waters 33 taking in consideration the spatial representativeness of the above mention nine environments. Spatial analysis applying Geographical Information Systems to determine areas with greater incidence of both types of contaminants were also performed. With regard to heavy metals, Zn showed values under the detection limits in all samples, the remainder metals appeared in concentrations surpassing the

  8. Utilization of farm animal genetic resources in a changing agro-ecological environment in the Nordic countries

    DEFF Research Database (Denmark)

    Kantanen, Juha; Løvendahl, Peter; Strandberg, Erling

    2015-01-01

    Livestock production is the most important component of northern European agriculture and contributes to and will be affected by climate change. Nevertheless, the role of farm animal genetic resources in the adaptation to new agro-ecological conditions and mitigation of animal production’s effects....... There are several genetic questions that should be considered in strategies promoting adaptation to climate change and mitigation of environmental effects of livestock production. For example, it may become important to choose among breeds and even among farm animal species according to their suitability...... on climate change has been inadequately discussed despite there being several important associations between animal genetic resources and climate change issues. The sustainability of animal production systems and future food security require access to a wide diversity of animal genetic resources...

  9. Utilization of farm animal genetic resources in a changing agro-ecological environment in the Nordic countries.

    Science.gov (United States)

    Kantanen, Juha; Løvendahl, Peter; Strandberg, Erling; Eythorsdottir, Emma; Li, Meng-Hua; Kettunen-Præbel, Anne; Berg, Peer; Meuwissen, Theo

    2015-01-01

    Livestock production is the most important component of northern European agriculture and contributes to and will be affected by climate change. Nevertheless, the role of farm animal genetic resources in the adaptation to new agro-ecological conditions and mitigation of animal production's effects on climate change has been inadequately discussed despite there being several important associations between animal genetic resources and climate change issues. The sustainability of animal production systems and future food security require access to a wide diversity of animal genetic resources. There are several genetic questions that should be considered in strategies promoting adaptation to climate change and mitigation of environmental effects of livestock production. For example, it may become important to choose among breeds and even among farm animal species according to their suitability to a future with altered production systems. Some animals with useful phenotypes and genotypes may be more useful than others in the changing environment. Robust animal breeds with the potential to adapt to new agro-ecological conditions and tolerate new diseases will be needed. The key issue in mitigation of harmful greenhouse gas effects induced by livestock production is the reduction of methane (CH4) emissions from ruminants. There are differences in CH4 emissions among breeds and among individual animals within breeds that suggest a potential for improvement in the trait through genetic selection. Characterization of breeds and individuals with modern genomic tools should be applied to identify breeds that have genetically adapted to marginal conditions and to get critical information for breeding and conservation programs for farm animal genetic resources. We conclude that phenotyping and genomic technologies and adoption of new breeding approaches, such as genomic selection introgression, will promote breeding for useful characters in livestock species.

  10. Utilization of farm animal genetic resources in a changing agro-ecological environment in the Nordic countries

    Directory of Open Access Journals (Sweden)

    Juha eKantanen

    2015-02-01

    Full Text Available Livestock production is the most important component of northern European agriculture and contributes to and will be affected by climate change. Nevertheless, the role of farm animal genetic resources in the adaptation to new agro-ecological conditions and mitigation of animal production’s effects on climate change has been inadequately discussed despite there being several important associations between animal genetic resources and climate change issues. The sustainability of animal production systems and future food security require access to a wide diversity of animal genetic resources.There are several genetic questions that should be considered in strategies promoting adaptation to climate change and mitigation of environmental effects of livestock production. For example, it may become important to choose among breeds and even among farm animal species according to their suitability to a future with altered production systems. Some animals with useful phenotypes and genotypes may be more useful than others in the changing environment.Robust animal breeds with the potential to adapt to new agro-ecological conditions and tolerate new diseases will be needed. The key issue in mitigation of harmful greenhouse gas effects induced by livestock production is the reduction of methane (CH4 emissions from ruminants. There are differences in CH4 emissions among breeds and among individual animals within breeds that suggest a potential for improvement in the trait through genetic selection.Characterization of breeds and individuals with modern genomic tools should be applied to identify breeds that have genetically adapted to marginal conditions and to get critical information for breeding and conservation programmes for farm animal genetic resources. We conclude that phenotyping and genomic technologies and adoption of new breeding approaches, such as genomic selection introgression, will promote breeding for useful characters in livestock species.

  11. Effects of Introduced and Indigenous Viruses on Native Plants: Exploring Their Disease Causing Potential at the Agro-Ecological Interface

    Science.gov (United States)

    Vincent, Stuart J.; Coutts, Brenda A.; Jones, Roger A. C.

    2014-01-01

    The ever increasing movement of viruses around the world poses a major threat to plants growing in cultivated and natural ecosystems. Both generalist and specialist viruses move via trade in plants and plant products. Their potential to damage cultivated plants is well understood, but little attention has been given to the threat such viruses pose to plant biodiversity. To address this, we studied their impact, and that of indigenous viruses, on native plants from a global biodiversity hot spot in an isolated region where agriculture is very recent (plant species, we used introduced generalist and specialist viruses, and indigenous viruses, to inoculate plants of 15 native species belonging to eight families. We also measured resulting losses in biomass and reproductive ability for some host–virus combinations. In addition, we sampled native plants growing over a wide area to increase knowledge of natural infection with introduced viruses. The results suggest that generalist introduced viruses and indigenous viruses from other hosts pose a greater potential threat than introduced specialist viruses to populations of native plants encountered for the first time. Some introduced generalist viruses infected plants in more families than others and so pose a greater potential threat to biodiversity. The indigenous viruses tested were often surprisingly virulent when they infected native plant species they were not adapted to. These results are relevant to managing virus disease in new encounter scenarios at the agro-ecological interface between managed and natural vegetation, and within other disturbed natural vegetation situations. They are also relevant for establishing conservation policies for endangered plant species and avoiding spread of damaging viruses to undisturbed natural vegetation beyond the agro-ecological interface. PMID:24621926

  12. Effects of introduced and indigenous viruses on native plants: exploring their disease causing potential at the agro-ecological interface.

    Science.gov (United States)

    Vincent, Stuart J; Coutts, Brenda A; Jones, Roger A C

    2014-01-01

    The ever increasing movement of viruses around the world poses a major threat to plants growing in cultivated and natural ecosystems. Both generalist and specialist viruses move via trade in plants and plant products. Their potential to damage cultivated plants is well understood, but little attention has been given to the threat such viruses pose to plant biodiversity. To address this, we studied their impact, and that of indigenous viruses, on native plants from a global biodiversity hot spot in an isolated region where agriculture is very recent (viruses readily. To establish their potential to cause severe or mild systemic symptoms in different native plant species, we used introduced generalist and specialist viruses, and indigenous viruses, to inoculate plants of 15 native species belonging to eight families. We also measured resulting losses in biomass and reproductive ability for some host-virus combinations. In addition, we sampled native plants growing over a wide area to increase knowledge of natural infection with introduced viruses. The results suggest that generalist introduced viruses and indigenous viruses from other hosts pose a greater potential threat than introduced specialist viruses to populations of native plants encountered for the first time. Some introduced generalist viruses infected plants in more families than others and so pose a greater potential threat to biodiversity. The indigenous viruses tested were often surprisingly virulent when they infected native plant species they were not adapted to. These results are relevant to managing virus disease in new encounter scenarios at the agro-ecological interface between managed and natural vegetation, and within other disturbed natural vegetation situations. They are also relevant for establishing conservation policies for endangered plant species and avoiding spread of damaging viruses to undisturbed natural vegetation beyond the agro-ecological interface.

  13. Response of vegetation and soil carbon and nitrogen storage to grazing intensity in semi-arid grasslands in the agro-pastoral zone of northern china.

    Science.gov (United States)

    Xu, Min-Yun; Xie, Fan; Wang, Kun

    2014-01-01

    Overgrazing has been the primary cause of grassland degradation in the semi-arid grasslands of the agro-pastoral transition zone in northern China. However, there has been little evidence regarding grazing intensity impacts on vegetation change and soil C and N dynamics in this region. This paper reports the effects of four grazing intensities namely un-grazed (UG), lightly grazed (LG), moderately grazed (MG) and heavily grazed (HG) on vegetation characteristics and soil properties of grasslands in the Guyuan county in the agro-pastoral transition region, Hebei province, northern China. Our study showed that the vegetation height, canopy cover, plant species abundance and aboveground biomass decreased significantly with increased grazing intensity. Similarly, soil organic carbon (SOC) and total nitrogen (STN) in the 0-50 cm were highest under UG (13.3 kg C m-2 and 1.69 kg N m-2) and lowest under HG (9.8 kg C m-2 and 1.22 kg N m-2). Soil available nitrogen (SAN) was significantly lower under HG (644 kg N hm-2) than under other treatments (725-731 kg N hm-2) in the 0-50 cm. Our results indicate that the pasture management of "take half-leave half" has potential benefits for primary production and livestock grazing in this region. However, grazing exclusion was perhaps the most effective choice for restoring degraded grasslands in this region. Therefore, flexible rangeland management should be adopted in this region.

  14. Agro-ecological aspects when applying the remaining products from agricultural biogas processes as fertilizer in crop production

    Energy Technology Data Exchange (ETDEWEB)

    Bermejo Dominguez, Gabriela

    2012-06-11

    With the increase of biogas production in recent years, the amount of digestates or the remaining residues increased accordingly. Every year in Germany more than 50 million tons of digestates are produced, which are used as fertilizer. Thus nutrients return into the circulation of agricultural ecosystems. However, the agro-ecological effects have not been deeply researched until now. For this reason, the following parameters were quantified: the influence of dry and liquid fermentation products on the yield of three selected crops in comparison to or in combination with mineral-N-fertilizers in on-farm experiments; the growth, development and yield of two selected crops in comparison to mineral-N-fertilizer, liquid manure and farmyard manure in a randomized complete block design; selected soil organisms as compared to mineral-N-fertilizer, liquid manure and farmyard manure in a randomized complete block design. In addition, the mineralization of dry and wet digestates in comparison with liquid manure and farmyard manure was investigated in order to evaluate the effects of different fertilizers on the humus formation under controlled conditions. The 2-year results of on-farm experiments showed that for a sandy soil, the combination of digestates in autumn and mineral-N-fertilizer in spring for winter crops (wheat, rye and rape) brought the highest yields. The wet digestate achieved the highest dry-matter yield as the only fertilizer for maize in spring. In a clayey soil, the use of 150 kg ha{sup -1} N mineral-N-fertilizer brought the highest grain yield. These results were similar to the ones obtained by the application of dry digestates, if they were applied in two doses. Maize showed no signif-icant differences between the dry-matter yields of the different treatments. The results in the field experiments from 2009 to 2011 showed that the effect of digestates on the yield of winter wheat and Sorghum sudanense was up to 15 % lower than the effect of the mineral

  15. Is there willingness to buy and pay a surcharge for agro-ecological products? Case study of the production of vegetables in Xochimilco, Mexico.

    Science.gov (United States)

    Revollo-Fernández, Daniel

    2016-04-01

    Around the world there are approximately 2.5 trillion small-scale farmers, most of them subsistence farmers. In the 1970s the green revolution unfolded, which brought benefits to some producers, but it also brought costs, especially for small producers. Agro-ecology is presented as an alternative, but it is necessary to examine whether it is accepted in the markets, especially in developing countries. This study proves that there is a potential market, in this case in Mexico, but that it will depend on some socio-economic variables such as age, income, gender, product information, among others. Similarly, it is evident that buyers are willing to make an additional payment as compensation. Agro-ecology should not be considered as subsistence farming incompatible with the markets. It offers good prospects for increasing production and improving the sustainability of agriculture in marginal areas with few economic resources. © 2015 Society of Chemical Industry.

  16. Study on Regional Agro-ecological Risk and Pressure Supported by City Expansion Model and SERA Model - A Case Study of Selangor, Malaysia

    OpenAIRE

    Shi , Xiaoxia; Zhang , Yaoli; Peng , Cheng

    2010-01-01

    International audience; This study revealed the influence of city expansion on the agro-ecological risks through the analysis and prediction of city expansion in different periods and study on the change of risk and pressure on the regional agricultural eco-environment. The city expansion of Selangor, Malaysia (as a case) was predicted based on relevant spatial and attribute data as well as simulation prediction models of city expansion. Subsequently, the ecological risk and pressure in the s...

  17. The population structure of wild sorghum species in agro-ecological ...

    African Journals Online (AJOL)

    There is need to understand the genetic structure of wild sorghums that grow alongside cultivated traditional sorghum varieties in order to assess the potential effect of crop genes in wild populations. In this study, 175 wild sorghum samples were collected from 13 agroecological zones (AEZs) from three counties in Western ...

  18. AGRO-ECOLOGICAL AND SOCIO-ECONOMIC ASPECTS OF CROP PROTECTION IN CHILI-BASED AGRIBUSINESS IN CENTRAL JAVA

    Directory of Open Access Journals (Sweden)

    Joko Mariyono

    2017-11-01

    Full Text Available The purpose of this study is to analyze the socio-economic and agro-ecological aspects of chili production in three selected communities of three districts —Magelang, Brebes, and Rembang—that represent distinct agro-ecosystems of chili cultivation within Central Java province. This is to answer a problem statement that chili farming still faces crop protection aspects as limiting factors in chili production. This study uses quantitative descriptive methods. Data were compiled from a survey of 160 chili farmers in 2010-2011. The results show that yield loss due to pests and diseases was considerable, and some of these problems were becoming difficult to control. The three top pests were thrips, mites, and whitefly; and the top three diseases were Anthracnose, Gemini-viruses, and Phytophthora. During the wet season, risk of anthracnose was very high; in the dry season, risk of yield lost to Gemini-viruses and Phytophthora was high. The potential losses could reach 100%. There is a crucial need to solve the problems by enhancing farmers’ knowledge and involving research institutions focusing on crop protection strategy.

  19. Estimation of the carrying capacity of grazing land in the buffer zone ...

    African Journals Online (AJOL)

    The study revealed that the Dry matter yield (DMY) from natural pastures was 3.54 tones ha-1yr-1 and the Potential Dry Matter (PDM) production from crop residues was 33.130 tons ha-1 yr-1, the total area under grazing was 49,197ha, the total feed resource potentially available for livestock = 205,320 tons yr-1 and the ...

  20. Community vulnerability assessment index for flood prone savannah agro-ecological zone: A case study of Wa West District, Ghana

    Directory of Open Access Journals (Sweden)

    Effah Kwabena Antwi

    2015-12-01

    Full Text Available The savannah regions of Northern Ghana are characterized by smallholder farming systems and high levels of poverty. Over the past two decades, communities in the regions have become more prone to climate and human-induced disasters in the form of annual floods and droughts. This study evaluates the degree and magnitude of vulnerability in four communities subjected to similar climate change induced flood events and propose intervention options. The study employs rural participatory research approaches in developing four vulnerability categories namely socio-economic, ecological, engineering and political; which were used to develop indicators that aided the calculation of total community vulnerability index for each community. The findings indicate that the state of a community's vulnerability to flood is a composite effect of the four vulnerability index categories which may act independently or concurrently to produce the net effect. Based on a synthesis of total vulnerability obtained in each community, Baleufili was found to be the least vulnerable to flood due to its high scores in engineering, socio-economic and political vulnerability indicators. Baleufili and Bankpama were the most ecologically vulnerable communities. The selection of vulnerability index categories and associated indicators were grounded in specific local peculiarities that evolved out of engagement with community stakeholders and expert knowledge of the socioecological landscape. Thus, the Total Community Vulnerability Assessment Framework (TCVAF provides an effective decision support for identifying communities’ vulnerability status and help to design both short and long term interventions options that are community specific as a way of enhancing their coping and adaptive capacity to disasters.

  1. In Vitro Morphological Characteristics of Pyrenophora tritici-repentis Isolates from Several Algerian Agro-Ecological Zones

    Directory of Open Access Journals (Sweden)

    Hamida Benslimane

    2017-04-01

    Full Text Available Tan spot caused by the fungus Pyrenophora triticirepentis is a serious disease of wheat, which is on increase in recent years in Mediterranean region. In the field this fungus produces a diamond-shaped necrotic lesions with a yellow halo on wheat foliage. The objective of this study was to characterize and compare several monospore isolates of P. tritici-repentis collected from different infected wheat fields in various locations of Algeria, and find the morphological differences between them, if any. The results revealed wide morphologically variation among the isolates based on colony colors and texture, mycelial radial growth and conidial size.

  2. Land husbandry: an agro-ecological approach to land use and management Part 1: Considerations of landscape conditions

    Directory of Open Access Journals (Sweden)

    Francis Shaxson

    2014-09-01

    Full Text Available In this, the first of two papers, the roles of key features of any landscape in determining potentials for erosional losses of soil and water are considered from an agro-ecological viewpoint. In this light, the effectiveness of past commonly-accepted approaches to soil and water conservation are often found to have been inadequate. In many cases they have tackled symptoms of land degradation without appreciating fully the background causes, which often relate to inadequate matching of land-use/land-management with features of the landscape. A number of reasons for this mismatch are suggested. Understanding the ecological background to land husbandry (as defined below will improve the effectiveness of attempts to tackle land degradation. In particular, an ecologically based approach to better land husbandry helps to foresee potential problems in some detail, so that appropriate forward planning can be undertaken to avoid them. This paper describes some practical ways of undertaking an appropriate survey of significant landscape features, enabling the definition and mapping of discrete areas of different land-use incapability classes. This is accompanied by an example of how the outcome was interpreted and used to guide the selection of appropriate areas which were apparently suitable for growing flue-cured tobacco within an area of ca. 140 km2 in Malawi. This process relied on knowledge and experience in various disciplines (interpretation of air-photos, topographic survey, soil survey, vegetation analysis, hydrology, soil & water conservation, geology, agronomy so as to ensure that the mapping process was based on the principles of better land husbandry.

  3. Agro-Ecological Class Stability Decreases in Response to Climate Change Projections for the Pacific Northwest, USA

    Directory of Open Access Journals (Sweden)

    Harsimran Kaur

    2017-07-01

    Full Text Available Climate change will impact bioclimatic drivers that regulate the geospatial distribution of dryland agro-ecological classes (AECs. Characterizing the geospatial relationship between present AECs and their bioclimatic controls will provide insights into potential future shifts in AECs as climate changes. The major objectives of this study are to quantify empirical relationships between bioclimatic variables and the current geospatial distribution of six dryland AECs of the inland Pacific Northwest (iPNW of the United States; and apply bioclimatic projections from downscaled climate models to assess geospatial shifts of AECs under current production practices. Two Random Forest variable selection algorithms, VarSelRF and Boruta, were used to identify relevant bioclimatic variables. Three bioclimatic variables were identified by VarSelRF as useful for predictive Random Forest modeling of six AECs: (1 Holdridge evapotranspiration index; (2 spring precipitation (March, April, and May; and (3 precipitation of the warmest 4-month season (June, July, August, and September. Super-imposing future climate scenarios onto current agricultural production systems resulted in significant geospatial shifts in AECs. The Random Forest model projected a 58 and 63% increase in area under dynamic annual crop-fallow-transition (AC-T and dynamic grain-fallow (GF AECs, respectively. By contrast, a 46% decrease in area was projected for stable AC-T and dynamic annual crop (AC AECs across all future time periods for Representative Concentration Pathway (RCP 8.5. For the same scenarios, the stable AC and GF AECs showed the least declines in area (8 and 13%, respectively, compared to other AECs. Future spatial shifts from stable to dynamic AECs, particularly to dynamic AC-T and dynamic GF AECs would result in more use of fallow, a greater hazard for soil erosion, greater cropping system uncertainty, and potentially less cropping system flexibility. These projections are

  4. Enteric methane emissions and their response to agro-ecological and livestock production systems dynamics in Zimbabwe.

    Science.gov (United States)

    Svinurai, Walter; Mapanda, Farai; Sithole, Dingane; Moyo, Elisha N; Ndidzano, Kudzai; Tsiga, Alois; Zhakata, Washington

    2018-03-01

    Without disregarding its role as one of the key sources of sustainable livelihoods in Zimbabwe and other developing countries, livestock production contributes significantly to greenhouse gas (GHG) emissions through enteric fermentation. For the livestock sector to complement global efforts to mitigate climate change, accurate estimations of GHG emissions are required. Methane emissions from enteric fermentation in Zimbabwe were quantified over 35years under four production systems and five agro-ecological regions. The Intergovernmental Panel on Climate Change emission factor methodology was used to derive CH 4 emissions from seven livestock categories at national level. Emission intensities based on human population, domestic export of livestock meat and climate variables were used to assess emission drivers and predict future emission trends. Over the past 35years, enteric fermentation CH 4 emissions from all livestock categories ranged between 158.3 and 204.3Ggyear -1 . Communal lands, typified by indigenous livestock breeds, had the highest contribution of between 58% and 75% of the total annual emissions followed by livestock from large scale commercial (LSC) farms. The decreasing livestock population on LSC farms and consequent decline in production could explain the lack of a positive response of CH 4 emissions to human population growth, and decreasing emissions per capita over time at -0.3kg CH 4 capita -1 year -1 . The emissions trend showed that even if Zimbabwe's national livestock population doubles in 2030 relative to the 2014 estimates, the country would still remain with similar magnitude of CH 4 emission intensity as that of 1980. No significant correlations (P>0.05) were found between emissions and domestic export of beef and pork. Further research on enhanced characterisation of livestock species, population and production systems, as well as direct measurements and modelling of emissions from indigenous and exotic livestock breeds were

  5. 3D Agro-ecological Land Use Planning Using Surfer Tool for Sustainable Land Management in Sumani Watershed, West Sumatra Indonesia

    Directory of Open Access Journals (Sweden)

    Aflizar

    2013-09-01

    Full Text Available Estimation of soil erosion 3D (E3D provides basic information that can help manage agricultural areas sustainably, which has not been sufficiently conducted in Indonesia. Sumani watershed is main rice production area in West Sumatra which has experienced environmental problem such as soil erosion and production problem in recent years. 3D Agro-ecological land use planning based on soil erosion 3D hazard and economic feasibility analyses consist of production cost and prize data for each crop. Using a kriging method in Surfer tool program, have been developed data base from topographic map, Landsat TM image, climatic data and soil psychochemical properties. Using these data, the Universal Soil Loss Equation was used for spatial map of soil erosion 3D and proposed a 3D agro-ecological land use planning for sustainable land management in Sumani watershed. A 3D Agro-ecological land use planning was planned under which the land use type would not cause more than tolerable soil erosion (TER and would be economically feasible. The study revealed that the annual average soil erosion from Sumani watershed was approximately 76.70 Mg ha-1yr-1 in 2011 where more than 100 Mg ha-1yr-1 was found on the cultivated sloping lands at agricultural field, which constitutes large portion of soil erosion in the watershed. Modification of land use with high CP values to one with lower CP values such as erosion control practices by reforestation, combination of mixed garden+beef+chicken (MBC, terrace (TBC or contour cropping+beef+chicken (CBC and sawah+buffalo+chicken (SBC could reduce soil erosion rate by 83.2%, from 76.70 to 12.9 Mg ha-1 yr-1, with an increase in total profit from agricultural production of about 9.2% in whole Sumani watershed.

  6. The Participatory Construction of Agro-Ecological Knowledge As A Soil Conservation Strategy In The Mountain Region of Rio de Janeiro State (Brazil

    Directory of Open Access Journals (Sweden)

    de Assis Renato Linhares

    2018-01-01

    Full Text Available Agriculture in the mountain region of Rio de Janeiro State is characterized by intensive soil use and input. Such mountainous environments are vulnerable to climate events; thus, the current article presents a report on methods applied to exchange academic and traditional knowledge. The aim is to expand farmers’ perception about the need of implementing agro-ecological practices, mainly soil management practices, which are important for agricultural sustainability in mountainous environments. The study was conducted in a Nova Friburgo family production unit, in the mountain region of Rio de Janeiro State (Brazil. It consisted of implementing three observation and soil organic-matter management units. The idea was to reduce the incidence of clubroot of crucifers disease caused by Plasmidiophora brassicae. The soil fauna was discussed with local farmers, with emphasis on the association between ecological processes and soil management. The present study improved the discussion with farmers and the need of introducing other innovative conservation practices such as no-tillage system and participatory research based on agro-ecological propositions.

  7. Production function analysis for smallholder semi-subsistence and semi-commercial poultry production systems in three agro-ecological regions in Northern provinces of Vietnam

    DEFF Research Database (Denmark)

    Tung, Dinh Xuan; Rasmussen, Svend

    2005-01-01

    A formal cross section survey of 360 smallholder poultry keeping farms located in three agro-ecological regions in Vietnam was conducted. Cobb-Douglas production functions were applied to analyse and compare semi-subsistence and semi-commercial smallholder poultry systems in three regions....... The general assumption is that the poultry production output at the farm level depends on the number of birds, feed amount, labor amount, garden size, income level and veterinary costs. In this study statistical tests were conducted to analyze the differences between regions and production systems....... The results from the analysis of production functions shows that the coefficients of flock size, feed amount per bird, labour amount per bird, household income level, and veterinary costs were highly significant in different models. Garden size has a significant influence only among the poultry farmers...

  8. Agro-ecological analysis for the EU water framework directive: an applied case study for the river contract of the Seveso basin (Italy).

    Science.gov (United States)

    Bocchi, Stefano; La Rosa, Daniele; Pileri, Paolo

    2012-10-01

    The innovative approach to the protection and management of water resources at the basin scale introduced by the European Union water framework directive (WFD) requires new scientific tools. WFD implementation also requires the participation of many stakeholders (administrators, farmers and citizens) with the aim of improving the quality of river waters and basin ecosystems through cooperative planning. This approach encompasses different issues, such as agro-ecology, land use planning and water management. This paper presents the results of a methodology suggested for implementing the WFD in the case of the Seveso river contract in Italy, one of the recent WFD applications. The Seveso basin in the Lombardy region has been one of the most rapidly urbanizing areas in Italy over the last 50 years. First, land use changes in the last 50 years are assessed with the use of historical aerial photos. Then, elements of an ecological network along the river corridor are outlined, and different scenarios for enhancing existing ecological connections are assessed using indicators from graph theory. These scenarios were discussed in technical workshops with involved stakeholders of the river contract. The results show a damaged rural landscape, where urbanization processes have decimated the system of linear green features (hedges/rows). Progressive reconnections of some of the identified network nodes may significantly increase the connectivity and circuitry of the study area.

  9. Characterisation and performance evaluation of twenty accessions of sweet potato (Ipomoea batatas (L.) Lam.) in the coastal savannah agro-ecological zone of Ghana

    International Nuclear Information System (INIS)

    Sossah, F.L.

    2012-01-01

    This study assessed the genetic diversity, using morphological and protein markers, as well as incidence of viral diseases among 20 accessions of sweet potato. Morphological analysis was carried out using 47 traits while protein analysis was performed with sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Sample plants collected from the field were tested for viruses using nitrocellulose membrane enzyme-linked immuno-sorbent assay (NCM-ELISA) and PCR for a DNA virus (Sweet potato Leaf curl virus). Scions from symptomatic plants were grafted onto Ipomoea setosa, a nearly universal indicator plant for sweet potato viruses, and leaves were tested using NCM-ELISA. From the cluster analysis, the accessions were grouped into two clusters at a genetic similarity index of 61.6%. The accessions ER001 and HMA2 were shown to be possible duplicates. Accession US 020 recorded the highest total root yield and harvest index of 56.32 t/ha and 57.11% respectively. Similarly, two pairs of accession SA/BNARI and UE 007 as well as HMA I and US 029 were identified as duplicates based on their protein banding patterns. While, three entries, LOCAL I, US 004 and UK/BNARI were also identified as a single entity based on their banding patterns for leaf and tuber proteins. Symptoms observed in the field varied from vein clearing, chlorosis, leaf reduction to stunting and the highest index of symptom severity for only diseased plants (ISSdp) was 3.63 recorded for US 029. The highest disease incidence (100%) was recorded at 11 WAP and 12 WAP. NCM-ELISA test detected eight viruses out of ten, with SA/BNARI exhibiting all the eight viruses. Mixed infections ranged from duplet to octaplet. The indicator plant I. setosa grafted with scions from sweet potato showed clear symptoms similar to those observed on the field. PCR test using SPG3/SPG4 primers detected SPLCV in the UK/BNARI accessions. Based on the morphological characters as well as response to virus infection, two accessions, US 020 and FREEMA, may be recommended for future breeding work. (au)

  10. Exploring Farmers’ Indigenous Knowledge of Soil Quality and Fertility Management Practices in Selected Farming Communities of the Guinea Savannah Agro-Ecological Zone of Ghana

    Directory of Open Access Journals (Sweden)

    Richard Ansong Omari

    2018-03-01

    Full Text Available Efforts to improve soil productive capacity aimed at boosting crop production in the Northern Ghana has primarily focused on field-based experiments with little documentation on farmer practice and local indigenous knowledge of soil management. A sample group of 114 farmers from five farming communities in the Guinea Savannah was interviewed to evaluate their indigenous knowledge of crop production practices in the context of soil health, fertilization management, and crop yield. Data were collected using semi-structured interviews and responses for each category were calculated using simple proportions. Farmers’ fertilization practice was primarily influenced by fertilization resource availability and crop yield response. The results showed that inorganic fertilization was the commonest fertilization type among farmers. Farmer local indicators of soil health were predominantly limited to visually observable signs such as presence or absence of indicator plants, growth vigor of plants, soil color, and tilth, texture, and compaction. Non-tactile and visible indicators, notably soil chemical composition and presence of soil microorganisms, was rarely used. The listed indicators were congruent with scientific reports, although some knowledge gaps, particularly on the use of indicator plants, were identified. The use of indicator plants as determinants of healthy or non-healthy soils appeared to be influenced by the ease of control of weeds, its utilitarian benefits, benefits to the soil, and threats on cultivated crops. Famers were well informed about the decreasing crop yield. Fertilization practices and limitations in soil management practices with proposed capacity building approaches aimed at enhancing productive capacities of cultivated farmlands are discussed.

  11. Agro-ecological zoning for wheat (Triticum aestivum, sugar beet (Beta vulgaris and corn (Zea mays on the Mashhad plain, Khorasan Razavi province

    Directory of Open Access Journals (Sweden)

    Ehsan Neamatollahi

    2012-06-01

    Full Text Available Climate is the most important factor determining the sustainability of agricultural production systems. A qualitative land evaluation was carried out for the Mashhad plain, Khorasan Razavi province, Iran, to assess the suitability of the land to grow the locally most important crops, i.e. wheat (Triticum aestivum, sugar beet (Beta vulgaris and corn (Zea mays using a Geographical Information System (GIS. The possible growing seasons were defined as early (10 September–20 June and late (10 October–20 July season for wheat, early (15 March–15 October and late (15 April–15 November season for sugar beet, and early (1 May–1 November and late (15 May–15 November season for corn. The study area covered approximately 99.915 ha−1. Climate variables were taken into account including maximum, optimum and minimum daily average temperatures and were obtained from 30 years agro-meteorological data set from 12 synoptic stations. Growing Degree Days (GDDs were determined for wheat, sugar beet, and corn crops from sowing to harvest. To produce digital elevation model for Mashhad plain two sources were used on utilization of the IRS III satellite images with resolution that is 23.5 m, and topographic maps with scale of 1:25000. Aspect and slope layers were produced by Arc GIS 9.2 software. The study identified suitable elevation, slope, and GDDs for optimal growth and indicated that high yields are possible for wheat, sugar beet, and corn on the Mashhad plain. The study also identified the most suitable regions of the Mashhad plain for each crop.

  12. Exploring Farmers’ Indigenous Knowledge of Soil Quality and Fertility Management Practices in Selected Farming Communities of the Guinea Savannah Agro-Ecological Zone of Ghana

    OpenAIRE

    Richard Ansong Omari; Sonoko Dorothea Bellingrath-Kimura; Elsie Sarkodee Addo; Yosei Oikawa; Yoshiharu Fujii

    2018-01-01

    Efforts to improve soil productive capacity aimed at boosting crop production in the Northern Ghana has primarily focused on field-based experiments with little documentation on farmer practice and local indigenous knowledge of soil management. A sample group of 114 farmers from five farming communities in the Guinea Savannah was interviewed to evaluate their indigenous knowledge of crop production practices in the context of soil health, fertilization management, and crop yield. Data were co...

  13. Analyzing anthropogenic pressures in soils of agro-ecological protected coastal wetlands in L'Albufera de Valencia Natural Park, Spain

    Science.gov (United States)

    Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Gimeno, Eugenia; Picó, Yolanda

    2013-04-01

    Coastal wetlands, despite the importance of their environmental and ecological functions, are areas that suffer of great pressures. Most of them are produced by the rapid development of the surrounding artificial landscapes. Socio-economic factors such as population growth and urban-industrial surfaces expansion introduce pressures on the nearby environment affecting the quality of natural and agricultural landscapes. The present research analyses interconnections among landscapes (urban, agricultural and natural) under the hypothesis that urban-artificial impacts could be detected on soils of an agro-ecological protected area, L'Albufera de Valencia, Natural Park, located in the vicinity or the urban area of the City of Valencia, Spain. It has been developed based on Environmental Forensics criteria witch attend two types of anthropogenic pressures: (1) direct, due to artificialization of soil covers that produce anthropogenic soil sealing, and (2) indirect, which are related to water flows coming from urban populations throw artificial water networks (sewage and irrigation systems) and that ultimately will be identified by the presence of o emerging-pharmaceuticals contaminants in soils of the protected area. For the first case, soil sealing a methodology based on temporal comparison of two digital layers for the years 1991 and 2011 applying Geographical Information Systems and Landscapes Metrics were undertaken. To determine presence of emerging contaminants 15 soil samples within the Natural Park were analyzed applying liquid chromatography tandem mass spectrometry for the detection of 17 pharmaceutical compounds. Results show that both processes are present in the Natural Park with a clear geographical pattern. Either soil sealing or detection of pharmaceuticals are more intensive in the northern part of the study area. This is related to population density (detection of pharmaceuticals) and land cover conversion from agricultural and natural surfaces to

  14. Phytoplankton growth balanced by clam and zooplankton grazing and net transport into the low-salinity zone of the San Francisco Estuary

    Science.gov (United States)

    Kimmerer, Wim J.; Thompson, Janet K.

    2014-01-01

    We estimated the influence of planktonic and benthic grazing on phytoplankton in the strongly tidal, river-dominated northern San Francisco Estuary using data from an intensive study of the low salinity foodweb in 2006–2008 supplemented with long-term monitoring data. A drop in chlorophyll concentration in 1987 had previously been linked to grazing by the introduced clam Potamocorbula amurensis, but numerous changes in the estuary may be linked to the continued low chlorophyll. We asked whether phytoplankton continued to be suppressed by grazing and what proportion of the grazing was by benthic bivalves. A mass balance of phytoplankton biomass included estimates of primary production and grazing by microzooplankton, mesozooplankton, and clams. Grazing persistently exceeded net phytoplankton growth especially for larger cells, and grazing by microzooplankton often exceeded that by clams. A subsidy of phytoplankton from other regions roughly balanced the excess of grazing over growth. Thus, the influence of bivalve grazing on phytoplankton biomass can be understood only in the context of limits on phytoplankton growth, total grazing, and transport.

  15. Analysis of molecular genetic diversity in a representative collection of foxtail millet [Setaria italica (L.) P. Beauv.] from different agro-ecological regions of India.

    Science.gov (United States)

    Kumari, Ratna; Dikshit, N; Sharma, Deepali; Bhat, K V

    2011-10-01

    Foxtail millet [Setaria italica (L.) P. Beauv.], an important crop of East Asia is known for its drought tolerance and was once an indispensible crop of vast rainfed areas in semi-arid regions in India. In India it is cultivated in Andhra Pradesh, Karnataka, Maharashtra, Tamil Nadu, Rajasthan, Madhya Pradesh, Uttar Pradesh and north eastern states. The grain finds use in several local recipes such as roti (bread), jaula, singal, sirol. Foxtail millet grain contains 12.3 % protein, 4.7 % fat, 60.6 % carbohydrates, and 3.2 % ash. The present study was conducted to analyse the genetic diversity among foxtail accessions from different states of India and a few exotic accessions using RAPD and ISSR techniques and identify diverse accessions for use in variety improvement programmes. A set of 125 foxtail millet accessions selected from 11 different agro-ecological regions of India were analyzed using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) marker techniques. A total of 146 (115 RAPD and 31 ISSR) scoreable markers were generated with 16 RAPD and four ISSR primers. The dendrogram generated using Nei's genetic distances and principal component analyses revealed presence of two clusters and two subclusters in group I. The accessions from Andhra Pradesh, Karnataka, Maharashtra and Uttarakhand were more diverse since they were distributed in both the clusters. There was no clear geographical differentiation observable. The bootstrap support for the major groups identified was strong (above 80 %) indicating good statistical support. The average value of Nei and Li's genetic distance was lowest (0.081) for accessions from West Bengal while the collections from Karnataka showed highest dissimilarity (average genetic distance = 0.239). The average genetic distance for all 125 accessions together was 0.177 indicating presence of only moderate genetic diversity in the collections. The analysis of molecular variance indicated that only 2

  16. Effects of Different Plant Species and Different Sowing Dates on Forage Yield, Grazing Capacity and Estimated Carcass Weight in the Continental Climate Zones

    OpenAIRE

    ÇAKMAKÇI, Sadık; AYDINOĞLU, Bilal; ARSLAN, Mehmet

    2014-01-01

    This research was conducted to study the effects of artificial sowing with various plant species and different sowing dates on forage yield, grazing capacity and estimated carcass weight in rangelands under continental dry conditions. Artificial rangelands were established on Akpınar plateau near Kemer-Burdur 1675 m above sea level using 4 different plant species sown at 5 different sowing dates. Later, grazing capacity and carcass weight were estimated in terms of forage yield. The results s...

  17. Genótipos de capim-elefante sob pastejo no período de seca na Zona da Mata de Pernambuco: fatores relacionados à eficiência de pastejo Elephantgrass genotypes under grazing during the dry period in the Forest Zone of Pernambuco: factors related to grazing efficiency

    Directory of Open Access Journals (Sweden)

    Márcio Vieira da Cunha

    2007-04-01

    Full Text Available O experimento foi realizado com o objetivo de avaliar fatores relacionados à eficiência de pastejo de cinco genótipos de Pennisetum sp. (CE 08 A.D., Venezuela, HV-241, Elefante B e Hexaplóide no período seco do ano na Zona da Mata de Pernambuco. Os genótipos foram manejados sob lotação rotacionada (44 dias de descanso e quatro dias de pastejo ao longo de dois ciclos de pastejo. Adotou-se delineamento experimental em blocos ao acaso, com parcelas subdivididas (os genótipos representaram as parcelas e os ciclos de pastejo, as subparcelas e quatro repetições. As massas de lâmina foliar total, verde e senescente pré-pastejo foram analisadas em seis repetições. O acúmulo e a eficiência de pastejo de lâmina foliar verde foram avaliados em delineamento em blocos casualizados, com quatro repetições. Os genótipos CE 08 A.D. e Elefante B apresentaram maiores massas de lâmina foliar total (1.374 kg de MS/ha e verde pré-pastejo (737 kg de MS/ha e maior acúmulo (654 kg de MS/ha/44 dias e eficiência de pastejo de lâmina foliar verde (80%. No HV-241, a alta eficiência de pastejo (100% do acúmulo lâmina foliar verde esteve associada ao baixo acúmulo de lâmina foliar verde (155 kg de MS/ha/44 dias. A menor eficiência de pastejo foi observada no Hexaplóide (59% do acúmulo de lâmina foliar verde, possivelmente em virtude das altas perdas sob pastejo (30% da massa de lâmina foliar total pré-pastejo. A massa de lâmina foliar verde diminuiu mais acentuadamente até o segundo dia de pastejo, enquanto as perdas de lâmina foliar total foram maiores no 2º e 3º dias de pastejo. Os genótipos CE 08 A.D. e Elefante B têm potencial para serem utilizados em sistemas de lotação rotacionada na Zona da Mata pernambucana.The experiment was carried out to evaluate factors related to the grazing efficiency of five Pennisetum sp. genotypes (CE 08 A.D., Venezuela, HV-241, Elephant B and Hexaplóide during the dry period in the Forest Zone

  18. Evaluation of growth parameters and forage yield of Sugar Graze and Jumbo Plus sorghum hybrids under three different spacings during the maha season in the dry zone of Sri Lanka

    Directory of Open Access Journals (Sweden)

    Hajarooba Gnanagobal

    2018-01-01

    Full Text Available A field experiment to evaluate the growth parameters and fodder yields of Sugar Graze and Jumbo Plus under occasional irrigation was conducted at 3 different plant spacings (30 × 15, 30 × 45 and 30 × 60 cm on a red-yellow latosol in the dry zone of Sri Lanka from August 2015 to January 2016. The design was a randomized block with 3 replications. Initial harvesting of fodder was done 60 days after planting and 2 ratoon yields were assessed at successive 60-day intervals. Plant spacing was inversely related (P<0.05 to dry matter (DM yield with the narrowest spacing (30 × 15 cm producing yields of 14.1 t DM/ha for Sugar Graze and 12.6 t DM/ha for Jumbo Plus at the initial harvest. Plant spacing also influenced leaf area, stem girth, root length and plant height in the initial harvest. Sugar Graze produced higher yields than Jumbo Plus at the initial and second ratoon harvests. Yields from ratoon crops were about 30% of those for the initial harvest. Further studies are needed to determine how these findings apply under the low-rainfall conditions of the yala season, and chemical analyses and animal feeding studies would provide valuable information on the nutritional value of the different forages.

  19. Maize grown in succession to green manure under agro-ecology based systems=Milho cultivado em sucessão a adubos verdes em sistemas sob bases agroecológicas

    Directory of Open Access Journals (Sweden)

    Leandro Flávio Carneiro

    2016-02-01

    Full Text Available Fertilisation is a strategic practice in view of the many functions it carries out in agricultural environments. In the case of crop arrangements based on agro-ecology, its importance increases, given that for agricultural ecosystems the maximum of autonomy is sought. Arrangements with maize crops are promising, as they enhance results of economic interest in the crop. In the State of Mato Grosso do Sul, Brazil (MS, a study was developed to evaluate the performance of maize grown in succession to green manure in agro-ecology based systems. The study was carried out in the 2009/2010 crop year, in two distinct ecoregions (Dourados and Itaquiraí, and comprised ten treatments, being the cultivation of: Crotalaria juncea, Cajanus cajan, Canavalia ensiformis, Mucuna pruriens, Stizolobium aterrimum, Pennisetum glaucum, Sorghum bicolor, C. juncea intercropped and P. glaucum, a mixture of the green manure, and a control (spontaneous plants. Following management, the dry matter and amount of accumulated nutrients in the shoots were evaluated. The maize was sown ten days after the management of green manure. Plant height and ear insertion, weight of the ears without straw (green corn, crop-residue dry weight and dry grain yield were evaluated. The results show that growing maize in succession to legumes, results in an increase in ear production and grain yield, especially in M. pruriens, S. aterrimum, C. cajan, C. ensiformis, C. juncea, a mixture of the green manure, and C. juncea intercropped with P. glaucum.=A adubação é uma prática estratégica face às multifunções que exerce nos ambientes agrícolas. Tratando-se de arranjos de cultivos em bases agroecológicas, a sua importância aumenta, tendo em vista que se busca a máxima autonomia nos agroecossistemas. Arranjos com a cultura do milho são promissores, pois potencializa os resultados da cultura de interesse econômico. Em Mato Grosso do Sul, desenvolveuse um estudo com o objetivo de avaliar

  20. Integrating remote sensing and conventional grazing/browsing models for modelling carrying capacity in southern African rangelands

    Science.gov (United States)

    Adjorlolo, C.; Botha, J. O.; Mhangara, P.; Mutanga, O.; Odindi, J.

    2014-10-01

    Woody vegetation encroachment into grasslands or bush thickening, a global phenomenon, is transforming the Southern African grassland systems into savanna-like landscapes. Estimation of woody vegetation is important to rangeland scientists and land managers for assessing its impact on grass production and calculating its grazing and browsing capacity. Assessment of grazing and browsing components is often challenging because agro-ecological landscapes of this region are largely characterized by small scale and heterogeneous land-use-land-cover patterns. In this study, we investigated the utility of high spatial resolution remotely sensing data for modelling grazing and browsing capacity at landscape level. Woody tree density or Tree Equivalents (TE) and Total Leaf Mass (LMASS) data were derived using the Biomass Estimation for Canopy Volume (BECVOL) program. The Random Forest (RF) regression algorithm was assessed to establish relationships between these variables and vegetation indices (Simple Ratio and Normalized Difference Vegetation Index), calculated using the red and near infrared bands of SPOT5. The RF analysis predicted LMASS with R2 = 0.63 and a Root Mean Square Error (RMSE) of 1256 kg/ha compared to a mean of 2291kg/ha. TE was predicted with R2 = 0.55 and a RMSE = 1614 TE/ha compared to a mean of 3746 TE/ha. Next, spatial distribution maps of LMASS/ha and TE/ha were derived using separate RF regression models. The resultant maps were then used as input data into conventional grazing and browsing capacity models to calculate grazing and browsing capacity maps for the study area. This study provides a sound platform for integrating currently available and future remote sensing satellite data into rangeland carrying capacity modelling and monitoring.

  1. Grazing and grazing management terminology in Southern Africa ...

    African Journals Online (AJOL)

    The former group includes veld, fynbos, karoo, grassveld, bushveld, sourveld. sweetveld, pastures, leys, permanent pastures, cultivated pastures, introduced pastures, species selective grazing, area selective grazing, grazing capacity, current grazing capacity and potential grazing capacity. Some of these terms are well ...

  2. Grazing Impact Oscillations

    NARCIS (Netherlands)

    Weger, J.G.; Water, van de W.; Molenaar, J.

    2000-01-01

    An impact oscillator is a periodically driven system that hits a wall when its amplitude exceeds a critical value. We study impact oscillations where collisions with the wall are with near-zero velocity (grazing impacts). A characteristic feature of grazing impact dynamics is a geometrically

  3. Evaluating sustainable and profitable cropping sequences with cassave and four legume crops: Effects on soil fertility and maize yields in the forest/savannah transitional agro-ecological zone of Ghana

    NARCIS (Netherlands)

    Adjei-Nsiah, S.; Kuyper, T.W.; Leeuwis, C.; Abekoe, M.K.; Giller, K.E.

    2007-01-01

    Rotations are important practices for managing soil fertility on smallholder farms. Six cropping sequences (cassava, pigeonpea, mucuna-maize-mucuna, cowpea-maize-cowpea, maize-maize-maize, and speargrass fallow) were evaluated during 2003-2004 in Wenchi district of Ghana for their effects on the

  4. Use of quality indicators for long-term evaluation of heavy metals content in soils of an agro-ecological protected wetland: L'Albufera de Valencia Natural Park, Valencia, Spain

    Science.gov (United States)

    Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Palop, Carla

    2015-04-01

    Due to the social, economical and environmental importance of agro-ecological wetlands, strategies for periodical evaluation of their environmental quality should be developed, particularly in those areas were a mixture of land uses are supporting the survival of wildlife and migrant species as is the case of most Mediterranean coastal wetlands. The aim of this work is to develop a strategy for a long-term assessment of the environmental quality of soils in a rice-wetland: L'Albufera Natural Park, Spain, in the surroundings of the metropolitan area of Valencia. The area was officially declared as Natural Park in 1986, integrating both the traditional irrigation system and the ecological importance derived from being a Mediterranean Wetland that is now transformed to a large extent in a rice-wetland allowing the presence of a large variety of migrant spices. The methodology consisted in the monitoring of 20 sites distributed in 5 sectors in and around the natural park of potentially contrasting anthropogenic pressure and land use. Soil samples collection were instrumented in two campaigns. The first one was in 1989 (three years after the official declaration as Natural Park of the wetland), and the second 19 years later in 2008. Seven heavy metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) were analyzed to determine its total and extractable fractions by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of metals. To evaluate the quality of soils at each sampling date four indicators were obtained, namely, Contamination Factor (CF), Geoaccumulation Index (Igeo), Pollution Load Index (PLI) and Potential Ecological Risk Index (PERI). Results obtained with quality indicators were further compared to obtain temporal and spatial trends using Geographical Information systems procedures. In general, there is a reduction of metal contents in the study area in both dates. The trend of metals according to average

  5. The quantification of grazing capacity from grazing — and ...

    African Journals Online (AJOL)

    The relation between rangeland condition and grazing capacity was determined along a degradation gradient. In studying agronomic values of forage species, the average production per tuft was combined with its grazing preferences, to link grazing values for species in the semi-arid grasslands of southern Africa.

  6. The Grazing Capacity and Stocking Rate of the Gongoshi Grazing ...

    African Journals Online (AJOL)

    This study assessed the grazing capacity and stocking rate of the Gongoshi grazing reserve in Adamawa State, Nigeria. Determination of the grazing capacity was carried out by assessing the forage yield, while forage yield was assessed by clipping of desirable herbage within a series of quadrants (1m2 in size) distributed ...

  7. Bivalve grazing can shape phytoplankton communities

    Science.gov (United States)

    Lucas, Lisa; Cloern, James E.; Thompson, Janet K.; Stacey, Mark T.; Koseff, Jeffrey K.

    2016-01-01

    The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.

  8. Mixed grazing with heifers and pregnant sows

    OpenAIRE

    Soegaard, Karen; Sehested, Jakob; Danielsen, Viggo

    2000-01-01

    In 1999, a mixed grazing system with heifers and pregnant soews was compared with grazing systems with heifers and sows alone. Normally, herbage quality used for sow grazing is not optimal for high herbage intake and it was therefore examined whether mixed grazing with heifers could improve the grazing system. Herbage quality and botanical composition of the sward was best where heifers grazed alone, followed by swards with mixed grazing and the poorest quality and composition were in swards ...

  9. Combined effects of climatic gradient and domestic livestock grazing on reptile community structure in a heterogeneous agroecosystem.

    Science.gov (United States)

    Rotem, Guy; Gavish, Yoni; Shacham, Boaz; Giladi, Itamar; Bouskila, Amos; Ziv, Yaron

    2016-01-01

    Grazing plays an important role in shaping ecological communities in human-related ecosystems. Although myriad studies have explored the joint effect of grazing and climate on plant communities, this interactive effect has rarely been studied in animals. We hypothesized that the effect of grazing on the reptile community varies along a climatic gradient in relation to the effect of grazing on habitat characteristics, and that grazing differentially affects reptiles of different biogeographic regions. We tested our hypotheses by collecting data on environmental characteristics and by trapping reptiles in four heterogeneous landscapes experiencing differing grazing intensities and distributed along a sharp climatic gradient. We found that while reptile diversity increased with grazing intensity at the mesic end of the gradient, it decreased with grazing intensity at the arid end. Moreover, the proportion of reptile species of differing biogeographic origins varied with the interactive effect of climate and grazing. The representation of species originating in arid biogeographic zones was highest at the arid end of the climatic gradient, and representation increased with grazing intensity within this area. Regardless of the climatic context, increased grazing pressure results in a reduction in vegetation cover and thus in changes in habitat characteristics. By reducing vegetation cover, grazing increased habitat heterogeneity in the dense mesic sites and decreased habitat heterogeneity in the arid sites. Thus, our results suggest that the same direction of habitat alteration caused by grazing may have opposite effects on biodiversity and community composition in different climatic contexts.

  10. Caracterização da produção agroecológica do sul do Rio Grande do Sul e sua relação com a mecanização agrícola Agro ecological production characterization in the south of the State of Rio Grande do Sul related to farm machinery

    Directory of Open Access Journals (Sweden)

    Sandro S. Teixeira

    2009-03-01

    Full Text Available A agricultura agroecológica tem-se destacado como uma das alternativas de renda para os pequenos agricultores devido à crescente busca por parte da população por alimentação mais saudável. No Rio Grande do Sul, a Associação Regional de Produtores Agroecológicos da Região Sul (Arpasul, constituída por 48 famílias, é representativa do processo de produção e de comercialização de produtos agroecológicos, servindo como referencial para o presente estudo. O objetivo principal deste trabalho foi o levantamento das necessidades dos produtores agroecológicos em relação à mecanização agrícola. As informações obtidas foram baseadas no sistema de produção utilizado, sendo caracterizados aspectos referentes à propriedade, às operações agrícolas e às necessidades específicas de máquinas e implementos. Por meio deste estudo, foi evidenciada a carência no atendimento das demandas específicas, na área de máquinas agrícolas para esse segmento, podendo servir como referencial para o desenvolvimento de novas máquinas e/ou aperfeiçoamento das existentes. A semeadora de milho e feijão foi a máquina que a maioria dos agricultores pesquisados indicou como sua maior necessidade.Ecological agriculture has stand out as an alternative of income for small farmers due to the people's awareness about the consumption of healthier food. In the State of Rio Grande do Sul, the Regional Association of Agro ecological Farmers in South Region (Arpasul, constituted by 48 families, is representative of this production and commercialization process which is being used as a referential for the present study. The main purpose of this work was the assessment of these agro ecological farmers' needs related to farm machinery. The information obtained was based in the usual production system, where aspects referent to farm, agricultural operations and specific needs about machines and implements were characterized. This research evidenced the

  11. Assessment of the Effects of Emerging Grazing Policies on Land ...

    African Journals Online (AJOL)

    ADOWIE PERE

    build in agroforestry system of agriculture to suit each ecological zone. This is with a view to solving socio-economic problems of ... Free grazing has a number of ecological effects which may be either positive or negative. .... because it reduces water and air movement into and through the soil, and therefore reduces water.

  12. Prevalence of cryptosporidium oocyst in calves grazing along river ...

    African Journals Online (AJOL)

    The present study was conducted to investigate the point prevalence of Cryptosporidium oocysts infection in calves grazing along the bank of Rima River Sokoto in October 2011. The river bank is a converging zone for domestic animals reared in different quarters of the town and the surrounding settlements. A total number ...

  13. Suitability Analysis and Projected Climate Change Impact on Banana and Coffee Production Zones in Nepal.

    Directory of Open Access Journals (Sweden)

    Sailesh Ranjitkar

    Full Text Available The Government of Nepal has identified opportunities in agricultural commercialization, responding to a growing internal demand and expansion of export markets to reduce the immense trade deficit. Several cash crops, including coffee and bananas, have been identified in the recently approved Agriculture Development Strategy. Both of these crops have encouraged smallholder farmers to convert their subsistence farming practices to more commercial cultivation. Identification of suitable agro-ecological zones and understanding climate-related issues are important for improved production and livelihoods of smallholder farmers. Here, the suitability of coffee and banana crops is analyzed for different agro-ecological zones represented by Global Environmental Stratification (GEnS. Future shifts in these suitability zones are also predicted. Plantation sites in Nepal were geo-referenced and used as input in species distribution modelling. The multi-model ensemble model suggests that climate change will reduce the suitable growing area for coffee by about 72% across the selected emission scenarios from now to 2050. Impacts are low for banana growing, with a reduction in suitability by about 16% by 2050. Bananas show a lot of potential for playing an important role in Nepal as a sustainable crop in the context of climate change, as this study indicates that the amount of area suited to banana growing will grow by 40% by 2050. Based on our analysis we recommend possible new locations for coffee plantations and one method for mitigating climate change-related problems on existing plantations. These findings are expected to support planning and policy dialogue for mitigation and support better informed and scientifically based decision-making relating to these two crops.

  14. Suitability Analysis and Projected Climate Change Impact on Banana and Coffee Production Zones in Nepal.

    Science.gov (United States)

    Ranjitkar, Sailesh; Sujakhu, Nani M; Merz, Juerg; Kindt, Roeland; Xu, Jianchu; Matin, Mir A; Ali, Mostafa; Zomer, Robert J

    The Government of Nepal has identified opportunities in agricultural commercialization, responding to a growing internal demand and expansion of export markets to reduce the immense trade deficit. Several cash crops, including coffee and bananas, have been identified in the recently approved Agriculture Development Strategy. Both of these crops have encouraged smallholder farmers to convert their subsistence farming practices to more commercial cultivation. Identification of suitable agro-ecological zones and understanding climate-related issues are important for improved production and livelihoods of smallholder farmers. Here, the suitability of coffee and banana crops is analyzed for different agro-ecological zones represented by Global Environmental Stratification (GEnS). Future shifts in these suitability zones are also predicted. Plantation sites in Nepal were geo-referenced and used as input in species distribution modelling. The multi-model ensemble model suggests that climate change will reduce the suitable growing area for coffee by about 72% across the selected emission scenarios from now to 2050. Impacts are low for banana growing, with a reduction in suitability by about 16% by 2050. Bananas show a lot of potential for playing an important role in Nepal as a sustainable crop in the context of climate change, as this study indicates that the amount of area suited to banana growing will grow by 40% by 2050. Based on our analysis we recommend possible new locations for coffee plantations and one method for mitigating climate change-related problems on existing plantations. These findings are expected to support planning and policy dialogue for mitigation and support better informed and scientifically based decision-making relating to these two crops.

  15. Grazing incidence beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

    1985-01-01

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  16. Effect of different grazing pressure by lambs grazing Lolium perenne ...

    African Journals Online (AJOL)

    high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the quality of herbage consumed by lambs grazing Lolium perenne and Dactylis glomerata pastures in spring.

  17. 25 CFR 167.8 - Grazing rights.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Grazing rights. 167.8 Section 167.8 Indians BUREAU OF... rights. (a) The Superintendent shall determine grazing rights of bona fide live-stock owners based on recommendations of District Grazing Committees. Grazing rights shall be recognized for those permittees having...

  18. Radiobiological problems concerning grazing animals following the Chernobyl accident

    International Nuclear Information System (INIS)

    Prister, B.S.; Lazarev, N.M.; Romanov, L.M.

    1997-01-01

    Chernobyl accident took place on April 26 1986, which was the beginning of the grazing season, when there was not enough fodder on the farms and the cattle was grazed on the open territory. Therefore grazing animal-breeding was the most radioactively affected branch. The consumption of contaminated fodder and surface contamination with radioactive precipitation caused the accumulation of considerable ingested doses in the organisms of animals (up to 1 GY). Radioactive damage caused to the thyroid by the selective accumulation of radioiodine (mainly 131 I) is of particular attention. Cumulative doses of thyroid irradiation in mammals were much higher than for the other organs. Thus, in cows during their grazing on the contaminated pastures outside 30-km zone the ratio of ingested doses of the thyroid and whole body was 130:1 and more, therefore, radiation effects could have a certain negative effect, concerning the agricultural animals in the zone of accidental release influence. Accumulated ingested doses in the thyroid of cows on the contaminated territory in a number of cases caused the complete destruction of the thyroid (doses above 600 Gy), which provided the loss of milk productivity and reproductive qualities of the animals. Lower doses caused the functional disturbances, which in most cases have been levelled during the years after the accident

  19. Grazing Incidence Optics Technology

    Science.gov (United States)

    Ramsey, Brian; Smith, W. Scott; Gubarev, Mikhail; McCracken, Jeff

    2015-01-01

    This project is to demonstrate the capability to directly fabricate lightweight, high-resolution, grazing-incidence x-ray optics using a commercially available robotic polishing machine. Typical x-ray optics production at NASA Marshall Space Flight Center (MSFC) uses a replication process in which metal mirrors are electroformed on to figured and polished mandrels from which they are later removed. The attraction of this process is that multiple copies can be made from a single master. The drawback is that the replication process limits the angular resolution that can be attained. By directly fabricating each shell, errors inherent in the replication process are removed. The principal challenge now becomes how to support the mirror shell during all aspects of fabrication, including the necessary metrology to converge on the required mirror performance specifications. This program makes use of a Zeeko seven-axis computer-controlled polishing machine (see fig. 1) and supporting fabrication, metrology, and test equipment at MSFC. The overall development plan calls for proof-of-concept demonstration with relatively thick mirror shells (5-6 mm, fig. 2) which are straightforward to support and then a transition to much thinner shells (2-3 mm), which are an order of magnitude thinner than those used for Chandra. Both glass and metal substrates are being investigated. Currently, a thick glass shell is being figured. This has enabled experience to be gained with programming and operating the polishing machine without worrying about shell distortions or breakage. It has also allowed time for more complex support mechanisms for figuring/ polishing and metrology to be designed for the more challenging thinner shells. These are now in fabrication. Figure 1: Zeeko polishing machine.

  20. Effect of different grazing pressures by lambs grazing Lolium ...

    African Journals Online (AJOL)

    high (HGP), medium (MGP) and low (LGP), corresponding to 30, 50 and 75 g available DM/kg BW/day, respectively] on the performance of lambs grazing Lolium perenne and Dactylis glomerata pastures in spring. Feed intakes and average ...

  1. The influence of urine and dung deposition on patch grazing ...

    African Journals Online (AJOL)

    Urine deposition may consequently be an important factor in patch initiation and patch development. Keywords: cattle; deposition; dung; grazing frequency; grazing intensity; grazing pattern; grazing patterns; herbage; patch grazing; sheep; sheep grazing; south africa; southern tall grassveld; ukulinga research station; urine

  2. Livestock grazing, wildlife habitat, and rangeland values

    Science.gov (United States)

    Paul R. Krausman; David E. Naugle; Michael R. Frisina; Rick Northrup; Vernon C. Bleich; William M. Block; Mark C. Wallace; Jeffrey D. Wright

    2009-01-01

    Livestock managers make and implement grazing management decisions to achieve a variety of objectives including livestock production, sustainable grazing, and wildlife habitat enhancement. Assessed values of grazing lands and ranches are often based on aesthetics and wildlife habitat or recreational values, which can exceed agricultural values, thus providing...

  3. 25 CFR 173.6 - Stock grazing.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Stock grazing. 173.6 Section 173.6 Indians BUREAU OF... WITHDRAWN OR ACQUIRED IN CONNECTION WITH INDIAN IRRIGATION PROJECTS § 173.6 Stock grazing. Permittees may graze upon lands covered by such permits, such stock as may be required in connection with the purposes...

  4. 25 CFR 168.5 - Grazing capacity.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Grazing capacity. 168.5 Section 168.5 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING REGULATIONS FOR THE HOPI PARTITIONED LANDS AREA § 168.5 Grazing capacity. (a) The Area Director shall prescribe the maximum number of each...

  5. Prevalence of sorghum anthracnose in different agro-ecologies of ...

    African Journals Online (AJOL)

    ACSS

    Cercospora zeae-maydis and related. Cercospora fungi. Ph.D. Thesis,. Swedish University of Agricultural. Sciences, Uppsala, Sweden. Ruecker, G.R., Park, S.J., Sali, T. and. Pender, J. 2003. Strategic targeting of development policies to a complex region: A GIS Based Stratification. Applied to Uganda. ZEF-Discussion.

  6. Agro-ecological system analysis (AESA) and farm plannning

    DEFF Research Database (Denmark)

    Vaarst, Mette; Nalunga, Jane

    2016-01-01

    on knowledge on which crops support each other. The surrounding nature must be considered in the planning, e.g. rainfall, animals in the environment, where some of them can be predators and some can eat the crops. Herbs and weeds can prove to be valuable sources of nutrients, medicine or bio-pesticides....

  7. Lagrangian studies of phytoplankton growth and grazing relationships in a coastal upwelling ecosystem off Southern California

    Science.gov (United States)

    Landry, Michael R.; Ohman, Mark D.; Goericke, Ralf; Stukel, Michael R.; Tsyrklevich, Kate

    2009-12-01

    Experimental studies of phytoplankton growth and grazing processes were conducted in the coastal upwelling system off Point Conception, California to test the hypothesis that phytoplankton growth and grazing losses determine, to first order, the local dynamics of phytoplankton in the upwelling circulation. Eight experiments of 3-5 days each were conducted over the course of two cruises in May-June 2006 and April 2007 following the trajectories of satellite-tracked drifters. Rates of phytoplankton growth and microzooplankton grazing were determined by daily in situ dilution incubations at 8 depths spanning the euphotic zone. Mesozooplankton grazing was assessed by gut fluorescence analysis of animals collected from net tows through the euphotic zone. We compared directly the net rates of change observed for the ambient phytoplankton community to the net growth rates predicted from experimental determinations of each process rate. The resulting relationship accounted for 91% of the variability observed, providing strong support for the growth-grazing hypothesis. In addition, grazing by mesozooplankton was unexpectedly high and variable, driving a substantial positive to negative shift in phytoplankton net rate of change between years despite comparable environmental conditions and similar high growth rates and suggesting strong top-down control potential. The demonstrated agreement between net ambient and experimental community changes is an important point of validation for using field data to parameterize models. Data sets of this type may provide an important source of new information and rate constraints for developing better coupled biological-physical models of upwelling system dynamics.

  8. Composição nutricional de pastagens de capim-Elefante submetido a duas estratégias de manejo em pastejo = Nutritional composition of elephant grass pastures submitted to two management strategies under grazing

    Directory of Open Access Journals (Sweden)

    Gilmar Roberto Meinerz

    2008-10-01

    Full Text Available Realizou-se o trabalho com o objetivo de avaliar o efeito de estratégias de manejo sobre a composição nutricional de pastagens de capim-Elefante. No Tratamento 1, o capim-Elefante foi manejado de acordo com princípios agroecológicos; no Tratamento 2, convencionalmente. Na área correspondente ao sistema agroecológico, o capim-Elefante estava estabelecido em linhas afastadas a 3 m, onde, no espaço entre linhas, no período hibernal, foi implantado azevém e, no período estival, permitiu-se o desenvolvimento de espécies de crescimento espontâneo. Na área referente ao sistema convencional, o capim-Elefante estava estabelecido em linhas espaçadas a 1,4 m. Em cada pastejo, foram coletadas amostras por meio da técnica de simulação de pastejo para determinação das porcentagens de proteína bruta (PB, de fibra em detergente neutro (FDN, da digestibilidade in vitro da matéria seca (DIVMS, da matéria orgânica (DIVMO e dos nutrientes digestíveis totais (NDT. O delineamento experimental utilizado foi inteiramente casualizado, com dois tratamentos, duas repetições em parcelas subdivididas no tempo. Observou-se resultadosuperior (p This research was conducted with the objective of evaluating the effect of management strategies on the nutritional composition of elephant grass pastures. In treatment 1, the elephant grass was managed according to agro-ecological principles; in treatment 2, it was managed conventionally. In the agro-ecological systemarea, elephant grass was established in rows spaced 3 m apart, where ryegrass was planted in the space between rows during the winter period, and the development of spontaneous growth species was permitted in the summer period. In the conventional system area,elephant grass was established in rows spaced 1.4m apart. In each grazing cycle, using the hand-plucking technique, samples were collected for determination of the percentiles of crude protein (CP, neutral detergent fiber (NDF, dry matter

  9. Ecology of grazing lawns in Africa.

    Science.gov (United States)

    Hempson, Gareth P; Archibald, Sally; Bond, William J; Ellis, Roger P; Grant, Cornelia C; Kruger, Fred J; Kruger, Laurence M; Moxley, Courtney; Owen-Smith, Norman; Peel, Mike J S; Smit, Izak P J; Vickers, Karen J

    2015-08-01

    Grazing lawns are a distinct grassland community type, characterised by short-stature and with their persistence and spread promoted by grazing. In Africa, they reveal a long co-evolutionary history of grasses and large mammal grazers. The attractiveness to grazers of a low-biomass sward lies in the relatively high quality of forage, largely due to the low proportion of stem material in the sward; this encourages repeat grazing that concomitantly suppresses tall-grass growth forms that would otherwise outcompete lawn species for light. Regular grazing that prevents shading and maintains sward quality is thus the cornerstone of grazing lawn dynamics. The strong interplay between abiotic conditions and disturbance factors, which are central to grazing lawn existence, can also cause these systems to be highly dynamic. Here we identify differences in growth form among grazing lawn grass species, and assess how compositional differences among lawn types, as well as environmental variables, influence their maintenance requirements (i.e. grazing frequency) and vulnerability to degradation. We also make a clear distinction between the processes of lawn establishment and lawn maintenance. Rainfall, soil nutrient status, grazer community composition and fire regime have strong and interactive influences on both processes. However, factors that concentrate grazing pressure (e.g. nutrient hotspots and sodic sites) have more bearing on where lawns establish. Similarly, we discuss the relevance of enhanced rates of nitrogen cycling and of sodium levels to lawn maintenance. Grazer community composition and density has considerable significance to grazing lawn dynamics; not all grazers are adapted to foraging on short-grass swards, and differences in body size and relative mouth dimensions determine which species are able to convert tall-grass swards into grazing lawns under different conditions. Hence, we evaluate the roles of different grazers in lawn dynamics, as well as the

  10. Methane uptake and emissions in a typical steppe grazing system during the grazing season

    Science.gov (United States)

    Wang, Xiaoya; Zhang, Yingjun; Huang, Ding; Li, Zhiqiang; Zhang, Xiaoqing

    2015-03-01

    This study investigated the effects of livestock grazing on CH4 emissions by testing six grazing conditions at Guyuan State Key Monitoring and Research Station of Grassland Ecosystem (China) in 2011 and 2012. Under all grazing systems, steppe soils were measured to be CH4 sinks. The uptake of CH4 by grassland was primarily determined by topsoil (7 cm) temperature and soil (0-7 cm) moisture in grassland at short-term grazing and non-grazing. The cumulative uptake of CH4 during the grazing period for all conditions was 0.88-3.23 kg hm-2 CH4, and the highest level was observed in the continuously moderate grazing condition. Reducing grazing stocking in the short-term did not significantly change the uptake of CH4 when compared with continuously heavy grazing condition. Enteric CH4 emissions were not significantly affected by the grazing period or conditions. The uptake of CH4 by grassland soil offset 3.1-8.6% of the CH4 emissions from the grazing sheep and was most effective at the continuously moderate grazing condition. These findings imply that continuously moderate grazing is the best approach considered here for optimizing the soil as a sink for atmospheric CH4.

  11. The grazing pattern of Muturu cattle under range system | Nweze ...

    African Journals Online (AJOL)

    Eighty Muturu cattle were grazed on rangeland, twice daily for two years to determine their grazing pattern. Twenty bulls and cows each between two to four years and forty calves between one to three months were used. The field grazing time (FGT), active grazing time (GT) and grazing travel time (GTT) were monitored.

  12. Grass composition and rangeland condition of the major grazing ...

    African Journals Online (AJOL)

    One area represented lightly grazed government ranches or parks which were used as benchmarks, another area represented the seasonal grazing areas with an intermediate grazing pressure and the remaining were the heavily grazed roadsides, lakeshores and other communal grazing lands. The range condition ...

  13. Response of ecosystem CO2fluxes to grazing intensities - a five-year experiment in the Hulunber meadow steppe of China.

    Science.gov (United States)

    Yan, R R; Tang, H J; Lv, S H; Jin, D Y; Xin, X P; Chen, B R; Zhang, B H; Yan, Y C; Wang, X; Murray, Philip J; Yang, G X; Xu, L J; Li, L H; Zhao, S

    2017-08-25

    Grazing is the primary land use in the Hulunber meadow steppe. However, the quantitative effects of grazing on ecosystem carbon dioxide (CO 2 ) fluxes in this zone remain unclear. A controlled experiment was conducted from 2010 to 2014 to study the effects of six stocking rates on CO 2 flux, and the results showed that there were significant differences in CO 2 fluxes by year, treatment, and month. The effects of light and intermediate grazing remained relatively constant with grazing year, whereas the effects of heavy grazing increased substantially with grazing duration. CO 2 flux significantly decreased with increasing grazing intensity and duration, and it was significantly positively correlated with rainfall, soil moisture (SM), the carbon to nitrogen ratio (C/N ratio), soil available phosphorus (SAP), soil NH 4 + -N, soil NO 3 - N, aboveground biomass (AGB), coverage, height, and litter and negatively correlated with air temperature, total soil N (TN) and microbial biomass N (MBN). A correspondence analysis showed that the main factors influencing changes in CO 2 emissions under grazing were AGB, height, coverage, SM, NH 4 + -N and NO 3 - N. Increased rainfall and reduced grazing resulted in greater CO 2 emissions. Our study provides important information to improve our understanding of the role of livestock grazing in GHG emissions.

  14. A grazing clock for measurement of time spent grazing by cattle ...

    African Journals Online (AJOL)

    To date, time spent grazing has been measured most successfully using an electronic grazing clock. Difficulties experienced with this clock however, were that temperature and stage in the life of the batteries affected the readings. Further, periods of grazing shorter than the units of time registered by the clock could not be ...

  15. The grazing capacity of sweetveld: 1 A technique to record grazing ...

    African Journals Online (AJOL)

    A technique is proposed for measuring the grazing capacity of sweet grassveld. The suggested procedure is to record the parameter on plots simulating individual camps in rotational grazing systems. This allows considerably smaller experimental areas to be used than in conventional stocking rate trials. Grazing capacity is ...

  16. Grazing incidence diffraction : A review

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, B. [LTPCM, ENSEEG. St. Martin d`Heres. (France)

    1996-09-01

    Different Grazing Incidence Diffraction (GID) methods for the analysis of thin films and multilayer structures are reviewed in three sections: the reflectivity is developed in the first one, which includes the non-specular diffuse scattering. The second one is devoted to the extremely asymmetric Bragg diffraction and the third one to the in-plane Bragg diffraction. Analytical formulations of the scattered intensities are developed for each geometry, in the framework of the kinetical analysis as well as the dynamical theory. Experimental examples are given to illustrate the quantitative possibility of the GID techniques.

  17. Performance and parasitosis in heifers grazing mixed with sows

    OpenAIRE

    Sehested, Jakob; Monrad, J.; Søegaard, Karen; Danielsen, Viggo

    2000-01-01

    The aim of the study was to investigate the effect of mixed grazing with first season heifers and pregnant sows on animal performance, gastro-intestinal helminths, pasture quality and sward structure during three grazing seasons. This presentation will focus on results from 1999, primarily regarding performance and parasitosis in heifers. There have been no earlier reports on such mixed grazing systems. Three grazing systems were studied in replicate: 1) Heifers grazing alone; 2) sows grazing...

  18. Performance of sheep grazing Brachiaria decumbens, Panicum ...

    African Journals Online (AJOL)

    Performance of sheep grazing Brachiaria decumbens, Panicum maximum and Pennisetum purpureum in combination with gliricidia sepium. ... The animals weregrazed continuously for 28 days in the sub plots. Sheep grazing the Gliricidia/Panicum plot had a higher (P < 001) growth rate (38 g d-1) than those animals ...

  19. Herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Meijs, J.A.C.

    1981-01-01

    An extensive review of the literature is given of
    - nine possible methods for estimating herbage intake by grazing ruminants, with special attention to the sward-cutting and indirect animal methods
    - the factors determining the herbage intake by grazing ruminants.

    The

  20. 75 FR 29572 - Information Collection; Grazing Management

    Science.gov (United States)

    2010-05-26

    ... Control Number 1004-0019] Information Collection; Grazing Management AGENCY: Bureau of Land Management... submitted an information collection request to the Office of Management and Budget (OMB) for a 3-year... INFORMATION: Title: Grazing Management (43 CFR 4120). OMB Number: 1004-0019. Forms: 4120-6 (Cooperative Range...

  1. Patterns of plant selection by grazing cattle in two savanna ...

    African Journals Online (AJOL)

    Patterns of plant selection by grazing cattle in two savanna grasslands: A plant's eye view. ... African Journal of Range and Forage Science ... had been previously grazed generally had a greater influence on the amount a tuft was grazed during an individual grazing event than species identity, location or moribund material.

  2. Productivity of grasslands under continuous and rotational grazing

    NARCIS (Netherlands)

    Lantinga, E.A.

    1985-01-01

    In the Netherlands, rotational grazing, with grazing periods of 2 to 5 days, is the most common grazing system at present. In contrast with other countries of North-western Europe, the continuous grazing system is used here only to a limited extent. However, the results of numerous

  3. 36 CFR 222.11 - Grazing advisory boards.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Grazing advisory boards. 222... MANAGEMENT Grazing and Livestock Use on the National Forest System § 222.11 Grazing advisory boards. (a... statutory grazing advisory board in accordance with provisions of the Federal Land Policy and Management Act...

  4. Grazing and biodiversity: from selective foraging to wildlife habitats

    OpenAIRE

    Wallis de Vries, M.F.

    2016-01-01

    Livestock grazing in low-intensity farming systems is a key aspect in the conservation of Europe's biodiversity, which reaches high levels of species richness in semi-natural grasslands. With the demise of traditional grazing systems, the design of viable low-intensity grazing systems for the future requires a good understanding of grazing impacts on biodiversity. Here, I review various scale-dependent aspects of selective grazing and how they may affect biodiversity. Insects such as butterfl...

  5. Grazing and pasture management for biodiversity benefit

    OpenAIRE

    Rook, Andrew; Tallowin, Jeremy

    2003-01-01

    International audience; The primary role of grazing animals in grassland biodiversity management is maintenance and enhancement of sward structural heterogeneity, and thus botanical and faunal diversity, by selective defoliation due to dietary choices, treading, nutrient cycling and propagule dispersal. Most research on dietary choices uses model systems that require considerable extrapolation to more complex communities. Grazing animals' diets are constrained by temporal and spatial changes ...

  6. Grazing behavior and intake of goats rotationally grazing Tanzania-grass pasture with different post-grazing residues

    Directory of Open Access Journals (Sweden)

    Marcia H.M.R. Fernandes

    2016-05-01

    Full Text Available This study aimed to evaluate intake and ingestive behavior of goats rotationally grazing Tanzania (Panicum maximum cv. Tanzânia 1 pastures with 2 levels of post-grazing residue. The experimental area consisted of 1.2 ha of Tanzania pasture divided into 12 paddocks (24 areas, managed under 2 post-grazing residues: low green (leaf + stem herbage mass (GHM post-grazing (LR, approximately 1,500 kg/ha GHM; and high GHM post-grazing (HR, approximately 3,000 kg/ha GHM. Each paddock was grazed for 3 consecutive days (D1, D2, D3 followed by 33 days rest and evaluated from October 2005 to April 2006. Animal behavior (grazing time, bite rate and bite size/weight was evaluated on each grazing day. While goats spent more time grazing on LR than HR (P=0.02, bite rate did not differ between treatments or among days (P=0.31 and averaged 26.5 bites/min. In contrast, bite weight was greater in HR (0.15 g/bite than in LR (0.12 g/bite, and decreased from D1 to D3 (P<0.001. Absolute dry matter intake of goats was greater in the HR (2.19 kg/d than the LR (1.89 kg/d treatment; however, differences were not significant (P>0.05 when intake was determined on a body weight or metabolic weight basis. Our findings are consistent with the general assumption that bite weight is a trade-off between quantity and quality of the herbage mass and is the main determinant of animal performance. More studies are needed to determine animal performance on the various treatments and to determine management strategies to provide a desirable balance between animal weight gain and pasture stability.Keywords: Animal behavior, foraging, grazing systems, Megathyrsus maximus, plant - animal relations.DOI: 10.17138/TGFT(491-100

  7. Mineral supplementation for grazing ruminants

    International Nuclear Information System (INIS)

    McDowell, L.R.; Conrad, J.H.; Ellis, G.L.

    1986-01-01

    Grazing ruminants to which concentrate feeds cannot be economically fed must rely on self-feeding of mineral supplements. A number of factors affect mineral consumption of free-choice mixtures. Livestock exhibit little nutritional wisdom and will select palatable mixtures in preference to mixtures designed to meet their requirements. Palatability and appetite stimulators are often used to achieve a more uniform herd-wide consumption. It is best to formulate free-choice mixtures on the basis of analyses or other available data. However, when no information on mineral status is known, a free-choice complete mineral supplement is warranted. A 'complete' mineral mixture usually includes salt, a low fluoride P source, Ca, Co, Cu, I, Mn and Zn. Selenium, Mg, K, S, Fe or additional elements can be incorporated into a mineral supplement as new information suggests a need. The detriment to ruminant production caused by providing Ca, Se and Cu in excess can be greater than any benefit derived by providing a mineral supplement. In regions where high forage Mo predominates, three to five times the Cu content in mineral mixtures is needed to counteract Mo toxicity. Supplemental minerals are most critical during the wet season, when cattle are gaining weight rapidly and energy and protein supplies are adequate. Economic return on mineral supplementation is high. (author)

  8. 25 CFR 166.307 - Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not...

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Will the grazing capacity be increased if I graze... § 166.307 Will the grazing capacity be increased if I graze adjacent trust or non-trust rangelands not covered by the permit? No. You will not receive an increase in grazing capacity in the permit if you graze...

  9. Prevalence and zoonotic aspects of small ruminant mange in the lateritic and waterlogged zones, southern Benin

    Directory of Open Access Journals (Sweden)

    Sahidou Salifou

    Full Text Available An epidemiological survey was undertaken from March to September 2010 to assess the prevalence and zoonotic aspects of scabies in small ruminants in two agro-ecological zones in southern Benin. Small ruminant (n = 444 smallholders and 1,807 of their animals (1,233 West African dwarf goats and 574 West African dwarf sheep were included in the study. The animals underwent physical examination and, when scabies-like lesions were found, crusts and integument scrapings were collected for microscopic parasitological tests. The samples collected in each survey were coded in accordance with the owner-animal pairings in order to assess the degree of correlation between mange cases in humans (smallholders and their animals. The overall prevalence of scabies was 28.33% and 9.5% in animals and smallholders (human cases respectively. Infestations were significantly (p < 0.001 more frequent in goats (39.6% than in sheep. The uniqueness of the etiological agent (Sarcoptes scabiei, the very high predictive value of human scabies in infected farms (83.67% and a very high odds ratio (OR = 2,019.25 indicate that small ruminant scabies has been transmitted to smallholders by their animals. Close contact between these smallholders and their animals was a determining factor in this interspecies communicability of sarcoptic mange.

  10. The grazing capacity of sweetveld: 2. A model to estimate grazing ...

    African Journals Online (AJOL)

    The relations between grazing capacity and three independent variables were investigated in the False Thornveld of the Eastern Cape. The variables were veld condition, rainfall and density of woody species. These relations were used to develop a preliminary model to assess grazing capacity in the veld type. Despite its ...

  11. Feed selection and radiocaesium intake by reindeer, sheep and goats grazing alpine summer habitats in southern Norway

    International Nuclear Information System (INIS)

    Staaland, H.; Garmo, T.H.; Hove, K.; Pedersen, O.

    1995-01-01

    Radiocaesium concentrations ( 137 Cs) were measured in extrusa from oesophageally fistulated sheep, goats and reindeer grazing alpine summer vegetation in Griningsdalen, Southern Norway in the period 1987-1989. The experiments with sheep and goats were conducted in different sub-alpine areas. The reindeer were, in addition, grazed in three areas in the low alpine zone. Grazing bouts lasted for 10-20 min and bite selections were recorded every 15 s through the grazing bout. Reindeer and goats had the most diverse food selection whereas sheep fed mainly on grasses, forbs and to some extent, on leaves of willow. The reindeer extrusa had the highest radiocaesium activity, apparently to a large extent caused by intake of lichens in areas where this type of plants were present. Depending on the type of vegetation in the grazed areas the transfer of radiocaesium from soil to grazed vegetation (Bq kg -1 dry extrusa/Bq m -2 soil) was estimated to 0.02-0.04 in sheep, 0.02-0.05 in goats and 0.02-0.43 in reindeer for 1987. (author)

  12. Cattle grazing and conservation of a meadow-dependent amphibian species in the Sierra Nevada.

    Directory of Open Access Journals (Sweden)

    Leslie M Roche

    Full Text Available World-wide population declines have sharpened concern for amphibian conservation on working landscapes. Across the Sierra Nevada's national forest lands, where almost half of native amphibian species are considered at risk, permitted livestock grazing is a notably controversial agricultural activity. Cattle (Bos taurus grazing is thought to degrade the quality, and thus reduce occupancy, of meadow breeding habitat for amphibian species of concern such as the endemic Yosemite toad (Anaxyrus [ = Bufo] canorus. However, there is currently little quantitative information correlating cattle grazing intensity, meadow breeding habitat quality, and toad use of meadow habitat. We surveyed biotic and abiotic factors influencing cattle utilization and toad occupancy across 24 Sierra Nevada meadows to establish these correlations and inform conservation planning efforts. We utilized both traditional regression models and Bayesian structural equation modeling to investigate potential drivers of meadow habitat use by cattle and Yosemite toads. Cattle use was negatively related to meadow wetness, while toad occupancy was positively related. In mid and late season (mid July-mid September grazing periods, cattle selected for higher forage quality diets associated with vegetation in relatively drier meadows, whereas toads were more prevalent in wetter meadows. Because cattle and toads largely occupied divergent zones along the moisture gradient, the potential for indirect or direct negative effects is likely minimized via a partitioning of the meadow habitat. During the early season, when habitat use overlap was highest, overall low grazing levels resulted in no detectable impacts on toad occupancy. Bayesian structural equation analyses supported the hypothesis that meadow hydrology influenced toad meadow occupancy, while cattle grazing intensity did not. These findings suggest cattle production and amphibian conservation can be compatible goals within this

  13. Modeling dynamics of tundra plant communities on the Yamal Peninsula, Russia, in response to climate change and grazing pressure

    International Nuclear Information System (INIS)

    Yu, Q; Epstein, H E; Frost, G V; Walker, D A; Forbes, B C

    2011-01-01

    Understanding the responses of the arctic tundra biome to a changing climate requires knowledge of the complex interactions among the climate, soils and biological system. This study investigates the individual and interaction effects of climate change and reindeer grazing across a variety of climate zones and soil texture types on tundra vegetation community dynamics using an arctic vegetation model that incorporates the reindeer diet, where grazing is a function of both foliar nitrogen concentration and reindeer forage preference. We found that grazing is important, in addition to the latitudinal climate gradient, in controlling tundra plant community composition, explaining about 13% of the total variance in model simulations for all arctic tundra subzones. The decrease in biomass of lichen, deciduous shrub and graminoid plant functional types caused by grazing is potentially dampened by climate warming. Moss biomass had a nonlinear response to increased grazing intensity, and such responses were stronger when warming was present. Our results suggest that evergreen shrubs may benefit from increased grazing intensity due to their low palatability, yet a growth rate sensitivity analysis suggests that changes in nutrient uptake rates may result in different shrub responses to grazing pressure. Heavy grazing caused plant communities to shift from shrub tundra toward moss, graminoid-dominated tundra in subzones C and D when evergreen shrub growth rates were decreased in the model. The response of moss, lichen and forbs to warming varied across the different subzones. Initial vegetation responses to climate change during transient warming are different from the long term equilibrium responses due to shifts in the controlling mechanisms (nutrient limitation versus competition) within tundra plant communities.

  14. Modeling the grazing effect on dry grassland carbon cycling with modified Biome-BGC grazing model

    Science.gov (United States)

    Luo, Geping; Han, Qifei; Li, Chaofan; Yang, Liao

    2014-05-01

    Identifying the factors that determine the carbon source/sink strength of ecosystems is important for reducing uncertainty in the global carbon cycle. Arid grassland ecosystems are a widely distributed biome type in Xinjiang, Northwest China, covering approximately one-fourth the country's land surface. These grasslands are the habitat for many endemic and rare plant and animal species and are also used as pastoral land for livestock. Using the modified Biome-BGC grazing model, we modeled carbon dynamics in Xinjiang for grasslands that varied in grazing intensity. In general, this regional simulation estimated that the grassland ecosystems in Xinjiang acted as a net carbon source, with a value of 0.38 Pg C over the period 1979-2007. There were significant effects of grazing on carbon dynamics. An over-compensatory effect in net primary productivity (NPP) and vegetation carbon (C) stock was observed when grazing intensity was lower than 0.40 head/ha. Grazing resulted in a net carbon source of 23.45 g C m-2 yr-1, which equaled 0.37 Pg in Xinjiang in the last 29 years. In general, grazing decreased vegetation C stock, while an increasing trend was observed with low grazing intensity. The soil C increased significantly (17%) with long-term grazing, while the soil C stock exhibited a steady trend without grazing. These findings have implications for grassland ecosystem management as it relates to carbon sequestration and climate change mitigation, e.g., removal of grazing should be considered in strategies that aim to increase terrestrial carbon sequestrations at local and regional scales. One of the greatest limitations in quantifying the effects of herbivores on carbon cycling is identifying the grazing systems and intensities within a given region. We hope our study emphasizes the need for large-scale assessments of how grazing impacts carbon cycling. Most terrestrial ecosystems in Xinjiang have been affected by disturbances to a greater or lesser extent in the past

  15. Effect of nitrogen and phosphorous on Farm Plantations in various ...

    African Journals Online (AJOL)

    use

    of different suitable species of plants. The results of the soil analysis of various Agro ecological zones and the consequent recommendation of the associated suitable species, aids the agrofarmers to pick out the best possible option. Key words: Soil analysis, agro-ecological zones, agroforestry, nitrogen and phosphorous.

  16. An analysis of the fundamentals of grazing management systems ...

    African Journals Online (AJOL)

    An analysis of the fundamentals of grazing management systems. Booysen PD. Abstract. The resting and grazing components of grazing management cycles as practiced in South Africa are evaluated from the points of view of objective and effect. While the desirability of resting for seeding and an increase in vigour is ...

  17. Impact of Prosopis (mesquite) invasion and clearing on the grazing ...

    African Journals Online (AJOL)

    Our results indicate that Prosopis invasion (>13% mean canopy cover) can lower grazing capacity in Nama Karoo rangeland, whereas clearing Prosopis from such rangeland can, even under heavy grazing, substantially improve grazing capacity within 4–6 years. Keywords: exotic invasive plants, management, natural ...

  18. A review of experiments comparing systems of grazing management ...

    African Journals Online (AJOL)

    Experiments comparing different systems of grazing management on natural pastures in various parts of the world are reviewed. In experiments in which various rotational systems were tested against continuous grazing, fewer than half revealed pasture improvement relative to continuous grazing. In the majority of ...

  19. Performance and Grazing Pattern of West African Dwarf Sheep to ...

    African Journals Online (AJOL)

    Sixty (60) West African Dwarf sheep managed semi intensively and grazing on natural pastures were used in a study to determine the performance and grazing pattern to seasonal forage supply and quality. The animals were allowed to graze for about 6 hours daily for four months each in the dry and wet seasons, ...

  20. Grazing capacity estimates: why include biomass estimates from ...

    African Journals Online (AJOL)

    Forage for ruminants in the dry season were assessed and matched with feed requirements in three villages in Zimbabwe, namely; Chiweshe, Makande and Mudzimu. Stocking rates were compared with grazing capacity to determine grazing intensities. Grazing capacities were estimated with and without crop residues to ...

  1. Grazing and biodiversity: from selective foraging to wildlife habitats

    NARCIS (Netherlands)

    Wallis de Vries, M.F.

    2016-01-01

    Livestock grazing in low-intensity farming systems is a key aspect in the conservation of Europe's biodiversity, which reaches high levels of species richness in semi-natural grasslands. With the demise of traditional grazing systems, the design of viable low-intensity grazing systems for the future

  2. Livestock grazing behaviour along a degradation gradient in the ...

    African Journals Online (AJOL)

    Six each of male cattle, sheep, goats and camels, with average masses of 200, 35, 30 and 220 kg, respectively, were used and randomly assigned for unrestricted grazing. Species selectivity, grazing time, grazing intensity and number of bites were recorded. Forage mass intake per animal per day was estimated through a ...

  3. Recent trends in grazing management philosophy in South Africa ...

    African Journals Online (AJOL)

    In contrast, considerably more evidence has emerged to support the general philosophy which has built up over the years on such issues as optimum stocking rates, periods of absence, stocking densities and the required number of camps in grazing layouts. Keywords: change; grazing intensity; grazing management; herd ...

  4. Response of lambs to continuous and rotational grazing at four ...

    African Journals Online (AJOL)

    was grazed either continuously or rotationally at four grazing intensities by three successive sets of weaned lambs for the winter, spring and summer periods, respectively. The "put-and-take" system was applied. In the case of continuous grazing, amounts of available dry matter (DM) per hectare were varied, whereas with ...

  5. Impact of Livestock Grazing on Abundance and Community ...

    African Journals Online (AJOL)

    A survey of the impact of cattle grazing on macro invertebrate fauna of Ovia River was carried out between January and June 2004. Macro invertebrate and water samples were collected from three sampling locations; station I (new grazing area for cattle), station II (initial grazing area) and station III (control location). A total ...

  6. The economic cost of noxious weeds on Montana grazing lands

    Science.gov (United States)

    We distributed a 16-question survey concerning noxious weed abundances, impacts and management to livestock producers grazing on privately-owned or leased grazing lands in Montana. The noxious weeds most commonly reported as being present on respondents’ grazing units were Canada thistle (64% of gra...

  7. The evaluation of pastures and grazing management in terms of ...

    African Journals Online (AJOL)

    The evaluation of pastures and grazing management in terms of livestock production. ... African Journal of Range and Forage Science ... Abstract. Grazing research in South Africa has been largely pasture oriented and consequently there is still a need to fully evaluate many of our more important pasture types and grazing ...

  8. How Does “Hunger” Level Impact Grazing Behavior?

    Science.gov (United States)

    Grazing behavior can be influenced through feeding and grazing management decisions. Research at our USDA-ARS lab showed that ruminal fill, or how ‘hungry’ the cow is, can affect grazing behavior. Cows that had less ruminal fill took a bigger bite that was shallow and wide, compared to a ‘full’ cow ...

  9. Assessment of the Effects of Emerging Grazing Policies on Land ...

    African Journals Online (AJOL)

    The consequences of these affect lives, properties and the environment. The country now has approximately 210 persons and 180 grazing animals per kilometer square of land and 15,000 persons and 12,500 grazing animals per kilometer square of water. With the population of both man and grazing animals increasing at ...

  10. 25 CFR 166.305 - When is grazing capacity determined?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false When is grazing capacity determined? 166.305 Section 166... and Operations Management § 166.305 When is grazing capacity determined? Before we grant, modify, or approve a permit, in consultation with the Indian landowners, we will establish the total grazing capacity...

  11. Longer rest periods for intensive rotational grazing limit diet quality ...

    African Journals Online (AJOL)

    Longer rest periods for intensive rotational grazing limit diet quality of sheep without enhancing environmental benefits. ... This experiment was established to compare three intensive rotational grazing strategies (fast rotation [FR], average 57-day rest; slow rotation [SR], average 114-day rest; and flexible grazing [FX], based ...

  12. Forage patch use by grazing herbivores in a South African grazing ecosystem

    NARCIS (Netherlands)

    Venter, J.A.; Nabe-Nielsen, J.; Prins, H.H.T.; Slotow, R.

    2014-01-01

    Understanding how different herbivores make forage patch use choices explains how they maintain an adequate nutritional status, which is important for effective conservation management of grazing ecosystems. Using telemetry data, we investigated nonruminant zebra (Equus burchelli) and ruminant red

  13. Chapter 2: Livestock and Grazed Lands Emissions

    Science.gov (United States)

    A total of 342 MMT CO2 eq. of greenhouse gasses (GHGs) were emitted from livestock, managed livestock waste, and grazed land in 2013. This represents about 66% of total emissions from the agricultural sector, which totaled 516 MMT CO2 eq. Compared to the base line year (1990), emissions from livesto...

  14. Dietary selection by steers grazing kikuyu

    African Journals Online (AJOL)

    being grazeA for a period of 3,5 days in a four-week rotation, at ... Cattle improve the quality of their diet by actively seeking ... of stem in their diet. This would explain why the stem fraction mad~ no significant contribution to the equation predicting diet~ry selection. A:1unusual fact which emerged is that the animals selected.

  15. Estimating phosphorus intake by grazing sheep

    African Journals Online (AJOL)

    Estimating phosphorus intake in grazing sheep is ditficult since hand-picked ... Thus to establish the intake of phosphorus, a method other than forage .... between the mean (tSD) levels in the ribs of the sheep and the. S.-Afr. Tydskr. Veek. 19g3, l3(3) of phosphorus and feed they consumed. Determination. Specimen".

  16. 50 CFR 35.9 - Livestock grazing.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Livestock grazing. 35.9 Section 35.9 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE..., reconstruction or relocation of only those livestock management improvements and structures which existed within...

  17. Ecology of grazing lawns in Africa

    CSIR Research Space (South Africa)

    Hempson, GP

    2014-09-01

    Full Text Available rates of nitrogen cycling and of sodium levels to lawn maintenance. Grazer community composition and density has considerable significance to grazing lawn dynamics; not all grazers are adapted to foraging on short-grass swards, and differences in body...

  18. Optimal grazing management strategies: evaluating key concepts ...

    African Journals Online (AJOL)

    Rangeland management strategies must be based on robust ecological and economic concepts if they are to be effective and profitable. Thus, the aim of this paper was to examine concepts related to grazing and resting of grassland and associated effects on grassland productivity and energy flow to livestock. Our review ...

  19. Phosphorus supplementation of Karakul sheep grazing natural ...

    African Journals Online (AJOL)

    The phosphorus (P) status of adult Karakul ewes grazing natural pasture was determined by measuring the P content of blood, saliva, faecal, and bone samples. The ewes were divided into four groups of 20 ewes each, viz. ewes supplemented with P+ and P- which lambed during May and October. All lambs born were ...

  20. The effects of zero grazing in Ethiopia

    NARCIS (Netherlands)

    Cao, De E.; Berg, van den M.M.; Tizale, C.Y.; Wondwosen, T.

    2013-01-01

    In the high lands of Ethiopia, almost every plot of farmland is allotted for crop husbandry, leaving no or only road sides and marginal lands for grazing. However, land is scarce in these areas and this limits the role of crop production in poverty alleviation and it also limits the availability of

  1. Woodlands Grazing Issues in Mediterranean Basin

    Science.gov (United States)

    Campos, P.

    2009-04-01

    In Mediterranean basin, woodlands grazing still continue to be important commercial owners' benefits. These owners manage woodlands vegetations as if they were not at risk of degradation and declining. Frequently, no temporally grazing set-aside is taken into account to avoid overgrazing of annual and perennial vegetations. Although less common, in the northern shore of Mediterranean basin undergrazing might increase the frequency and the number of catastrophic forest fires. This under/over grazing regime occurs in the Mediterranean basin woodlands with contrasted differences on land property rights, local economies and government livestock policy incentives. Spain and Tunisia are examples of these Mediterranean livestock contrasts. Most of Spanish Mediterranean woodlands and livestock herds are large private ownerships and owners could maintain their lands and livestock herds properties on the basis of moderate cash-income compensation against land revaluation and exclusive amenity self-consumption. The later is less tangible benefit and it could include family land legacy, nature enjoyment, country stile of life development, social status and so on. In public woodlands, social and environmental goals -as they are cultural heritage, biodiversity loss mitigation, soil conservation and employment- could maintain market unprofitable woodlands operations. Last three decades Spanish Mediterranean woodlands owners have increased the livestock herds incentivized by government subsidies. As result, grazing rent is pending on the level of European Union and Spanish government livestock subsidies. In this context, Spanish Mediterranean woodlands maintain a high extensive livestock stoking population, which economy could be called fragile and environmentally unsustainable because forest degradation and over/under grazing practices. Tunisian Mediterranean woodlands are state properties and livestock grazing is practice as a free private regimen. Livestock herds are small herd

  2. Ammonia emissions of a rotational grazing system

    Science.gov (United States)

    Voglmeier, Karl; Häni, Christoph; Jocher, Markus; Ammann, Christof

    2017-04-01

    Intensive agricultural livestock production is the main source of air pollution by ammonia (NH3). Grazing is considered to reduce emissions significantly. However, ammonia emissions measurements on pastures are very rare and most emission models base their emissions factors for grazing on studies from the 1990s, which report a large emission range from 2.7% to 13.6% of the applied total ammonia nitrogen (TAN). We present first results of the Posieux pasture experiment in 2016 where NH3 concentration and fluxes were measured during the grazing season. The applied methods include an eddy covariance system with a two channel reactive nitrogen (Nr) converter measuring in parallel the sum of oxidized Nr species and the sum of the total Nr species. The difference of the two channels corresponds to the sum of reduced Nr species. Furthermore four MiniDOAS instruments for line integrated concentration measurements without an inlet system were used. The fluxes were estimated by applying a backward Lagrangian stochastic model (bLS) to the concentration difference of paired MiniDOAS up- and downwind of a sub-plot of the field. Monitoring of dung (visual survey) and urine patch locations (with soil electrical conductivity sensor) was carried out after each grazing rotation on selected sub-plots. It helped to compute statistics of the dung/urine patch distribution on the pasture. The experimental setup and the environmental conditions resulted in high temporal and spatial dynamics of NH3 concentrations and fluxes. The calculated fluxes were used to estimate the total net emission during the grazing period. Based on the average dung/urine patch distribution on the field an emission factor for the pasture was computed and compared to results from the literature. We discuss the applicability and limitations of the two measurement systems, reconsider the main emission drivers and explain differences in the results.

  3. Quantification of uncertainties in global grazing systems assessment

    Science.gov (United States)

    Fetzel, T.; Havlik, P.; Herrero, M.; Kaplan, J. O.; Kastner, T.; Kroisleitner, C.; Rolinski, S.; Searchinger, T.; Van Bodegom, P. M.; Wirsenius, S.; Erb, K.-H.

    2017-07-01

    Livestock systems play a key role in global sustainability challenges like food security and climate change, yet many unknowns and large uncertainties prevail. We present a systematic, spatially explicit assessment of uncertainties related to grazing intensity (GI), a key metric for assessing ecological impacts of grazing, by combining existing data sets on (a) grazing feed intake, (b) the spatial distribution of livestock, (c) the extent of grazing land, and (d) its net primary productivity (NPP). An analysis of the resulting 96 maps implies that on average 15% of the grazing land NPP is consumed by livestock. GI is low in most of the world's grazing lands, but hotspots of very high GI prevail in 1% of the total grazing area. The agreement between GI maps is good on one fifth of the world's grazing area, while on the remainder, it is low to very low. Largest uncertainties are found in global drylands and where grazing land bears trees (e.g., the Amazon basin or the Taiga belt). In some regions like India or Western Europe, massive uncertainties even result in GI > 100% estimates. Our sensitivity analysis indicates that the input data for NPP, animal distribution, and grazing area contribute about equally to the total variability in GI maps, while grazing feed intake is a less critical variable. We argue that a general improvement in quality of the available global level data sets is a precondition for improving the understanding of the role of livestock systems in the context of global environmental change or food security.

  4. Response of mountain meadows to grazing by recreational pack stock

    Science.gov (United States)

    Cole, David N.; Van Wagtendonk, Jan W.; McClaran, Mitchel P.; Moore, Peggy E.; McDougald, Neil K.

    2004-01-01

    Effects of recreational pack stock grazing on mountain meadows in Yosemite National Park were assessed in a 5-year study. Yosemite is a designated wilderness, to be managed such that its natural conditions are preserved. Studies were conducted in 3 characteristic meadow types: shorthair sedge (Carex filifolia Nutt.), Brewer's reed grass (Calamagrostis breweri Thurber), and tufted hairgrass [Deschampsia cespitosa (L.) Beauv.]. Horses and mules grazed experimental plots at intensities of 15 to 69% utilization for 4 seasons. In all 3 meadows, grazing caused decreases in productivity. The mean reduction after 4 years of grazing was 18% in the shorthair sedge meadow, 17% in the Brewer's reed grass meadow, and 22% in the tufted hairgrass meadow. Grazing also caused shifts in basal groundcover (usually a reduction in vegetation cover and increase in bare soil cover), and changes in species composition. Productivity and vegetation cover decreased as percent utilization increased, while bare soil cover increased as utilization increased. Changes in species composition were less predictably related to differences in grazing intensity. Passive management of grazing is insufficient in wilderness areas that are regularly used by groups with recreational stock. Wilderness managers need to monitor meadow conditions and the grazing intensities that occur. Our study suggests that biomass and ground cover are more sensitive indicators of grazing impact than species composition. Managers must make decisions about maximum acceptable levels of grazing impact and then develop guidelines for maximum use levels, based on data such as ours that relates grazing intensity to meadow response.

  5. Birds bias offspring sex ratio in response to livestock grazing.

    Science.gov (United States)

    Prior, Gina L; Evans, Darren M; Redpath, Stephen; Thirgood, Simon J; Monaghan, Pat

    2011-12-23

    Livestock grazing, which has a large influence on habitat structure, is associated with the widespread decline of various bird species across the world, yet there are few experimental studies that investigate how grazing pressure influences avian reproduction. We manipulated grazing pressure using a replicated field experiment, and found that the offspring sex ratio of a common upland passerine, the meadow pipit Anthus pratensis, varied significantly between grazing treatments. The proportion of sons was lowest in the ungrazed and intensively grazed treatments and highest in treatments grazed at low intensity (by sheep, or a mixture of sheep and cattle). This response was not related to maternal body condition. These results demonstrate the sensitivity of avian reproductive biology to variation in local conditions, and support growing evidence that too much grazing, or the complete removal of livestock from upland areas, is detrimental for common breeding birds.

  6. Reindeer grazing in subarctic boreal forest - influences on the soil carbon dynamics

    Science.gov (United States)

    Koster, Kajar; Berninger, Frank; Köster, Egle; Pumpanen, Jukka

    2015-04-01

    Reindeer (Rangifer tarandus L.) are the most important large mammalian herbivores in the northern ecosystems , which have many effects on plant diversity, soil nutrient cycling and soil organic matter decomposition. Changes caused by reindeer in vegetation have indirect effects on physical features of the soil e.g. soil microclimate, root biomass and also on soil C dynamics. Earlier, the role of reindeer grazing in ground vegetation dynamics and in soil carbon (C) dynamics has been mostly investigated in open tundra heaths. The objectives of this study were to examine if and how the reindeer grazing (and the possible temperature changes in soil caused by heavy grazing) is affecting the soil C dynamics (CO2 efflux from the soil, C storage in soil, microbial biomass in the soil). In a field experiment in Finnish Lapland, in Värriö Strict Nature Reserve (67° 46' N, 29° 35' E) we have assessed the changes occurring in above- and belowground biomasses, and soil C dynamics (CO2 efflux, soil C content, soil microbial biomass C) among areas grazed and ungrazed by reindeer. Our study areas are located in the northern boreal subarctic coniferous forest at the zone of the last intact forest landscapes in Fennoscandia, where large areas of relatively undisturbed subarctic Scots pine (Pinus sylvestris L.) forests can still be found. The sample plots located in the Värriö Strict Nature Reserve (10 sample plots in total established in year 2013) are situated along the borderline between Finland and Russia, where the ungrazed area was excluded from the reindeer grazing already in 1918, to prevent the Finnish reindeer from going to the Russian side and there are not many reindeer on Russian side of the area. To characterize the stands we have established circular sample plots on areas with a radius of 11.28 m, where different tree characteristics were measured (diameter at 1.3 m, height, height of a tree, crown height, crown diameter, stand age, etc.). On every sample plot

  7. Population Dynamics and Transcriptomic Responses of Chorthippus albonemus (Orthoptera: Acrididae) to Herbivore Grazing Intensity

    OpenAIRE

    Xinghu Qin; Xinghu Qin; Xinghu Qin; Jingchuan Ma; Jingchuan Ma; Xunbing Huang; Xunbing Huang; Robert L. Kallenbach; T. Ryan Lock; Md. Panna Ali; Zehua Zhang; Zehua Zhang

    2017-01-01

    Livestock grazing can trigger outbreaks of insect pests in steppe ecosystems of Inner Mongolia in China. However, the physiological responses of the grasshopper Chorthippus albonemus to grazing are not well-understood. Here we investigated the effects of sheep grazing on the population dynamics and transcriptomic response of C. albonemus. We collected the insects three times (about 20 days apart) in 1.33-ha plots in which there were no grazing, light grazing, moderate grazing, heavy grazing, ...

  8. The current status of grazing incidence optics

    International Nuclear Information System (INIS)

    Aschenbach, B.

    1983-01-01

    The developments in the area of grazing incidence optics with emphasis on telescopes for use in X-ray astronomy are reviewed. The performance of existing high-resolution telescopes is outlined and compared with those expected from future missions like ROSAT and AXAF. Starting from the basic principles of X-ray reflection and scattering, an attempt is made to highlight the current understanding of X-ray mirror physics using new theoretical ideas as well as experimental laboratory results. (author)

  9. Neutron Reflectivity and Grazing Angle Diffraction

    OpenAIRE

    Ankner, J. F.; Majkrzak, C. F.; Satija, S. K.

    1993-01-01

    Over the last 10 years, neutron reflectivity has emerged as a powerful technique for the investigation of surface and interfacial phenomena in many different fields. In this paper, a short review of some of the work on neutron reflectivity and grazing-angle diffraction as well as a description of the current and planned neutron rcflectometers at NIST is presented. Specific examples of the characterization of magnetic, superconducting, and polymeric surfaces and interfaces are included.

  10. Neutron Reflectivity and Grazing Angle Diffraction.

    Science.gov (United States)

    Ankner, J F; Majkrzak, C F; Satija, S K

    1993-01-01

    Over the last 10 years, neutron reflectivity has emerged as a powerful technique for the investigation of surface and interfacial phenomena in many different fields. In this paper, a short review of some of the work on neutron reflectivity and grazing-angle diffraction as well as a description of the current and planned neutron rcflectometers at NIST is presented. Specific examples of the characterization of magnetic, superconducting, and polymeric surfaces and interfaces are included.

  11. The Effect of Different Type of Herbivores, Grazing Types and Grazing Intensities on Alpine Basiphillous Vegetation of the Romanian Carpathians

    Science.gov (United States)

    Ballová, Zuzana; Pekárik, Ladislav; Šibík, Jozef

    2017-04-01

    The major purpose of the present study was to test the hypothesis that there are significant differences in vegetation structure, plant species composition, and soil chemical properties in relation to type of grazing animals, various levels of grazing intensity and grazing type, and if potential differences alter with ecosystem productivity (increase in more productive ecosystems). The study was conducted in three mountain ranges of the Romanian Carpathians with a predominance of alkaline substrates (the Bucegi Mts, the Little Retezat Mts and the Ceahlău Massif). Statistical analyses were performed in R statistical software environment. The effects of grazing animals (cattle, horses and sheep), grazing types (fence, regular, irregular) and grazing intensity (low, medium, high) on the community structure were tested using ordination methods. In the case of soil properties, General Linear Mixed Model was applied. Special statistical approach eliminated the differences between the examined mountains and sites. Type of grazing animal does not significantly influence species cover but it is related to specific species occurrence. According to our results, grazing horses had similar effects as cattle compared to sheep. Grazing in restricted areas (surrounded by fence) and regular unrestricted grazing were more similar if compared to irregular grazing. When comparing the intensity of grazing, high and medium intensity were more similar to each other than to the low intensity grazing. Cattle grazed sites had significantly higher lichens cover, while the sheep patches were covered with increased overall herb layer (forbs, graminoids and low shrubs together). Medium grazing intensity decreased the lichens cover, cover of overall herb layer, and total vegetation cover compared to high and low grazing intensity. Grazing type had important impact on the lichens cover and cover of overall herb layer. The lichens cover appeared to decrease while the cover of overall herb layer

  12. Continuous feral horse grazing and grazing exclusion in mountain pampean grasslands in Argentina

    Science.gov (United States)

    de Villalobos, A. E.; Zalba, S. M.

    2010-09-01

    This paper evaluates changes in the composition and structure of plant communities and plant functional groups associated with the continuous presence of feral horses in mountain pampean grasslands in Argentina in order to explore the potential effects of horse removal on vegetation restoration. Specific and functional richness, diversity, evenness, spatial heterogeneity and above-ground biomass were compared between areas subjected to ten years of intensive grazing by horses and exclosures of the same age. Forbs, shrubs and rosettes were more abundant after ten years of grazing, while the spatial heterogeneity of perennial grasses was higher in long-term grazed areas. Nevertheless, grasslands showed good recovery after horse removal, with greater species diversity and evenness, higher abundance of perennial grasses, greater above-ground biomass and lower percentages of exotic species. An understanding of the effect of feral animals on plant communities will lead to the design of a strategy of adaptive management and monitoring tools for measuring the condition of grasslands.

  13. Effect of Restricted Grazing Time on the Foraging Behavior and Movement of Tan Sheep Grazed on Desert Steppe

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2013-05-01

    Full Text Available To investigate the effect of restricted grazing time on behavior of Tan sheep on desert steppe, forty 4-months old male Tan sheep with an original body weight (BW of 15.62±0.33 kg were randomly allocated to 4 grazing groups which corresponded to 4 different restricted grazing time treatments of 2 h/d (G2, 4 h/d (G4, 8 h/d (G8 and 12 h/d (G12 access to pasture. The restricted grazing times had a significant impact on intake time, resting time, ruminating time, bite rate and movement. As the grazing time decreased, the proportion of time spent on intake, bite rate and grazing velocity significantly (p<0.05 increased, but resting and ruminating time clearly (p<0.05 decreased. The grazing months mainly depicted effect on intake time and grazing velocity. In conclusion, by varying their foraging behavior, Tan sheep could improve grazing efficiency to adapt well to the time-limited grazing circumstance.

  14. The effect of grazing on cow mortality in Danish dairy herds

    DEFF Research Database (Denmark)

    Burow, Elke; Thomsen, Peter Thorup; Sørensen, Jan Tind

    2011-01-01

    to a zero-grazing herd having automatic milking system. In traditional milking system, mortality was reduced to 75% in grazing compared to zero-grazing herds. Within the grazing herds, the risk of mortality decreased with increasing number of hours on pasture during the season. Free access between barn...... a questionnaire survey of grazing procedures on these herds in 2008. In all, 131 of the herds were identified as summer grazing and 260 as zero-grazing herds. The mortality was affected by an interaction of summer grazing and milking system. The risk of a cow dying was reduced to 46% in a grazing compared...

  15. OPTIMIZATION OF GRAZING CAPACITY IN TEMPORARY PASTURE CROPS, GRAZED WITH SHEEP, IN HILL AREAS

    Directory of Open Access Journals (Sweden)

    MARIA SAUER

    2009-05-01

    Full Text Available The researches performed in the Caransebeş hill area made evident the opportunities of the temporary pasture crops consisted of intensive red clover and perennial graminaceous associations. Each type of the associations studied produced the biggest DM yields under conditions of direct grazing with animals, at an animal load of 2 UVM/ha. The most balanced proportion between legume and graminaceous species (52 : 48% was obtained in the second year of production, in the variant grazed with 2 UVM/ha.

  16. Grazing of Raphanus sativus. L (Japanese radish). | N.F.G. | African ...

    African Journals Online (AJOL)

    The performance of young woolled sheep was markedly better when grazing Japanese radish early in winter, when more leaf was available. Continuous grazing resulted in better performance than rotational or zero grazing. Keywords: continuous grazing; grazing; japanese radish; leaves; nooitgedacht research station; ...

  17. Dynamics of grazing lawn formation: An experimental test of the role of scale-dependent processes

    NARCIS (Netherlands)

    Cromsigt, J.P.G.M.; Olff, H.

    2008-01-01

    Grazing lawns are characteristic for African savanna grasslands, standing out as intensely grazed patches of stoloniferous grazing-tolerant grass species. Grazing lawn development has been associated with grazing and increased nutrient input by large migratory herds. However, we argue that in

  18. Dynamics of grazing lawn formation : an experimental test of the role of scale-dependent processes

    NARCIS (Netherlands)

    Cromsigt, Joris P. G. M.; Olff, Han; Setälä, Heikki

    2008-01-01

    Grazing lawns are characteristic for African savanna grasslands, standing out as intensely grazed patches of stoloniferous grazing-tolerant grass species. Grazing lawn development has been associated with grazing and increased nutrient input by large migratory herds. However, we argue that in

  19. Possibilities and constraints for grazing in high output dairy systems

    OpenAIRE

    Hennessy, D.; Delaby, L.; Pol, van den, A.; Shalloo, L.

    2015-01-01

    In temperate and oceanic regions, grazed grass is the lowest cost feed available for milk production. In other regions, grazed grass is less important but can contribute to the diet of livestock. Within high output systems the interaction between the animal and sward is challenging for a host of reasons, includingintake and milk production potential, substitution, grass allowance, quality, etc., which often means that grass utilisation and quality are compromised. Adaptation of grazing manage...

  20. Developmental instability and fitness in Periploca laevigata experiencing grazing disturbance

    Science.gov (United States)

    Alados, C.L.; Giner, M.L.; Dehesa, L.; Escos, J.; Barroso, F.; Emlen, J.M.; Freeman, D.C.

    2002-01-01

    We investigated the sensitivity of developmental instability measurements (leaf fluctuating asymmetry, floral radial asymmetry, and shoot translational asymmetry) to a long‐standing natural stress (grazing) in a palatable tannin‐producing shrub (Periploca laevigata Aiton). We also assessed the relationship between these measures of developmental instability and fitness components (growth and floral production). Developmental instability, measured by translational asymmetry, was the most accurate estimator of a plant’s condition and, consequently, environmental stress. Plants with less translational asymmetry grew more and produced more flowers. Plants from the medium‐grazed population were developmentally more stable, as estimated by translational and floral asymmetry, than either more heavily or more lightly grazed populations. Leaf fluctuating asymmetry was positively correlated with tannin concentration. The pattern of internode growth also responded to grazing impact. Plants under medium to heavy grazing pressure accelerated early growth and consequently escaped herbivory later in the season, i.e., at the beginning of the spring, when grazing activity was concentrated in herbaceous plants. Periploca laevigata accelerated growth and finished growing sooner than in the other grazing treatment. Thus, its annual growth was more mature and less palatable later in the season when grazers typically concentrate on shrubs. The reduction of developmental instability under medium grazing is interpreted as a direct effect of grazing and not as the release from competition.

  1. Ecological Effects of Grazing in the Northern Tianshan Mountains

    Directory of Open Access Journals (Sweden)

    Xiaotao Huang

    2017-11-01

    Full Text Available Identifying the effects of grazing is critical for the conservation, protection and sustainable use of arid grassland ecosystems. However, research regarding the ecological effects of grazing along mountainous elevation gradients is limited in arid areas, particularly at the regional scale. Using the Biome-BGC grazing model, we explored the effects of grazing on grassland net primary productivity (NPP, evapotranspiration (ET and water use efficiency (WUE from 1979 to 2012 along an elevation gradient in the northern Tianshan Mountains. The NPP, ET and WUE values were generally lower under the grazing scenario than under the ungrazed scenario; the differences between the grazing and ungrazed scenarios showed increasing trends over time; and distinct spatial heterogeneity in these differences was observed. Distinct decreases in NPP and WUE under the grazing scenario mainly occurred in regions with high livestock consumption. The decrease in ET was greater in mountainous areas with high grazing intensity due to decreased transpiration and increased surface runoff. This study contributes to a better understanding of the ecological effects of grazing along an elevation gradient in the northern Tianshan Mountains and provides data to support the scientific management of grassland ecosystems.

  2. Dietary selection of sheep grazing the semi-arid grasslands of Inner Mongolia, China at different grazing intensities.

    Science.gov (United States)

    Schiborra, A; Gierus, M; Wan, H W; Glindemann, T; Wang, C J; Susenbeth, A; Taube, F

    2010-08-01

    The objective of this study was to investigate dietary selection of sheep grazing semi-arid grassland in Inner Mongolia, China, using the difference in organic matter digestibility (OMD) of herbage ingested and herbage on offer as indicator for selection. Faecal N was used as digestibility index for herbage ingested (FOMD), while OMD of herbage on offer (GOMD) was estimated from gas production obtained by the Hohenheim gas test. It was hypothesized that the difference between FOMD and GOMD is high, when grazing animals select against low quality herbage provided that herbage is abundant. In a grazing experiment, six grazing intensities (1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 sheep/ha), representing light to very heavy grazing intensity for the semi-arid grassland, were compared. The amount of herbage on offer decreased with increasing grazing intensity. Independent statistical analysis of FOMD and GOMD showed that the differences between grazing intensities for both OMD determinations (FOMD: 54.0-57.3%, GOMD: 55.2-57.5%) were not significant (p > 0.05). The difference between FOMD and GOMD was not significant for grazing intensities, but varied between sampling periods from -4 to 1 percentage units. In conclusion, the lack of significance for the difference between FOMD and GOMD suggests that for the semi-arid grassland of Inner Mongolia, China, sheep did not select their feed due to a homogeneous nutritional composition of herbage on offer in 2005, regardless of grazing intensity.

  3. Iodine-129 in thyroids of grazing animals

    International Nuclear Information System (INIS)

    Ballad, R.V.; Holman, D.W.; Hennecke, E.W.; Johnson, J.E.; Manuel, O.K.; Nicholson, L.M.

    1976-01-01

    A combination of neutron activation and mass spectrometry has been used to determine the concentrations of fissiogenic 129 I and stable 127 I in thyroids of grazing animals and in mineral iodine. The 129 I/ 127 I ratios are lowest in mineral iodine and in a given area lower in cow thyroids than in deer thyroids. Near saturation levels of mineral iodine in commercial feeds and salt licks may account for differences in the 129 I levels of cows and deer. Values of the 129 I/ 127 I ratio in deer appear to vary inversely with the iodine concentration of the thyroid. (author)

  4. Influence of rainfall and grazing on the compositional change of the ...

    African Journals Online (AJOL)

    Keywords: Communal grazing; Grazing intensity; Mortality; Relative biomass; Sites; Sward structure changes; Treatments; Tuft size changes; Tuft sizes; cattle; digitaria eriantha; forbs; grazing; tuft size; herbaceous layer; composition; recruitment; herbaceous composition; sandveld; gazankulu; abundance; pogonarthria ...

  5. Modelling nitrous oxide emissions from grazed grassland systems

    International Nuclear Information System (INIS)

    Wang Junye; Cardenas, Laura M.; Misselbrook, Tom H.; Cuttle, Steve; Thorman, Rachel E.; Li Changsheng

    2012-01-01

    Grazed grassland systems are an important component of the global carbon cycle and also influence global climate change through their emissions of nitrous oxide and methane. However, there are huge uncertainties and challenges in the development and parameterisation of process-based models for grazed grassland systems because of the wide diversity of vegetation and impacts of grazing animals. A process-based biogeochemistry model, DeNitrification-DeComposition (DNDC), has been modified to describe N 2 O emissions for the UK from regional conditions. This paper reports a new development of UK-DNDC in which the animal grazing practices were modified to track their contributions to the soil nitrogen (N) biogeochemistry. The new version of UK-DNDC was tested against datasets of N 2 O fluxes measured at three contrasting field sites. The results showed that the responses of the model to changes in grazing parameters were generally in agreement with observations, showing that N 2 O emissions increased as the grazing intensity increased. - Highlights: ► Parameterisation of grazing system using grazing intensity. ► Modification of UK D NDC for the UK soil and weather conditions. ► Validation of the UK D NDC against measured data of N 2 O emissions in three UK sites. ► Estimating influence of animal grazing practises on N 2 O emissions. - Grazing system was parameterised using grazing intensity and UK-DNDC model was modified and validated against measured data of N 2 O emissions in three UK sites.

  6. Milk production, grazing behavior and nutritional status of dairy cows grazing two herbage allowances during winter

    Directory of Open Access Journals (Sweden)

    Miguel Ruiz-Albarran

    2016-03-01

    Full Text Available Winter grazing provides a useful means for increasing the proportion of grazed herbage in the annual diet of dairy cows. This season is characterized by low herbage growth rate, low herbage allowance, and low herbage intake and hence greater needs for supplements to supply the requirements of lactating dairy cows. The aim of this study was to determine the influence of herbage allowance (HA offered to autumn calving dairy cows grazing winter herbage on milk production, nutritional status, and grazing behavior. The study took 63 d using 32 multiparous Holstein-Friesian dairy cows. Prior to experimental treatment, milk production averaged 20.2 ± 1.7 kg d-1, body weight was 503 ± 19 kg, and days in milking were 103 ± 6. Experimental animals were randomly assigned to two treatments according to HA offered above ground level: low (17 kg DM cow-1 d-1 vs. high HA (25 kg DM cow¹ d¹. All cows were supplemented with grass silage supplying daily 6.25 and 4.6 kg DM of concentrate (concentrate commercial plus high corn moisture. Decreasing HA influenced positively milk production (+25%, milk protein (+20 kg, and milk fat (+17 kg per hectare; however no effects on milk production per cow or energy metabolic status were observed in the cows. In conclusion, a low HA showed to be the most significant influencing factor on milk and milk solids production per hectare in dairy cows grazing restricted winter and supplemented with grass silage and concentrate; but no effect on the milk production per cow was found.

  7. Level and determinants of food insecurity in East and West Gojjam zones of Amhara Region, Ethiopia: a community based comparative cross-sectional study

    Directory of Open Access Journals (Sweden)

    Achenef Motbainor

    2016-06-01

    (AOR = 1.638, 95 % CI: 1.015, 2.643, household monthly income quartiles, 1st (AOR = 2.756, 95 % CI: 1.902, 3.993, and 2nd (AOR =1.897, 95 % CI: 1.299, 2.775 were the significant socio-demographic determinants in east Gojjam zone. Illiterate mothers (AOR = 1.388, 95 % CI: 1.011, 1.905, household monthly income quartiles, 1st (AOR = 3.110232, 95 % CI: 2.366, 4.415, 2nd (AOR =2.618, 95 % CI: 1.892, 3.622 and 3rd (AOR = 2.177, 95 % CI: 1.6911, 2.803 were the significant socio-demographic predictors in west Gojjam zone. Rural residential area (AOR = 3.201, 95 % CI: 1.832, 5.594 and (AOR = 2.425, 95 % CI: 1.79, 3.272, highland agro-ecology (AOR = 2.193, 95 % CI: 1.348, 3.569 and AOR = 3.669, 95 % CI: 2.442, 5.513 and lack of livestock (AOR = 1.553, 95 % CI: 1.160, 2.078 and AOR = 1.568 95 % CI: 1.183, 2.080 were significant environmental predictors in east and west Gojjam zones respectively. Conclusion Food insecurity is highly prevalent in both study areas; however, there are different predictor factors. Intervention strategies should give emphasis to women’s education, diversified income generating opportunities, and for each agro-ecological zone, mixed agriculture strategy.

  8. The evaluation of four Eragrostis curvula ecotypes with grazing sheep.

    African Journals Online (AJOL)

    There were no significant differences in the dry matter production and chemical composition of the clipped samples of the ecotypes. Keywords: afrikaans; chemical composition; dry matter production; ecotypes; eragrostis curvula; grazing; live mass; live mass gains; open rotational grazing system; production; sheep; south ...

  9. The selenium status of grazing herbivores in different regions of ...

    African Journals Online (AJOL)

    Unknown

    The selenium status of grazing herbivores in different regions of Southern Africa. J. B. J. van Ryssen. Dept of Animal and Wildlife Sciences, University of Pretoria, 0002 Pretoria, South Africa. E-mail:jvryssen@postino.up.ac.za. Although a substantial amount of information is available on the selenium status of grazing animals ...

  10. Influence of grazing management on the production of an irrigated ...

    African Journals Online (AJOL)

    The production of an irrigated grass/legume pasture was determined using Merino ewes on rotational and continuous grazing systems. The clover content of the pasture declined, while the grass content increased under both systems. The lucerne content of the rotationally-grazed pastures did not change, but lucerne failed ...

  11. Grass species selection patterns on rotationally-grazed Dohne ...

    African Journals Online (AJOL)

    Herbaceous species preference was studied during autumn and winter periods of occupation, on rotationally-grazed Dohne Sourveld, at four different stocking rates. Reports on species selection by cattle and sheep grazing together. Illustrates with graphsLanguage: English. Keywords: Grass species; Herbage availibility; ...

  12. Soil contamination of plant surfaces from grazing and rainfall interactions

    International Nuclear Information System (INIS)

    Hinton, T.G.; Stoll, J.M.; Tobler, L.

    1995-01-01

    Contaminants often attach to soil particles, and their subsequent environmental transport is largely determined by processes that govern soil movement. We examined the influence of grazing intensity on soil contamination of pastures. Four different grazing densities of sheep were tested against an ungrazed control plot. Scandium concentrations were determined by neutron activation analysis and was used as a tracer of soil adhesion on vegetation. Soil loadings ( g soil kg -1 dry plant) increased 60% when grazing intensity was increased by a factor of four (p 0.003). Rain and wind removed soil from vegetation in the ungrazed control plots, but when grazing sheep were present, an increase in rain from 0.3 to 9.7 mm caused a 130% increase in soil contamination. Multiple regression was used to develop an equation that predicts soil loadings as a function of grazing density, rainfall and wind speed (p = 0.0001, r 2 = 0.78). The model predicts that if grazing management were to be used as a tool to reduce contaminant intake from inadvertent consumption of resuspended soil by grazing animals, grazing densities would have to be reduced 2.5 times to reduce soil loadings by 50%. (author)

  13. Using dual-purpose crops in sheep-grazing systems.

    Science.gov (United States)

    Dove, Hugh; Kirkegaard, John

    2014-05-01

    The utilisation of dual-purpose crops, especially wheat and canola grown for forage and grain production in sheep-grazing systems, is reviewed. When sown early and grazed in winter before stem elongation, later-maturing wheat and canola crops can be grazed with little impact on grain yield. Recent research has sought to develop crop- and grazing-management strategies for dual-purpose crops. Aspects examined have been grazing effects on crop growth, recovery and yield development along with an understanding of the grazing value of the crop fodder, its implications for animal nutrition and grazing management to maximise live-weight gain. By alleviating the winter 'feed gap', the increase in winter stocking rate afforded by grazing crops allows crop and livestock production to be increased simultaneously on the same farm. Integration of dual-purpose wheat with canola on mixed farms provides further systems advantages related to widened operational windows, weed and disease control and risk management. Dual-purpose crops are an innovation that has potential to assist in addressing the global food-security challenge. © 2013 Society of Chemical Industry.

  14. Assessment of the Effects of Emerging Grazing Policies on Land ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: This study examines the effects of the emerging grazing policies on land degradation in Nigeria using soil, vegetation and sustainability as ... of the latter by the animals. In most areas strict rules exist to check this practice. .... grazing reserve also encourages the uniform deployment of the cattle. It is in view of ...

  15. Veld composition in relation to grazing capacity. | Barnes | African ...

    African Journals Online (AJOL)

    Present methods of evaluating veld composition in relation to grazing capacity can be criticised on grounds of subjectivity, especially with regard to the assignment of relative values to the constituent species. Data relating to botanical composition and estimated grazing capacity, derived from long-term animal production ...

  16. A theoretical analysis of foraging efficiency of grazing animals | RI ...

    African Journals Online (AJOL)

    A mathematical model of the change in quantity of forage during grazing is constructed, assuming (1) that forage requirement by grazing animals is constant, and (2) that intake is equal to requirement when forage is in free supply but (3) that below a certain supply level intake becomes restricted and is proportional to supply ...

  17. Day and night grazing by cattle in the Sahel

    NARCIS (Netherlands)

    Ayantunde, A.A.; Fernandez-Rivera, S.; Hiernaux, P.H.; Keulen, van H.; Udo, H.M.J.

    2002-01-01

    The influence of night grazing on feeding behavior, nutrition and performance of cattle was studied. Twenty-four steers weighing 367 kg (SD = 76) grazed either from 0900 to 1900 (day grazers), 2100 to 0700 (night grazers) or 0900 to 1900 and 2400 to 0400 (day-and-night grazers) during 13 weeks. Four

  18. Mixed farming in a grazing reserve in Northern Nigeria | Babalobi ...

    African Journals Online (AJOL)

    Nigeria's main pastoral development strategy is the settlement of pastoralists in grazing reserves. The goal of the strategy is to turn such nomadic pastoralists into mixed farmers who will take up crop farming to supplement livestock farming. Using the Bobi Grazing Reserve, Niger State, Nigeria as case study, the attainment ...

  19. Possibilities and constraints for grazing in high output dairy systems

    NARCIS (Netherlands)

    Hennessy, D.; Delaby, L.; Pol, van den A.; Shalloo, L.

    2015-01-01

    In temperate and oceanic regions, grazed grass is the lowest cost feed available for milk production. In other regions, grazed grass is less important but can contribute to the diet of livestock. Within high output systems the interaction between the animal and sward is challenging for a host of

  20. The grazing index method of range condition assessment | du Toit ...

    African Journals Online (AJOL)

    Owing to the difficulty of examining succession theory in the Karoo, it is suggested the ecological index method (EIM), be replaced by the grazing index method (GIM), through the introduction of grazing index values (GIV) for Karoo plant species. The GIM may provide more acceptable range condition scores and more ...

  1. Effect of grazing frequency and intensity on Lolium perenne L ...

    African Journals Online (AJOL)

    The cellulase dry matter disappearance (CDMD) and herbage nitrogen (N) of Lolium perenne (perennial ryegrass) were evaluated for pastures grown under subtropical conditions for two years, under five combinations of grazing frequency and intensity, each applied in a rotational grazing system. These quality factors were ...

  2. Grazing Intensity Does Not Affect Plant Diversity in Shortgrass Steppe

    Science.gov (United States)

    Responses of livestock gain and forage production to grazing intensity in shortgrass steppe are well-established, but effects on basal cover and plant diversity are less so. A long-term grazing intensity study was initiated on shortgrass steppe at the Central Plains Experimental Range (USDA-Agricult...

  3. Influence of sward characteristics on grazing behaviour and short ...

    African Journals Online (AJOL)

    The feasibility of intensifying grazing studies in the tropics, particularly in Nigeria, to examine the behaviour of ruminants in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria. Key Words: Sward characteristics; Grazing ...

  4. Hydrologic properties of grazed perennial swards in semiarid ...

    African Journals Online (AJOL)

    Identification of plant resources that persist under grazing pressure, support desirable levels of production and at the same time protect the grazing environment is central to sustainable livestock production. This study assessed the infiltration capacity and soil loss associated with perennial swards subjected to different ...

  5. Identification of key grass species under grazing in the Highland ...

    African Journals Online (AJOL)

    Relative abundances of rangeland species have for many years been used to index trends in range condition following the impact of grazing. All species recorded in a botanical survey are usually classified according to their assumed reaction to grazing using the increaser and decreaser groups. We used a gradient ...

  6. Resilience of soils and vegetation subjected to different grazing ...

    African Journals Online (AJOL)

    The resilience of rangeland soils and vegetation to different levels of grazing is still poorly understood. A study was conducted to determine the recovery of a rangeland grazed at different intensities and allowed a two-year rest period. The following treatments were applied to 0.5 hectare plots: 0, 4, 8 and 16 heifers per ...

  7. Estimation of grazing by herbivores from analysis of dung | Mabinya ...

    African Journals Online (AJOL)

    The two acids can also be recovered from the dung of various herbivores and their presence can be used as evidence of grazing by animals such as cattle, hippopotamus and warthogs. The reduced presence of these compounds in the dung of goats supports the fact that goats both graze and browse. Analysis of the dung ...

  8. Grazing behaviour and diet selection of Barotse cattle on a ...

    African Journals Online (AJOL)

    Grazing behaviour and diet selection of cattle were studied on a communally grazed floodplain and its adjacent wooded uplands in western Zambia to identify the interaction between basic herd management practices, foraging behaviour and body condition of cattle. On average, the cattle spent nine hours and 29 minutes ...

  9. Effect of mowing and grazing on ramet emergence of Leymus ...

    African Journals Online (AJOL)

    The invasive Leymus racemosus species is mainly established by ramets (or clonal seedling). A field experiment was conducted in the spring of 2004 to investigate the effects on the surface soil temperature caused by mowing, grazing and grazing exclusion, and the influence of these factors on the ramets emergence ...

  10. Review: Behavior and daily grazing patterns of cattle

    NARCIS (Netherlands)

    Gregorini, P.; Tamminga, S.; Gunther, S.A.

    2006-01-01

    Grazing ruminants consume their food in discrete grazing events. The frequency and distribution of these events depend on the current physiological state of the animal and its environment. Within a small spatio-temporal scale, foraging decisions such as when to begin, which frequency, and how to

  11. Vegetation patterns and nutrients in relation to grazing pressure and ...

    African Journals Online (AJOL)

    A major challenge confronting managers of extensive grazing systems is uneven use of erbaceous forage plants by livestock. The concentration of grazing in preferred areas or around foci points (e.g. water points) eventually results in adverse impacts in soil nutrients, vegetation structure, production and composition.

  12. Transformation of a savanna grassland by drought and grazing | O ...

    African Journals Online (AJOL)

    The relative effects of drought and heavy grazing on the floristic composition, population size and and structure, and basal cover of an African savanna grassland were differentiated by comparing changes over eight years over eight years, which included a severe drought year, across a gradient of grazing history. Drought ...

  13. Ecological status of species on grazing gradients on the shallow ...

    African Journals Online (AJOL)

    Grasses on the shallow soils of the western grassland biome of South Africa were classified on their ecological status on the basis of their reaction to grazing. Vegetation data were gathered in such a way that those of different successional stages could be identified. An ordination technique was used to define the grazing ...

  14. Fish meal supplementation to early lactation Jersey cows grazing ...

    African Journals Online (AJOL)

    This trial was conducted to test the hypothesis that early lactation cows grazing ryegrass pasture and receiving maize and mineral supplementation could respond to additional supplementation with a protein source such as fish meal. Multiparous Jersey cows in early to mid lactation that grazed annual ryegrass pasture in ...

  15. Grasses grazed by springbok and sheep | R. | African Journal of ...

    African Journals Online (AJOL)

    Grazing habits were determined by analysis of rumina from slaughtered springbok and sheep where springbok grazed together with Merino sheep in False Upper Karoo and together with Dorper sheep in Kalahari Thornveld. Results show that in both veld types, grass constituted about 39 percent of the dry mass intake of ...

  16. Effect of mowing and grazing on ramet emergence of Leymus ...

    African Journals Online (AJOL)

    user

    2011-03-21

    Mar 21, 2011 ... experiment was conducted in the spring of 2004 to investigate the effects on the surface soil temperature caused by mowing, grazing and grazing exclusion, and the influence of these factors on the ramets emergence characteristics. The primary effect of the treatments was significant changes in.

  17. Grazing depletes forb species diversity in the mesic grasslands of ...

    African Journals Online (AJOL)

    Forbs constitute over 80% of the species richness of mesic grassland but their response to grazing is largely unknown. The influence of grazing on the forb composition, richness and diversity of two species-rich grasslands in the coastal hinterland and midlands of KwaZulu-Natal, South Africa was examined in plots subject ...

  18. Mixed Grazing Systems Benefit both Upland Biodiversity and Livestock Production

    Science.gov (United States)

    Fraser, Mariecia D.; Moorby, Jon M.; Vale, James E.; Evans, Darren M.

    2014-01-01

    Background With world food demand expected to double by 2050, identifying farming systems that benefit both agricultural production and biodiversity is a fundamentally important challenge for the 21st century, but this has to be achieved in a sustainable way. Livestock grazing management directly influences both economic outputs and biodiversity on upland farms while contributing to potentially damaging greenhouse gas emissions, yet no study has attempted to address these impacts simultaneously. Methods Using a replicated, landscape-scale field experiment consisting of five management ‘systems’ we tested the effects of progressively altering elements within an upland farming system, viz i) incorporating cattle grazing into an upland sheep system, ii) integrating grazing of semi-natural rough grazing into a mixed grazing system based on improved pasture, iii) altering the stocking ratio within a mixed grazing system, and iv) replacing modern crossbred cattle with a traditional breed. We quantified the impacts on livestock productivity and numbers of birds and butterflies over four years. Results, Conclusion and Significance We found that management systems incorporating mixed grazing with cattle improve livestock productivity and reduce methane emissions relative to sheep only systems. Systems that also included semi-natural rough grazing consistently supported more species of birds and butterflies, and it was possible to incorporate bouts of summer grazing of these pastures by cattle to meet habitat management prescriptions without compromising cattle performance overall. We found no evidence that the system incorporating a cattle breed popular as a conservation grazer was any better for bird and butterfly species richness than those based on a mainstream breed, yet methane emissions from such a system were predicted to be higher. We have demonstrated that mixed upland grazing systems not only improve livestock production, but also benefit biodiversity

  19. Mixed grazing systems benefit both upland biodiversity and livestock production.

    Directory of Open Access Journals (Sweden)

    Mariecia D Fraser

    Full Text Available With world food demand expected to double by 2050, identifying farming systems that benefit both agricultural production and biodiversity is a fundamentally important challenge for the 21(st century, but this has to be achieved in a sustainable way. Livestock grazing management directly influences both economic outputs and biodiversity on upland farms while contributing to potentially damaging greenhouse gas emissions, yet no study has attempted to address these impacts simultaneously.Using a replicated, landscape-scale field experiment consisting of five management 'systems' we tested the effects of progressively altering elements within an upland farming system, viz i incorporating cattle grazing into an upland sheep system, ii integrating grazing of semi-natural rough grazing into a mixed grazing system based on improved pasture, iii altering the stocking ratio within a mixed grazing system, and iv replacing modern crossbred cattle with a traditional breed. We quantified the impacts on livestock productivity and numbers of birds and butterflies over four years.We found that management systems incorporating mixed grazing with cattle improve livestock productivity and reduce methane emissions relative to sheep only systems. Systems that also included semi-natural rough grazing consistently supported more species of birds and butterflies, and it was possible to incorporate bouts of summer grazing of these pastures by cattle to meet habitat management prescriptions without compromising cattle performance overall. We found no evidence that the system incorporating a cattle breed popular as a conservation grazer was any better for bird and butterfly species richness than those based on a mainstream breed, yet methane emissions from such a system were predicted to be higher. We have demonstrated that mixed upland grazing systems not only improve livestock production, but also benefit biodiversity, suggesting a 'win-win' solution for farmers and

  20. Impact of grazing intensity during drought in an Arizona grassland.

    Science.gov (United States)

    Loeser, Matthew R R; Sisk, Thomas D; Crews, Timothy E

    2007-02-01

    The ecological benefits of changing cattle grazing practices in the western United States remain controversial, due in part to a lack of experimentation. In 1997 we initiated an experimental study of two rangeland alternatives, cattle removal and high-impact grazing, and compared grassland community responses with those with more conventional, moderate grazing practices. The study was conducted in a high-elevation, semiarid grassland near Flagstaff, Arizona (U.S.A.). We conducted annual plant surveys of modified Whittaker plots for 8 years and examined plant composition shifts among treatments and years. High-impact grazing had strong directional effects that led to a decline in perennial forb cover and an increase in annual plants, particularly the exotic cheatgrass (Bromus tectorum L.). A twofold increase in plant cover by exotic species followed a severe drought in the sixth year of the study, and this increase was greatest in the high-impact grazing plots, where native cover declined by one-half. Cattle removal resulted in little increase in native plant cover and reduced plant species richness relative to the moderate grazing control. Our results suggest that some intermediate level of cattle grazing may maintain greater levels of native plant diversity than the alternatives of cattle removal or high-density, short-duration grazing practices. Furthermore, episodic drought interacts with cattle grazing, leading to infrequent, but biologically important shifts in plant communities. Our results demonstrate the importance of climatic variation in determining ecological effects of grazing practices, and we recommend improving conservation efforts in arid rangelands by developing management plans that anticipate this variation.

  1. Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

    DEFF Research Database (Denmark)

    Kristensen, Troels; Thamsborg, S.M.; Andersen, Refsgaard

    2006-01-01

    Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2x2 factorial, replicated experiment with two sexes (steers v. heifers) and two...

  2. A narrower gap of grazing intensity. Reply to Fetzel et al. 2017. Seasonality constrains to livestock grazing intensity

    Science.gov (United States)

    Fetzel et al. (2017) globally mapped the gap between observed and potential grazing intensity (GI): the ratio between consumption by livestock and ANPP. Fetzel et al. (2017) estimated grazing land, forage production and livestock demand at a half-degree resolution. They mapped GI below 15% for most ...

  3. The influence of storage practices on aflatoxin contamination in maize in four agroecological zones of Benin, west Africa.

    Science.gov (United States)

    Hell; Cardwell; Setamou; Poehling

    2000-10-15

    Aflatoxin level in 300 farmers' stores in four agro-ecological zones in Benin, a west African coastal country, were determined over a period of 2 years. At sampling a questionnaire was used to evaluate maize storage practices. Farmers were asked what storage structure they used, their storage form, storage period, pest problems in storage and what was done against them. Beninese farmers often changed their storage structures during the storage period, transfering the maize from a drying or temporary store to a more durable one. Most of the farmers complained about insects damaging stored maize. Often, storage or cotton insecticides were utilized against these pests. Regression analysis identified those factors that were associated with increased or reduced aflatoxin.Maize samples in the southern Guinea and Sudan savannas were associated with higher aflatoxin levels and the forest/savanna mosaic was related to lower toxin levels. Factors associated with higher aflatoxin were: storage for 3-5 months, insect damage and use of Khaya senegalensis-bark or other local plants as storage protectants. Depending on the agroecological zone, storage structures that had a higher risk of aflatoxin development were the "Ago", the "Secco", the "Zingo" or storing under or on top of the roof of the house. Lower aflatoxin levels were related to the use of storage or cotton insecticides, mechanical means or smoke to protect against pests or cleaning of stores before loading them with the new harvest. Fewer aflatoxins were found when maize was stored in the "Ago" made from bamboo or when bags were used as secondary storage containers.

  4. Figure and finish of grazing incidence mirrors

    International Nuclear Information System (INIS)

    Takacs, P.Z.; Church, E.L.

    1989-08-01

    Great improvement has been made in the past several years in the quality of optical components used in synchrotron radiation (SR) beamlines. Most of this progress has been the result of vastly improved metrology techniques and instrumentation permitting rapid and accurate measurement of the surface finish and figure on grazing incidence optics. A significant theoretical effort has linked the actual performance of components used as x-ray wavelengths to their topological properties as measured by surface profiling instruments. Next-generation advanced light sources will require optical components and systems to have sub-arc second surface figure tolerances. This paper will explore the consequences of these requirements in terms of manufacturing tolerances to see if the present manufacturing state-of-the-art is capable of producing the required surfaces. 15 refs., 14 figs., 2 tabs

  5. Riparian Meadow Response to Modern Conservation Grazing Management

    Science.gov (United States)

    Oles, Kristin M.; Weixelman, Dave A.; Lile, David F.; Tate, Kenneth W.; Snell, Laura K.; Roche, Leslie M.

    2017-09-01

    Riparian meadows occupy a small proportion of the public lands in the western United States but they provide numerous ecosystem services, including the production of high-quality forage for livestock grazing. Modern conservation management strategies (e.g., reductions in livestock stocking rates and adoption of new riparian grazing standards) have been implemented to better balance riparian conservation and livestock production objectives on publicly managed lands. We examined potential relationships between long-term changes in plant community, livestock grazing pressure and environmental conditions at two spatial scales in meadows grazed under conservation management strategies. Changes in plant community were not associated with either livestock stocking rate or precipitation at the grazing allotment (i.e., administrative) scale. Alternatively, both grazing pressure and precipitation had significant, albeit modest, associations with changes in plant community at the meadow (i.e., ecological site) scale. These results suggest that reductions in stocking rate have improved the balance between riparian conservation and livestock production goals. However, associations between elevation, site wetness, precipitation, and changes in plant community suggest that changing climate conditions (e.g., reduced snowpack and changes in timing of snowmelt) could trigger shifts in plant communities, potentially impacting both conservation and agricultural services (e.g., livestock and forage production). Therefore, adaptive, site-specific management strategies are required to meet grazing pressure limits and safeguard ecosystem services within individual meadows, especially under more variable climate conditions.

  6. Riparian Meadow Response to Modern Conservation Grazing Management.

    Science.gov (United States)

    Oles, Kristin M; Weixelman, Dave A; Lile, David F; Tate, Kenneth W; Snell, Laura K; Roche, Leslie M

    2017-09-01

    Riparian meadows occupy a small proportion of the public lands in the western United States but they provide numerous ecosystem services, including the production of high-quality forage for livestock grazing. Modern conservation management strategies (e.g., reductions in livestock stocking rates and adoption of new riparian grazing standards) have been implemented to better balance riparian conservation and livestock production objectives on publicly managed lands. We examined potential relationships between long-term changes in plant community, livestock grazing pressure and environmental conditions at two spatial scales in meadows grazed under conservation management strategies. Changes in plant community were not associated with either livestock stocking rate or precipitation at the grazing allotment (i.e., administrative) scale. Alternatively, both grazing pressure and precipitation had significant, albeit modest, associations with changes in plant community at the meadow (i.e., ecological site) scale. These results suggest that reductions in stocking rate have improved the balance between riparian conservation and livestock production goals. However, associations between elevation, site wetness, precipitation, and changes in plant community suggest that changing climate conditions (e.g., reduced snowpack and changes in timing of snowmelt) could trigger shifts in plant communities, potentially impacting both conservation and agricultural services (e.g., livestock and forage production). Therefore, adaptive, site-specific management strategies are required to meet grazing pressure limits and safeguard ecosystem services within individual meadows, especially under more variable climate conditions.

  7. Examining ecological consequences of feral horse grazing using exclosures

    Science.gov (United States)

    Beever, E.A.; Brussard, P.F.

    2000-01-01

    Although feral horses have inhabited western North America since the end of the 16th century, relatively little synecological research has been conducted to quantitatively characterize how they interact with ecosystem components. Because feral horses exhibit watering behavior markedly different from that of domestic cattle, it is particularly important to evaluate response of ecosystem elements near water sources to horse use. To assess this response, we performed live-trapping of small mammals and 2-tiered vegetative sampling in 2 mountain ranges in central Nevada in the interior Great Basin, USA. At low elevations, plots around horse-excluded springs exhibited notably greater plant species richness, percent cover, and abundance of grasses and shrubs, as well as more small mammal burrow entrances than plots at horse-grazed springs. At high elevations, meadows protected from grazing exhibited maximum vegetation heights 2.8 times greater than vegetation grazed by horses only and 4.5 times greater than vegetation grazed by horses and cattle. Species richness in quadrats was most different between the horse-and-cattle-grazed meadow and its ungrazed counterpart, suggesting the possibility of synergistic effects of horse and cattle grazing in the same location. This study, the first in the Great Basin to investigate quantitatively ecosystem consequences of feral horse use with exclosures, represents a preliminary step in identifying factors that determine the magnitude of horse grazing impacts. 

  8. Managing variations in dairy cow nutrient supply under grazing.

    Science.gov (United States)

    Peyraud, J L; Delagarde, R

    2013-03-01

    Grazed pasture, which is the cheapest source of nutrients for dairy cows, should form the basis of profitable and low-input animal production systems. Management of high-producing dairy cows at pasture is thus a major challenge in most countries. The objective of the present paper is to review the factors that can affect nutrient supply for grazing dairy cows in order to point out areas with scope for improvement on managing variations in nutrient supply to achieve high animal performance while maintaining efficient pasture utilisation per hectare (ha). Reviewing the range in animal requirements, intake capacity and pasture nutritive values shows that high-producing cows cannot satisfy their energy requirements from grazing alone and favourable to unfavourable situations for grazing dairy cows may be classified according to pasture quality and availability. Predictive models also enable calculation of supplementation levels required to meet energy requirements in all situations. Solutions to maintain acceptable level of production per cow and high output per ha are discussed. Strategies of concentrate supplementation and increasing use of legumes in mixed swards are the most promising. It is concluded that although high-producing cow cannot express their potential milk production at grazing, there is scope to improve animal performance at grazing given recent developments in our understanding of factors influencing forage intake and digestion of grazed forages.

  9. Soil and vegetation under Bison bonasus grazing in the Kaluzhskie Zaseki Reserve (Central European Russia)

    Science.gov (United States)

    Khanina, Larisa; Bobrovsky, Maxim; Shashkov, Maxim; Ivanova, Natalia; Ivashchenko, Kristina

    2017-04-01

    Plant diversity and soil characteristics including soil macrofauna and microbial biomass were studied in two areas of the Reserve affected by grazing of semi-free-ranging European bison population during the decade. The study areas are surrounded by broad-leaved forest co-dominated by Quercus robur, Fraxinus excelsior, Tilia cordata, Ulmus glabra, Acer platanoides and A. campestre. Aiming to assess impacts of the bison population on soil and vegetation, we studied two series of conjugated biotopes: (1) a meadow with feeder, (2) a transition zone: the forest edge with damaged tree trunks, trampled soil and fragmented ground vegetation and (3) a forest without visible signs of bison activities. One biotope series was located on loamy soils and other one on sandy-loams. The following samplings of soil and vegetation were conducted in each biotope in two areas: (1) plant species list with their coverage in three vegetation layers in 5 square plots of 100 m2 was compiled; (2) earthworms were sampled in 8 monoliths of 25x25x35 cm and handy sorted to estimate earthworm diversity, number and biomass; (3) soil was also sampled from 0 to 10 cm soil depths with 4 replications to estimate soil physico-chemical characteristics and soil microbial biomass. Preliminary results showed relatively high ecological difference of the areas on loams and sandy-loams: soil on loams was richer in the main chemical elements, such as C, N, Ca and K. At that, in both areas, meadow soils were richer than forest soils in C, N, Ca, P and K. The highest values of C and N were observed in the transition zones and they were closed to values observed in the meadow soils. Total amount of exchangeable cations and Ca most strongly decreased from meadow to forest soils with the intermediate values in the transition zones. Despite the ecological differences of the areas, paired biotopes were similar to each other in structure of vegetation communities. For 10 years of grazing, forest vegetation was

  10. Management and Yield Prediction of Kunugi (Quercus acutissima) Grazing Forests

    OpenAIRE

    Mitsuo, Matsumoto; Kenjirou, Honda; Juuro, Kurogi; Forest Management Division, Forestry and Forest Products Research Institute; Formerly Kyushu Research Center, Forestry and Forest Products Research Institute; Formerly Kyushu Research Center, Forestry and Forest Products Research Institute

    1999-01-01

    This study deals with grazing in kunugi (Quercus acutissima) forests in the Aso district of Kyushu Island in southwest Japan. These forests are managed for production of bed-logs for shiitake mushrooms and cow-calf farming. One of their characteristics is short-term rotation such as 10-15 years for bed-logs and a year for calf production. A forest grazing experiment was begun in Minamioguni to look at forest growth, vegetation change and grazing intensity. Stem densities dropped in a few year...

  11. Quantifying the impact of livestock grazing on soil physical properties

    Science.gov (United States)

    Fučík, Petr; Zajíček, Antonín; Holubík, Ondřej

    2014-05-01

    Livestock grazing is considered to have a noticeable influence on soil properties, when pedocompaction / soil pore reduction induced either by cattle or sheeps may curtail water residence time and accelerate the beginning and volume of overland flow. However, direct measurements of soil physical parameters and their changes under different pastoral management are seldom reported in central European conditions. Knowledge about these alterations are indispensable for setting the proper, soil and water conservative grazing management in the view of increasing areas of pastures, not only in the Czech Republic. Impact of cattle grazing on changes of soil properties was studied in three experimental upland catchments in the Czech Republic, differing in soil characteristics and grazing management. Values of soil saturated hydraulic conductivity (Ks), assessed three times a year in-situ during 2012 - 2013 with pressure infiltrometers, were compared for grazed and ungrazed cambisols, pseudogleys and gleysols, for grazing intensity ranging from 0.5 to 2 Livestock units / ha. Soil bulk density (BD) and macroporosity (MP) were determined before and after grazing season every year with ring 100 cm3 steel cyllinders. These parameters were measured also on heavily treaded plots by cattle - hotspots - in each catchment. Ks values on grazed plots were significantly lower (on average by 39 - 66 %) than on ungrazed sites, BD values were reduced on average by 15 % and MP values were lower roughly about 22 % on grazed plots. Ks values on hotspots were lower by 50 - 90 %, BD values by 5 - 18 % and MP values by 8 - 28 % comparing to the rest of grazed areas. Decrease of soil infiltration capacity was influenced by grazing intensity and soil characteristics. The greatest reductions concerning infiltration capacity were manifested in soils being periodically waterlogged (either by surface or by groundwater). A profound influence on the infiltration process was revealed in pasture soils

  12. Farmers' perception on the importance of variegated grasshopper (Zonocerus variegatus (L.)) in the agricultural production systems of the humid forest zone of Southern Cameroon

    Science.gov (United States)

    Kekeunou, Sévilor; Weise, Stephan; Messi, Jean; Tamò, Manuel

    2006-01-01

    Background Zonocerus variegatus (Linnaeus, 1758) (Orthoptera: Pyrgomorphidae) is known as an agricultural pest in West and Central Africa. However, its importance in the agricultural production system in Cameroon has not been investigated. The study assesses farmers' perception on the importance of Z. variegatus in the agricultural production systems of the humid forest zone of Southern Cameroon. Methods Research was carried out in 5 villages of each of three Agro-Ecological, Cultural and Demographic Blocks (AECD-Blocks) of the Forest Margin Benchmark Area (FMBA). In each village, a semi-structured survey was used; male and female groups of farmers were interviewed separately. Results Z. variegatus is present throughout the humid forest zone of Southern Cameroon, where it is ranked as the third most economically important insect pest of agriculture. In the farmers' opinion, Z. variegatus is a polyphagous insect with little impact on young perennial crops. The length of the pre-farming fallow does not affect Z. variegatus pest pressure in the following crops. The increased impact of the grasshopper observed today in the fields, compared to what existed 10 years ago is as a result of deforestation and increase in surface of herbaceous fallow. The damage caused by Z. variegatus is higher in fields adjacent to C. odorata and herbaceous fallows than in those adjacent to forests and shrubby fallows. The fight against this grasshopper is often done through physical methods carried out by hand, for human consumption. The farmers highlight low usage of the chemical methods and a total absence of biological and ecological methods. Conclusion Farmers' perception have contributed to understanding the status of Z. variegatus in the humid forest zone of Southern Cameroon. The results are in general similar to those obtained in other countries. PMID:16573815

  13. Farmers' perception on the importance of variegated grasshopper (Zonocerus variegatus (L. in the agricultural production systems of the humid forest zone of Southern Cameroon

    Directory of Open Access Journals (Sweden)

    Messi Jean

    2006-03-01

    Full Text Available Abstract Background Zonocerus variegatus (Linnaeus, 1758 (Orthoptera: Pyrgomorphidae is known as an agricultural pest in West and Central Africa. However, its importance in the agricultural production system in Cameroon has not been investigated. The study assesses farmers' perception on the importance of Z. variegatus in the agricultural production systems of the humid forest zone of Southern Cameroon. Methods Research was carried out in 5 villages of each of three Agro-Ecological, Cultural and Demographic Blocks (AECD-Blocks of the Forest Margin Benchmark Area (FMBA. In each village, a semi-structured survey was used; male and female groups of farmers were interviewed separately. Results Z. variegatus is present throughout the humid forest zone of Southern Cameroon, where it is ranked as the third most economically important insect pest of agriculture. In the farmers' opinion, Z. variegatus is a polyphagous insect with little impact on young perennial crops. The length of the pre-farming fallow does not affect Z. variegatus pest pressure in the following crops. The increased impact of the grasshopper observed today in the fields, compared to what existed 10 years ago is as a result of deforestation and increase in surface of herbaceous fallow. The damage caused by Z. variegatus is higher in fields adjacent to C. odorata and herbaceous fallows than in those adjacent to forests and shrubby fallows. The fight against this grasshopper is often done through physical methods carried out by hand, for human consumption. The farmers highlight low usage of the chemical methods and a total absence of biological and ecological methods. Conclusion Farmers' perception have contributed to understanding the status of Z. variegatus in the humid forest zone of Southern Cameroon. The results are in general similar to those obtained in other countries.

  14. Effects of post-grazing forage mass on a beef cattle grazing system on Tanzânia grass pastures

    Directory of Open Access Journals (Sweden)

    Marco Antonio Penati

    2014-06-01

    Full Text Available The objective of this study was to evaluate the effect of grazing intensity on herbage accumulation, animal performance, and total system yield on irrigated Tanzania grass pastures under rotational stocking. The experiment was conducted from October 1999 to January 2001, in a complete randomized block design with four replications. Treatments consisted of three grazing intensities, represented by the following quantities of green forage dry mass remaining after grazing: 1,000 (high intensity, 2,500 (intermediate intensity and 4,000 (low intensity kg ha−1. Grazing cycles were of 36 days (33 rest and 3 grazing. The values observed at the end of the experiment for post grazing forage mass were close to the proposed values. Forage yield was 25,278, 36,850, and 34,144 kg DM ha−1, whereas animal performance was 0.398, 0.541, and 0.564 kg BW day−1for high, intermediate and low intensities, respectively. Grazing intensity was positive related to the stocking rate (6.5, 5.2 and 4.1 AU ha−1 at high, intermediate and low intensities, respectively. Total system yield was not affected by treatments, ranging between 1,518 and 1,287 kg BW ha−1 year−1.

  15. Economic modelling of grazing management against gastrointestinal nematodes in dairy cattle

    NARCIS (Netherlands)

    Voort, van der M.; Meensel, Van J.; Lauwers, L.; Haan, de M.H.A.; Evers, A.G.; Huylenbroeck, Van G.; Charlier, J.

    2017-01-01

    Grazing management (GM) interventions, such as reducing the grazing time or mowing pasture before grazing, have been proposed to limit the exposure to gastrointestinal (GI) nematode infections in grazed livestock. However, the farm-level economic effects of these interventions have not yet been

  16. The effect of continuous and rotational grazing of sourveld on the ...

    African Journals Online (AJOL)

    It was thus concluded that cattle continued to graze selectively regardless of the grazing method or the stocking intensity. Keywords: cattle grazing; crude protein; digestibility; dry matter digestibility; grasses; grazing; herbage; kokstad agricultural research station; leaf fraction; leaves; oesophageal fistulas; protein; rotational ...

  17. Impact of grazing management on hibernating caterpillars of the butterfly Melitaea cinxia in calcareous grasslands

    NARCIS (Netherlands)

    Noordwijk, C.G.E.; Flierman, D.E.; Remke, E.; Wallis de Vries, M.F.; Berg, M.P.

    2012-01-01

    Semi-natural grasslands are increasingly grazed by large herbivores for nature conservation purposes. For many insects such grazing is essential for the conservation of their habitat, but at the same time, populations decrease at high grazing intensity. We hypothesised that grazing management may

  18. Impact of grazing on hibernating caterpillars of the calcareous grassland butterfly Melitaea cinxia.

    NARCIS (Netherlands)

    van Noordwijk, C.G.E.; Flierman, D.E.; Remke, E.; Wallis de Vries, M.F.; Berg, M.P.

    2012-01-01

    Semi-natural grasslands are increasingly grazed by large herbivores for nature conservation purposes. For many insects such grazing is essential for the conservation of their habitat, but at the same time, populations decrease at high grazing intensity. We hypothesised that grazing management may

  19. Impact of processing on in vitro digestion of milk from grazing organic and confined conventional herds

    Science.gov (United States)

    Debate on differences between milk from grazing and non-grazing cows has not addressed the effects that standard processing may have on milk digestibility. In this study, raw milk from grazing organic (ORG) and non-grazing conventional (CONV) herds was adjusted to 0 and 3.25% fat and processed as fo...

  20. Compensatory growth of Festuca rubra after grazing : can migratory herbivores increase their own harvest during staging?

    NARCIS (Netherlands)

    Van der Graaf, AJ; Stahl, J; Bakker, JP

    2005-01-01

    1. The grazing optimization hypothesis predicts increased production and quality of plants grazed at intermediate grazing pressures. Following this hypothesis, herbivores will be able to increase their own harvest by repeated grazing. We tested the predictions of this hypothesis for Barnacle Geese,

  1. Phosphorus and the grazing ruminant. 1. The effect of ...

    African Journals Online (AJOL)

    grazing Dorper ewes, with (+ P) and without (- P) phosphorus (P) supplementation, was investigated over 4,5 years at Armoedsvlakte (notorious for its P-deficient soils) to establish whether sheep are as susceptible to a P deficiency as cattle.

  2. Which grazing management practices are most appropriate for ...

    African Journals Online (AJOL)

    continuous, conventional, or high-intensity grazing by sheep, cattle, or sheep plus cattle) on grassland biodiversity integrity. Selected indicators covered landscape composition, structure and functioning. High-intensity systems and continuous ...

  3. Fertility of Zero-Grazed Dairy Cattle following Hormone Treatment ...

    African Journals Online (AJOL)

    Time Artificial Insemination. ... delayed onset of puberty are some of the limiting factors to attainment of optimum reproductive efficiency in zero-grazed herds. ... Treated animals had timed artificial insemination (AI) 8-24 hours after the last injection.

  4. Effect of alternate and simultaneous grazing on endoparasite infection in sheep and cattle

    OpenAIRE

    Brito, Daiana Lima; Dallago, Bruno Stéfano Lima; Louvandini, Helder; Santos, Viviane Rodrigues Verdolin dos; Torres, Sonia Emília Figueirêdo de Araújo; Gomes, Edgard Franco; Amarante, Alessandro Francisco Talamini do; Melo, Cristiano Barros de; McManus, Concepta Margaret

    2013-01-01

    This experiment was carried out on 8 ha of Panicum maximum cv. Tanzania pastures, with rotational grazing consisting of 7 days of occupation and 21 days of rest. Four treatments were evaluated: cattle grazing alone (BOV), sheep grazing alone (OVI), cattle and sheep grazing simultaneously (SIM) and cattle grazing followed by sheep (alternate - ALT). Twenty heifers and 30 male Santa Inês lambs were used. Fecal egg count (FEC) and fecal cultures were carried out. Blood was also collected to exam...

  5. The need fora agro-ecological intelligence to preparing agriculture for climate change

    NARCIS (Netherlands)

    Bindraban, P.S.

    2012-01-01

    Gratefully, the quality of life for billions of people will improve drastically during the coming decades. This implies that the production of virtually every commodity will have to increase dramatically. Agriculture-related activities ought to provide food, feed, and non-edible plant-based

  6. Performance evaluation of quality protein maize genotypes across various maize production agro ecologies of Nepal

    Directory of Open Access Journals (Sweden)

    Jiban Shrestha

    2015-12-01

    Full Text Available To identify superior quality protein maize genotypes for grain yield under different agro climatic conditions of terai and hill districts in Nepal, the coordinated varietal trials (CVT were conducted at Dailekh, Doti, Salyan, Lumle and Pakhribas in 2013 and Salyan, Pakhribas and Kabre in 2014 during summer season and coordinated farmer’s field trials (CFFT at Surkhet and Dailekh in 2013 and Salyan, Pakhribas and Khumaltar in 2014 during summer season. The experiment was carried out using randomized complete block design with three replications for CVT and CFFT. Across the locations and years the superior genotypes found under CVT were S01SIYQ, S01SIWQ-2 and Poshilo Makai-1 where as S99TLYQ-HG-AB, S99TLYQ-B and Poshilo Makai-1 were found superior genotypes under CFFT. The superior genotypes derived from CFFT will be promoted further for similar environments across the country.

  7. Agro-ecological benefits of faba bean for rainfed Mediterranean cropping systems

    Directory of Open Access Journals (Sweden)

    Paolo Ruisi

    2017-09-01

    Full Text Available This paper reviews the main results from a set of experiments carried out in a semiarid Mediterranean environment during the past 25 years on faba bean (Vicia faba L., a crop traditionally grown in southern Italy and Sicily under rainfed conditions. These experiments focused on the residual effects of faba bean on subsequent crop(s and assessment of the nitrogen (N balance during the crop cycle, paying attention to both the environmental release of N (losses via volatilisation and denitrification and estimates of N2 fixation as influenced by tillage system, intercropping, and presence/absence of mycorrhizal inoculum. Faba bean relied on N2 fixation more than other grain legumes typically grown in the Mediterranean region (e.g., chickpea. Contributing reasons were the higher plant N demand of faba bean and its lower capacity to use soil mineral N. This implies higher N benefits for subsequent crop(s as well as higher risk of N losses from the plant–soil– atmosphere system via leaching, denitrification, and volatilisation. Results from these experiments contribute to better defining the role of faba bean in Mediterranean agro-ecosystems and to identifying technical solutions that maximise the potential benefits of faba bean as a fertility-building crop.

  8. Epidemiological study of bovine brucellosis in three agro-ecological areas of central Oromiya, Ethiopia.

    Science.gov (United States)

    Jergefa, T; Kelay, B; Bekana, M; Teshale, S; Gustafson, H; Kindahl, H

    2009-12-01

    A cross-sectional sero-epidemiological study of bovine brucellosis was conducted between September 2005 and March 2006 in three separate agroecological areas of central Oromiya, Ethiopia. In this study, a total of 176 clusters (farms) and 1,238 animals were selected, using the one-stage cluster sampling method. Fifty-nine clusters and 423 animals were selected from the lowland areas; 58 clusters and 385 animals from the midland areas and 59 clusters and 430 animals from the highlands. Serum samples were collected from a total of 1,238 animals older than six months. The rose bengal plate test and complement fixation test were used as screening and confirmatory tests, respectively, to detect Brucella seropositivity. Questionnaires were also administered to 176 households to gather information on the farm and livestock. Results showed that the overall seroprevalence of bovine brucellosis at the individual animal level was 2.9% (low). The seroprevalence was 4.2% in the lowlands, 1.0% in the midlands and 3.4% in the highlands. The overall seroprevalence at the herd level was 13.6% (moderate). At the herd level, seroprevalence in the lowlands was 17%; in the midlands: 5.1%; and in highland areas: 18.6%. Logistic regression analysis, revealed that the breed of cattle and the method of disposing of aborted foetuses and foetal membranes had a statistically significant effect on individual animal seroprevalence (p < 0.05). In lowland areas, the breed (p < 0.05), animal management system (p <0.05), mating method (p < 0.05), herd size (p < 0.05) and source of replacement stock (p <0.05) all had significant effects on individual animal seroprevalence.

  9. Agro-ecological characterization as a tool for sustainable use of inland valley

    NARCIS (Netherlands)

    Windmeijer, P.N.; Duivenbooden, van N.

    1996-01-01

    Inland valleys cover some 22-52 million hectares in West Africa. In spite of their agricultural potential, they are used marginally. The large physical and biotic complexity and heterogeneity of inland valleys explain why little progress has been madein their systematic characterization. Building on

  10. AGRO-ECOLOGICAL AND YIELD ENHANCING EFFECTS OF ACID SOIL LIMING

    Directory of Open Access Journals (Sweden)

    Jan Siuta

    2015-01-01

    Full Text Available Ecological and yield enhancing effects of soil liming have since long been recognized and appreciated by farmers, therefore, liming is considered to be an essential part of sustainable farming system. In the Polish agriculture, liming in the amount of about 100 kg/ha of CaO was applied as late as by the end of the sixties of the last century. In the year 1975, the average national CaO consumption was 120.8 kg/ha, although it varied from 23.2 kg/ha in Częstochowa region to 428 kg/ha in Opolskie Voievodeship. The largest average CaO consumption on a country scale (202 kg/ha was noted in the year 1989 while on a regional scale the consumption fluctuated from 43 kg/ha in Kraków Voievodeship to 424 kg/ha in Słupsk Voievodeship. A dramatic decline in the countrywide CaO consumption (by about 40 kg/ha occurred in the economical year 1995/1996, and the decreasing trend had been observed until the years 2004/2005. A subsequent drop in CaO consumption (by about 60% was noted in the years 2009/2010 – 2011/2012. According to the national agricultural census in 2010, the countrywide use of CaO attained up to 40.5 kg/ha on farmland in good agriculture, while only 10.4 kg/ha in Świętokrzyskie Voievodeship and 12.9 kg/ha in Małopolskie Voievodeship. In the years 1975–1998, the yields of four main grain crops as well as those of rapeseed and mustard spinach were distinctly synchronized with the consumption of lime fertilizers. No apparent relationship, however, was found between the yield size and the index of quality of agricultural production space (from 48.3 points in Nowosądeckie Voievodeship to 86.2 points in Zamojskie Voievodeship. However, in the years 1999–2012, the yields of four main grain crops as well as those of rapeseed and mustard spinach were to a lesser degree synchronized with the intensity of CaO use than the abovementioned yields from the years 1975–1998. A considerable trend towards decreasing CaO consumption starting from 1995 until 2013, poses a serious threat to ecological and yield enhancing properties of the soil environment. The threat will be more intense still as the application of organic fertilization (manure, green manure and compost becomes more and more limited. Advancing trend to remove plant biomass from agro-ecosystems leads to the degradation of ecological and productive functions of farmland. The latter trend is related to energy plantations and to using biomass as biofuel.

  11. Evaluation of vegetable-faba bean (Vicia faba L.) intercropping under Latvian agro-ecological conditions.

    Science.gov (United States)

    Lepse, Līga; Dane, Sandra; Zeipiņa, Solvita; Domínguez-Perles, Raul; Rosa, Eduardo As

    2017-10-01

    Monoculture is used mostly in conventional agriculture, where a single crop is cultivated on the same land for a period of at least 12 months. In an organic and integrated growing approach, more attention is paid to plant-environment interactions and, as a result, diverse growing systems applying intercropping, catch crops, and green manure are being implemented. Thus, field experiments for evaluation of vegetable/faba bean full intercropping efficiency, in terms of vegetable and faba bean yield and protein content, were set up during two consecutive growing seasons (2014 and 2015). Data obtained showed that the most efficient intercropping variants were cabbage/faba bean (cabbage yield 1.27-2.91 kg m -2 , immature faba bean pods 0.20-0.43 kg m -2 ) and carrot/faba bean (carrot yield 1.67-2.28 kg m -2 , immature faba bean pods 0.10-0.52 kg m -2 ), whilst onion and faba bean intercrop is not recommended for vegetable growing since it induces a very low onion yield (0.66-1.09 kg m -2 ), although the highest immature faba bean pod yield was found in the onion/faba bean intercropping scheme (up to 0.56 kg m -2 ). Vegetable/faba bean intercropping can be used in practical horticulture for carrot and cabbage growing in order to ensure sustainable farming and environmentally friendly horticultural production. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. IMPORTANCE OF AGRO-ECOLOGICAL AND ECONOMIC STRATEGIC MANAGEMENT WITHIN THE TERTIARY SECTOR

    Directory of Open Access Journals (Sweden)

    SLOBODAN POPOVIĆ

    2015-12-01

    Full Text Available The aim of this paper is to emphasize the importance of eco-agro-tourism within the tertiary sector economy countries, primarily in terms of the overall development of society as a whole. This question is particularly evident in terms of the Great Depression and every attempt to find out through improvement of business according to the author deserves attention. The authors make conclusions that agro significantly affects the rural areas in the states that are struggling to achieve development in all spheres of economy. In addition, the authors conclude that there is the impact of eco-agro-tourism and environmental and natural environment in which people live. The impact it has on the following levels such as: general, cultural, demographic, social, and economic, and others. Based on that clearly stands out as a multidisciplinary focus and the basis of observation of eco-agro-tourism. Race for financial gain often overlooked and natural environment in which BITIS people. Eco-agro-tourism includes a range of activities, services and additional facilities organized by the population mainly lives in the countryside or on family farms that have potential chances of developing structural attract tourists and generate income that are not standard. The authors conclude that organic agriculture can affect the development of the economy especially in rural areas, with it can to promote the concept of farm to be a new view to promote the development of approaches, such as: organic production, traditional crafts in order to increase the total supply, product sales to tourists that are manufactured on farm and more. Consequently, 159 Annals of the „Constantin Brâncuşi” University of Târgu Jiu, Economy Series, Issue 6/2015 „ACADEMICA BRÂNCUŞI” PUBLISHER, ISSN 2344 – 3685/ISSN-L 1844 - 7007 the authors' conclusion would be that the agro-tourism and eco-tourism have a chance to create a more substantial income people BITIS in the countryside, which produce in their possession, and that tourists can sell their produce at retail-sale prices that are far more of the standard price of agricultural production.

  13. Agro-ecological drivers of rural out-migration to the Maya Biosphere Reserve, Guatemala

    International Nuclear Information System (INIS)

    López-Carr, David

    2012-01-01

    Migration necessarily precedes environmental change in the form of deforestation and soil degradation in tropical settlement frontiers. But what environmental factors may contribute to these migration streams in the first place? Identification of the environmental characteristics related to this process is crucial for understanding how environmental change and migration may form recurrent feedback loops. Further understanding of this process could be useful for developing policies to both reduce environmentally induced migration from origin areas and also palliate significant environmental change unleashed by settler deforestation in destination areas. Evidently, apprehension of this holistic process cannot be approached only from the destination since this ignores environmental and other antecedents to rural out-migration. This letter presents data from surveys conducted in areas of high out-migration to the agricultural frontier in northern Guatemala. The results suggest that land scarcity and degradation in origin communities are linked to out-migration in general and to the forest frontier of northern Guatemala in particular. (letter)

  14. Cascading trophic interactions in the littoral zone: an enclosure experiment in shallow Lake Stigsholm, Denmark

    DEFF Research Database (Denmark)

    Jeppesen, E.; Søndergaard, M.; Søndergaard, M.

    2002-01-01

    The importance of grazer versus resource control has been extensively studied in the pelagic zone of lakes. In contrast, comparatively little is known about trophic interactions within the littoral zone. We conducted an experiment in the littoral zone of a eutrophic shallow lake using six 20 m2......, zooplankton grazing was equivalent to production in M+, but amounted to littoral zones do not alone feed on particles produced in the water, but also exploit alternative sources such as periphyton...... hypothesize that the strong cascading effects of zooplankton on chlorophyll-a and microorganisms in the littoral zone at natural fish densities are restricted to eutrophic lakes with high plant densities....

  15. Nitrous oxide production and consumption by denitrification in a grassland: Effects of grazing and hydrology.

    Science.gov (United States)

    Hu, Jing; Inglett, Kanika S; Clark, Mark W; Inglett, Patrick W; Ramesh Reddy, K

    2015-11-01

    Denitrification is generally recognized as a major mechanism contributing to nitrous oxide (N2O) production, and is the only known biological process for N2O consumption. Understanding factors controlling N2O production and consumption during denitrification will provide insights into N2O emission variability, and potentially predict capacity of soils to serve as sinks or sources of N2O. This study investigated the effects of hydrology and grazing on N2O production and consumption in a grassland based agricultural watershed. A batch incubation study was conducted on soils (0-10 cm) collected along a hydrological gradient representing isolated wetland (Center), transient zone (Edge) and pasture upland (Upland), from both grazed and ungrazed areas. Production and consumption potentials of N2O were quantified on soils under four treatments, including (i) ambient condition, and amended with (ii) NO3(-), (iii) glucose-C, and (iv) NO3(-) +glucose-C. The impacts of grazing on N2O production and consumption were not observed. Soils in hydrologically distinct zones responded differently to N2O production and consumption. Under ambient conditions, both production and consumption rates of Edge soils were higher than those observed for Center and Upland soils. Results of amended incubations suggested NO3(-) was a key factor limiting N2O production and consumption rates in all hydrological zones. Over 5-d incubation with NO3(-) amendment, cumulative production and consumption of N2O for Center soils were 1.6 and 3.3 times higher than Edge soils, and 3.6 and 7.6 times higher than Upland soils, respectively. However, cumulative N2O net production for Edge soils was the highest, with 2 to 3 times higher than Upland and Center soils. Our results suggest that the transient areas between wetland and upland are likely to be "hot spots" of N2O emissions in this ecosystem. Wetlands within agricultural landscapes can potentially function to reduce both NO3(-) leaching and N2O emissions

  16. Grazing weakens temporal stabilizing effects of diversity in the Eurasian steppe.

    Science.gov (United States)

    Ren, Haiyan; Taube, Friedhelm; Stein, Claudia; Zhang, Yingjun; Bai, Yongfei; Hu, Shuijin

    2018-01-01

    Many biodiversity experiments have demonstrated that plant diversity can stabilize productivity in experimental grasslands. However, less is known about how diversity-stability relationships are mediated by grazing. Grazing is known for causing species losses, but its effects on plant functional groups (PFGs) composition and species asynchrony, which are closely correlated with ecosystem stability, remain unclear. We conducted a six-year grazing experiment in a semi-arid steppe, using seven levels of grazing intensity (0, 1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 sheep per hectare) and two grazing systems (i.e., a traditional, continuous grazing system during the growing period (TGS), and a mixed one rotating grazing and mowing annually (MGS)), to examine the effects of grazing system and grazing intensity on the abundance and composition of PFGs and diversity-stability relationships. Ecosystem stability was similar between mixed and continuous grazing treatments. However, within the two grazing systems, stability was maintained through different pathways, that is, along with grazing intensity, persistence biomass variations in MGS, and compensatory interactions of PFGs in their biomass variations in TGS. Ecosystem temporal stability was not decreased by species loss but rather remain unchanged by the strong compensatory effects between PFGs, or a higher grazing-induced decrease in species asynchrony at higher diversity, and a higher grazing-induced increase in the temporal variation of productivity in diverse communities. Ecosystem stability of aboveground net primary production was not related to species richness in both grazing systems. High grazing intensity weakened the temporal stabilizing effects of diversity in this semi-arid grassland. Our results demonstrate that the productivity of dominant PFGs is more important than species richness for maximizing stability in this system. This study distinguishes grazing intensity and grazing system from diversity effects on

  17. Sero-positivity and associated risk factors for contagious bovine pleuropneumonia under two cattle production systems in North Central Nigeria.

    Science.gov (United States)

    Alhaji, Nma Bida; Babalobi, Olutayo Olajide

    2016-02-01

    A cross-sectional survey of 765 cattle in 125 nomadic and 375 cattle in 125 sedentary herds was conducted to investigate prevalence and risk factors for contagious bovine pleuropneumonia (CBPP) in the two production systems of Niger State in North Central Nigeria, between January and August 2013. Data on herd characteristics were collected using structured questionnaires administered on herd owners. Serological analysis was conducted using competitive enzyme linked immunosorbent assay (c-ELISA) test. Descriptive, univariate, and multivariate statistical analyses were conducted with OpenEpi version 2.3.1 software. Statistical significance was held at P production systems was 14.0 % (CI 12.1-16.1). Age and agro-ecological zones were significantly (P production. Agro-ecological zone C had the highest sero-prevalence (25.3 %, CI 20.2-31.0). No significant cattle factors were detected in sedentary production. Factors significantly associated with CBPP occurrence at herd-level were contacts with other herds during grazing (P production systems. Sero-diagnosis and risk factor identification should be institutionalized as elements of epidemio-surveillance and control strategies for CBPP, especially in resource-poor pastoralists' settlements in Nigeria.

  18. Rotation grazing as a conservation management tool : Vegetation changes after six years of application in a salt marsh ecosystem

    NARCIS (Netherlands)

    Lagendijk, D. D. Georgette; Howison, Ruth A.; Esselink, Peter; Ubels, Richard; Smit, Christian

    2017-01-01

    Grazing is commonly used in conservation to promote biodiversity, but the search for a grazing management regime that optimises biodiversity is still ongoing. Rotation grazing, where grazing is followed by a relatively long period of non-grazing, is a relative new tool in conservation management,

  19. Sound Zones

    DEFF Research Database (Denmark)

    Møller, Martin Bo; Olsen, Martin

    2017-01-01

    Sound zones, i.e. spatially confined regions of individual audio content, can be created by appropriate filtering of the desired audio signals reproduced by an array of loudspeakers. The challenge of designing filters for sound zones is twofold: First, the filtered responses should generate...... an acoustic separation between the control regions. Secondly, the pre- and post-ringing as well as spectral deterioration introduced by the filters should be minimized. The tradeoff between acoustic separation and filter ringing is the focus of this paper. A weighted L2-norm penalty is introduced in the sound...

  20. Grazing management in an integrated crop-livestock system: soybean development and grain yield

    Directory of Open Access Journals (Sweden)

    Taise Robinson Kunrath

    Full Text Available ABSTRACTGrazing livestock in integrated crop-livestock systems can cause impacts in the subsequent crop cycle. Aiming to investigate how grazing could affect soybean, the 9th crop cycle of a pasture/soybean rotation was assessed. Treatments were grazing intensities (10, 20, 30 and 40 cm of sward height applied since 2001 in a mixed of oat and annual ryegrass; and an additional no grazing area as control. Treatments were arranged in a completely randomized block design with three replicates. Grazing affected soybean population and the mass of individual nodules (P0.05. Soybean yield showed differences among treatments, but no difference was found between grazed and non-grazed areas. Grazing intensities impact the coverage and frequency of weeds (P>0.05. In conclusion, grazing intensity impacts different parameters of soybean yield and development, but only the grazing intensity of 10 cm can jeopardize the succeeding soybean crop.

  1. Alfalfa weevil (Coleoptera:Curculionidae) management in alfalfa by spring grazing with cattle.

    Science.gov (United States)

    Buntin, G D; Bouton, J H

    1996-12-01

    The effect of continuous, intensive grazing by cattle in the 1st alfalfa growth cycle on larval densities of the alfalfa weevil, Hyera postica (Gyllenhal), was evaluated in "Alfagraze' and "Apollo' alfalfa, which are tolerant and not tolerant to grazing, respectively. In small-cage exclusion trials, grazing reduced larval numbers in 1991 by 65% in Alfagraze and by 32% in Apollo. Larval numbers in 1992 were low (alfalfa weevil larvae caused moderate leaf injury in 1993 and severe injury in 1994 before grazing reduced larval numbers. Use of permethrin at 0.11 kg (AI)/ha or carbofuran or chlorpyrifos at 0.28 kg (AI)/ha effectively reduced larval numbers and prevented leaf injury before grazing began. Therefore, a combination of an early application of an insecticide treatment with a short grazing restriction followed by continuous grazing will control alfalfa weevil larvae while allowing cattle to graze and directly use forage of grazing-tolerant alfalfa.

  2. Grazing-induced BVOC fluxes from a managed grassland

    Science.gov (United States)

    Mozaffar, Ahsan; Schoon, Niels; Bachy, Aurelie; Digrado, Anthony; Heinesch, Bernard; Aubinet, Marc; Fauconnier, Marie-laure; Delaplace, Pierre; Dujardin, Patrick; Amelynck, Crist

    2017-04-01

    Grassland ecosystems cover one fourth of the Earth's land surface and are both sources and sinks of Biogenic Volatile Organic Compounds (BVOCs) which play an important role in atmospheric chemistry and air pollution. The use of grassland for cattle breeding is a common practice in many parts of the world. As it has been widely demonstrated that plants emit large bursts of BVOCs when they are mechanically damaged, grass tearing and trampling during grazing are expected to induce large BVOC emissions as well. Nevertheless, to the best of our knowledge, no study has been performed on BVOC fluxes from grazed grassland yet. Therefore investigations were performed using automated dynamic chambers in a managed grassland in Belgium over the 2015 and 2016 growing season. BVOC fluxes, together with carbon dioxide (CO2) and water vapor (H2O) fluxes from grazed and undisturbed grassland were followed simultaneously using PTR-MS (Proton Transfer Reaction-Mass Spectrometry) and a LI-840 non-dispersive IR gas analyzer. In addition, air in the chamber was sampled occasionally for GC-MS (Gas Chromatography-Mass Spectrometry) analysis to assist compound identification. Significant differences between grazed and undisturbed grassland patches were observed in terms of BVOC, CO2 and H2O vapor fluxes. Grazing by cows was found to result in enhanced emissions of several BVOCs such as methanol, acetaldehyde, acetone, acetic acid and Green Leaf Volatiles (GLVs), and induced BVOC emissions generally lasted for around 5 days following a grazing event. Quantitative data on the impact of grazing on BVOC, CO2 and H2O exchange between grassland and the atmosphere will be presented, and correlations between BVOC fluxes and environmental conditions will be discussed.

  3. Functional diversity increases ecological stability in a grazed grassland.

    Science.gov (United States)

    Hallett, Lauren M; Stein, Claudia; Suding, Katharine N

    2017-03-01

    Understanding the factors governing ecological stability in variable environments is a central focus of ecology. Functional diversity can stabilize ecosystem function over time if one group of species compensates for an environmentally driven decline in another. Although intuitively appealing, evidence for this pattern is mixed. We hypothesized that diverse functional responses to rainfall will increase the stability of vegetation cover and biomass across rainfall conditions, but that this effect depends on land-use legacies that maintain functional diversity. We experimentally manipulated grazing in a California grassland to create land-use legacies of low and moderate grazing, across which we implemented rainout shelters and irrigation to create dry and wet conditions over 3 years. We found that the stability of the vegetation cover was greatly elevated and the stability of the biomass was slightly elevated across rainfall conditions in areas with histories of moderate grazing. Initial functional diversity-both in the seed bank and aboveground-was also greater in areas that had been moderately grazed. Rainfall conditions in conjunction with this grazing legacy led to different functional diversity patterns over time. Wet conditions led to rapid declines in functional diversity and a convergence on resource-acquisitive traits. In contrast, consecutively dry conditions maintained but did not increase functional diversity over time. As a result, grazing practices and environmental conditions that decrease functional diversity may be associated with lasting effects on the response of ecosystem functions to drought. Our results demonstrate that theorized relationships between diversity and stability are applicable and important in the context of working grazed landscapes.

  4. Population Dynamics and Transcriptomic Responses of Chorthippus albonemus (Orthoptera: Acrididae to Herbivore Grazing Intensity

    Directory of Open Access Journals (Sweden)

    Xinghu Qin

    2017-11-01

    Full Text Available Livestock grazing can trigger outbreaks of insect pests in steppe ecosystems of Inner Mongolia in China. However, the physiological responses of the grasshopper Chorthippus albonemus to grazing are not well-understood. Here we investigated the effects of sheep grazing on the population dynamics and transcriptomic response of C. albonemus. We collected the insects three times (about 20 days apart in 1.33-ha plots in which there were no grazing, light grazing, moderate grazing, heavy grazing, or overgrazing. Our results showed that continuous grazing significantly decreased plant biomass and influenced plant succession. Total insect species diversity significantly declined along the grazing intensity gradient and over time. Results of the first two collections of C. albonemus indicated that moderate grazing significantly increased the abundance of C. albonemus. However, abundance was significantly decreased in plots that were overgrazed, possibly because of food stress and environmental pressures. Under moderate grazing, betA and CHDH genes were significantly upregulated in C. albonemus. In response to higher grazing intensity, upregulated genes included those involved in serine-type peptidase activity, anatomical structure development, and sensory organ development; downregulated genes included those involved in the structural constituents of the ribosome and ribosome processes. Genes strongly upregulated in response to heavy grazing pressure included adaptive genes such as those encoding ankyrin repeat domain-containing protein and HSP. These findings improve our understanding of the role of the transcriptome in C. albonemus population response to livestock grazing and may provide useful targets for grasshopper control.

  5. Effects of past and present livestock grazing on herpetofauna in a landscape-scale experiment.

    Science.gov (United States)

    Kay, Geoffrey M; Mortelliti, Alessio; Tulloch, Ayesha; Barton, Philip; Florance, Daniel; Cunningham, Saul A; Lindenmayer, David B

    2017-04-01

    Livestock grazing is the most widespread land use on Earth and can have negative effects on biodiversity. Yet, many of the mechanisms by which grazing leads to changes in biodiversity remain unresolved. One reason is that conventional grazing studies often target broad treatments rather than specific parameters of grazing (e.g., intensity, duration, and frequency) or fail to account for historical grazing effects. We conducted a landscape-scale replicated grazing experiment (15,000 km 2 , 97 sites) to examine the impact of past grazing management and current grazing regimes (intensity, duration, and frequency) on a community of ground-dwelling herpetofauna (39 species). We analyzed community variables (species richness and composition) for all species and built multiseason patch-occupancy models to predict local colonization and extinction for the 7 most abundant species. Past grazing practices did not influence community richness but did affect community composition and patch colonization and extinction for 4 of 7 species. Present grazing parameters did not influence community richness or composition, but 6 of the 7 target species were affected by at least one grazing parameter. Grazing frequency had the most consistent influence, positively affecting 3 of 7 species (increased colonization or decreased extinction). Past grazing practice affected community composition and population dynamics in some species in different ways, which suggests that conservation planners should examine the different grazing histories of an area. Species responded differently to specific current grazing practices; thus, incentive programs that apply a diversity of approaches rather than focusing on a change such as reduced grazing intensity should be considered. Based on our findings, we suggest that determining fine-scale grazing attributes is essential for advancing grazing as a conservation strategy. © 2016 Society for Conservation Biology.

  6. The effects of timing of grazing on plant and arthropod communities in high-elevation grasslands.

    Science.gov (United States)

    Davis, Stacy C; Burkle, Laura A; Cross, Wyatt F; Cutting, Kyle A

    2014-01-01

    Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important implications for plant and higher trophic level responses. We experimentally assessed how timing of cattle grazing affected plant and arthropod communities in high-elevation grasslands of southwest Montana to better evaluate its use as a tool for multi-trophic level management. We manipulated timing of grazing, with one grazing treatment beginning in mid-June and the other in mid-July, in two experiments conducted in different grassland habitat types (i.e., wet meadow and upland) in 2011 and 2012. In the upland grassland experiment, we found that both early and late grazing treatments reduced forb biomass, whereas graminoid biomass was only reduced with late grazing. Grazing earlier in the growing season versus later did not result in greater recovery of graminoid or forb biomass as expected. In addition, the density of the most ubiquitous grassland arthropod order (Hemiptera) was reduced by both grazing treatments in upland grasslands. A comparison of end-of-season plant responses to grazing in upland versus wet meadow grasslands revealed that grazing reduced graminoid biomass in the wet meadow and forb biomass in the upland, irrespective of timing of grazing. Both grazing treatments also reduced end-of-season total arthropod and Hemiptera densities and Hemiptera biomass in both grassland habitat types. Our results indicate that both early and late season herbivory affect many plant and arthropod characteristics in a similar manner, but grazing earlier may negatively impact species of conservation concern requiring forage earlier in the growing season.

  7. The influence of host genotype X environment Interactions on the ...

    African Journals Online (AJOL)

    1993, 1993-1994 and 1994-1995) in three agro-ecological zones in Nigeria to study their reaction to cassava anthracnose disease (CAD), caused by Colletotrichum gloeosporioides, investigate genotype x environment (G x E) interaction ...

  8. Search Results | Page 123 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2013-01-01

    Physiological and biochemical response of local landrace and chickpea varieties to rhizobium inoculation and planting dates under different agro-ecological zones of Ethiopia. Published date. January 1, 2013. Papers. Sanitation URBAN AREAS HEALTH HAZARDS WATER QUALITY DISADVANTAGED GROUPS SLUMS ...

  9. Phenotypic diversity and phylogenetic relationship between the ...

    African Journals Online (AJOL)

    Phenotypic diversity and phylogenetic relationship between the Bakosi/Baweri and other pig breeds ( Sus scrofa Domesticus ) in the humid forest with monomodal rainfall agro-ecological zone of Cameroon.

  10. Search Results | Page 125 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2013-01-01

    Physiological and biochemical response of local landrace and chickpea varieties to rhizobium inoculation and planting dates under different agro-ecological zones of Ethiopia. Published date. January 1, 2013. Papers. Sanitation URBAN AREAS HEALTH HAZARDS WATER QUALITY DISADVANTAGED GROUPS SLUMS ...

  11. Daily intake of lactating crossbred cows grazing elephant grass rotationally

    Directory of Open Access Journals (Sweden)

    Aroeira Luiz Januário Magalhães

    2001-01-01

    Full Text Available The goal of this trial was to estimate the total dry matter (TDMI and daily pasture dry matter intakes (PDMI by lactating crossbred Holstein - Zebu cows grazing elephant grass (Pennisetum purpureum Schum. paddocks submitted to different rest periods. Three groups of 24 cows were used during two years. The paddocks were grazed during three days at the stocking rate of 4.5 cows/ha. Treatments consisted of resting periods of 30 days without concentrate and resting periods of 30, 37.5 and 45 days with 2 kg/cow/day of 20.6% crude protein concentrate. From July to October, pasture was supplemented with chopped sugarcane plus 1% urea. Total daily dry matter intake was estimated using the extrusa in vitro dry matter digestibility and the fecal output with chromium oxide. Regardless of the treatment the estimated average TDMI was 2.7, 2.9 and 2.9±0.03% and the mean PDMI was 1.9, 2.1 and 2.1±0.03% of body weight in the first, second and third grazing day, respectively (P<0.05. Only during the summer pasture quality was the same whichever the grazing day. Sugarcane effectively replaced grazing pasture, mainly in the first day when pasture dry matter intake was lowest.

  12. Community responses of arthropods to a range of traditional and manipulated grazing in shortgrass steppe.

    Science.gov (United States)

    Newbold, T A Scott; Stapp, Paul; Levensailor, Katherine E; Derner, Justin D; Lauenroth, William K

    2014-06-01

    Responses of plants to grazing are better understood, and more predictable, than those of consumers in North American grasslands. In 2003, we began a large-scale, replicated experiment that examined the effects of grazing on three important arthropod groups-beetles, spiders, and grasshoppers-in shortgrass steppe of north-central Colorado. We investigated whether modifications of the intensity and seasonality of livestock grazing alter the structure and diversity of macroarthropod communities compared with traditional grazing practices. Treatments represented a gradient of grazing intensity by cattle and native herbivores: long-term grazing exclosures; moderate summer grazing (the traditional regime); intensive spring grazing; intensive summer grazing; and moderately summer-grazed pastures also inhabited by black-tailed prairie dogs (Cynomys ludovicianus Ord). Beetles and spiders were the most common groups captured, comprising 60% and 21%, respectively, of 4,378 total pitfall captures. Grasshopper counts were generally low, with 3,799 individuals observed and densities grazing treatments, responding not only to long-term grazing conditions, but also to the short-term, more-intensive grazing manipulations. In response, arthropods were, in general, relatively insensitive to these grazing-induced structural changes. However, species-level analyses of one group (Tenebrionidae) revealed both positive and negative effects of grazing treatments on beetle richness and activity-density. Importantly, these responses to grazing were more pronounced in a year when spring-summer rainfall was low, suggesting that both grazing and precipitation-which together may create the greatest heterogeneity in vegetation structure-are drivers of consumer responses in this system.

  13. Horse grazing systems: understory biomass and plant biodiversity of a Pinus radiata stand

    Directory of Open Access Journals (Sweden)

    Antonio Rigueiro-Rodríguez

    2012-02-01

    Full Text Available Horse grazing systems may affect productivity and biodiversity of understory developed under Pinus radiata D. Don silvopastoral systems, while acting as a tool to reduce the risk of fire. This study compared continuous and rotational grazing systems effect upon biomass, fractions of stem, sprouts, leaves and woody parts of Ulex europaeus L. and alpha (Species Richness, Shannon-Wiener and beta (Jaccard and Magurran biodiversity for a period of four years in a P. radiata silvopastoral system. The experiment consisted of a randomized block design of two treatments (continuous and rotational grazing. Biomass, and species abundances were measured - biodiversity metrics were calculated based on these results for a two years of grazing and two years of post-grazing periods. Both continuous and rotational grazing systems were useful tools for reducing biomass and, therefore, fire risk. The rotational grazing system caused damage to the U. europaeus shrub, limiting its recovery once grazing was stopped. However, the more intensive grazing of U. europaeus plants under rotational had a positive effect on both alpha and beta biodiversity indexes due to the low capacity of food selection in the whole plot rather than continuous grazing systems. Biomass was not affected by the grazing system; however the rotational grazing system is more appropriate to reduce U. europaeus biomass and therefore forest fire risk at a long term and to enhance pasture biodiversity than the continuous grazing system.

  14. Heterotrophic nanoflagellate grazing facilitates subarctic Atlantic bloom development

    DEFF Research Database (Denmark)

    Paulsen, Maria Lund; Riisgaard, Karen; St. John, Michael

    2017-01-01

    and was substantially higher than the growth of the larger microzooplankton (MZP), i.e. ciliates and dinoflagellates. During the first experiment, small phytoplankton dominated and overall protist grazing (HNF + MZP) was low. In the later experiments, MZP grazing on HNF became evident; however, MZP were not able......-down control of small-sized phytoplankton, thus paving the way for a diatomdominated spring bloom. To assess the trophic role of protist grazers during the winter to spring transition, 3 experiments were performed using size-fractionated surface water from the Iceland Basin (March−April 2012......). These experiments demonstrated heterotrophic nanoflagellates (HNF) grazing of picophytoplankton to be a key pathway, even though these are rarely considered as important phytoplankton grazers in high-latitude systems. The growth rate of HNF was significantly correlated to the biomass of picophytoplankton...

  15. Atypical myopathy in grazing horses: a first exploratory data analysis.

    Science.gov (United States)

    Votion, Dominique-M; Linden, Annick; Delguste, Catherine; Amory, Hélène; Thiry, Etienne; Engels, Patrick; van Galen, Gaby; Navet, Rachel; Sluse, Francis; Serteyn, Didier; Saegerman, Claude

    2009-04-01

    Over the last decade, atypical myopathy (AM) in grazing horses has emerged in several European countries. An exploratory analysis was conducted to determine horse- and pasture-level indicators or factors associated with AM in Belgium. Belgian cases of AM confirmed by histology (n=57) were compared to their healthy co-grazing horses (n=77) and to pastured horses not involved with AM as controls (n=386). The pastures where confirmed cases were grazing (42 pastures; 38 sites; 44 incidences of AM) were compared with those of the controls (216 pastures; 96 sites; no incidence of AM). Statistically significant (Phorses (young age, inactivity, body condition poor to normal), management practices (permanent pasturing, spreading of manure) and pasture characteristics (humid, sloping pastures, accumulated dead leaves, presence of waterway) may increase the risk of AM. Specific interventions based on these factors might help to reduce the incidence of AM.

  16. 1000 years of sustainable grazing in Nordic conditions?

    DEFF Research Database (Denmark)

    Brandt, Jesper

    , in practice linking detailed contextualized accumulated knowledge on nature processes at landscape level with constant social conflict regulations at a local and regional level. Often it worked, but in some situations (e.g. with marked changes in social or economic conditions, or by changing climatic...... years this modern tradition has also been preferred by investigations to find solutions for non-sustainable types of land use in grazing systems. However, much sustainability-relevant wisdom has been accumulated in historical grazing-systems that should be included in the repertoire of knowledge...... conditions) it did not. Based on many years of studying the landscape and ecological and social conditions of the Faroese grazing system since the first Faeroese law  the Sheep Letter from 1298  I have tried to derive some lessons concerning possibilities and limitations in the use of historical knowledge...

  17. Changes in vegetation and grazing capacity following honey mesquite control

    Science.gov (United States)

    McDaniel, Kirk C.; Brock, John H.; Haas, Robert H.

    1982-01-01

    Honey mesquite kill and suppression, vegetation response, and changes in grazing use and capacity were evaluated following brush control in north-central Texas. Tree grubbing was most effective for eliminating honey mesquite, but because of soil and plant damage the treatment did not increase grazing capacity or improve range condition compared to nontreated rangeland. Aerial application of 2,4,5-T + picloram was more effective in klllmg and defoliating honey mesquite than 2,4,5-T alone, but both treatments significantly increased forage production. The 2,4,5-T + picloram and 2,4,5-T sprays provided a 7 to 16% increase in grazing capacity over a 4-year period on light and heavy honey mesquite infested pastures, respectively.

  18. High motility reduces grazing mortality of planktonic bacteria

    DEFF Research Database (Denmark)

    Matz, Carsten; Jurgens, K.

    2005-01-01

    We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... that the number of predator-prey contacts increased with bacterial swimming speed, but ingestion rates dropped at speeds of >25 mum s(-1) as a result of handling problems with highly motile cells. Comparative studies of a moderately motile strain (45 mum s-1) further revealed changes in the bacterial swimming...... speed distribution due to speed-selective flagellate grazing. Better long-term survival of the highly motile strain was indicated by fourfold-higher bacterial numbers in the presence of grazing compared to the moderately motile strain. Putative constraints of maintaining high swimming speeds were tested...

  19. Coastal zone

    International Nuclear Information System (INIS)

    2002-01-01

    The report entitled Climate Change Impacts and Adaptation : A Canadian Perspective, presents a summary of research regarding the impacts of climate change on key sectors over the past five years as it relates to Canada. This chapter on the coastal zone focuses on the impact of climate change on Canada's marine and Great Lakes coasts with tips on how to deal with the impacts associated with climate change in sensitive environments. This report is aimed at the sectors that will be most affected by adaptation decisions in the coastal zone, including fisheries, tourism, transportation and water resources. The impact of climate change in the coastal zone may include changes in water levels, wave patterns, storm surges, and thickness of seasonal ice cover. The Intergovernmental Panel on Climate Change projects global average sea level will rise between 9 and 88 centimetres between 1990 to 2100, but not all areas of Canada will experience the same rate of future sea level change. The main physical impact would be shoreline change that could result in a range of biophysical and socio-economic impacts, some beneficial, some negative. The report focuses on issues related to infrastructure and communities in coastal regions. It is noted that appropriate human adaptation will play a vital role in reducing the extent of potential impacts by decreasing the vulnerability of average zone to climate change. The 3 main trends in coastal adaptation include: (1) increase in soft protection, retreat and accommodation, (2) reliance on technology such as geographic information systems to manage information, and (3) awareness of the need for coastal adaptation that is appropriate for local conditions. 61 refs., 7 figs

  20. Understanding the effectiveness of vegetated streamside management zones for protecting water quality (Chapter 5)

    Science.gov (United States)

    Philip Smethurst; Kevin Petrone; Daniel Neary

    2012-01-01

    We set out to improve understanding of the effectiveness of streamside management zones (SMZs) for protecting water quality in landscapes dominated by agriculture. We conducted a paired-catchment experiment that included water quality monitoring before and after the establishment of a forest plantation as an SMZ on cleared farmland that was used for extensive grazing....

  1. Nearly-grazing optimal trajectories for aeroassisted orbital transfer

    Science.gov (United States)

    Miele, A.; Mease, K. D.; Basapur, V. K.

    1986-01-01

    In the present treatment of optimal control problems arising in the study of coplanar aeroassisted orbital transfer, the hybrid combination of propulsive parameters in space and aerodynamic maneuvers employing lift modulation in the sensible atmosphere indicates that the optimal energy-viewpoint solution is the grazing trajectory; this trajectory is characterized by favorable values of the peak heating rate and the peak dynamic pressure. Numerical solutions are obtained by means of the sequential gradient restoration algorithm for optimal control problems. It is found that nearly-grazing trajectories yielding the least-square value of the path inclination have desirable characteristics from the standpoints of energy, heating rate, and dynamic pressure.

  2. Preliminary results from a shallow water benthic grazing study

    Science.gov (United States)

    Jones, N.L.; Monismith, Stephen G.; Thompson, Janet K.

    2005-01-01

    The nutrient-rich, shallow waters of San Francisco Bay support high rates of primary production, limited not by nutrients but by light availability and benthic grazing (Alpine and others 1992; Cloern 1982). Phytoplankton blooms are an important food source for upper trophic levels. Consequently animal populations, such as fish, may suffer under conditions of high benthic bivalve grazing. It has been hypothesized that several species of fish are suffering as a result of severe decreases in available phytoplankton since the introduction of Potamocorbula amurensis into San Francisco Bay (Feyrer 2003).

  3. X-ray grazing incidence diffraction from multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P.; Swygenhoven, H. van; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Grazing incidence scattering geometries using synchrotron radiation have been applied in order to characterise the roughness profiles and the structural coherence of multilayers. The lateral correlation length of the roughness profiles was evaluated using diffuse reflectivity in the `out of plane` geometry. This type of measurement is the only diffuse reflectivity technique allowing large lateral momentum transfer. It is typically suitable for correlation lengths smaller than 1000 A. The lateral structural coherence length of Ni{sub 3}Al/Ni multilayers as a function of the layer thickness was obtained by grazing incidence diffraction (GID). 3 figs., 1 ref.

  4. Impact of grazing on range plant community components under arid Mediterranean climate in northern Syria

    NARCIS (Netherlands)

    Niane, A.A.

    2013-01-01

    Keywords: Rotational grazing, full protection, continuous grazing species richness, species diversity, soil seed bank, Bayesian methods, Salsola vermiculata, seed longevity, rangeland management, Syria.   Rangelands represent 70% of the semi-arid and arid Mediterranean land mass. It is a

  5. Impact of Graze-­‐Out in Hard Red Winter Wheat Production

    OpenAIRE

    Neupane, Diwash; Moss, Charles B.

    2014-01-01

    We investigate the relationship between wheat graze-­‐out and cattle-­‐wheat price ratio and moisture level and examine the impact of graze-­‐out on wheat yield in major wheat-­‐producing states in US. Results indicate that cattle-­‐wheat price ratio and moisture level affect farmers’ graze out decision and graze-­‐out have significant impact on wheat yield.

  6. Effect of grazing cycle on milk production of cows on kikuyu pasture ...

    African Journals Online (AJOL)

    The effect of different rotational grazing cycle lengths on milk production, body weight, herbage intake, digestibility and grazing time was investigated. Pastures were stocked at two Friesian cows per ha and grazed for l, 2 or 4-day periods of 15, 30 or 60 days rotation cycles, respectively. Data were recorded during the ...

  7. Ruminant Grazing of Cover Crops: Effects on Soil Properties and Agricultural Production

    Science.gov (United States)

    Poffenbarger, Hanna

    2010-01-01

    Integrating livestock into a cropping system by allowing ruminant animals to graze cover crops may yield economic and environmental benefits. The effects of grazing on soil physical properties, soil organic matter, nitrogen cycling and agricultural production are presented in this literature review. The review found that grazing cover crops…

  8. Herbage availability €rs a stress factor on grazed Coastcross II ...

    African Journals Online (AJOL)

    LWG/ha by optimum dravermoe relatief klein. Keywords: Herbage availability, stocking rate, weight gain, con- tinuous grazing, rotational grazing, Coastcross II. Introduction. Stocking rate is known to be one of the most important fac- tors affecting live weight gain (LWG) of animals grazing pastures (Jones & Sandland, 1974).

  9. Prescribed grazing for management of invasive vegetation in a hardwood forest understory

    Science.gov (United States)

    Ronald A. Rathfon; Songlin Fei; Jason Tower; Kenneth Andries; Michael. Neary

    2014-01-01

    Land managers considering prescribed grazing (PG) face a lack of information on animal stocking rates, timing of grazing, and duration of grazing to achieve desired conditions in natural ecosystems under invasion stress from a variety of nonnative invasive plant (NNIP) species. In this study we tested PG treatments using goats for reducing NNIP brush species and...

  10. [Microbial community structure of the alpine meadow under different grazing styles in Naqu prefecture of Tibet].

    Science.gov (United States)

    Niu, Lei; Liu, Ying-hui; Li, Yue; Ouyang, Sheng-nan

    2015-08-01

    To clarify the effects of grazing styles on the soil microbial community in the alpine meadow, we explored the changes of soil microbial community structure in the alpine meadow located in Naqu district of Tibet Autonomous Region by analyzing the soil chemical properties and phospholipid fatty acids (PLFAs). The results showed that the contents of soil total organic carbon, total phosphate and nitrate nitrogen under the different grazing styles followed the trend of 7-year rest grazing > free grazing > grazing prohibition. Except for the ratio of fungal PLFAs/bacterial PLFAs, total PLFAs, the bacterial PLFAs, the fungal PLFAs, the gram negative bacterial and the gram positive bacterial PLFAs over the different grazing types were in the order of 7-year rest grazing > 5-year grazing prohibition > 7-year and 9-year grazing prohibition. The principal component analysis (PCA) presented that the first principal component (PC1 = 74.6%) was mainly composed of monounsaturated fatty acids, polyunsaturated fatty acids and branched fatty acids, and the second principal component (PC2 = 13.2%) was mainly composed of saturated fatty acids and some monounsaturated fatty acids. Total PLFAs content was significantly positively correlated with microbial biomass carbon content. Compared with grazing prohibition, fallow grazing was best for the alpine meadow in Naqu district, and free grazing with light intensity was good for the alpine meadow.

  11. Seasonal changes in the quality of diet selected by cattle grazing the ...

    African Journals Online (AJOL)

    It is recommended that protein supplementation of animals grazing veld be initiated in February in the area. Keywords: cattle; cattle grazing; consumption; crude protein; diet; digestibility; dundee research station; grazing; in vitro digestibility; leaves; natal sour sandveld; plant parts; protein; quality; seasonal changes; south ...

  12. 36 CFR 251.103 - Mediation of term grazing permit disputes.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Mediation of term grazing... Lands § 251.103 Mediation of term grazing permit disputes. (a) Decisions subject to mediation. In those States with Department of Agriculture certified mediation programs, any holder of a term grazing permit...

  13. 25 CFR 166.306 - Can the BIA adjust the grazing capacity?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can the BIA adjust the grazing capacity? 166.306 Section 166.306 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Land and Operations Management § 166.306 Can the BIA adjust the grazing capacity? Yes. In consultation...

  14. EFFECTS OF FARMING SYSTEMS ON SPECIES COMPOSITION, NUTRIENT CONTENT AND DIGESTIBILTY OF FORAGES OF THE NATURAL PASTURE OF ASSOSA ZONE (WESTERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Beyene Teklu

    2010-07-01

    Full Text Available Forage species of the natural pasture of Assosa Zone of Benshangule-Gumuz (Western Ethiopia were identified and their chemical composition and in vitro dry matter digestibility (IVDMD determined. Data were collected from two farming systems (shifting cultivation: SC and permanent farming system: PFS and two grazing types (communal grazing land: CGL, riverside grazing land: RSGL. 18 grasses, 2 legumes, sedge, 2 forbs and 17 trees/shrubs were identified from the natural pasture of both farming systems. Hyparrhenia rufa had significantly lower (P

  15. The evolution of institutions and rules governing communal grazing ...

    African Journals Online (AJOL)

    This paper traces the tradition and evolution of the institutions and rules governing communal grazing lands in Botswana. It shows how the problem of resource overuse arose partly from the dismantling and delegitimization of traditional resource management institutions that occurred during the colonial period, and was ...

  16. Holistic Management: Misinformation on the Science of Grazed Ecosystems

    Directory of Open Access Journals (Sweden)

    John Carter

    2014-01-01

    Full Text Available Over 3 billion hectares of lands worldwide are grazed by livestock, with a majority suffering degradation in ecological condition. Losses in plant productivity, biodiversity of plant and animal communities, and carbon storage are occurring as a result of livestock grazing. Holistic management (HM has been proposed as a means of restoring degraded deserts and grasslands and reversing climate change. The fundamental approach of this system is based on frequently rotating livestock herds to mimic native ungulates reacting to predators in order to break up biological soil crusts and trample plants and soils to promote restoration. This review could find no peer-reviewed studies that show that this management approach is superior to conventional grazing systems in outcomes. Any claims of success due to HM are likely due to the management aspects of goal setting, monitoring, and adapting to meet goals, not the ecological principles embodied in HM. Ecologically, the application of HM principles of trampling and intensive foraging are as detrimental to plants, soils, water storage, and plant productivity as are conventional grazing systems. Contrary to claims made that HM will reverse climate change, the scientific evidence is that global greenhouse gas emissions are vastly larger than the capacity of worldwide grasslands and deserts to store the carbon emitted each year.

  17. Livestock grazing affects the egg size of an insectivorous passerine.

    Science.gov (United States)

    Evans, Darren M; Redpath, Stephen M; Evans, Sharon A; Elston, David A; Dennis, Peter

    2005-09-22

    Livestock grazing is a major driver of ecosystem change, and has been associated with significant declines in various bird species worldwide. In Britain, there is particular concern that severe grazing pressure is deleteriously affecting vegetation and birds in upland regions. However, the mechanism by which grazing affects birds is unclear. Here, we report for the first time, to our knowledge, that sheep grazing pressure affects the egg size of a common upland passerine: the meadow pipit Anthus pratensis. We manipulated sheep stocking densities in a replicated field experiment, and found that plots with the highest stocking density contained nests with the smallest eggs, and that plots with low stocking density contained nests with the largest eggs. However, eggs laid in ungrazed plots were also small, suggesting that either too many sheep or their removal from upland areas might have a detrimental effect on pipit egg size. We found no significant effect on fledging success but the reduced post-fledging survival of young from smaller eggs, as seen in other studies, could partly explain declines in upland birds.

  18. Phosphorus and the grazing ruminant. 4. Blood and faecal grab ...

    African Journals Online (AJOL)

    Blood plasma and faecal grab samples were evaluated as indicators of P status of cattle grazing at two experimental sites (Glen and Armoedsvlakte). Plasma Pj levels clearly identified the - P cattle at Armoedsvlakte as being P deficient whilst at Glen the - P group tended towards lower levels than the supplemented cattle ...

  19. Grazing Incidence X-ray Scattering and Diffraction

    Indian Academy of Sciences (India)

    IAS Admin

    tion. In thia article, various aspects of surface X- ray diffraction and scattering are discussed with illustrations of some typical applications of these techniques. 1. ..... ray reflectivity. Here, X-rays are incident on the sample at very small grazing angles to the surface and below the critical angle, αc. As explained earlier, this ...

  20. Carcass mass gains of steers grazing star grass, with different ...

    African Journals Online (AJOL)

    Carcass mass gains of steers grazing dryland Cynodon aethiopicus cv. No. 2 Star grass pastures during the growing season were determined for each of 16 treatments comprising four levels of nitrogen fertilisation in combination with four overlapping sets of stocking rates. The treatments were repeated over four growing ...

  1. Research Note Identifying key grazing indicators to monitor trends in ...

    African Journals Online (AJOL)

    Research Note Identifying key grazing indicators to monitor trends in the veld condition of Lambert's Bay Strandveld, South Africa. ... from which a minimum number of species necessary to monitor trends in the condition of the veld were determined, making it user-friendly for land-users, extension officers and others. The key ...

  2. Contrasting effects of large herbivore grazing on smaller herbivores

    NARCIS (Netherlands)

    Bakker, E. S.; Olff, H.; Gleichman, J. M.

    2009-01-01

    Assemblages of large herbivores may compete For food or facilitate one another. However, small vertebrate herbivore species co-occurring with large herbivores may be affected by large herbivore grazing through changes in plant species composition, nutrient content and vegetation structure. These

  3. Production response of lambs receiving creep feed while grazing ...

    African Journals Online (AJOL)

    The aim of the study was to determine the production responses of lambs receiving either creep feed or not while grazing two different pastures. The production of ewes within each treatment was also recorded. The study was conducted at both the Kromme Rhee and Langgewens Research Farms. At Kromme Rhee, sheep ...

  4. Ingestive Behaviour of Grazing Ewes Given Two Levels of Concentrate

    African Journals Online (AJOL)

    It was expected that concentrate supplementation would reflect directly on forage intake owing to the substitution effect, which causes sheep where the supplement supplied a small proportion of net energy requirement, to have a greater grazing intensity. The two breeds differed in the time spent ruminating or lying, with the ...

  5. Sound management may sequester methane in grazed rangeland ecosystems

    Science.gov (United States)

    Considering their contribution to global warming, the sources and sinks of methane (CH4) should be accounted when undertaking a greenhouse gas inventory for grazed rangeland ecosystems. The aim of this study was to evaluate the mitigation potential of current ecological management programs implement...

  6. Biomass requirements from natural pastures for livestock grazing ...

    African Journals Online (AJOL)

    The problem of seasonal shortages of herbage production from natural pastures in the Ethiopian highlands was investigated. This was done by comparing the available biomass amounts on the pastures with biomass amounts required for livestock grazing and for protecting land slope from soil erosion within a given slope ...

  7. Improved grazing activity of dairy heifers in shaded tropical grasslands

    Directory of Open Access Journals (Sweden)

    Andréia Cristina Tavares de Mello

    Full Text Available ABSTRACT: Trees in the production systems can effectively reduce hot weather-induced stress in the Brazilian Midwest. High temperatures cause changes in animals daily routine, and trees into pastures can promote benefits. The aim of this research was to evaluate the behavior of dairy heifers in silvopastoral systems in the state of Mato Grosso, Brazil. A herd of 24 crossbreed heifers (3/4 and 7/8 Holstein/Zebu, 350kg average weight, was evaluated over three seasons. Piatã grass was managed under three shade levels: full-sun, moderate-shade, and intensive-shade provided by 10 to 12m high Eucalyptus trees. Behavior data were collected every 15 minutes from 8:30h to 16h. Shade availability significantly impacted heifer behavior, mainly affecting grazing frequency and time during the hottest hours. Grazing behavior was affected by shade levels during the different seasons. Heifers showed preferred grazing times. Heifers in the intensive-shade system visited shady areas during the hottest hours throughout the seasons. Heifers in the full sun-system avoided grazing during the warmer times, ceasing feeding activities. Our results from the Brazilian Midwest showed that shade availability causes breed heifers to change their daily routine.

  8. Enhancing soil and landscape quality in smallholder grazing systems

    Science.gov (United States)

    Grasslands constitute the largest global land use and are an important part of agricultural and ecological systems on every continent, across a wide range of potential productivity. Ruminant livestock grazing on these lands constitutes an important form of agricultural production. It is estimated th...

  9. Methane emissions measured directly from grazing livestock in New Zealand

    Science.gov (United States)

    Lassey, Keith R.; Ulyatt, Marcus J.; Martin, Ross J.; Walker, Carolyn F.; David Shelton, I.

    We report measurements of methane emissions from individual ruminant livestock-both sheep and dairy cows-grazing pasture typical of New Zealand lowlands in the temperate southwest Pacific. These are the first measurements reported from grazing sheep, and among the first from grazing cattle. The measurement technique, developed at Washington State University, enables emission rates to be determined from analyses of "breath" samples collected while grazing. More than 250 measurements of daily methane emission from 50 sheep (8 months old) were made, with flock-mean emission 18.9 ± 0.8 g hd -1 d -1. Although emissions were weakly correlated with feed intake, they represented a 4.6 ± 0.1 % average loss of gross dietary energy. The corresponding mean emission based on 40 measurements of daily emissions from 10 lactating dairy cows was 263 ± 10 g hd -1 d -1, approximately 6.2% of estimated gross energy intake. A notable feature was the large inter-sheep variability in daily methane emission (factor of 1.4 range) that could not be attributed to variable intake. This would appear to suggest an appreciable diversity of methanogenetic response to digestion, and may be significant in the search for strategies to control emissions of this greenhouse gas.

  10. Bite frequency measured by head pitch movements in grazing experiment

    DEFF Research Database (Denmark)

    Oudshoorn, Frank W.; S. Nadimi, Esmaeil; Jørgensen, Rasmus Nyholm

    2010-01-01

    sensors placed on the head of the cows, bite frequency was registered manually by noting the rip off sound during a specified time bout. Sward registrations comprised grass length measurement by rising plate meter , grass quality by laboratory analysis of hand harvested grass simulating the cows grazing...

  11. Effect of continuous grazing in the Dohne Sourveld on species ...

    African Journals Online (AJOL)

    As the intensity of defoliation increases, decrease in grass cover is associated with an increase of forbs, such as Senecio retrorsus. Keywords: andropogon appendiculatus; basal cover; botanical composition; continuous grazing; defoliation; disturbance history; dohne sourveld; elionurus muticus; grass cover; grasses; ...

  12. Bacterial production, protozoan grazing, and mineralization in stratified Lake Vechten

    NARCIS (Netherlands)

    Bloem, J.

    1989-01-01

    The role of heterotrophic nanoflagellates (HNAN, size 2-20 μm) in grazing on bacteria and mineralization of organic matter in stratified Lake Vechten was studied.

    Quantitative effects of manipulation and fixation on HNAN were checked. Considerable losses were caused by

  13. Mixed livestock grazing in diverse temperate and semi-arid ...

    African Journals Online (AJOL)

    ... and continuity and for animal welfare will increasingly drive production processes. In this paper, the potential of mixed grazing for higher output of quality animal products, within these constraints, is assessed under both temperate and semi-arid conditions. Complementary behavioural patterns between domestic livestock ...

  14. Grazing on Regeneration Sites Encourages Pine Seedling Growth

    Science.gov (United States)

    Raymond D. Ratliff; Renee G. Denton

    1995-01-01

    Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the...

  15. (Orthoptera: Acridoidea) in communally grazed and protected savanna

    African Journals Online (AJOL)

    1995-01-18

    Jan 18, 1995 ... pared with a lightly grazed area and a mowed airstrip, in adjacent protected land, in the Mpumalanga lowveld,. South Africa. Plant species ... and frost was rare. The areas were underlain by Basement. Complex strata of the Bandelierkop Complex, typified by potassic granites and grandiorite. Sampling was ...

  16. Butterfly responses to prairie restoration through fire and grazing

    Science.gov (United States)

    Vogel, Jennifer A.; Debinski, Diane M.; Koford, Rolf R.; Miller, J.R.

    2007-01-01

    The development of land for modern agriculture has resulted in losses of native prairie habitat. The small, isolated patches of prairie habitat that remain are threatened by fire suppression, overgrazing, and invasion by non-native species. We evaluated the effects of three restoration practices (grazing only, burning only, and burning and grazing) on the vegetation characteristics and butterfly communities of remnant prairies. Total butterfly abundance was highest on prairies that were managed with burning and grazing and lowest on those that were only burned. Butterfly species richness did not differ among any of the restoration practices. Butterfly species diversity was highest on sites that were only burned. Responses of individual butterfly species to restoration practices were highly variable. In the best predictive regression model, total butterfly abundance was negatively associated with the percent cover of bare ground and positively associated with the percent cover of forbs. Canonical correspondence analysis revealed that sites with burned only and grazed only practices could be separated based on their butterfly community composition. Butterfly communities in each of the three restoration practices are equally species rich but different practices yield compositionally different butterfly communities. Because of this variation in butterfly species responses to different restoration practices, there is no single practice that will benefit all species or even all species within habitat-specialist or habitat-generalist habitat guilds. ?? 2007 Elsevier Ltd. All rights reserved.

  17. Stability, resilience and animal production in continuously grazed ...

    African Journals Online (AJOL)

    The Jones-Sandland model, popularly used in southern Africa, may be criticised because it ignores firstly the long-term effects of grazing intensity on the acceptability and productivity of pasture or veld, and secondly possible discontinuities in the animal performance - stocking rate relationship. A mathematical model is ...

  18. Thermal balance of cattle grazing winter range: model application.

    Science.gov (United States)

    Keren, E N; Olson, B E

    2006-05-01

    Beef cattle grazing semiarid foothill rangeland of the Northern Rockies during winter may be exposed to cold temperatures and high winds while grazing pastures with low nutritional value. Cattle can physiologically and behaviorally respond to the changing environment to lower their metabolic requirements and reduce the effects of cold exposure. Requirements of grazing cattle may be overpredicted with models developed in controlled settings that do not account for energy-conserving behaviors. We refined a simple thermal balance equation to model heat exchange of free-ranging cattle. We accounted for the complex interactions between animal behavior and the changing natural environment by applying the insulation characteristics of the cattle's tissue and coat to a simple geometric shape of an asymmetric ellipsoid at different orientations to the sun and wind. We compared the model predictions with heat production measured in 3 studies, and in all cases the model predictions were similar to those reported. Model simulations indicate behaviors, such as lying and orientation to the sun, mitigated the effects of extreme weather. For many combinations of winter weather variables, metabolic requirements increased only slightly due to cold exposure of mature beef cattle in a near-maintenance state. The results indicate that solar radiation contributes strongly to the thermal balance of a cow. Thus, previous models that do not account for the irradiative environment may overestimate metabolic requirements of cattle acclimated to grazing winter range.

  19. Phytoplankton Growth and Microzooplankton Grazing in the Subtropical Northeast Atlantic

    Science.gov (United States)

    Cáceres, Carlos; Taboada, Fernando González; Höfer, Juan; Anadón, Ricardo

    2013-01-01

    Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres. PMID:23935946

  20. Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic.

    Directory of Open Access Journals (Sweden)

    Carlos Cáceres

    Full Text Available Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E. Our design included two phytoplankton size fractions (0.2-5 µm and >5 µm and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11-1.60 d(-1, especially in the case of the large fraction. Grazing rates were also high (0.15-1.29 d(-1, suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.

  1. Performance assessment and grazing pattern of semi-intensively ...

    African Journals Online (AJOL)

    Performance assessment and grazing pattern of semi-intensively managed Maradi goats supplemented with Palm Kernel Cake and Poultry Dropping ... Animals that were supplemented with T1 had highest significant (P<0.05) water consumption compared with animals supplemented with T2, T3 and T4 which had similar ...

  2. Long-term livestock grazing increases the recruitment success of ...

    African Journals Online (AJOL)

    These effects are proportional to density. ... However, these changes did not alter landscape-scale mound basal area or volume. ... We suggest that livestock grazing provides additional forage resources for termites through litter breakup and dung production, leading to greater mound recruitment and thus densities, whilst ...

  3. Animal health management practices in zero grazing dairy units in ...

    African Journals Online (AJOL)

    This study aimed at investigating the animal health management practices in zero grazing dairy units. A questionnaire was used to assess the veterinary practices including the administration of antibiotics and other veterinary inputs to promote growth, prevent and treat diseases. Sixty-five (65) respondents were involved in ...

  4. Determining grazing capacity in Namibia with the aid of remote ...

    African Journals Online (AJOL)

    The Namibian rangelands consist of a mixture of herbaceous and woody components. The main source of income is from farming systems with grass production the predominant source of forage. For rangeland managers to utilise this source sustainably, the accurate determination of grazing capacity is vital since it allows ...

  5. Magnetic alignment in grazing and resting cattle and deer

    Czech Academy of Sciences Publication Activity Database

    Begall, S.; Červený, Jaroslav; Neef, J.; Burda, H.; Vojtěch, O.

    2008-01-01

    Roč. 105, č. 36 (2008), s. 13451-13455 ISSN 0027-8424 Institutional research plan: CEZ:AV0Z60930519 Keywords : grazing behavior * magnetic alignment * magnetoreception * resting behavior * spatial orientation Subject RIV: EH - Ecology, Behaviour Impact factor: 9.380, year: 2008

  6. The impact of grazing on forage quality of the herbaceous ...

    African Journals Online (AJOL)

    Reports on research conducted in the Mamoro cork oak forest of Morocco to describe the impacts of sheep grazing in March, April, May and June of 1987 and 1988 on seasonal changes in forage quality of the herbaceous vegetation. The study showed that trends in herbage quality were related mainly to plant maturity.

  7. Creation and preservation of vegetation patterns by grazing

    NARCIS (Netherlands)

    Mouissie, A. Maarten; Apol, M. Emile F.; Heil, Gerrit W.; van Diggelen, Rudy

    2008-01-01

    Structural patterns of tall stands ("tussock") and short stands ("lawn") are observed in grazed vegetation throughout the world. Such structural vegetation diversity influences plant and animal diversity. A possible mechanism for the creation and preservation of such patterns is a positive feedback

  8. Grazing trials with sheep on kikuyu ( Pennisetum clandestinum ...

    African Journals Online (AJOL)

    Grazing capacity was proportional to the yield of foggage. Although the percentage leaf in the foggage in the different treatments varied from 72 to 89, only some 50% of the total herbage was utilized. The estimates of quality indicated that a higher level of utilization would have resulted in poorer sheep performance.

  9. Soil and vegetation changes across a Succulent Karoo grazing ...

    African Journals Online (AJOL)

    Over-grazed areas close to the watering point had shallow soils with a greater potential for crusting and therefore poorer water capacity. Mainly short-lived succulents (Mesembryanthemaceae) were recorded here, while under-utilised veld far from the watering point was identified by plant groupings dominated by Antimima ...

  10. Occurrence of Clinical Dermatophilosis in Zero-grazed Dairy Cattle ...

    African Journals Online (AJOL)

    Dermatophilosis was clinically diagnosed and confirmed by isolation of Dermatophilus congolensis in three cows in a herd of seven zero-grazed dairy cattle. The lesions observed were matting together of hair into small tufts (greasy crusts) and discrete circumscribed lesions covered with creamy greasy crusts. The matting ...

  11. Performance of different vegetation indices in assessing degradation of community grazing lands in Indian arid zone

    Science.gov (United States)

    Kumar, Suresh; Bastin, Gary; Friedel, Margaret; Narain, Pratap; Saha, D. K.; Ahuja, U. R.; Mathur, B. K.

    2006-12-01

    Vegetation in arid community grazinglands shows monsoonal growth. Its matching phenology with crops makes its detection difficult during July to September. While crops are harvested during September-October, using satellite data thereafter for the natural vegetation seems most appropriate but by then it turns dry. An index capable of sensing dry vegetation was needed since conventional NDVI is sensitive to greenness of vegetation. Performance of NDVI vis-à-vis another index, PD54, based on cover was therefore compared in assessing degradation of grazinglands. The PD54 was used to isolate anthropogenic impacts from environmental induced degradation by analyzing satellite images from dry and wet seasons. Substantial absence of appreciable vegetation response indicated poor resilience and severe degradation. Five grazinglands in Shergarh tehsil of Jodhpur district in Rajasthan were studied following above approach. Ground radiometric observations were recorded. Satellite data of IRS 1C/1D/P6 with LISS 3 sensor for both pre and post monsoon season were acquired for three contrasting wet-dry season events. These were geometrically registered and radiometrically calibrated to calculate an index of vegetation cover PD54 as well as NDVI. PD54 is a perpendicular vegetation index based on the green and red spectral band width. The PD54 and NDVI calculated from spectro-radiometer were related to vegetation cover measured on ground in permanent plots. This confirmed that PD54 was superior index for estimating cover in arid dry grasslands. These ground vegetation trends in a good rainfall year (2001) with drought year (2002) were related with satellite data for a protected and four unprotected grazinglands. NDVI failed to detect any vegetation in protected areas supporting excellent grass cover which was succinctly brought out by PD54. Successful validation of PD54 in detecting degradation of 13 additional sites confirmed its efficacy. These findings have implication in forage availability assessments, forage forecasting, drought preparedness, pastoralism and transhumance.

  12. Simulating grazing practices in a complete livestock system model: estimating soil carbon storage and greenhouse gas emissions in grazed versus un-grazed agroecosystems using the Manure-DNDC model

    Science.gov (United States)

    Campbell, E. E.; Dorich, C.; Contosta, A.; Varner, R. K.

    2017-12-01

    In livestock agroecosystems, the combined contributions of enteric fermentation, manure management, and livestock grazing and/or feed production play an important role in agroecosystem carbon (C) storage and GHG losses, with complete livestock system models acting as important tools to evaluate the full impacts of these complex systems. The Manure-DeNitrification-DeComposition (DNDC) model is one such example, simulating impacts on C and nitrogen cycling, estimating methane, carbon dioxide, nitrous oxide, and ammonium dynamics in fields, manure storage, and enteric emissions. This allows the evaluation of differences in GHG and soil C impacts between conventional and organic dairy production systems, which differ in their use of grazed pasture versus confined feeding operations. However, Manure-DNDC has received limited testing in representing variations in grazed pasture management (i.e. intensive rotational grazing versus standard grazing practices). Using a set of forage biomass, soil C, and GHG emissions data collected at four sites across New England, we parameterized and validated Manure-DNDC estimations of GHG emissions and soil C in grazed versus un-grazed systems. Soil observations from these sites showed little effect from grazing practices, but larger soil carbon differences between farms. This may be due to spatial variation in SOC, making it difficult to measure and model, or due to controls of edaphic properties that make management moot. However, to further address these questions, model development will be needed to improve Manure-DNDC simulation of rotational grazing, as high stocking density grazing over short periods resulted in forage not re-growing sufficiently within the model. Furthermore, model simulations did not account for variation in interactions between livestock and soil given variability in field microclimates, perhaps requiring simulations that divide a single field into multiple paddocks to move towards more accurate evaluation of

  13. Technical note: utilization of sainfoin by grazing steers and a method for predicting daily gain from small-plot grazing data.

    Science.gov (United States)

    Mowrey, D P; Matches, A G; Preston, R L

    1992-07-01

    Sainfoin (Onobrychis viciaefolia Scop.) is adapted to the calcareous soils of the southern Great Plains and can provide early season forage that does not induce bloating; however, little is known about performance by ruminants grazing sainfoin. Our objective was to determine the effect of plant growth stage and grazing pressures on potential animal production from sainfoin as predicted from energy intake as a multiple of maintenance. Nitrogen-fertilized (100 kg of N/ha) Renumex sainfoin was grown under irrigation on a Pullman clay loam (fine, mixed, thermic Torretic Paleustoll) near Lubbock, TX. Light (L), medium (M), and heavy (H) grazing pressures were applied with steers grazing sainfoin that was at the bud (B), flower (F), and seed shatter (S) stages of growth. The L, M, and H pressures were grazed to remove 50, 75, and 90% of the standing plant height. Across growth stages, L, M, and H grazing pressures averaged 52, 69, and 87% removal of pregrazed herbage mass. Dry matter intake as a percentage of BW of steers averaged 3.9, 2.8, and 1.7 for L, M, and H grazing pressures. Across growth stages, predicted live weight gain for L, M, and H grazing pressures averaged .86, .67, and .03 kg/d. Our findings indicate that the multiple of maintenance method may be useful for evaluating treatments from small-plot grazing experiments.

  14. Patterns in Greater Sage-grouse population dynamics correspond with public grazing records at broad scales

    Science.gov (United States)

    Monroe, Adrian; Aldridge, Cameron L.; Assal, Timothy J.; Veblen, Kari E.; Pyke, David A.; Casazza, Michael L.

    2017-01-01

    Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004–2014, we modeled population trends in response to grazing level (represented by a relative grazing index) and timing across a gradient in vegetation productivity as measured by the Normalized Vegetation Difference Index (NDVI). We found grazing can have both positive and negative effects on Sage-grouse populations depending on the timing and level of grazing. Sage-grouse populations responded positively to higher grazing levels after peak vegetation productivity, but populations declined when similar grazing levels occurred earlier, likely reflecting the sensitivity of cool-season grasses to grazing during peak growth periods. We also found support for the hypothesis that effects of grazing management vary with local vegetation productivity. These results illustrate the importance of broad-scale analyses by revealing patterns in Sage-grouse population trends that may not be inferred from studies at finer scales, and could inform sustainable grazing management in these ecosystems.

  15. Plant compensation to grazing and soil carbon dynamics in a tropical grassland.

    Science.gov (United States)

    Ritchie, Mark E

    2014-01-01

    The effects of grazing on soil organic carbon (SOC) dynamics, particularly in the tropics, are still poorly understood. Plant compensation to grazing, whereby plants maintain leaf area (C input capacity) despite consumption (C removal) by grazers, has been demonstrated in tropical grasslands but its influence on SOC is largely unexplored. Here, the effect of grazing on plant leaf area index (LAI) was measured in a field experiment in Serengeti National Park, Tanzania. LAI changed little for grazing intensities up to 70%. The response curve of LAI versus grazing intensity was used in a mass balance model, called SNAP, of SOC dynamics based on previous data from the Serengeti. The model predicted SOC to increase at intermediate grazing intensity, but then to decline rapidly at the highest grazing intensities. The SNAP model predictions were compared with observed SOC stocks in the 24 grazed plots of a 10-year grazing exclosure experiment at eight sites across the park that varied in mean annual rainfall, soil texture, grazing intensity and plant lignin and cellulose. The model predicted current SOC stocks very well (R (2) > 0.75), and suggests that compensatory plant responses to grazing are an important means of how herbivores might maintain or increase SOC in tropical grasslands.

  16. Livestock grazing intensity affects abundance of Common shrews (Sorex araneus) in two meadows in Denmark.

    Science.gov (United States)

    Schmidt, Niels M; Olsen, Henrik; Leirs, Herwig

    2009-01-20

    Current nature conservation in semi-natural grasslands often includes grazing and hay cutting, as well as the abandonment of draining. Semi-natural grassland and in particular meadows constitute important habitat type for a large number of animal species in today's fragmented and intensively cultivated landscape of Europe. Here we focus on the population characteristics of Common shrews Sorex araneus in relation to livestock grazing intensity in two wet meadows in western Denmark. High grazing intensity had a significant negative effect on Common shrew number compared to low grazing intensity and no grazing. Common shrew abundance was generally, but not significantly, higher on the low grazing intensity plots than on the ungrazed controls. No differences in body mass, sex ratio, or reproductive output between Common shrew individuals from the various grazing treatments were found. No negative effects of low intensity grazing on Common shrew abundance were found compared to the ungrazed control. Low intensity grazing thus seems a suitable management regime for Common shrews, when grazing is needed as part of the meadow management scheme. High intensity grazing on the other hand is not a suitable management tool.

  17. Is grazing exclusion effective in restoring vegetation in degraded alpine grasslands in Tibet, China?

    Directory of Open Access Journals (Sweden)

    Yan Yan

    2015-06-01

    Full Text Available Overgrazing is considered one of the key disturbance factors that results in alpine grassland degradation in Tibet. Grazing exclusion by fencing has been widely used as an approach to restore degraded grasslands in Tibet since 2004. Is the grazing exclusion management strategy effective for the vegetation restoration of degraded alpine grasslands? Three alpine grassland types were selected in Tibet to investigate the effect of grazing exclusion on plant community structure and biomass. Our results showed that species biodiversity indicators, including the Pielou evenness index, the Shannon–Wiener diversity index, and the Simpson dominance index, did not significantly change under grazing exclusion conditions. In contrast, the total vegetation cover, the mean vegetation height of the community, and the aboveground biomass were significantly higher in the grazing exclusion grasslands than in the free grazed grasslands. These results indicated that grazing exclusion is an effective measure for maintaining community stability and improving aboveground vegetation growth in alpine grasslands. However, the statistical analysis showed that the growing season precipitation (GSP plays a more important role than grazing exclusion in which influence on vegetation in alpine grasslands. In addition, because the results of the present study come from short term (6–8 years grazing exclusion, it is still uncertain whether these improvements will be continuable if grazing exclusion is continuously implemented. Therefore, the assessments of the ecological effects of the grazing exclusion management strategy on degraded alpine grasslands in Tibet still need long term continued research.

  18. Patterns in Greater Sage-grouse population dynamics correspond with public grazing records at broad scales.

    Science.gov (United States)

    Monroe, Adrian P; Aldridge, Cameron L; Assal, Timothy J; Veblen, Kari E; Pyke, David A; Casazza, Michael L

    2017-06-01

    Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004-2014, we modeled population trends in response to grazing level (represented by a relative grazing index) and timing across a gradient in vegetation productivity as measured by the Normalized Vegetation Difference Index (NDVI). We found grazing can have both positive and negative effects on Sage-grouse populations depending on the timing and level of grazing. Sage-grouse populations responded positively to higher grazing levels after peak vegetation productivity, but populations declined when similar grazing levels occurred earlier, likely reflecting the sensitivity of cool-season grasses to grazing during peak growth periods. We also found support for the hypothesis that effects of grazing management vary with local vegetation productivity. These results illustrate the importance of broad-scale analyses by revealing patterns in Sage-grouse population trends that may not be inferred from studies at finer scales, and could inform sustainable grazing management in these ecosystems. © 2017 by the Ecological Society of America.

  19. Mesozooplankton biomass and grazing responses to Cyclone Opal, a subtropical mesoscale eddy

    Science.gov (United States)

    Landry, Michael R.; Decima, Moira; Simmons, Melinda P.; Hannides, Cecelia C. S.; Daniels, Emy

    2008-05-01

    As part of E-Flux III cruise studies in March 2005, plankton net collections were made to assess the effects of a cyclonic cold-core eddy (Cyclone Opal) on the biomass and grazing of mesozooplankton. Mesozooplankton biomass in the central region of Cyclone Opal, an area of uplifted nutricline and a subsurface diatom bloom, averaged 0.80±0.24 and 1.51±0.59 g DW m -2, for day and night tows, respectively. These biomass estimates were about 80% higher than control (OUT) stations, with increases more or less proportionately distributed among size classes from 0.2 to >5 mm. Though elevated relative to surrounding waters south of the Hawaiian Islands (Hawai'i lee), total biomass and size distribution in Cyclone Opal were almost exactly the same as contemporary measurements made at Stn. ALOHA, 100 km north of the islands, by the HOT (Hawaii Ocean Time-series) Program. Mesozooplankton biomass and community composition at the OUT stations were also similar to ALOHA values from 1994 to 1996, preceding a recent decadal increase. These comparisons may therefore provide insight into production characteristics or biomass gradients associated with decadal changes at Stn. ALOHA. Gut fluorescence estimates were higher in Opal than in ambient waters, translating to grazing impacts of 0.11±0.02 d -1 (IN) versus 0.03±0.01 d -1 (OUT). Over the depth-integrated euphotic zone, mesozooplankton accounted for 30% of the combined grazing losses of phytoplankton to micro- and meso-herbivores in Opal, as compared to 13% at control stations. Estimates of active export flux by migrating zooplankton averaged 0.81 mmol C m -2 d -1 in Cyclone Opal and 0.37 mmol C m -2 d -1 at OUT stations, 53% and 24%, respectively, of the carbon export measured by passive sediment traps. Migrants also exported 0.18 mmol N m -2 d -1 (117% of trap N flux) in Cyclone Opal compared to 0.08 mmol N m -2 d -1 (51% of trap flux) at control stations. Overall, the food-web importance of mesozooplankton increased in

  20. Positive short-term effects of sheep grazing on the alpine avifauna.

    Science.gov (United States)

    Loe, Leif Egil; Mysterud, Atle; Stien, Audun; Steen, Harald; Evans, Darren M; Austrheim, Gunnar

    2007-02-22

    Grazing by large herbivores may negatively affect bird populations. This is of great conservation concern in areas with intensive sheep grazing. Sheep management varies substantially between regions, but no study has been performed in less intensively grazed systems. In a fully replicated, landscape scale experiment with three levels of sheep grazing, we tested whether the abundance and diversity of an assemblage of mountain birds were negatively affected by grazing or if grazing facilitated the bird assemblage. Density of birds was higher at high sheep density compared with low sheep density or no sheep by the fourth grazing season, while there was no clear effect on bird diversity. Thus, agricultural traditions and land use politics determining sheep density may change the density of avifauna in either positive or negative directions.

  1. Grazing effects on plant community succession of early- and mid-seral seeded grassland compared to shortgrass steppe

    Science.gov (United States)

    Milchunas, Daniel G.; Vandever, Mark W.

    2013-01-01

    Questions: Grazing may speed or slow secondary succession, and the direction may depend on seral stage and relative tolerance of native perennial grasses compared with annual invasive species. How does grazing affect succession where undisturbed communities have a long evolutionary history of grazing by native herbivores and are tolerant to livestock grazing?

  2. Testing the limits of resistance: a 19-year study of Mediterranean grassland response to grazing regimes.

    Science.gov (United States)

    Sternberg, Marcelo; Golodets, Carly; Gutman, Mario; Perevolotsky, Avi; Ungar, Eugene D; Kigel, Jaime; Henkin, Zalmen

    2015-05-01

    A synthesis of a long-term (19 years) study assessing the effects of cattle grazing on the structure and composition of a Mediterranean grassland in north-eastern Israel is presented, with new insights into the response of the vegetation to grazing management and rainfall. We hypothesized that the plant community studied would be resistant to high grazing intensities and rainfall variability considering the combined long history of land-use and unpredictable climatic conditions where this community evolved. Treatments included manipulations of stocking densities (moderate, heavy, and very heavy) and of grazing regimes (continuous vs. seasonal), in a factorial design. The effect of interannual rainfall variation on the expression of grazing impacts on the plant community was minor. The main effects of grazing on relative cover of plant functional groups were related to early vs. late seasonal grazing. Species diversity and equitability were remarkably stable across all grazing treatments. A reduction in tall grass cover at higher stocking densities was correlated with increased cover of less palatable groups such as annual and perennial thistles, as well as shorter and prostrate groups such as short annual grasses. This long-term study shows that interannual fluctuations in plant functional group composition could be partly accounted for by grazing pressure and timing, but not by the measured rainfall variables. Grazing affected the dominance of tall annual grasses. However, the persistence of tall grasses and more palatable species over time, despite large differences in grazing pressure and timing, supports the idea that Mediterranean grasslands are highly resistant to prolonged grazing. Indeed, even under the most extreme grazing conditions applied, there were no signs of deterioration or collapse of the ecosystem. This high resistance to grazing intensity and interannual fluctuation in climatic conditions should favor the persistence of the plant community under

  3. Effects of different grazing intensities on grassland production in China: a meta-analysis.

    Science.gov (United States)

    Yan, Liang; Zhou, Guangsheng; Zhang, Feng

    2013-01-01

    Grazing is one of the main grassland disturbances in China, and it is essential to quantitatively evaluate the effects of different grazing intensities on grassland production for grassland carbon budget and sustainable use. A meta-analysis was conducted to reveal general response patterns of grassland production to grazing in China. We used weighted log response ratio to assess the effect size, and 95% confidence intervals to give a sense of the precision of the estimate. Grazing effects were estimated as a percentage change relative to control (%). A total of 48 studies, including 251 data sets, were included in the meta-analysis. Grazing significantly decreased total biomass by 58.34% (95% CI: -72.04%∼-37.94%, CI: Confidence Interval), increased root/shoot ratio by 30.58% and decreased litter by 51.41% (95% CI: -63.31%∼-35.64%). Aboveground biomass and belowground biomass decreased significantly by 42.77% (95% CI: -48.88%∼-35.93%) and 23.13% (95% CI: -39.61%∼-2.17%), respectively. However, biomass responses were dependent on grazing intensity and environmental conditions. Percentage changes in aboveground biomass to grazing showed a quadratic relationship with precipitation in light grazing intensity treatment and a linear relationship in moderate and heavy grazing intensity treatment, but did not change with temperature. Grazing effects on belowground biomass did not change with precipitation or temperature. Compared to the global average value, grazing had greater negative effects on grassland production in China. Grazing has negative effects on grassland biomass and the grazing effects change with environmental conditions and grazing intensity, therefore flexible rangeland management tactics that suit local circumstances are necessary to take into consideration for balancing the demand of grassland utilization and conservation.

  4. Effects of different grazing intensities on grassland production in China: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Liang Yan

    Full Text Available Grazing is one of the main grassland disturbances in China, and it is essential to quantitatively evaluate the effects of different grazing intensities on grassland production for grassland carbon budget and sustainable use.A meta-analysis was conducted to reveal general response patterns of grassland production to grazing in China. We used weighted log response ratio to assess the effect size, and 95% confidence intervals to give a sense of the precision of the estimate. Grazing effects were estimated as a percentage change relative to control (%.A total of 48 studies, including 251 data sets, were included in the meta-analysis. Grazing significantly decreased total biomass by 58.34% (95% CI: -72.04%∼-37.94%, CI: Confidence Interval, increased root/shoot ratio by 30.58% and decreased litter by 51.41% (95% CI: -63.31%∼-35.64%. Aboveground biomass and belowground biomass decreased significantly by 42.77% (95% CI: -48.88%∼-35.93% and 23.13% (95% CI: -39.61%∼-2.17%, respectively. However, biomass responses were dependent on grazing intensity and environmental conditions. Percentage changes in aboveground biomass to grazing showed a quadratic relationship with precipitation in light grazing intensity treatment and a linear relationship in moderate and heavy grazing intensity treatment, but did not change with temperature. Grazing effects on belowground biomass did not change with precipitation or temperature. Compared to the global average value, grazing had greater negative effects on grassland production in China.Grazing has negative effects on grassland biomass and the grazing effects change with environmental conditions and grazing intensity, therefore flexible rangeland management tactics that suit local circumstances are necessary to take into consideration for balancing the demand of grassland utilization and conservation.

  5. Critical review of the impacts of grazing intensity on soil organic carbon storage and other soil quality indicators in extensively managed grasslands.

    Science.gov (United States)

    Abdalla, M; Hastings, A; Chadwick, D R; Jones, D L; Evans, C D; Jones, M B; Rees, R M; Smith, P

    2018-02-01

    Livestock grazing intensity (GI) is thought to have a major impact on soil organic carbon (SOC) storage and soil quality indicators in grassland agroecosystems. To critically investigate this, we conducted a global review and meta-analysis of 83 studies of extensive grazing, covering 164 sites across different countries and climatic zones. Unlike previous published reviews we normalized the SOC and total nitrogen (TN) data to a 30 cm depth to be compatible with IPCC guidelines. We also calculated a normalized GI and divided the data into four main groups depending on the regional climate (dry warm, DW; dry cool, DC; moist warm, MW; moist cool, MC). Our results show that taken across all climatic zones and GIs, grazing (below the carrying capacity of the systems) results in a decrease in SOC storage, although its impact on SOC is climate-dependent. When assessed for different regional climates, all GI levels increased SOC stocks under the MW climate (+7.6%) whilst there were reductions under the MC climate (-19%). Under the DW and DC climates, only the low (+5.8%) and low to medium (+16.1%) grazing intensities, respectively, were associated with increased SOC stocks. High GI significantly increased SOC for C4-dominated grassland compared to C3-dominated grassland and C3-C4 mixed grasslands. It was also associated with significant increases in TN and bulk density but had no effect on soil pH. To protect grassland soils from degradation, we recommend that GI and management practices should be optimized according to climate region and grassland type (C3, C4 or C3-C4 mixed).

  6. Optimising stocking rate and grazing management to enhance environmental and production outcomes for native temperate grasslands

    Science.gov (United States)

    Badgery, Warwick; Zhang, Yingjun; Huang, Ding; Broadfoot, Kim; Kemp, David; Mitchell, David

    2015-04-01

    Stocking rate and grazing management can be altered to enhance the sustainable production of grasslands but the relative influence of each has not often been determined for native temperate grasslands. Grazing management can range from seasonal rests through to intensive rotational grazing involving >30 paddocks. In large scale grazing, it can be difficult to segregate the influence of grazing pressure from the timing of utilisation. Moreover, relative grazing pressure can change between years as seasonal conditions influence grassland production compared to the relative constant requirements of animals. This paper reports on two studies in temperate native grasslands of northern China and south eastern Australia that examined stocking rate and regionally relevant grazing management strategies. In China, the grazing experiment involved combinations of a rest, moderate or heavy grazing pressure of sheep in spring, then moderate or heavy grazing in summer and autumn. Moderate grazing pressure at 50% of the current district average, resulted in the better balance between maintaining productive and diverse grasslands, a profitable livestock system, and mitigation of greenhouse gases through increased soil carbon, methane uptake by the soil, and efficient methane emissions per unit of weight gain. Spring rests best maintained a desirable grassland composition, but had few other benefits and reduced livestock productivity due to lower feed quality from grazing later in the season. In Australia, the grazing experiment compared continuous grazing to flexible 4- and 20-paddock rotational grazing systems with sheep. Stocking rates were adjusted between systems biannually based on the average herbage mass of the grassland. No treatment degraded the perennial pasture composition, but ground cover was maintained at higher levels in the 20-paddock system even though this treatment had a higher stocking rate. Overall there was little difference in livestock production (e.g. kg

  7. Compressive behaviour of the soil in buffer zones under different management practices in Finland

    Directory of Open Access Journals (Sweden)

    M. RÄTY

    2008-12-01

    Full Text Available Soil structure that favours infiltration is essential for successful functioning of vegetated buffer zones. We measured bulk density, air permeability and precompression stress in a clay soil (Vertic Cambisol and a sandy loam (Haplic Regosol in Finland, to identify management-related changes in the physical and mechanical properties in the surface soil of buffer zones. In addition, the impact of texture on these properties was studied at depths down to 180?200 cm. Soil cores (240 cm3 were sampled from a cultivated field, from buffer zones harvested by grazing (only in a clay soil or by cutting and removing the vegetation, and from buffer zones covered with natural grass vegetation. The samples were equilibrated at a matric potential of -6 kPa and compressed at a normal stress range of 20-400 kPa (7 h, followed by stress removal (1 h. Generally, the clay soil was more compressible than the sandy loam. Due to trampling by cattle, the young grazed buffer zone (0-3 cm had the largest bulk density and the smallest total porosity. For the grazed sites, reduced air permeability (2.7-5.1 × 10-5 m s-1 was found, compared with that of the buffer zone under natural vegetation (15-22 × 10-5 m s-1, indicating decreased pore continuity. Although the old grazed site was easily compressed, compared with the younger site, it showed a greater resilience capacity due to the protective cover of organic residues accumulated on the soil surface.

  8. Ingestive behaviour, herbage intake and grazing efficiency of beef cattle steers on Tanzania guineagrass subjected to rotational stocking managements

    OpenAIRE

    Difante,Gelson dos Santos; Euclides,Valéria Pacheco Batista; Nascimento Júnior,Domicio do; Silva,Sila Carneiro da; Torres Júnior,Roberto Augusto de Almeida; Sarmento,Daniel Oliveira de Lucena

    2009-01-01

    The objective of this experiment was to evaluate the ingestive behaviour, herbage intake and grazing efficiency of beef cattle steers grazing on Panicum maximum Jacq. cv. Tanzania subjected to different rotational stocking intensities. Treatments corresponded to two post-grazing conditions (residues of 25 and 50 cm) associated with a pre-grazing condition of 95% sward canopy light interception during regrowth (LI). The grazing time increased linearly with the duration of the occupation period...

  9. An improved grazed class method to estimate species selection and dry matter intake by cows at pasture

    OpenAIRE

    Bruno Martin; Giampiero Lombardi; Philippe Pradel; Anne Farruggia; Mauro Coppa

    2011-01-01

    Research has recently focused on pasture species intake by ruminants due to their influence on animal product quality. A field-applicable method which investigates species intake and selection, was tested on two dairy cow grazing systems: continuous grazing on a highly-biodiverse pasture (C) and rotational grazing on a moderately-diverse sward (R). In addition to the grazed class method, which evaluates the percentage of grazed dry matter (DM) per species according to the residual height of t...

  10. Protozoan grazing reduces the current output of microbial fuel cells.

    Science.gov (United States)

    Holmes, Dawn E; Nevin, Kelly P; Snoeyenbos-West, Oona L; Woodard, Trevor L; Strickland, Justin N; Lovley, Derek R

    2015-10-01

    Several experiments were conducted to determine whether protozoan grazing can reduce current output from sediment microbial fuel cells. When marine sediments were amended with eukaryotic inhibitors, the power output from the fuel cells increased 2-5-fold. Quantitative PCR showed that Geobacteraceae sequences were 120 times more abundant on anodes from treated fuel cells compared to untreated fuel cells, and that Spirotrichea sequences in untreated fuel cells were 200 times more abundant on anode surfaces than in the surrounding sediments. Defined studies with current-producing biofilms of Geobacter sulfurreducens and pure cultures of protozoa demonstrated that protozoa that were effective in consuming G. sulfurreducens reduced current production up to 91% when added to G. sulfurreducens fuel cells. These results suggest that anode biofilms are an attractive food source for protozoa and that protozoan grazing can be an important factor limiting the current output of sediment microbial fuel cells. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Adjustable Grazing-Incidence X-Ray Optics

    Science.gov (United States)

    O'Dell, Stephen L.; Reid, Paul B.

    2015-01-01

    With its unique subarcsecond imaging performance, NASA's Chandra X-ray Observatory illustrates the importance of fine angular resolution for x-ray astronomy. Indeed, the future of x-ray astronomy relies upon x-ray telescopes with comparable angular resolution but larger aperture areas. Combined with the special requirements of nested grazing-incidence optics, mass, and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. The goal of this technology research is to enable the cost-effective fabrication of large-area, lightweight grazing-incidence x-ray optics with subarcsecond resolution. Toward this end, the project is developing active x-ray optics using slumped-glass mirrors with thin-film piezoelectric arrays for correction of intrinsic or mount-induced distortions.

  12. Active Full-Shell Grazing-Incidence Optics

    Science.gov (United States)

    Davis, Jacqueline M.; Elsner, Ronald F.; Ramsey, Brian D.; O'Dell, Stephen L.; Kolodziejczak, Jeffery; Weisskopf, Martin C.; Gubarev, Mikhail V.

    2016-01-01

    MSFC has a long history of developing full-shell grazing-incidence x-ray optics for both narrow (pointed) and wide field (surveying) applications. The concept presented in this paper shows the potential to use active optics to switch between narrow and wide-field geometries, while maintaining large effective area and high angular resolution. In addition, active optics has the potential to reduce errors due to mounting and manufacturing lightweight optics. The design presented corrects low spatial frequency error and has significantly fewer actuators than other concepts presented thus far in the field of active x-ray optics. Using a finite element model, influence functions are calculated using active components on a full-shell grazing-incidence optic. Next, the ability of the active optic to effect a change of optical prescription and to correct for errors due to manufacturing and mounting is modeled.

  13. Impact of grazing on carbon balance of a Belgian grassland

    Science.gov (United States)

    Jérôme, Elisabeth; Beckers, Yves; Bodson, Bernard; Moureaux, Christine; Dumortier, Pierre; Beekkerk van Ruth, Joran; Aubinet, Marc

    2013-04-01

    This work analyzes the impact of grazing on the carbon balance of a grassland grazed by the Belgian Blue breed of cattle. The research was run at the Dorinne terrestrial observatory (DTO). The experimental site is a permanent grassland of ca. 4.2 ha located in the Belgian Condroz (50° 18' 44" N; 4° 58' 07" E; 248 m asl.). Other studies are conducted at the DTO including measurements of methane (CH4) and nitrous oxide fluxes (Dumortier et al., Geophysical Research Abstracts, Vol. 15, EGU2013-2083-1, 2013; Beekkerk van Ruth et al., Geophysical Research Abstracts, Vol. 15, EGU2013-3211, 2013, respectively). Grassland carbon budget (Net Biome Productivity, NBP) was calculated from Net Ecosystem Exchange (NEE) measured by eddy covariance by taking imports and exports of organic C and losses of carbon as CH4 into account. After 2 years of measurements (May 2010 - May 2012), the grassland behaved on average as a CO2 source (NEE = 73 ±31 g C m-2 y-1). After inclusion of all the C inputs and outputs the site was closed to equilibrium (NBP = 23 ±34 g C m-2 y-1). To analyze the impact of grazing on CO2 fluxes, we studied the temporal evolution of gross maximal photosynthetic capacity GPPmax and dark respiration Rd (deduced from the response of daytime fluxes to radiation over 5-day windows). We calculated GPPmax and Rd variation between the end and the beginning of grazing or non-grazing periods (ΔGPPmax and ΔRd, respectively). We observed a significant decrease of GPPmax during grazing periods and measured a ΔGPPmax dependence on the average stocking rate. This allows us to quantify the assimilation reduction due to grass consumption by cattle. On the contrary, no Rd decrease was observed during grazing periods. Moreover, we found that cumulated monthly NEE increased significantly with the average stocking rate. In addition, a confinement experiment was carried out in order to analyze livestock contribution to Total Ecosystem Respiration. Each experiment extended over

  14. An X-ray grazing incidence phase multilayer grating

    CERN Document Server

    Chernov, V A; Mytnichenko, S V

    2001-01-01

    An X-ray grazing incidence phase multilayer grating, representing a thin grating placed on a multilayer mirror, is proposed. A high efficiency of grating diffraction can be obtained by the possibility of changing the phase shift of the wave diffracted from the multilayer under the Bragg and total external reflection conditions. A grazing incidence phase multilayer grating consisting of Pt grating stripes on a Ni/C multilayer and optimized for the hard X-ray range was fabricated. Its diffraction properties were studied at photon energies of 7 and 8 keV. The obtained maximum value of the diffraction efficiency of the +1 grating order was 9% at 7 keV and 6.5% at 8 keV. The data obtained are in a rather good accordance with the theory.

  15. Understanding the effects of a new grazing policy: the impact of seasonal grazing on shrub demography in the Inner Mongolian steppe

    NARCIS (Netherlands)

    Li, Shou-Li; Yu, F.H.; Werger, M.J.A.; Dong, M.; Ramula, S.; Zuidema, P.A.

    2013-01-01

    1.Grazing by livestock is a common land use in arid and semi-arid areas. Developing sustainable grazing regimes that conserve vegetation and maintain productivity is therefore important in these ecosystems. To solve environmental problems induced by overgrazing in Chinese semi-arid regions, the

  16. Milk yield and somatic cell score of northeastern United States organic dairy farms during the grazing and non-grazing seasons

    Science.gov (United States)

    The objective of this study was to evaluate milk yield and composition of organically-certified dairy herds during grazing season (GS) and non-grazing season (NGS) in the Northeast region of the United States. Dairy Herd Improvement records of Holstein, Jersey, and Holstein-Jersey crossbred cows fro...

  17. Influence of elk grazing on soil properties in Rocky Mountain National Park

    Science.gov (United States)

    Binkley, Dan; Singer, F.; Kaye, M.; Rochelle, R.

    2003-01-01

    We used three 35-year exclosures to examine the effects of high elk populations on a variety of soil properties in three vegetation types: upland sagebrush, aspen, and meadow. Grazing and hoof action by elk significantly increased bulk density (from 0.87 kg/l ungrazed to 0.94 kg/l grazed), with greater effects on soils with fewer rocks. Grazing substantially reduced extractable calcium, magnesium, potassium and phosphorus in the sagebrush type, but not in the aspen or meadow types. The only grazing effect on pH came in aspen types, where grazing prevented aspen establishment, and kept soil pH about 0.7 units higher than under aspen inside the exclosures. Grazing had no overall effect on total soil C and N across all exclosures and vegetation types. The availability of soil nitrogen, indexed by in-field resin bags and net mineralization in soil cores, showed little overall effect of grazing. Limited data on soil leaching indicated a possibility of strong increases in nitrate leaching with grazing for an aspen vegetation type at one exclosure. Although we found little effect of grazing on soil N supply, we note that N fertilization doubled the production of grasses and shrubs; if grazing eventually led to changes in soil N supply, species composition and growth would likely change. ?? 2003 Elsevier B.V. All rights reserved.

  18. Effects of cattle grazing on small mammal communities in the Hulunber meadow steppe.

    Science.gov (United States)

    Cao, Chan; Shuai, Ling-Ying; Xin, Xiao-Ping; Liu, Zhi-Tao; Song, Yan-Ling; Zeng, Zhi-Gao

    2016-01-01

    Small mammals play important roles in many ecosystems, and understanding their response to disturbances such as cattle grazing is fundamental for developing sustainable land use strategies. However, how small mammals respond to cattle grazing remains controversial. A potential cause is that most of previous studies adopt rather simple experimental designs based solely on the presence/absence of grazing, and are thus unable to detect any complex relationships between diversity and grazing intensity. In this study, we conducted manipulated experiments in the Hulunber meadow steppe to survey small mammal community structures under four levels of grazing intensities. We found dramatic changes in species composition in native small mammal communities when grazing intensity reached intermediate levels (0.46 animal unit/ha). As grazing intensity increased, Spermophilus dauricus gradually became the single dominant species. Species richness and diversity of small mammals in ungrazed and lightly grazed (0.23 animal unit/ha) area were much higher than in intermediately and heavily grazed area. We did not detect a humped relationship between small mammal diversity and disturbance levels predicted by the intermediate disturbance hypothesis (IDH). Our study highlighted the necessity of conducting manipulated experiments under multiple grazing intensities.

  19. Effect of grazing on methane uptake from Eurasian steppe of China.

    Science.gov (United States)

    Tang, Shiming; Zhang, Yujuan; Zhai, Xiajie; Wilkes, Andreas; Wang, Chengjie; Wang, Kun

    2018-03-20

    The effects of grazing on soil methane (CH 4 ) uptake in steppe ecosystems are important for understanding carbon sequestration and cycling because the role of grassland soil for CH 4 uptake can have major impacts at the global level. Here, a meta-analysis of 27 individual studies was carried out to assess the response patterns of soil CH 4 uptake to grazing in steppe ecosystems of China. The weighted log response ratio was used to assess the effect size. We found that heavy grazing significantly depressed soil CH 4 uptake by 36.47%, but light and moderate grazing had no significant effects in grassland ecosystem. The response of grassland soil CH 4 uptake to grazing also was found to depend upon grazing intensity, grazing duration and climatic types. The increase in soil temperature and reduced aboveground biomass and soil moisture induced by heavy grazing may be the major regulators of the soil CH 4 uptake. These findings imply that grazing effects on soil CH 4 uptake are highly context-specific and that grazing in different grasslands might be managed differently to help mitigate greenhouse gas emissions.

  20. Introducing cattle grazing to a noxious weed-dominated rangeland shifts plant communities

    Directory of Open Access Journals (Sweden)

    Josh S. Davy

    2015-10-01

    Full Text Available Invasive weed species in California's rangelands can reduce herbaceous diversity, forage quality and wildlife habitat. Small-scale studies (5 acres or fewer have shown reductions of medusahead and yellow starthistle using prescribed grazing on rangelands, but little is published on the effects of pasture-scale (greater than 80 acres prescribed grazing on weed control and plant community responses. We report the results of a 6-year collaborative study of manager-applied prescribed grazing implemented on rangeland that had not been grazed for 4 years. Grazing reduced medusahead but did not alter yellow starthistle cover. Medusahead reductions were only seen in years that did not have significant late spring rainfall, suggesting that it is able to recover from heavy grazing if soil moisture is present. Later season grazing appears to have the potential to suppress medusahead in all years. In practice, however, such grazing is constrained by livestock drinking water availability and forage quality, which were limited even in years with late spring rainfall. Thus, we expect that grazing treatments under real-world constraints would reduce medusahead only in years with little late spring rainfall. After 10 years of grazing exclusion, the ungrazed plant communities began to shift, replacing medusahead with species that have little value, such as ripgut and red brome.

  1. Transcriptome responses in alfalfa associated with tolerance to intensive animal grazing

    Science.gov (United States)

    Wang, Junjie; Zhao, Yan; Ray, Ian; Song, Mingzhou

    2016-01-01

    Tolerance of alfalfa (Medicago sativa L.) to animal grazing varies widely within the species. However, the molecular mechanisms influencing the grazing tolerant phenotype remain uncharacterized. The objective of this study was to identify genes and pathways that control grazing response in alfalfa. We analyzed whole-plant de novo transcriptomes from grazing tolerant and intolerant populations of M. sativa ssp. falcata subjected to grazing by sheep. Among the Gene Ontology terms which were identified as grazing responsive in the tolerant plants and differentially enriched between the tolerant and intolerant populations (both grazed), most were associated with the ribosome and translation-related activities, cell wall processes, and response to oxygen levels. Twenty-one grazing responsive pathways were identified that also exhibited differential expression between the tolerant and intolerant populations. These pathways were associated with secondary metabolite production, primary carbohydrate metabolic pathways, shikimate derivative dependent pathways, ribosomal subunit composition, hormone signaling, wound response, cell wall formation, and anti-oxidant defense. Sequence polymorphisms were detected among several differentially expressed homologous transcripts between the tolerant and intolerant populations. These differentially responsive genes and pathways constitute potential response mechanisms for grazing tolerance in alfalfa. They also provide potential targets for molecular breeding efforts to develop grazing-tolerant cultivars of alfalfa. PMID:26763747

  2. The ability of winter grazing to reduce wildfire size, intensity ...

    Science.gov (United States)

    A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience more fire-induced mortality of native perennial bunchgrasses. The authors also presented several statements regarding the benefits of winter grazing on post-fire plant community responses. However, this commentary will show that the study by Davies et al. has underlying methodological flaws, lacks data necessary to support their conclusions, and does not provide an accurate discussion on the effect of grazing on rangeland ecosystems. Importantly, Davies et al. presented no data on the post-fire mortality of the perennial bunchgrasses or on the changes in plant community composition following their experimental fires. Rather, Davies et al. inferred these conclusions based off their observed fire behavior metrics of maximum temperature and a term described as the “heat load”. However, neither metric is appropriate for elucidating the heat flux impacts on plants. This lack of post-fire data, several methodological flaws, and the use of inadequate metrics describing heat cast doubts on the authors’ ability to support their stated conclusions. This article is a commentary highlights the scientific shortcomings in a forthcoming paper by Davies et al. in the International Journal of Wildland Fire. The study has methodological flaw

  3. Additives in ensiling palisade grass managed under grazing intensities

    Directory of Open Access Journals (Sweden)

    Felipe Barros Macedo

    2015-10-01

    Full Text Available Conservation of summer forage excess represents a management strategy to meet animals' needs for dry matter in the shortage period, but has been poorly studied. Silage can be used for this purpose. This study analyzed the production of palisade grass silage from pasture subjected to different grazing intensities with and without additive, determining losses by gases and effluents and chemical composition of silage. The experiment was a 4 x 3 factorial completely randomized design, with four replications. The factors were: 1st – herbage allowance of 5% (5 kg dry matter 100 kg-1 of animal weight day-1, 10, 15 and 20%. The pasture was managed under rotational stocking with 35-day grazing cycles (7 days of occupation and 28 days of rest and 2nd - additives: a control; b citrus pulp pellets; c biological inoculant for grass silage. The forage of palisade grass harvested from pastures subjected to low-intensity grazing showed quantitative and qualitative characteristics for ensiling. However, high humidity and low fermentable carbohydrate require the use of additive, favor the fermentation process and increase the nutritional quality of silage.

  4. Effects of grazing strategy on limiting nitrate leaching in grazed grass-clover pastures on coarse sandy soil

    DEFF Research Database (Denmark)

    Hansen, Elly Møller; Eriksen, Jørgen; Søegaard, Karen

    2012-01-01

    Urinations of ruminants on grazed pastures increase the risk of nitrate leaching. The study investigated the effect of reducing the length of the grazing season on nitrate leaching from a coarse sandy, irrigated soil during 2006–2007 and 2007–2008. In both years, precipitation was above the long...... concentrations of 23, 19 and 13 mg/L for an estimated proportion area occupied by urine patches of 0.33, 0.26 and 0.16, respectively. Thus, N concentrations in G and CG exceeded the EU limit of 11.3 mg N/L. Under the prevailing conditions, the time of urination did not appear important. The estimated background...

  5. From grazing marks to collapsed cliffs - intertidal bioerosion on all scales

    Science.gov (United States)

    Kázmér, Miklós; Taboroši, Danko; Hsieh, Meng-Long; Shafeea Leman, Mohd; Aziz Ali, Che; Roslan Mohamed, Kamal; Choowong, Montri

    2014-05-01

    Rocky shores - particularly in limestone areas of tropical, subtropical, and some temperate regions - are subject to intense bioerosion. Detailed field studies along the Gulf of Siam and the Andaman coast of Thailand, Langkawi Islands of Malaysia, southern Java and Bali in Indonesia, Palau Islands, and Okinawa revealed the presence of rich populations of bioeroding organisms in the intertidal zone. Molluscs capable of damaging rock (the chiton Acanthopleura, limpets, and whelks) leave grazing traces as they feed on bacterial and algal biofilms and chasmolithic and endolithic microorganisms. Boring sponges (Entobia), bivalves (Gastrochaenolites and others), boring sipunculid worms (Caulostrepsis), and sea urchins (Echinometra) drill deeper to hide from predators beneath the rock surface. Individually, members of these taxa leave marks ranging from sub-millimetre to the metre scale, but collectively, their erosion creates marine notches, several-metres-deep features extending between low and high tide marks. When cliffs overhanging these notches collapse, landscape-scale scars are left behind. The various bioeroders display a clear vertical zonation between low and high tide. These are dictated by environmental stress, food availability, competition, and predation. Typical inhabitants of present-day zones include - from top to bottom - littorinid snails, patellid limpets, chitons, boring bivalves, and boring sea urchins. Each organism leaves a characteristic mark in the bedrock. Trace fossils found in the 'wrong place' - either too high or too low compared to the present-day occurrence of the animals - suggest changes in relative sea level. Similarly, sea level changes are suggested by the presence of compound markings produced through overprinting by organisms that live in different ecological zones. Preservation and obliteration of traces depends on the rates of sea level change and coastal denudation. Morphology of bioerosional markings and their vertical zonation

  6. Transitions and coexistence along a grazing gradient in the Eurasian steppe

    Science.gov (United States)

    Ren, Haiyan; Taube, Friedelm; Zhang, Yingjun; Bai, Yongfei; Hu, Shuijin

    2017-04-01

    Ecological resilience theory has often been applied to explain species coexistence and range condition assessment of various community states and to explicate the dynamics of ecosystems. Grazing is a primary disturbance that can alter rangeland resilience by causing hard-to-reverse transitions in grasslands. Yet, how grazing affects the coexistence of plant functional group (PFG) and transition remains unclear. We conducted a six-year grazing experiment in a typical steppe of Inner Mongolia, using seven grazing intensities (0, 1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 sheep/ hectare) and two grazing systems (i.e. a continuous annual grazing as in the traditional grazing system, and a mixed grazing system combining grazing and haymaking), to examine grazing effects on plant functional group shifts and species coexistence in the semi-arid grassland system. Our results indicate that the relative richness of dominant bunchgrasses and forbs had a compensatory coexistence at all grazing intensities, and the richness of rhizomatous grasses fluctuated but was persistent. The relative productivity of dominant bunchgrasses and rhizomatous grasses had compensatory interactions with grazing intensity and grazing system. Dominant bunchgrasses and rhizomatous grasses resist grazing effects by using their dominant species functional traits: high specific leaf area and low leaf nitrogen content. Our results suggest that: 1. Stabilizing mechanisms beyond grazing management are more important in determining plant functional group coexistence and ecological resilience. 2. Plant functional group composition is more important in influencing ecosystem functioning than diversity. 3. Ecosystem resilience at a given level is related to the biomass of dominant PFG, which is determined by a balanced shift between dominant species biomass. The relatively even ecosystem resilience along the grazing gradient is attributed to the compensatory interactions of dominant species in their biomass variations

  7. Grazing exit versus grazing incidence geometry for x-ray absorption near edge structure analysis of arsenic traces

    International Nuclear Information System (INIS)

    Meirer, F.; Streli, C.; Wobrauschek, P.; Zoeger, N.; Pepponi, G.

    2009-01-01

    In the presented study the grazing exit x-ray fluorescence was tested for its applicability to x-ray absorption near edge structure analysis of arsenic in droplet samples. The experimental results have been compared to the findings of former analyses of the same samples using a grazing incidence (GI) setup to compare the performance of both geometries. Furthermore, the investigations were accomplished to gain a better understanding of the so called self-absorption effect, which was observed and investigated in previous studies using a GI geometry. It was suggested that a normal incidence-grazing-exit geometry would not suffer from self-absorption effects in x-ray absorption fine structure (XAFS) analysis due to the minimized path length of the incident beam through the sample. The results proved this assumption and in turn confirmed the occurrence of the self-absorption effect for GI geometry. Due to its lower sensitivity it is difficult to apply the GE geometry to XAFS analysis of trace amounts (few nanograms) of samples but the technique is well suited for the analysis of small amounts of concentrated samples

  8. Pasture size effects on the ability of off-stream water or restricted stream access to alter the spatial/temporal distribution of grazing beef cows.

    Science.gov (United States)

    Bisinger, J J; Russell, J R; Morrical, D G; Isenhart, T M

    2014-08-01

    For 2 grazing seasons, effects of pasture size, stream access, and off-stream water on cow distribution relative to a stream were evaluated in six 12.1-ha cool-season grass pastures. Two pasture sizes (small [4.0 ha] and large [12.1 ha]) with 3 management treatments (unrestricted stream access without off-stream water [U], unrestricted stream access with off-stream water [UW], and stream access restricted to a stabilized stream crossing [R]) were alternated between pasture sizes every 2 wk for 5 consecutive 4-wk intervals in each grazing season. Small and large pastures were stocked with 5 and 15 August-calving cows from mid May through mid October. At 10-min intervals, cow location was determined with Global Positioning System collars fitted on 2 to 3 cows in each pasture and identified when observed in the stream (0-10 m from the stream) or riparian (0-33 m from the stream) zones and ambient temperature was recorded with on-site weather stations. Over all intervals, cows were observed more (P ≤ 0.01) frequently in the stream and riparian zones of small than large pastures regardless of management treatment. Cows in R pastures had 24 and 8% less (P stream and riparian zones than U or UW pastures regardless of pasture size. Off-stream water had little effect on the presence of cows in or near pasture streams regardless of pasture size. In 2011, the probability of cow presence in the stream and riparian zones increased at greater (P stream and riparian zones increased at greater (P stream and riparian zone increased less (P streams with unrestricted access.

  9. N leaching to groundwater from dairy production involving grazing over the winter on a clay-loam soil.

    Science.gov (United States)

    Necpalova, M; Fenton, O; Casey, I; Humphreys, J

    2012-08-15

    This study investigated concentrations of various N species in shallow groundwater (grazing over the winter period on a clay loam soil with a high natural attenuation capacity in southern Ireland (52°51'N, 08°21'W) over a 2-year period. A dense network of shallow groundwater piezometers was installed to determine groundwater flow direction and N spatial and temporal variation. Estimated vertical travel times through the unsaturated zone (Grazing over the winter had no effect on N losses to groundwater. Mean concentrations of DON, NH(4)(+)-N, NO(2)(-)-N and NO(3)(-)-N were 2.16, 0.35, 0.01 and 0.37 mg L(-1) respectively. Soil attenuation processes such as denitrification and DNRA resulted in increased NH(4)(+)-N levels. For this reason, DON and NH(4)(+)-N represented the highest proportion of N losses from the site. Some of the spatial and temporal variation of N concentrations was explained by correlations with selected chemical and hydro-topographical parameters (NO(3)(-)-N/Cl(-) ratio, distance of the sampling point from the closest receptor, watertable depth, depth of sampling piezometer, DOC concentration). A high explanatory power of NO(3)(-)-N/Cl(-) ratio and the distance of the sampling point from the closest receptor indicated the influence of point sources and groundwater-surface water interactions. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Competition drives the response of soil microbial diversity to increased grazing by vertebrate herbivores.

    Science.gov (United States)

    Eldridge, David J; Delgado-Baquerizo, Manuel; Travers, Samantha K; Val, James; Oliver, Ian; Hamonts, Kelly; Singh, Brajesh K

    2017-07-01

    Scientists have largely neglected the effects of grazing on soil microbial communities despite their importance as drivers of ecosystem functions and services. We hypothesized that changes in soil properties resulting from grazing regulate the diversity of soil microbes by releasing/suppressing subordinate microbial taxa via competition. To test this, we examined how intensity of vertebrate herbivores influences the diversity and composition of soil bacteria and fungi at 216 soil samples from 54 sites across four microsites. Increasing grazing intensity reduced soil carbon, suppressing the dominant bacterial phylum Actinobacteria (indirectly promoting bacterial diversity) and increasing the dominant fungal phylum Ascomycetes (indirectly reducing fungal diversity). Our data provide novel evidence that grazing modulates the diversity and composition of soil microbes via increases or reductions in competition by dominant taxa. Our results suggest that grazing can potentially alter soil function by altering microbial community composition, providing a clear link between grazing management, carbon availability and ecosystem functions. © 2017 by the Ecological Society of America.

  11. Grazing weakens temporal stabilizing effects of diversity in the Eurasian steppe

    OpenAIRE

    Ren, Haiyan; Taube, Friedhelm; Stein, Claudia; Zhang, Yingjun; Bai, Yongfei; Hu, Shuijin

    2017-01-01

    Abstract Many biodiversity experiments have demonstrated that plant diversity can stabilize productivity in experimental grasslands. However, less is known about how diversity–stability relationships are mediated by grazing. Grazing is known for causing species losses, but its effects on plant functional groups (PFGs) composition and species asynchrony, which are closely correlated with ecosystem stability, remain unclear. We conducted a six‐year grazing experiment in a semi‐arid steppe, usin...

  12. Reindeer grazing and soil nutrient cycling in boreal and tundra ecosystems

    OpenAIRE

    Stark, S. (Sari)

    2002-01-01

    Abstract In northernmost Fennoscandia, grazing by reindeer (Rangifer tarandus L.) has a substantial impact on the vegetation of boreal forests and arctic-alpine tundra heaths, which are reflected in below-ground processes, such as nutrient mineralization and soil organic matter decomposition. In the present thesis, the effects of reindeer grazing on soil nutrient cycling were studied by comparing grazed situation with an ungrazed control area in ten boreal forests a...

  13. Effects of precipitation on grassland ecosystem restoration under grazing exclusion in Inner Mongolia, China

    Science.gov (United States)

    Lu Hao; Ge Sun; Yongqiang Liu; Zhiqiu Gao; Junjie He; Tingting Shi; Bingjuan Wu

    2014-01-01

    China launched the ‘‘Returning Grazing Lands to Grasslands’’ project about a decade ago to restore severely degraded grasslands. Grassland grazing exclusion was one of the experimental approaches for achieving the grand goal. Here, we evaluate the long-term regional ecological effects of grassland grazing exclusion in the Xilingol region of Inner Mongolia, China. The...

  14. Traditional cattle grazing in a mosaic alkali landscape: effects on grassland biodiversity along a moisture gradient.

    Directory of Open Access Journals (Sweden)

    Péter Török

    Full Text Available Extensively managed pastures are of crucial importance in sustaining biodiversity both in local- and landscape-level. Thus, re-introduction of traditional grazing management is a crucial issue in grassland conservation actions worldwide. Traditional grazing with robust cattle breeds in low stocking rates is considered to be especially useful to mimic natural grazing regimes, but well documented case-studies are surprisingly rare on this topic. Our goal was to evaluate the effectiveness of traditional Hungarian Grey cattle grazing as a conservation action in a mosaic alkali landscape. We asked the following questions: (i How does cattle grazing affect species composition and diversity of the grasslands? (ii What are the effects of grazing on short-lived and perennial noxious species? (iii Are there distinct effects of grazing in dry-, mesophilous- and wet grassland types? Vegetation of fenced and grazed plots in a 200-ha sized habitat complex (secondary dry grasslands and pristine mesophilous- and wet alkali grasslands was sampled from 2006-2009 in East-Hungary. We found higher diversity scores in grazed plots compared to fenced ones in mesophilous- and wet grasslands. Higher cover of noxious species was typical in fenced plots compared to their grazed counterparts in the last year in every studied grassland type. We found an increasing effect of grazing from the dry- towards the wet grassland types. The year-to-year differences also followed similar pattern: the site-dependent effects were the lowest in the dry grassland and an increasing effect was detected along the moisture gradient. We found that extensive Hungarian Grey cattle grazing is an effective tool to suppress noxious species and to create a mosaic vegetation structure, which enables to maintain high species richness in the landscape. Hungarian Grey cattle can feed in open habitats along long moisture gradient, thus in highly mosaic landscapes this breed can be the most suitable

  15. Investigations on the effect of grazing intensity on the transfer of radionuclides to cow's milk

    International Nuclear Information System (INIS)

    Voigt, G.; Schotola, C.; Crout, N.M.J.; Absalom, J.

    1997-03-01

    For these investigations two farms were chosen. Farm A carries out a rotational grazing regime with 4 grazed pastures which is the more commonly used farm practice in Bavaria, farm B practises a continuous grazing regime with one grazed pasture only. In farm B a tenfold lower Cs-137 activity concentration was observed in milk though activity concentrations in soil and pasture grass were the same as that at farm A, indicating the same transfer rate soil-plant at both locations. It could be shown under normal agricultural conditions that with a higher grazing pressure lower activity concentrations in milk (in this case a factor of about 2 to 3) were obtained. Therefore changing stock density in combination with a continuous grazing regime on a given pasture after a major nuclear accident can be considered as a possible countermeasure which can be easily applied. Mainly to get more synchronised growth rates and a homogeneous distribution of radiocontamination plot experiments were performed to simulate the influence of grazing intensity. Under the experimental design used here no effect of grazing intensity on the transfer of radionuclides to vegetation could be found. Effects of grazing intensity as found for the farm experiment, therefore must be due to other sources than vegetation activities, and are presumably due to soil ingestion preventing uptake of soluble plant incorporated radiocaesium in the animal rumen. (orig./MG)

  16. Moderation is best: effects of grazing intensity on plant--flower visitor networks in Mediterranean communities.

    Science.gov (United States)

    Lazaro, Amparo; Tscheulin, Thomas; Devalez, Jelle; Nakas, Georgios; Stefanaki, Anastasia; Hanlidou, Effie; Petanidou, Theodora

    2016-04-01

    The structure of pollination networks is an important indicator of ecosystem stability and functioning. Livestock grazing is a frequent land use practice that directly affects the abundance and diversity of flowers and pollinators and, therefore, may indirectly affect the structure of pollination networks. We studied how grazing intensity affected the structure of plant-flower visitor networks along a wide range of grazing intensities by sheep and goats, using data from 11 Mediterranean plant-flower visitor communities from Lesvos Island, Greece. We hypothesized that intermediate grazing might result in higher diversity as predicted by the Intermediate Disturbance Hypothesis, which could in turn confer more stability to the networks. Indeed, we found that networks at intermediate grazing intensities were larger, more generalized, more modular, and contained more diverse and even interactions. Despite general responses at the network level, the number of interactions and selectiveness of particular flower visitor and plant taxa in the networks responded differently to grazing intensity, presumably as a consequence of variation in the abundance of different taxa with grazing. Our results highlight the benefit of maintaining moderate levels of livestock grazing by sheep and goats to preserve the complexity and biodiversity of the rich Mediterranean communities, which have a long history of grazing by these domestic animals.

  17. Grazing reduces soil greenhouse gas fluxes in global grasslands: a meta-analysis

    Science.gov (United States)

    Tang, Shiming; Tian, Dashuan; Niu, Shuli

    2017-04-01

    Grazing causes a worldwide degradation in grassland and likely alters soil greenhouse gas fluxes (GHGs). However, the general patterns of grazing-induced changes in grassland soil GHGs and the underlying mechanisms remain unclear. Thus, we synthesized 63 independent experiments in global grasslands that examined grazing impacts on soil GHGs (CO2, CH4 and N2O). We found that grazing with light or moderate intensity did not significantly influence soil GHGs, but consistently depressed them under heavy grazing, reducing CO2 emission by 10.55%, CH4 uptake by 19.24% and N2O emission by 28.04%. The reduction in soil CO2 was mainly due to decreased activity in roots and microbes (soil respiration per unit root and microbial biomass), which was suppressed by less water availability due to higher soil temperature induced by lower community cover under heavy grazing. N2O emission decreased with grazing-caused decline in soil total N. The inhibitory effect on methanotroph activities by water stress is responsible for the decreased CH4 uptake. Furthermore, grazing duration and precipitation also influenced the direction and magnitude of responses in GHGs fluxes. Overall, our results indicate that the reduction in soil CO2 and N2O emission under heavy grazing is partially compensated by the decrease in CH4 uptake, which is mainly regulated by variations in soil moisture.

  18. Effect of alternate and simultaneous grazing on endoparasite infection in sheep and cattle

    Directory of Open Access Journals (Sweden)

    Daiana Lima Brito

    Full Text Available This experiment was carried out on 8 ha of Panicum maximum cv. Tanzania pastures, with rotational grazing consisting of 7 days of occupation and 21 days of rest. Four treatments were evaluated: cattle grazing alone (BOV, sheep grazing alone (OVI, cattle and sheep grazing simultaneously (SIM and cattle grazing followed by sheep (alternate - ALT. Twenty heifers and 30 male Santa Inês lambs were used. Fecal egg count (FEC and fecal cultures were carried out. Blood was also collected to examine red and white cell series, total plasma protein (TPP, albumin and hemoglobin. FEC and estimated nematode pathogenicity index in sheep were lower in the SIM treatment. The Haemonchus spp. proportion was higher in isolated grazing systems. For sheep, mixed grazing was shown to reduce endoparasite infection, and SIM was better than ALT. For cattle, no difference between grazing systems was seen. Therefore, simultaneous grazing (sheep and cattle may be a tool for reducing the need for anthelmintic treatments in sheep.

  19. [Effect of grazing on the temperature sensitivity of soil respiration in Hulunber meadow steppe].

    Science.gov (United States)

    Wang, Xu; Yan, Rui-Rui; Deng, Yu; Yan, Yu-Chun; Xin, Xiao-Ping

    2014-05-01

    Grazing is one of the major human activities which lead to disturbance on grassland ecosystem. Quantifying the effect of grazing on the temperature sensitivity of soil respiration ( Q10 ) is essential for accurate assessment of carbon budget in grassland ecosystem. This study was conducted on the grazing gradients experiment platform in Hulunber meadow steppe. Soil respiration was measured by a dynamic closed chamber method (equipped with Li 6400-09, Lincoln, NE, USA) during the growing season in 2011. The results showed that soil respiration had significant seasonal variation and the maximum occurred in July, which was mainly dominated by temperature. The order of average soil respiration during the period from May to September in different treatments was G1 > GO > G2 > G3 > G4 > G5. Comparing with non-grazing treatment, Q10 under heavy grazing conditions (0. 92 Au hm-2) was reduced by about 10% , and was increased a little under light grazing conditions (0. 23 Au hm-2). There was a significant negative correlation between Q15 and grazing intensities (r = 0. 944, P temperature sensitivity of soil respiration to different degrees. The Q10 under different grazing gradients had positive linear regression relationships with aboveground biomass, belowground biomass, soil organic carbon and soil moisture. They could explain 71.0%-85.2% variations of Q10. It was suggested that the variation of Q10 was mainly determined by the change of biotic and environmental factors due to grazing.

  20. Temporal profiles of vegetation indices for characterizing grazing intensity on natural grasslands in Pampa biome

    Directory of Open Access Journals (Sweden)

    Amanda Heemann Junges

    2016-08-01

    Full Text Available ABSTRACT The Pampa biome is an important ecosystem in Brazil that is highly relevant to livestock production. The objective of this study was to analyze the potential use of vegetation indices to discriminate grazing intensities on natural grasslands in the Pampa biome. Moderate Resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI and Enhanced Vegetation Index (EVI images from Jan to Dec, 2000 to 2013 series, were analyzed for natural grassland experimental units managed under high (forage allowance of 5 ± 2 % live weight – LW, moderate (13 ± 5 % LW and low grazing intensity (19 ± 7 % LW. Regardless of intensity, the temporal profiles showed lower NDVI and EVI during winter, increased values in spring because of summer species regrowth, slightly decreased values in summer, especially in years when there is a water deficit, and increased values in the fall associated with the beginning of winter forage development. The average temporal profiles of moderate grazing intensity exhibited greater vegetation index values compared with low and high grazing intensities. The temporal profiles of less vegetation index were associated with lower green biomass accumulation caused by the negative impact of stocking rates on the leaf area index under high grazing intensity and a floristic composition with a predominance of tussocks under low grazing intensity. Vegetation indices can be used for distinguishing moderate grazing intensity from low and high intensities. The average EVI values can discriminate moderate grazing intensity during any season, and the NDVI values can discriminate moderate grazing intensity during spring and winter.

  1. Side-pumped Nd:YVO4 cw laser with grazing-incidence small angle configuration

    International Nuclear Information System (INIS)

    Camargo, Fabiola de Almeida

    2006-01-01

    Within the existing variety of laser cavity geometries and gain materials there is one combination that is particularly interesting because of its reduced complexity and high efficiency: the edge-pumped slab-laser using grazing-incidence geometry and a gain media with a very high pump absorption cross-section. In this work we studied a diode side-pumped Nd:YVO 4 cw laser. We describe a single and a multiple bounce laser configurations. We demonstrate 22 W of multimode output power for 35 watts of pump power with a single pass through the gain media. A high optical-to-optical conversion efficiency of 63% and a slope efficiency of 74% with a very compact and simple Nd:YVO 4 cavity that uses joint stability zones was achieved. The beam quality was M 2 = 26 x 11 in the horizontal and vertical direction, respectively. With a double pass configuration we achieved 17 watts with a better beam quality of M 2 = 3,4 x 3,7, in the horizontal and vertical direction, respectively. (author)

  2. Annual methane budgets of sheep grazing systems were regulated by grazing intensities in the temperate continental steppe: A two-year case study

    Science.gov (United States)

    Ma, Lei; Zhong, Mengying; Zhu, Yuhao; Yang, Helong; Johnson, Douglas A.; Rong, Yuping

    2018-02-01

    Methane (CH4) emission from animal husbandry accounts for a large percentage of anthropogenic contributions to CH4 emissions. Fully understanding of grazing management effects on the CH4 budget is essential for mitigating CH4 emissions in the temperate grazing steppe systems. Annual CH4 budgets for the sheep grazed steppes at various grazing intensities, un-grazing (UG, 0 sheep ha-1year-1), defer grazing (DG, 1.0 sheep ha-1 year-1), moderate grazing (MG, 1.43 sheep ha-1year-1), and heavy grazing (HG, 2.43 sheep ha-1year-1) were assessed across 2012-2014 in the agro-pastoral region of northern China. Annual soil CH4 uptake averaged across 2012-2014 were 1.1 ± 0.1, 2.4 ± 0.2, 2.2 ± 0.2, and 1.3 ± 0.1 kg CH4-C ha-1 for UG, DG (only 2013-2014), MG and HG sites. Non-growing season CH4 uptake comprised 50.0 ± 4.3% of annual CH4 uptake in 2012-2013 and 37.7 ± 2.0% in 2013-2014. DG and MG significantly promoted annual soil CH4 uptake (P 0.05). Bell-shaped relationship was presented between stocking rates and soil CH4 uptake (r2 = 0.59, P budgets for the grazed grasslands were -1.1 ± 0.1, 5.7 ± 0.6, 11.5 ± 1.5 and 15.5 ± 1.3 kg CH4-C ha-1 year-1 in UG, DG (only 2013-2014), MG and HG across 2012-2014. Soil CH4 uptake could offset 29.7 ± 5.6, 15.9 ± 4.3 and 6.8 ± 1.0% of total annual CH4 emissions from sheep, sheepfold and faeces in DG, MG, and HG. All grazed steppes are sources for atmospheric CH4 and the magnitude is regulated by grazing intensities. Sheep CH4 emissions for 1-g liveweight gain were 0.21, 0.32 and 0.37 g CH4-C in DG, MG and HG, respectively. DG is the recommended grazing management in this region to achieve greater herbage mass, higher sheep performance and lower CH4 emissions simultaneously.

  3. Using digital photography to examine grazing in montane meadows

    Science.gov (United States)

    McIlroy, Susan K.; Allen-Diaz, Barbara H.; Berg, Alexander C.

    2011-01-01

    Cattle (Bos taurus) numbers on national forests are allocated based on allotment grazing capacity, but spatial patterns of timing and density at smaller scales are difficult to assess. However, it is often in meadows or riparian areas that grazing may affect hydrology, biodiversity, and other important ecosystem characteristics. To explore real-time animal presence in montane meadows we distributed 18 digital cameras across nine sites in the Sierra National Forest, California. Our objectives were to document seasonal and diurnal presence of both cattle and mule deer (Odocoileus hemionus), identify the effects of three fencing treatments on animal distribution, and test digital photography as a tool for documenting cattle presence. We recorded 409 399 images during daylight hours for two grazing seasons, and we identified 5 084 and 24 482 cattle "marks" (instances of animal occurrence) in 2006 and 2007, respectively. Deer presence was much lower, with 331 marks in 2006 and 598 in 2007. Morning cattle presence was highest before 0800 hours both years (13.7% and 15.4% of total marks for 2006 and 2007, respectively). Marks decreased until 1100 hours and then increased around 1400 hours and remained relatively stable until 1900 hours. Marks then rose precipitously, with >20% of total marks recorded after 1900 hours both years. Deer presence was less than 10% per hour until 1800 hours, when >20% of total marks were recorded after this time both years. Among treatments, cattle marks were highest outside fences at partially fenced meadows, and deer were highest within completely fenced meadows. Our experience suggests that cameras are not viable tools for meadow monitoring due to variation captured within meadows and the time and effort involved in image processing and review.

  4. Ionization by ion impact at grazing incidence on insulator surface

    CERN Document Server

    Martiarena, M L

    2003-01-01

    We have calculated the energy distribution of electrons produced by ionization of the ionic crystal electrons in grazing fast ion-insulator surface collision. The ionized electrons originate in the 2p F sup - orbital. We observe that the binary peak appears as a double change in the slope of the spectra, in the high energy region. The form of the peak is determined by the initial electron distribution and its position will be affected by the binding energy of the 2p F sup - electron in the crystal. This BEP in insulator surfaces will appear slightly shifted to the low energy side with respect the ion-atom one.

  5. Grazing studies on selected plutonium-contaminated areas in Nevada

    International Nuclear Information System (INIS)

    Smith, D.D.

    1975-01-01

    A grazing study in Area 13 of the Nevada Test Site (NTS) was initiated in May of 1973 and is proceeding on schedule. The accomplishments to date in this study include the quarterly collection of ingesta samples from fistulated steers, the quarterly sacrifice and sampling of a goat, the semiannual sacrifice and sampling of selected adult and young cattle, and the quarterly determination of digestibility of range plants. Dietary habits were tabulated with favored plant species being: two grasses, Indian ricegrass and galleta; two shrubs, winter fat and four-winged saltbush; and one forb, Russian thistle. Other analytical data are not yet available. (auth)

  6. Grazing incidence XAFS under non-specular conditions

    International Nuclear Information System (INIS)

    Keil, Patrick; Luetzenkirchen-Hecht, Dirk; Frahm, Ronald

    2005-01-01

    The extended X-ray absorption fine structure technique (EXAFS) in the reflection mode under specular and non-specular conditions was used for the ex situ investigation of a sputter-deposited thin copper film on a float glass substrate. We prove the existence of a fine structure similar to EXAFS, which can be observed in the region of diffusely scattered intensities. It is shown that this new technique is surface sensitive for grazing angles above the critical angle of total reflection and an even higher surface sensitivity with respect to conventional reflection mode EXAFS can be achieved

  7. Review of grazing studies on plutonium-contaminated rangelands

    International Nuclear Information System (INIS)

    Smith, D.D.

    1977-01-01

    Literature is cited that has provided data on tissue actinide concentrations in grazing animals when the actinide dosages resulted from artificial administration or from periodic exposure. Only one long-term study is known where a reproducing beef herd was restricted to a plutonium-contaminated environment. Highlights of this study that are reviewed and discussed include: relationship of ingesta concentrations to food habits; tissue concentration related to length of exposure and level of exposure; and the concentration range in various tissues. Emphasis is given to the gonadal concentration which is approximately 25 times that of muscle and blood. Future study plans are also discussed

  8. Providing plastic zone extrusion

    Science.gov (United States)

    Manchiraju, Venkata Kiran; Feng, Zhili; David, Stan A.; Yu, Zhenzhen

    2017-04-11

    Plastic zone extrusion may be provided. First, a compressor may generate frictional heat in stock to place the stock in a plastic zone of the stock. Then, a conveyer may receive the stock in its plastic zone from the compressor and transport the stock in its plastic zone from the compressor. Next, a die may receive the stock in its plastic zone from the conveyer and extrude the stock to form a wire.

  9. Grazing intensity differentially regulates ANPP response to precipitation in North American semiarid grasslands.

    Science.gov (United States)

    Irisarri, J Gonzalo N; Derner, Justin D; Porensky, Lauren M; Augustine, David J; Reeves, Justin L; Mueller, Kevin E

    2016-07-01

    Grazing intensity elicits changes in the composition of plant functional groups in both shortgrass steppe (SGS) and northern mixed-grass prairie (NMP) in North America. How these grazing intensity-induced changes control aboveground net primary production (ANPP) responses to precipitation remains a central open question, especially in light of predicted climate changes. Here, we evaluated effects of four levels (none, light, moderate, and heavy) of long-term (>30 yr) grazing intensity in SGS and NMP on: (1) ANPP; (2) precipitation-use efficiency (PUE, ANPP : precipitation); and (3) precipitation marginal response (PMR; slope of a linear regression model between ANPP and precipitation). We advance prior work by examining: (1) the consequences of a range of grazing intensities (more grazed vs. ungrazed); and (2) how grazing-induced changes in ANPP and PUE are related both to shifts in functional group composition and physiological responses within each functional group. Spring (April-June) precipitation, the primary determinant of ANPP, was only 12% higher in NMP than in SGS, yet ANPP and PUE were 25% higher. Doubling grazing intensity in SGS and nearly doubling it in NMP reduced ANPP and PUE by only 24% and 33%, respectively. Increased grazing intensity reduced C 3 graminoid biomass and increased C 4 grass biomass in both grasslands. Functional group shifts affected PUE through biomass reductions, as PUE was positively associated with the relative abundance of C 3 species and negatively with C 4 species across both grasslands. At the community level, PMR was similar between grasslands and unaffected by grazing intensity. However, PMR of C 3 graminoids in SGS was eightfold higher in the ungrazed treatment than under any grazed level. In NMP, PMR of C 3 graminoids was only reduced under heavy grazing intensity. Knowing the ecological consequences of grazing intensity provides valuable information for mitigation and adaptation strategies in response to predicted

  10. Synergistic Interactions within a Multispecies Biofilm Enhance Individual Species Protection against Grazing by a Pelagic Protozoan

    Directory of Open Access Journals (Sweden)

    Prem K. Raghupathi

    2018-01-01

    Full Text Available Biofilm formation has been shown to confer protection against grazing, but little information is available on the effect of grazing on biofilm formation and protection in multispecies consortia. With most biofilms in nature being composed of multiple bacterial species, the interactions and dynamics of a multispecies bacterial biofilm subject to grazing by a pelagic protozoan predator were investigated. To this end, a mono and multispecies biofilms of four bacterial soil isolates, namely Xanthomonas retroflexus, Stenotrophomonas rhizophila, Microbacterium oxydans and Paenibacillus amylolyticus, were constructed and subjected to grazing by the ciliate Tetrahymena pyriformis. In monocultures, grazing strongly reduced planktonic cell numbers in P. amylolyticus and S. rhizophila and also X. retroflexus. At the same time, cell numbers in the underlying biofilms increased in S. rhizophila and X. retroflexus, but not in P. amylolyticus. This may be due to the fact that while grazing enhanced biofilm formation in the former two species, no biofilm was formed by P. amylolyticus in monoculture, either with or without grazing. In four-species biofilms, biofilm formation was higher than in the best monoculture, a strong biodiversity effect that was even more pronounced in the presence of grazing. While cell numbers of X. retroflexus, S. rhizophila, and P. amylolyticus in the planktonic fraction were greatly reduced in the presence of grazers, cell numbers of all three species strongly increased in the biofilm. Our results show that synergistic interactions between the four-species were important to induce biofilm formation, and suggest that bacterial members that produce more biofilm when exposed to the grazer not only protect themselves but also supported other members which are sensitive to grazing, thereby providing a “shared grazing protection” within the four-species biofilm model. Hence, complex interactions shape the dynamics of the biofilm and

  11. FORAGES AND PASTURES SYMPOSIUM: Improving soil health and productivity on grasslands using managed grazing of livestock.

    Science.gov (United States)

    Russell, J R; Bisinger, J J

    2015-06-01

    Beyond grazing, managed grasslands provide ecological services that may offer economic incentives for multifunctional use. Increasing biodiversity of plant communities may maximize net primary production by optimizing utilization of available light, water, and nutrient resources; enhance production stability in response to climatic stress; reduce invasion of exotic species; increase soil OM; reduce nutrient leaching or loading in surface runoff; and provide wildlife habitat. Strategically managed grazing may increase biodiversity of cool-season pastures by creating disturbance in plant communities through herbivory, treading, nutrient cycling, and plant seed dispersal. Soil OM will increase carbon and nutrient sequestration and water-holding capacity of soils and is greater in grazed pastures than nongrazed grasslands or land used for row crop or hay production. However, results of studies evaluating the effects of different grazing management systems on soil OM are limited and inconsistent. Although roots and organic residues of pasture forages create soil macropores that reduce soil compaction, grazing has increased soil bulk density or penetration resistance regardless of stocking rates or systems. But the effects of the duration of grazing and rest periods on soil compaction need further evaluation. Because vegetative cover dissipates the energy of falling raindrops and plant stems and tillers reduce the rate of surface water flow, managing grazing to maintain adequate vegetative cover will minimize the effects of treading on water infiltration in both upland and riparian locations. Through increased diversity of the plant community with alterations of habitat structure, grazing systems can be developed that enhance habitat for wildlife and insect pollinators. Although grazing management may enhance the ecological services provided by grasslands, environmental responses are controlled by variations in climate, soil, landscape position, and plant community

  12. A revised method for assessing veld condition. | N.M. | African ...

    African Journals Online (AJOL)

    These and additional, subjectively assessed parameters of the veld being evaluated, are compared to those of the benchmark - a site chosen to represent the agro-ecological ideal for the area. These data are then used to estimate the current grazing capacity. The method has been adapted to bushveld sites, where an ...

  13. Design and development of grazing incidence x-ray mirrors

    Science.gov (United States)

    Zuo, Fuchang; Mei, Zhiwu; Ma, Tao; Deng, Loulou; Shi, Yongqiang; Li, Liansheng

    2016-01-01

    X-ray pulsar navigation has attracted extensive attentions from academy and engineering domains. The navigation accuracy is can be enhanced through design of X-ray mirrors to focus X-rays to a small detector. The Wolter-I optics, originally proposed based on a paraboloid mirror and a hyperboloid mirror for X-ray imaging, has long been widely developed and employed in X-ray observatory. Some differences, however, remain in the requirements on optics between astronomical X-ray observation and pulsar navigation. The simplified Wolter-I optics, providing single reflection by a paraboloid mirror, is more suitable for pulsar navigation. In this paper, therefore, the grazing incidence X-ray mirror was designed further based on our previous work, with focus on the reflectivity, effective area, angular resolution and baffles. To evaluate the performance of the manufactured mirror, the surface roughness and reflectivity were tested. The test results show that the grazing incidence mirror meets the design specifications. On the basis of this, the reflectivity of the mirror in the working bandwidth was extrapolated to evaluate the focusing ability of the mirror when it works together with the detector. The purpose of our current work to design and develop a prototype mirror was realized. It can lay a foundation and provide guidance for the development of multilayer nested X-ray mirror with larger effective area.

  14. Degradation of abamectin and doramectin on sheep grazed pasture.

    Science.gov (United States)

    Erzen, Nevenka Kozuh; Kolar, Lucija; Flajs, Vesna Cerkvenik; Kuzner, Jernej; Marc, Irena; Pogacnik, Milan

    2005-08-01

    Avermectins are widely used veterinary medicines. They bind strongly to faeces in their non-metabolized form and their half-life in faeces depends on field conditions. There are conflicting data regarding the behaviour of avermectins in the environment. Therefore, we investigated the degradation of abamectin and doramectin on sheep grazed pasture under field conditions in soil, soil-faeces and faeces samples from day 6 to day 70 (abamectin) or to day 50 (doramectin) after sheep treatment. Field conditions were recorded periodically during the experiment. Degradation of abamectin in sheep faeces and in soil-faeces was observed until day 60, with small amounts present in faeces until 70 days post treatment. Because the concentration of abamectin residues in soil was very low on day 6 after treatment, further significant degradation could not be measured. The concentration of doramectin in all analysed matrices decreased rapidly until day 50. It can be concluded that high concentrations of both avermectins were present during the first 20 days after treatment and that field conditions have an important role in degradation of avermectins on grazed pasture of treated animals. Clear identification of the consequences of avermectin exposure and the period of the greatest environmental risk will require further investigations.

  15. Reducing supplementation frequency for Nellore beef steers grazing tropical pastures

    Directory of Open Access Journals (Sweden)

    Roberta Carrilho Canesin

    2014-04-01

    Full Text Available Reduced supplementation frequency is a broadly applied management practice. Ruminants consuming low quality forages/pastures, supplemented less than once daily are able to maintain body weight gain (BWG, efficiency of use of dry matter, nitrogen and other nutrients, as compared with animals supplemented once daily. We evaluated the feeding behavior, dry matter intake (DMI, dry matter and organic matter digestibility (DMD and OMD, BWG, Longissimus muscle area and backfat depth of Nellore steers raised on Brachiaria brizantha cv. Marandu pastures during the dry season, with different supplementation patterns. Thirty six animals (338 ± 40.7 kg were distributed over nine paddocks according to a completely randomized design. Treatments were based on supplementation frequency: once daily (OD, once daily except Saturdays and Sundays (SS, or on alternate days (AD, at 1.0 %, 1.4 % and 2.0 % BW, respectively. Average total DMI accounted for 1.6 % BW day-1, with no effect of supplementation frequency. Supplementation frequency had no effect on BWG or grazing time during the day. There was no difference in Longissimus muscle area animals supplemented daily, SS and AD. The backfat depth was thinner in animals supplemented AD, but even in this case, it was within the standards considered satisfactory for a finishing steer. Reducing supplementation frequency seems a good option to lower labor costs without affecting feed efficiency or carcass quality in beef cattle grazing tropical pastures.

  16. Governing Grazing and Mobility in the Samburu Lowlands, Kenya

    Directory of Open Access Journals (Sweden)

    Annemiek Pas

    2018-03-01

    Full Text Available Pastoral mobility is seen as the most effective strategy to make use of constantly shifting resources. However, mobile pastoralism as a highly-valued strategy to manage grazing areas and exploit resource variability is becoming more complex, due to recurrent droughts, loss of forage, government-led settlement schemes, and enclosure of land for community conservation, among other reasons. Yet knowledge of how Samburu pastoralists perceive these changes, and govern and innovate in their mobility patterns and resource use, has received limited attention. This paper seeks to understand how Samburu pastoralists in the drylands of northern Kenya use and govern natural resources, how livestock grazing and mobility is planned for, and how boundaries and territory are constructed and performed both within and beyond the context of (nongovernmental projects. Fieldwork for this paper was conducted in Sesia, Samburu East, and consisted of interviews, focus group discussions, and participatory observation. Findings show that livestock mobility involves longer periods and more complex distances due to a shrinking resource base and new rules of access. Although access was previously generated based on the value of reciprocity, the creation of new forms of resource management results in conditional processes of inclusion and exclusion. Policy and project implementation has historically been driven by the imperative to secure land tenure and improve pasture in bounded areas. Opportunities to support institutions that promote mobility have been given insufficient attention.

  17. Grazing in juvenile stages of some estuarine calanoid copepods

    Energy Technology Data Exchange (ETDEWEB)

    Allan, J.D. (Univ. of Maryland, College Park); Richman, S.; Heinle, D.R.; Huff, R.

    1977-01-01

    The grazing of juvenile Eurytemora affinis, Acartia tonsa and A. clausi from the Chesapeak Bay (USA) was investigated using natural particle distributions and freshly caught copepods, live-sorted into stages. Data were analyzed in greater than or equal to 110 size channels using an electronic particle counter, and filtering rates (FR) were estimated based on total particle removal (mean FR), and that for each size channel (giving maximum FR). Mean and maximum filtering rates increased from NVI (Nauplius Stage VI) through CVI (Copepodid Stage VI). Both rates plotted against weight satisfied a log fit best for A. tonsa, and a linear fit best for E. affinis. Results for A. tonsa were quite variable, apparently due to differences in temperature between experiments. Particle selection was investigated from the shape of the filtering rate curve over particle size. We define selective feeding by a FR curve which is higher in some size categories, and non-selective feeding by a flat FR curve. The general pattern was one of selective feeding in all copepodid stages of the three calanoid copepods investigated. E. affinis tended to ''track'' biomass peaks while Acartia spp.'s feeding was more variable, including feeding in size ranges of greater particle concentration, on larger particles, and in other size categories as well. Experiments with nauplii tended to yield flat FR curves, and it may be that selective grazing appears with, or is greatly accentuated by, metamorphosis from NVI to CI (Copepodid Stage I).

  18. Effect of the Silica Content of Diatoms on Protozoan Grazing

    Directory of Open Access Journals (Sweden)

    Shuwen Zhang

    2017-06-01

    Full Text Available This study examined the effect that silica content in diatom cells has on the behavior of protists. The diatoms Thalassiosira weissflogii and T. pseudonana were cultured in high or low light conditions to achieve low and high silica contents, respectively. These cells were then fed to a heterotrophic dinoflagellate Noctiluca scintillans and a ciliate Euplotes sp. in single and mixed diet experiments. Our results showed that in general, N. scintillans and Euplotes sp. both preferentially ingested the diatoms with a low silica content rather than those with a high silica content. However, Euplotes sp. seemed to be less influenced by the silica content than was N. scintillans. In the latter case, the clearance and ingestion rate of the low silica diatoms were significantly higher, both in the short (6-h and long (1-d duration grazing experiments. Our results also showed that N. scintillans required more time to digest the high silica-containing cells. As the high silica diatoms are harder to digest, this might explain why N. scintillans exhibits a strong preference for the low silica prey. Thus, the presence of high silica diatoms might limit the ability of the dinoflagellate to feed. Our findings suggest that the silica content of diatoms affects their palatability and digestibility and, consequently, the grazing activity and selectivity of protozoan grazers.

  19. Subacute ruminal acidosis (SARA) in grazing Irish dairy cows.

    Science.gov (United States)

    O'Grady, Luke; Doherty, Michael L; Mulligan, Finbar J

    2008-04-01

    Subacute ruminal acidosis (SARA) is a significant production disease of dairy cattle. Previous concerns have been raised over the occurrence of SARA in pasture-fed dairy cattle and the potential consequences of laminitis and lameness. Highly digestible perennial rye grass contains high concentrations of rapidly fermentable carbohydrate and low concentrations of physical effective fibre that may result in SARA. This study conducted a point prevalence survey of rumen health status in grazing Irish dairy cattle fed predominantly perennial rye grass-based pasture. The survey assessed rumen fluid, animal health status, milk production data and pasture composition. A total of 144 cows between 80 and 150 days in milk were sampled on 12 farms. Eleven percent of cows were classified as affected with SARA (pH 5.8). The study showed that low rumen pH is prevalent in grazing Irish dairy cattle consuming perennial rye grass-based pasture and raises concerns regarding effective pasture utilisation and possible consequences for animal health.

  20. The Marshall Grazing Incidence X-ray Spectrometer

    Science.gov (United States)

    Kobayashi, Ken; Winebarger, Amy R.; Savage, Sabrina; Champey, Patrick; Cheimets, Peter N.; Hertz, Edward; Bruccoleri, Alexander R.; Golub, Leon; Ramsey, Brian; Ranganathan, Jaganathan; Marquez, Vanessa; Allured, Ryan; Parker, Theodore; Heilmann, Ralf K.; Schattenburg, Mark L.

    2017-08-01

    The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument designed to obtain spatially resolved soft X-ray spectra of the solar atmosphere in the 6-24 Å (0.5-2.0 keV) range. The instrument consists of a single shell Wolter Type-I telescope, a slit, and a spectrometer comprising a matched pair of grazing incidence parabolic mirrors and a planar varied-line space diffraction grating. The instrument is designed to achieve a 50 mÅ spectral resolution and 5 arcsecond spatial resolution along a +/-4-arcminute long slit, and launch is planned for 2019. We report on the status and our approaches for fabrication and alignment for this novel optical system. The telescope and spectrometer mirrors are replicated nickel shells, and are currently being fabricated at the NASA Marshall Space Flight Center. The diffraction grating is currently under development by the Massachusetts Institute of Technology (MIT); because of the strong line spacing variation across the grating, it will be fabricated through e-beam lithography.

  1. MARKETTING SITUATIONS OF LIVESTOCK FEEDS IN WELMERA AND DENDI WEREDA OF WEST SHOA ZONE, ETHIOPIA

    OpenAIRE

    R. MESFIN; A. TESFAYE

    2012-01-01

    The paper explains the status of livestock feed resources and market situations in Welmera and Dendi weredas of West Shoa Zone, Ethiopia. The objective of the survey was to assess the potentials and constraints of feed resources and related marketing practices and suggest appropriate intervention options to overcome the constraints. Majority (76%) of the interviewed farmers have faced shortage of livestock feeds. The diminishing trend of grazing land from time to time, roughage, concentrate f...

  2. Illegal grazing in the Borgu sector of Kainji Lake National Park, Nigeria

    African Journals Online (AJOL)

    Effects of illegal grazing in the Borgu sector of Kainji Lake National Park was studied by identifying the level of utilization of some plant species in the park by livestock and determining the impact of trampling during grazing on the vegetation cover of the park. Two areas were chosen systematically for the study. The two ...

  3. Contrasting responses of insect communities to grazing intensity in lowland heathlands

    NARCIS (Netherlands)

    Wallis de Vries, Michiel; Noordijk, Jinze; Colijn, Ed O.; Smit, John T.; Veling, Kars

    2016-01-01

    Grazing at low stocking rates is often recommended for the preservation of the characteristic biodiversity of open landscapes. However, the fine-tuning of grazing management still lacks a good evidence base. This is particularly true for insect communities, as available evidence indicates that

  4. Using NDVI to estimate carbon fluxes from small rotationally grazed pastures

    Science.gov (United States)

    Satellite-based Normalized Difference Vegetation Index (NDVI) data have been extensively used for estimating gross primary productivity (GPP) and yield of grazing lands throughout the world. However, the usefulness of satellite-based images for monitoring rotationally-grazed pastures in the northea...

  5. Some effects of winter grazing of Dohne sour veld | PF | African ...

    African Journals Online (AJOL)

    The utilisation of spared sour veld poses practical problems. As a result of the development of high level protein or nitrogen supplements it has however become possible to efficiently graze spared veld. Results of experiments during three winters where spared sour veld was grazed off either by sheep or by cattle are given.

  6. Livestock Grazing Intensities and Soil Deterioration in the Semi-Arid ...

    African Journals Online (AJOL)

    ... from the moderately grazed site to soils close to the watering points (that is the heavily grazed site) via animal dung. The adoption of soil management techniques to conserve and enhance soil organic matter and nutrients appears crucial to the long-term productivity of the rangelands. Discovery and Innovation Vol. 13 no.

  7. Analyzing changes in productivity and carrying capacity under planned grazing in Madiama Commune, Mali (West Africa)

    OpenAIRE

    Badini, Oumar; Stockle, C.; Jones, J.; Bostick, M.; Kodio, Amadou; Keita, Moussa

    2004-01-01

    This presentation addresses the problems of overgrazing and degradation of pasture land. Policies that can increase pasture productivity and improve the carrying capacity and soil quality of pastures are assessed using CropSyst simulation modeling. Optimal grazing intensity and intervals (rotational grazing) are evaluated and discussed, based on model analysis from the Madiama commune in Mali (West Africa). ME (Management Entity)

  8. Physical impact of sheep grazing on arid Karoo subshrub/grass ...

    African Journals Online (AJOL)

    Grazing levels and rotational schemes need to be tailored to each individual farm or pasture, and more studies are needed on the resilience of rangelands and on separating the effects of grazing and climate. The direct short-term impact of three rates of stocking (4, 8 and 16 Small Stock Units-SSU/ha) was quantified in ...

  9. Long-term effects of grazing management and buffer strips on soil erosion from pastures

    Science.gov (United States)

    High grazing pressure can lead to soil erosion in pastures by compacting soil and increasing runoff and sediment delivery to waterways. Limited information exists on the effects of grazing management and best management practices (BMPs), such as buffer strips, on soil erosion from pastures. The obje...

  10. Plant community responses to livestock grazing: An assessment of alternative management practices in a semiarid grassland

    Science.gov (United States)

    Matthew R. Loeser; Thomas D. Sisk; Timothy E. Crews

    2001-01-01

    One of the most prevalent land-use practices in the American Southwest, and one of the most contentious issues among land-use policymakers, is the grazing of domestic livestock. In an effort to contribute scientific understanding to this debate, we have designed experiments comparing the effects of alternative grazing regimes on plant communities. In a semiarid...

  11. Grazing of Cymbopogon-Themeda veld in the dormant period | G ...

    African Journals Online (AJOL)

    The influence on summer-rested veld of grazing during autumn, winter and early summer was studied in Cymbopogon-Themeda veld at Potchefstroom. Continuous grazing throughout the winter period, and even during early summer, severely damaged species such as Themeda triandra, Eragrostis curvula and Digitaria ...

  12. An economic solution to the grazing management dilemma | PdV ...

    African Journals Online (AJOL)

    Hypothetical data relating stocking rate to daily animal livemass gain on different types of pasture under continuous grazing or one of two forms of rotational grazing have been employed to determine the net return on investment over a range of stocking rates. By determining the stocking rate at which this function reaches its ...

  13. Effects of livestock grazing on neotropical migratory landbirds in western North America

    Science.gov (United States)

    Carl E. Bock; Victoria A. Saab; Terrell D. Rich; David S. Dobkin

    1993-01-01

    Livestock grazing is a widespread and important influence on neotropical migratory birds in four major ecosystems in western North America: grasslands of the Great Plains and Southwest, riparian woodlands, Intermountain shrubsteppe, and open coniferous forests. We have reviewed available literature on avian responses to grazing in these habitats. Among 35 plains...

  14. Livestock Grazing, Golden Trout, and Streams in the Golden Trout Wilderness, California: Impacts and Management Implications

    Science.gov (United States)

    R. Knapp; K. Matthews

    1996-01-01

    Impacts of livestock grazing on California golden trout Oncorhynchus rnykiss aguabonita and their habitat were studied inside and outside of livestock exclosures in the Golden Trout Wilderness, California. In two consecutive years, the majority of stream physical characteristics showed large differences between grazed and ungrazed areas, and the directions of these...

  15. Effects of grazing intensity on small mammal population ecology in wet meadows

    DEFF Research Database (Denmark)

    Schmidt, Niels Martin; Olsen, Henrik; Bildsøe, Mogens

    2005-01-01

    Livestock grazing is common management practice in wet grasslands. However, knowledge of its effects on small mammals is limited. We studied the influence of grazing intensity on small mammals in general and field voles Microtus agrestis in particular in two Danish wet meadows, 1998-2000. Generally...

  16. Habitat preference of geese is affected by livestock grazing : Seasonal variation in an experimental field evaluation

    NARCIS (Netherlands)

    Mandema, Freek S.; Tinbergen, Joost M.; Stahl, Julia; Esselink, Peter; Bakker, Jan P.

    The number of staging geese in northwestern Europe has increased dramatically. Growing goose numbers put strong grazing pressure on agricultural pastures. Damage to agricultural land may be mitigated by managing nature reserves in order to optimally accommodate large numbers of grazing geese.

  17. Effect of grazing cycle on milk production of cows on kikuyu pasture

    African Journals Online (AJOL)

    different rotational grazing cycle lengths on milk production, body weight, herbage intake, digestibility and grazing .... Dry cows were included in the treatments to maintain the normal herd struc- ture and a constant stocking rate of two Friesian cows (550 kg. S. Afr. Tydskr. Veek., 1995 ..... as were consumed in other cycles.

  18. Root Characteristics of Perennial Warm-Season Grasslands Managed for Grazing and Biomass Production

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2013-07-01

    Full Text Available Minirhizotrons were used to study root growth characteristics in recently established fields dominated by perennial C4-grasses that were managed either for cattle grazing or biomass production for bioenergy in Virginia, USA. Measurements over a 13-month period showed that grazing resulted in smaller total root volumes and root diameters. Under biomass management, root volume was 40% higher (49 vs. 35 mm3 and diameters were 20% larger (0.29 vs. 0.24 mm compared to grazing. While total root length did not differ between grazed and biomass treatments, root distribution was shallower under grazed areas, with 50% of total root length in the top 7 cm of soil, compared to 41% in ungrazed exclosures. These changes (i.e., longer roots and greater root volume in the top 10 cm of soil under grazing but the reverse at 17–28 cm soil depths were likely caused by a shift in plant species composition as grazing reduced C4 grass biomass and allowed invasion of annual unsown species. The data suggest that management of perennial C4 grasslands for either grazing or biomass production can affect root growth in different ways and this, in turn, may have implications for the subsequent carbon sequestration potential of these grasslands.

  19. The effect of seasonal grazing on the infiltration capacity of soils in a ...

    African Journals Online (AJOL)

    The infiltration measurements were determined by means of a flood type concentric ring infiltrometer. The results showed that grazing during any one of the seasons reduced the infiltration capacity of the soils. The detrimental effects of summer and autumn grazing were, however, larger titan those of winter and spring ...

  20. Cattle grazing and fish recovery on US federal lands: can social-ecological systems science help?

    Science.gov (United States)

    Susan Charnley; Hannah Gosnell; Kendra L Wendel; Mary M Rowland; Michael J Wisdom

    2018-01-01

    In the western US, grazing management on federal lands containing habitat for fish species listed under the US Endangered Species Act (ESA) has sparked social conflict and litigation for decades. To date, the problem has been addressed through a top-down environmental governance system, but rangeland managers and grazing permittees now believe there is a need for more...

  1. The effect of past grazing intensity on the vigour of Themeda triandra ...

    African Journals Online (AJOL)

    , during a full season's rest, of tufts of Themeda triandra Forssk. and Tristachya leucothrix Nees, which (1) had not been grazed, (2) had been leniently, or (3) had been severely grazed during the previous two growing seasons. A sequential ...

  2. Representation of uncertainty and integration of PGIS-based grazing intensity maps using evidential belief functions

    NARCIS (Netherlands)

    Bemigisha, J.; Carranza, J.; Skidmore, A.K.; McCall, M.; Polce, C.; Prins, H.H.T.

    2009-01-01

    In a project to classify livestock grazing intensity using participatory geographic information systems (PGIS), we encountered the problem of how to synthesize PGIS-based maps of livestock grazing intensity that were prepared separately by local experts. We investigated the utility of evidential

  3. Grazing intensity on vegetation dynamics of a typical steppe in Northeast Inner Mongolia

    Science.gov (United States)

    Vegetation features radiating from residential areas in response to livestock grazing were quantified for an arid steppe rangeland in the Keshiketeng Banner, Chifeng Prefecture in northeastern Inner Mongolia in 2004 and 2006. The aim of this study was to estimate grazing impacts on the vegetation dy...

  4. The effects of continuous and rotational grazing of sourveld on the ...

    African Journals Online (AJOL)

    A grazing trial was conducted at the Kokstad Agricultural station to compare the dry matter digestibility (DMD) and crude protein content (CP) of diets selected by four fistulated cattle which were continuously and rotationally grazing sourveld. Two stocking rates of 1, 0 and 2, 3 animals/ha (0, 5 and 1, 2 LSU/ha) were applied ...

  5. Comparison of techniques for estimating herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.; Taweel, H.Z.; Tas, B.M.; Tamminga, S.; Elgersma, A.

    2005-01-01

    For estimating herbage intake during grazing, the traditional sward cutting technique was compared in grazing experiments in 2002 and 2003 with the recently developed n-alkanes technique and with the net energy method. The first method estimates herbage intake by the difference between the herbage

  6. Gradients in fracture force and grazing resistance across canopy layers in seven tropical grass species

    NARCIS (Netherlands)

    Jacobs, A.A.A.; Scheper, J.A.; Benvenutti, M.A.; Gordon, I.J.; Poppi, D.P.; Elgersma, A.

    2013-01-01

    In reproductive swards, stems can act as a barrier that affects the grazing behaviour of ruminant livestock. The barrier effect of stems is closely associated with both the force required to fracture the stems and the density of these stems (in combination, these make up grazing resistance), and

  7. Effects of buffer strips and grazing management on soil loss from pastures

    Science.gov (United States)

    Intensive grazing pressure can cause soil erosion from pastures causing increased sediment loading to aquatic systems. The objectives of this work were to determine the long-term effects of grazing management and buffer strips on soil erosion from pastures fertilized with broiler litter. Field stud...

  8. Effects of Livestock Grazing in Pastures in the Manaslu Conservation Area, Nepalese Himalaya

    Directory of Open Access Journals (Sweden)

    Sunita Thapa

    2016-08-01

    Full Text Available Livestock herding is a widespread practice in the mountains of Nepal, and grazing in the forest and pastures within protected areas is a main source of cattle fodder. Given the implications of grazing on biodiversity conservation and the need for sustainable management of pastures in the Manaslu Conservation Area of Nepal, we assessed grazing intensity along an elevational gradient following the Budhi Gandaki valley. The data set consisted of grazing intensities recorded every 250 m along a transect from 1400 to 5200 m above sea level and farmer interviews, after an initial satellite data analysis. Grazing and herd size were found to increase with increasing elevation, reflecting local livelihood dependency on cattle herding. Species richness was then analyzed along a grazing disturbance gradient at 7 goths (summer cattle shed in heavily grazed areas. Disturbance was found to be moderate at intermediate distances, where species richness was found to be higher; the results agree with the generally accepted intermediate-disturbance hypothesis. The plant species not affected, even at the locations with highest grazing, were unpalatable species. These results can be useful in decision making related to management of forests and pastures in the Manaslu Conservation Area as well as in Himalayan forests and grasslands in general.

  9. Grasshopper responses to fire and postfire grazing in the northern Great Plains vary among species

    Science.gov (United States)

    Rangeland management practices such as burning and grazing management may affect grasshopper populations by impacting development, survival and reproduction. Experiments are lacking in the northern Great Plains examining the effects of fire and grazing intensity on grasshoppers. As part of a larger ...

  10. Effect of abandoning highland grazing on nutrient balances and economic performance of Italian Alpine dairy farms

    NARCIS (Netherlands)

    Penati, C.; Berentsen, P.B.M.; Tamburini, A.; Sandruci, A.; Boer, de I.J.M.

    2011-01-01

    In many European mountain areas, such as the Alps, highland grazing is declining. In addition to its effect on natural landscape and biodiversity, abandoning highland grazing may affect dairy-farm profitability and have environmental consequences in the lowland. The objective of this study was to

  11. Grazing lawns contribute to the subsistence of medium-sized herbivores in dystrophic savannas

    NARCIS (Netherlands)

    Verweij, R.; Verrelst, J.; Loth, P.E.; Heitkönig, I.M.A.; Brunsting, A.M.H.

    2006-01-01

    Resource manipulation, such as the creation and maintenance of grazing lawns, may shape the structure of herbivore communities. We tested the hypothesis that grazing lawns contribute towards the subsistence of the Kobus kob kob in a dystrophic West African savanna, where kob and Hippopotamus

  12. Effect of three grazing intensities on selected soil properties in semi ...

    African Journals Online (AJOL)

    Our primary objective was to determine the effect of three grazing intensities within an intensive, short-duration grazing system on selected soil physical properties. Maximum compaction occurred in the A2/AB horizons, which has significantly higher (P < 0.05) penetrometer readings than the overlying A1/A horizons under ...

  13. Dairy cattle on Norwegian alpine rangelands – grazing preferences and milk quality

    NARCIS (Netherlands)

    Sickel, H; Abrahamsen, R K; Eldegard, K; Lunnan, T; Norderhaug, A; Petersen, M.A.; Sickel, M.; Steenhuisen, F.; Ohlson, M.

    2014-01-01

    The results from the study ‘Effects of vegetation and grazing preferences on the quality of alpine dairy products’ will be presented. The main objective of the project was to investigate the connections bet - ween alpine rangeland vegetation, landscape use and grazing preferences of free ranging

  14. Effects of livestock grazing on nutrient retention in a headwater stream of the Rio Puerco Basin

    Science.gov (United States)

    Mark A. Sewards; H. Maurice Valett

    1996-01-01

    Sediment and nutrient loss from headwater streams of sedimentary basins in the semi-arid Southwest have been attributed to both over-grazing by livestock and to climatic cycles that influence arroyo formation. Considerable effort has been directed toward the influence of livestock grazing on riparian species abundance and diversity. Less work has concentrated on the...

  15. Sierra Nevada grasslands: interactions between livestock grazing and ecosystem structure and function

    Science.gov (United States)

    Barbara H. Allen-Diaz

    2004-01-01

    Livestock grazing plays an integral role in the grass-dominated ecosystems of the Sierra Nevada. Grazing has been asserted to influence such key ecological characteristics as water quality, net primary productivity, nutrient cycling, plant and animal diversity, wildlife habitat availability, and oak regeneration (Belsky and others 1999, Kauffmann and Krueger 1984)....

  16. Vegetation selection by Angus crossbred vs. Raramuri Criollo nursing cows grazing Chihuauan Desert rangeland in summer

    Science.gov (United States)

    We examined vegetation selection patterns of nursing Angus X Hereford crossbred (AH) and Raramuri Criollo (RC) cows grazing Chihuahuan Desert vegetation during the growing season. Eleven cows of each group grazed separately in two large pastures (1190ha, 1165ha) from mid-July until mid-August 2015 (...

  17. Acoustic monitoring system to quantify ingestive behavior of free-grazing cattle

    Science.gov (United States)

    Methods to estimate intake in grazing livestock include using markers, visual observation, mechanical sensors that respond to jaw movement and acoustic recording. In most of the acoustic monitoring studies, the microphone is inverted on the forehead of the grazing livestock and the skull is utilize...

  18. A review of the feedbacks between bivalve grazing and ecosystem processes

    NARCIS (Netherlands)

    Prins, T.C.; Smaal, A.C.; Dame, R.F.

    1998-01-01

    This paper gives an overview of interactions between bivalve grazing and ecosystem processes, that may affect the carrying capacity of ecosystems for bivalve suspension feeders. These interactions consist of a number of positive and negative feedbacks. Bivalve grazing can result in local food

  19. Does grazing management matter for soil carbon sequestration in shortgrass steppe?

    Science.gov (United States)

    Considerable uncertainty remains regarding the potential of grazing management on semiarid rangelands to sequester soil carbon. Short-term (less than 1 decade) studies have determined that grazing management potentially influences fluxes of carbon, but such studies are strongly influenced by prevail...

  20. Grazer-induced chain lenght plasticity reduces grazing risk in a marine diatom

    DEFF Research Database (Denmark)

    Bergkvist, Johanna; Thor, Peter; Jakobsen, Hans Henrik

    2012-01-01

    . marinoi was exposed to chemical cues from caged A. tonsa without physical contact with the responding cells. The reductions in chain length significantly reduced copepod grazing; grazing rates on chains (four cells or more) were several times higher compared to that of single cells. This suggests...

  1. Number of camps for rotational grazing of veld | PD | African Journal ...

    African Journals Online (AJOL)

    The objective of camping veld (subdivision by fencing) is to permit rotational systems of utilization. The primary objectives in the application of rotational grazing to veld in Southern Africa are (i) to limit the period of stay so as to avoid grazing regrowth and (ii) to allow a sufficient period of absence for undisturbed regrowth of ...

  2. Implications of longer term rest from grazing in the sagebrush steppe

    Science.gov (United States)

    K.W. Davies; M. Vavra; B. Schultz; N. Rimbey

    2014-01-01

    Longer term grazing rest has occurred or been proposed in large portions of the sagebrush steppe based on the assumption that it will improve ecosystem properties. However, information regarding the influence of longer term rest from grazing is limited and has not been summarized. We synthesized the scientific literature on long-term rest in the sagebrush steppe to...

  3. Trends in grazing emission x-ray analysis techniques

    International Nuclear Information System (INIS)

    Grieken, R. van; Tsuji, K.; Injuk, J.

    2000-01-01

    In grazing-emission x-ray fluorescence (GEXRF) spectrometry, XRF is made surface-sensitive, not by grazing incidence of the exciting radiation as in total reflection XRF (TXRF), but by detecting only that part of fluorescence radiation that is emitted at grazing angles above a polished sample carrier or above a flat wafer. In case of GEXRF, and contrary to TXRF, wavelength-dispersive (WD) detection can be used. Applications are, in principle, similar to those of (variable angle) TXRF. At the laboratory scale, only prototype instruments are available, and the GEXRF unit can be an accessory to a commercial WD-XRF instrument. The detection limits of GEXRF are in the higher pg range, corresponding to a concentration of between 0.4-3 μg/l, if a sample volume of 100 μl is examined. Because of the WD detection, GEXRF also lends itself for the analysis of low-Z elements, from Z > 5; this is an advantage over conventional TXRF (but similar to TXRF using a thin-window energy-dispersive detector). Since the GEXRF prototype is a sequential rather than a simultaneous instrument, the analysis time is long when many elements have to be determined. Moreover, because the soft characteristic radiation is more strongly absorbed in its longer path through the matrix than in TXRF, the linear response for trace analysis using GEXRF is limited; this was proven by calculating the fluorescence intensities as a function of layer thickness and composition. The specimens are very limited in thickness. The sample preparation procedure for liquid or other samples to be analyzed with the GEXRF unit is thus very problematic. Results for water samples, bio-materials and pigment and aerosol samples have indeed shown that the quantitative nature of GEXRF for trace analysis is poor. The most promising features of GEXRF are in the field of surface and thin-layer analysis. Trace contaminations on silicon wafers can be determined and depth profiling can characterize stratified near-surface layers. But

  4. Hippopotamus and livestock grazing : Influences on riparian vegetation and facilitation of other herbivores in the Mara Region of Kenya

    NARCIS (Netherlands)

    Kanga, Erustus M.; Ogutu, Joseph O.; Piepho, Hans-Peter; Olff, Han

    Riparian savanna habitats grazed by hippopotamus or livestock experience seasonal ecological stresses through the depletion of herbaceous vegetation, and are often points of contacts and conflicts between herbivores, humans and their livestock. We investigated how hippopotamus and livestock grazing

  5. Molecular-based analysis of changes in indigenous milk microflora during the grazing period.

    Science.gov (United States)

    Hagi, Tatsuro; Kobayashi, Miho; Nomura, Masaru

    2010-01-01

    Variations in milk microflora caused by changes in the cow feeding environment (from inside to outside grazing) were analyzed using a molecular-based approach comprising denaturing gradient gel electrophoresis and real-time PCR. After 8 d of outside grazing, changes in milk microflora were observed. Denaturing gradient gel electrophoresis analysis showed that the predominant bacterial group in the milk belonged to the Lactobacillus species during the experimental period, whereas the genus Staphylococcus gained in numbers during the outside grazing period in addition to Lactobacillus. To investigate the quantitative dynamics of staphylococci, real-time PCR was performed using staphylococcal-specific primers. Real-time PCR analysis revealed that the population of staphylococci increased during the outside grazing period. Our combined denaturing gradient gel electrophoresis and real-time PCR approach enables precise monitoring of the dynamics of both total bacteria and specific bacterial species in milk. Our results provide information on grazing management and the manufacture of dairy products.

  6. Cold season soil respiration in response to grazing and warming in the High Arctic Svalbard

    DEFF Research Database (Denmark)

    Strebel, Ditte; Elberling, Bo; Morgner, Elke

    2010-01-01

    of Arctic Goose Habitat: Impacts of Land Use, Conservation and Elevated Temperatures). New measurements of soil CO2 effluxes, temperatures and water contents were regularly made from July to November 2007. SOC stocks were quantified, and the reactivity and composition measured by basal soil respiration (BSR...... in significantly higher CO2 effluxes. Different grazing intensities had no significant effects on observed soil respiration, but BSR rates at the mesic site (13-23 mu g CO2 g soil-C-1 h-1) were highest with moderate grazing and lowest in the absence of grazing. A limited effect of grazing on microbial respiration......The influence of goose grazing intensity and open-topped chambers (OTCs) on near-surface quantities and qualities of soil organic carbon (SOC) was evaluated in wet and mesic ecosystems in Svalbard. This study followed up a field experiment carried out in 2003-05 (part of the project Fragility...

  7. Effect of grazing on the cow welfare of dairy herds evaluated by a multidimensional welfare index

    DEFF Research Database (Denmark)

    Burow, E.; Rousing, T.; Thomsen, P. T.

    2013-01-01

    Structural development in the prime sector has led to increasing herd sizes and new barn systems, followed by less summer grazing for dairy cows in Denmark. Effects of grazing on single welfare measures in dairy cows - for example, the presence of integument alterations or mortality - have been...... studied under different conditions. However, the effect of grazing on welfare, conceptualised as the multidimensional physical and mental state of the animal, has not yet been studied in contemporary cubicle loose-housing systems. The aim of our study was to investigate, based on a Welfare Quality (R......) inspired multidimensional dairy cow welfare assessment protocol, the within-herd effect of summer grazing compared with winter barn housing in Danish dairy herds with cubicle free-stall systems for the lactating cows. Our hypothesis was that cow welfare in dairy herds was better during summer grazing than...

  8. Monitoring grazing intensity: an experiment with canopy spectra applied to satellite remote sensing

    Science.gov (United States)

    Li, Fei; Zhao, Ying; Zheng, Jiajia; Luo, Juhua; Zhang, Xiaoqiang

    2016-04-01

    The quantification of grassland grazing intensity (GI) and its detailed spatial distribution are important for grassland management and ecological protection. Remote sensing has great potential in these areas, but its use is still limited. This study analyzed the impacts of grazing on biophysical properties of vegetation and suggested using biomass to quantify GI because of its stability and interpretability. In comparison to a single spectral index, such as the red edge index (REI), combining REI and a cellulose absorption ratio index calculated from hyperspectral data performs better for biomass estimation. Further, an auxiliary spectral index, called the grazing monitoring index (GMI), was developed based on differences in spectral reflectance in the infrared range. Experiments in a grazing area of the Inner Mongolia grassland indicated that GMI can identify GI, with three range intervals (GMI blocks in the experimental grazing area. Overall, our study provides inspiration and ideas for using satellite remote sensing for evaluating plant production, standing biomass, and livestock impacts.

  9. Intake and milk production of goats grazing Sulla forage under different stocking rates

    Directory of Open Access Journals (Sweden)

    M. L. Alicata

    2010-04-01

    Full Text Available A total of 24 Girgentana goats was divided into 3 homogeneous groups grazing a sulla monoculture under stocking rate of 30, 50 or 70 goats/ha (LSR, MSR and HSR. Available biomass, herbage selected by goats and milk yield were measured and sampled. The DM intake of goats and its botanic composition and digestibility were assessed by the n-alkane method. Grazing at HSR was suspended 18 d before MSR and LSR (35 vs. 53 d, due to the low biomass availability. Over the first 35 d of grazing, the HSR reduced height and availability of herbage. The herbage intake and milk yield of goats increased from HSR to LSR, without relevant changes in milk quality. During all grazing period (53 d, the higher grazing pressure led to a lower total milk yield per goat, whereas the HSR produced the highest daily and total milk amount per ha.

  10. Seasonal foraging patterns of forest-grazing Japanese Black heifers with increased plasma total antioxidant capacity.

    Science.gov (United States)

    Haga, Satoshi; Nakano, Miwa; Nakao, Seiji; Hirano, Kiyoshi; Yamamoto, Yoshito; Sasaki, Hiroyuki; Ishizaki, Hiroshi

    2016-02-01

    Forest-grazing enables the intake of high total antioxidant capacity (TAC) plants that might be beneficial for the TAC status of cattle. This study evaluated the relation between the seasonal foraging patterns of forest-grazing Japanese Black (JB) heifers or the TAC levels in shrubs and trees and the changes of plasma TAC. We examined 12 JB heifers, four each of which were allocated to forest-grazing (F), pasture-grazing, and pen-housed groups. The plasma TAC level in F heifers on July 26, August 13, 30 and September 17 were significantly higher than those on April 27 and June 4 (P grazing cattle might be the increased foraging of TAC-rich shrubs and trees during summer-fall. © 2015 Japanese Society of Animal Science.

  11. Evolutionary trade-off between defence against grazing and competitive ability in a simple unicellular alga, Chlorella vulgaris.

    OpenAIRE

    Yoshida, Takehito; Hairston, Nelson G.; Ellner, Stephen P.

    2004-01-01

    Trade-offs between defence and other fitness components are expected in principle, and can have major qualitative impacts on ecological dynamics. Here we show that such a trade-off exists even in the simple unicellular alga Chlorella vulgaris. We grew algal populations for multiple generations in either the presence ('grazed algae') or absence ('non-grazed algae') of the grazing rotifer Brachionus calyciflorus, and then evaluated their defence and competitive abilities. Grazed algae were bett...

  12. Restricting Grazing on Federal Lands in the West to Protect Threatened and Endangered Species: Ranch and Livestock Sector Impacts

    OpenAIRE

    Jan Lewandrowski; Kevin Ingram

    2002-01-01

    Ranch and livestock sector impacts are estimated for a 10% reduction in grazing on federal lands in the West to protect threatened and endangered species. Two sets of species are considered. One set targets species listed due to grazing and the other targets species whose recovery plans include restrictions on grazing. Using the former set and assuming no substitution between alternative sources of forage, the grazing restriction reduces annual ranch and livestock sector incomes by $54.4 and ...

  13. Digesta kinetics, energy intake, grazing behavior, and body temperature of grazing beef cattle differing in adaptation to heat.

    Science.gov (United States)

    Sprinkle, J E; Holloway, J W; Warrington, B G; Ellist, W C; Stuth, J W; Forbes, T D; Greene, L W

    2000-06-01

    The objective of this study was to determine whether digesta kinetics, energy intake (EI, kcal ME intake x kg(-.75) x d(-1)), grazing behavior, or body temperature differed by breed, lactational state, or season of the year among cattle presumed to vary in adaptability to the subtropics. Two-year-old lactating and nonlactating Brahman x Angus (BA; n = 5, n = 5), Tuli x Angus (TA; n = 5, n = 4), and Angus (A; n = 4, n = 4) cows were used. During both early (ES) and late summer (LS), lactating cattle vs nonlactating cattle had greater gastrointestinal tract load (CM2) and EI (P .48). During LS, lactating cattle had decreased early morning rectal temperatures (P .26) late afternoon rectal temperatures compared with BA and TA. With data pooled over both grazing trials, BA cattle had the smallest CM2 (P .28) early morning rectal temperatures compared with BA during ES and LS. During LS, TA spent more time in the sun and less time in the shade than did either A or BA (P .50). During LS, EI for lactating A was greater than for BA and TA (P < .05), and EI for nonlactating BA was less than for A and TA (P < .05). Bite rate per minute for lactating cattle during ES was reduced (P < .03) by increased body condition score. Tuli x Angus cattle appear to be comparable to BA with respect to heat adaptation. It appears that EI demands are greater in a hot environment.

  14. Grazing alters net ecosystem C fluxes and the global warming potential of a subtropical pasture.

    Science.gov (United States)

    Gomez-Casanovas, Nuria; DeLucia, Nicholas J; Bernacchi, Carl J; Boughton, Elizabeth H; Sparks, Jed P; Chamberlain, Samuel D; DeLucia, Evan H

    2018-03-01

    The impact of grazing on C fluxes from pastures in subtropical and tropical regions and on the environment is uncertain, although these systems account for a substantial portion of global C storage. We investigated how cattle grazing influences net ecosystem CO 2 and CH 4 exchange in subtropical pastures using the eddy covariance technique. Measurements were made over several wet-dry seasonal cycles in a grazed pasture, and in an adjacent pasture during the first three years of grazer exclusion. Grazing increased soil wetness but did not affect soil temperature. By removing aboveground biomass, grazing decreased ecosystem respiration (R eco ) and gross primary productivity (GPP). As the decrease in R eco was larger than the reduction in GPP, grazing consistently increased the net CO 2 sink strength of subtropical pastures (55, 219 and 187 more C/m 2 in 2013, 2014, and 2015). Enteric ruminant fermentation and increased soil wetness due to grazers, increased total net ecosystem CH 4 emissions in grazed relative to ungrazed pasture (27-80%). Unlike temperate, arid, and semiarid pastures, where differences in CH 4 emissions between grazed and ungrazed pastures are mainly driven by enteric ruminant fermentation, our results showed that the effect of grazing on soil CH 4 emissions can be greater than CH 4 produced by cattle. Thus, our results suggest that the interactions between grazers and soil hydrology affecting soil CH 4 emissions play an important role in determining the environmental impacts of this management practice in a subtropical pasture. Although grazing increased total net ecosystem CH 4 emissions and removed aboveground biomass, it increased the net storage of C and decreased the global warming potential associated with C fluxes of pasture by increasing its net CO 2 sink strength. © 2017 by the Ecological Society of America.

  15. Changes in semi-arid plant species associations along a livestock grazing gradient.

    Directory of Open Access Journals (Sweden)

    Hugo Saiz

    Full Text Available In semi-arid ecosystems, vegetation is heterogeneously distributed, with plant species often associating in patches. These associations between species are not constant, but depend on the particular response of each species to environmental factors. Here, we investigated how plant species associations change in response to livestock grazing in a semi-arid ecosystem, Cabo de Gata-Níjar Natural Park in South East Spain. We established linear point-intercept transects at four sites with different grazing intensity, and recorded all species at each point. We investigated plant associations by comparing the number of times that each pair of species occurred at the same spatial point (co-occurrences, with the expected number of times based on species abundances. We also assessed associations for each shrub and grass species by considering all their pairs of associations and for the whole plant community by considering all pairs of associations on each site. At all sites, the plant community had a negative pattern of association, with fewer co-occurrences than expected. Negative association in the plant community increased at maximum grazing intensity. Most species associated as expected, particularly grass species, and positive associations were most important at intermediate grazing intensities. No species changed its type of association along the grazing gradient. We conclude that in the present plant community, grazing-resistant species compete among themselves and segregate in space. Some shrub species act as refuges for grazing-sensitive species that benefit from being spatially associated with shrub species, particularly at intermediate grazing intensities where positive associations were highest. At high grazing intensity, these shrubs can no longer persist and positive associations decrease due to the disappearance of refuges. Spatial associations between plant species and their response to grazing help identify the factors that organize

  16. Effects of livestock grazing on rangeland biodiversity: A meta-analysis of grouse populations.

    Science.gov (United States)

    Dettenmaier, Seth J; Messmer, Terry A; Hovick, Torre J; Dahlgren, David K

    2017-10-01

    Livestock grazing affects over 60% of the world's agricultural lands and can influence rangeland ecosystem services and the quantity and quality of wildlife habitat, resulting in changes in biodiversity. Concomitantly, livestock grazing has the potential to be detrimental to some wildlife species while benefiting other rangeland organisms. Many imperiled grouse species require rangeland landscapes that exhibit diverse vegetation structure and composition to complete their life cycle. However, because of declining populations and reduced distributions, grouse are increasingly becoming a worldwide conservation concern. Grouse, as a suite of upland gamebirds, are often considered an umbrella species for other wildlife and thus used as indicators of rangeland health. With a projected increase in demand for livestock products, better information will be required to mitigate the anthropogenic effects of livestock grazing on rangeland biodiversity. To address this need, we completed a data-driven and systematic review of the peer-reviewed literature to determine the current knowledge of the effects of livestock grazing on grouse populations (i.e., chick production and population indices) worldwide. Our meta-analysis revealed an overall negative effect of livestock grazing on grouse populations. Perhaps more importantly, we identified an information void regarding the effects of livestock grazing on the majority of grouse species. Additionally, the reported indirect effects of livestock grazing on grouse species were inconclusive and more reflective of differences in the experimental design of the available studies. Future studies designed to evaluate the direct and indirect effects of livestock grazing on wildlife should document (i) livestock type, (ii) timing and frequency of grazing, (iii) duration, and (iv) stocking rate. Much of this information was lacking in the available published studies we reviewed, but is essential when making comparisons between different

  17. Grazing responses in herbs in relation to herbivore selectivity and plant traits in an alpine ecosystem.

    Science.gov (United States)

    Evju, Marianne; Austrheim, Gunnar; Halvorsen, Rune; Mysterud, Atle

    2009-08-01

    Herbivores shape plant communities through selective foraging. However, both herbivore selectivity and the plant's ability to tolerate or resist herbivory may depend on the density of herbivores. In an alpine ecosystem with a long history of grazing, plants are expected to respond to both enhanced and reduced grazing pressures, and the interaction between plant traits and changes in species abundance are expected to differ between the two types of alteration of grazing regime. To understand the mechanisms behind species response, we investigated the relationship between sheep selectivity (measured in situ), plant traits and experimentally derived measures of change in species abundance as a response to the enhancement (from low to high density) or cessation (from low to zero density) of sheep grazing pressure over a six-year time period for 22 abundant herb species in an alpine habitat in south Norway. Sheep selected large, late-flowering herbs with a low leaf C/N ratio. Species that increased in abundance in response to enhanced grazing pressure were generally small and had high root/shoot ratios, thus exhibiting traits that reflect both resistance (through avoidance) and tolerance (through regrowth capacity) strategies. The abundance of selected species remained stable during the study period, and also under the enhanced grazing pressure treatment. There was, however, a tendency for selected species to respond positively to cessation of grazing, although overall responses to cessation of grazing were much less pronounced than responses to enhanced grazing. Avoidance through short stature (probably associated with increased light availability through the removal of tall competitors) as well as a certain amount of regrowth capacity appear to be the main mechanisms behind a positive response to enhanced grazing pressure in this study. The plant trait perspective clearly improves our insight into the mechanisms behind observed changes in species abundance when the

  18. Effect of Sources and Storage Conditions on Quality of Sorghum ...

    African Journals Online (AJOL)

    A study was conducted in three agro-ecological zones of Tanzania to investigate sources, status, quality and storage conditions of sorghum (Sorghum bicolor L.) seeds. Sorghum seed samples were collected from Kwimba (Lake zone), Chamwino (Central zone) and Kilosa (Eastern zone) districts. In surveyed districts 83.3 ...

  19. Short-term winter wheat (Triticum aestivum L.) cover crop grazing influence on calf growth, grain yield, and soil properties

    Science.gov (United States)

    Winter cover cropping has many agronomic benefits and can provide forages base for spring livestock grazing. Winter cover crop grazing has shown immediate economic benefits through increased animal production. Winter wheat pasture grazing is common in beef cow-calf production and stocker operations....

  20. Non-traditional Forages in a Managed Grazing System for Control of Gastrointestinal Parasites in Sheep: Preliminary Work

    Science.gov (United States)

    This project compared lambs grazing forage chicory (Cichorium intybus L.) with lambs grazing brown mid-rib forage sorghum (Sorghum bicolor (L.) Moench.) x sudangrass (Sorghum sudanense Piper) hybrid (BMR) to determine if anti-parasitic effects of chicory could be demonstrated. Lambs grazed these fo...

  1. Effects of livestock grazing on morphology, hydrology and nutrient retention in four riparian/stream ecosystems, New Mexico, USA

    Science.gov (United States)

    James R. Thibault; Douglas L. Moyer; Clifford N. Dahm; H. Maurice Valett; Michael C. Marshall

    1999-01-01

    Land-use practices such as livestock grazing influence the structure and function of riparian/stream ecosystems. In New Mexico, four streams were selected to determine the impact of moderate livestock grazing on morphology, solute transport, and nutrient retention. Each stream contained a reach currently exposed to grazing and an exclosed, ungrazed reach. Channel width...

  2. On the bistable zone of milling processes.

    Science.gov (United States)

    Dombovari, Zoltan; Stepan, Gabor

    2015-09-28

    A modal-based model of milling machine tools subjected to time-periodic nonlinear cutting forces is introduced. The model describes the phenomenon of bistability for certain cutting parameters. In engineering, these parameter domains are referred to as unsafe zones, where steady-state milling may switch to chatter for certain perturbations. In mathematical terms, these are the parameter domains where the periodic solution of the corresponding nonlinear, time-periodic delay differential equation is linearly stable, but its domain of attraction is limited due to the existence of an unstable quasi-periodic solution emerging from a secondary Hopf bifurcation. A semi-numerical method is presented to identify the borders of these bistable zones by tracking the motion of the milling tool edges as they might leave the surface of the workpiece during the cutting operation. This requires the tracking of unstable quasi-periodic solutions and the checking of their grazing to a time-periodic switching surface in the infinite-dimensional phase space. As the parameters of the linear structural behaviour of the tool/machine tool system can be obtained by means of standard modal testing, the developed numerical algorithm provides efficient support for the design of milling processes with quick estimates of those parameter domains where chatter can still appear in spite of setting the parameters into linearly stable domains. © 2015 The Authors.

  3. Community Perspectives on the On-Farm Diversity of Six Major Cereals and Climate Change in Bhutan

    Directory of Open Access Journals (Sweden)

    Tirtha Bdr. Katwal

    2015-01-01

    Full Text Available Subsistence Bhutanese farmers spread across different agro-ecological zones maintain large species and varietal diversity of different crops in their farm. However, no studies have been undertaken yet to assess why farmers conserve and maintain large agro-biodiversity, the extent of agro-ecological richness, species richness, estimated loss of traditional varieties and threats to the loss of on-farm agro-biodiversity. Information on the number of varieties cultivated by the farmers for six important staple crops were collected from nine districts and twenty sub-districts spread across six different agro-ecological zones of the country to understand farmers reasons for maintaining on-farm crop diversity, estimate agro-ecological richness, species richness and the overall loss of traditional varieties, to know the famers’ level of awareness on climate change and the different threats to crop diversity. The results from this study indicated that an overwhelming 93% of the respondents manage and use agro-biodiversity for household food security and livelihood. The average agro-ecological richness ranged from 1.17 to 2.26 while the average species richness ranged from 0.50 to 2.66. The average agro-ecological richness indicates a large agro-ecological heterogeneity in terms of the different species of staple crops cultivated. The average species richness on the other hand shows that agro-ecological heterogeneity determines the type and extent of the cultivation of the six different staple cereals under consideration. The overall loss of traditional varieties in a time period of 20 years stands at 28.57%. On climate change, 94% of the farmers recognize that local climate is changing while 86% responded that they are aware of the potential impacts of climate change on their livelihoods. Climate change and associated factors was considered the most imminent threat to the management and loss of on-farm agro-biodiversity. The results from this study

  4. Managed livestock grazing is compatible with the maintenance of plant diversity in semidesert grasslands.

    Science.gov (United States)

    Fensham, R J; Silcock, J L; Firn, J

    2014-04-01

    Even when no baseline data are available, the impacts of 150 years of livestock grazing on natural grasslands can be assessed using a combined approach of grazing manipulation and regional-scale assessment of the flora. Here, we demonstrate the efficacy of this method across 18 sites in the semidesert Mitchell grasslands of northeastern Australia. Fifteen-year-old exclosures (ungrazed and macropod grazed) revealed that the dominant perennial grasses in the genus Astrebla do not respond negatively to grazing disturbance typical of commercial pastoralism. Neutral, positive, intermediate, and negative responses to grazing disturbance were recorded amongst plant species with no single life-form group associated with any response type. Only one exotic species, Cenchrus ciliaris, was recorded at low frequency. The strongest negative response was from a native annual grass, Chionachne hubbardiana, an example of a species that is highly sensitive to grazing disturbance. Herbarium records revealed only scant evidence that species with a negative response to grazing have declined through the period of commercial pastoralism. A regional analysis identified 14 from a total of 433 plant species in the regional flora that may be rare and potentially threatened by grazing disturbance. However, a targeted survey precluded grazing as a cause of decline for seven of these based on low palatability and positive responses to grazing and other disturbance. Our findings suggest that livestock grazing of semidesert grasslands with a short evolutionary history of ungulate grazing has altered plant composition, but has not caused declines in the dominant perennial grasses or in species richness as predicted by the preceding literature. The biggest impact of commercial pastoralism is the spread of woody leguminous trees that can transform grassland to thorny shrubland. The conservation of plant biodiversity is largely compatible with commercial pastoralism provided these woody weeds are

  5. Sustainability, arid grasslands and grazing: New applications for technology

    Energy Technology Data Exchange (ETDEWEB)

    Pregenzer, A.L.; Parmenter, R.; Passell, H.D.; Budge, T.; Vande Caste, J.

    1999-12-08

    The study of ecology is taking on increasing global importance as the value of well-functioning ecosystems to human well-being becomes better understood. However, the use of technological systems for the study of ecology lags behind the use of technologies in the study of other disciplines important to human well-being, such as medicine, chemistry and physics. The authors outline four different kinds of large-scale data needs required by land managers for the development of sustainable land use strategies, and which can be obtained with current or future technological systems. They then outline a hypothetical resource management scenario in which data on all those needs are collected using remote and in situ technologies, transmitted to a central location, analyzed, and then disseminated for regional use in maintaining sustainable grazing systems. They conclude by highlighting various data-collection systems and data-sharing networks already in operation.

  6. Grazing intensity affects the environmental impact of dairy systems.

    Science.gov (United States)

    Aguirre-Villegas, H A; Passos-Fonseca, T H; Reinemann, D J; Larson, R

    2017-08-01

    Dairy products are major components of the human diet but are also important contributors to global environmental impacts. This study evaluated greenhouse gas (GHG) emissions, net energy intensity (NEI), and land use of confined dairy systems with increasing levels of pasture in the diet. A Wisconsin farm was modeled to represent practices adopted by dairy operations in a humid continental climate typical in the Great Lakes region and other climates that have large differences in seasonal temperatures. Five grazing scenarios (all of which contained some portion of confinement) were modeled based on different concentrations of dry matter intake from pasture and feed supplementation from corn grain, corn silage, and soybean meal. Scenarios that incorporate grazing consisted of 5 mo of pasture feeding from May to September and 7 mo of confined feeding from October to April. Environmental impacts were compared within the 5 scenarios that incorporate grazing and across 2 entirely confined scenarios with and without on-farm electricity production through anaerobic digestion (AD). To conduct a fair comparison, all scenarios were evaluated based on the same total amount of milk produced per day where resource inputs were adjusted according to the characteristics of each scenario. A cradle-to-farm gate life cycle assessment evaluated the environmental burdens that were partitioned by allocation between milk and meat and by system expansion when biogas-based electricity was produced. Overall, results for all scenarios were comparable. Enteric methane was the greatest contributor to GHG emissions, and the production of crops was the most energy-intense process. For the confined scenario without AD, GHG emissions were 0.87 kg of CO 2 equivalents, NEI was 1.59 MJ, and land use was 1.59 m 2 /kg of fat- and protein-corrected milk (FPCM). Anaerobic digestion significantly reduced emissions to 0.28 kg of CO 2 equivalents/kg of FPCM and reduced NEI to -1.26 MJ/kg of FPCM, indicating

  7. Image processing for grazing incidence fast atom diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Debiossac, Maxime; Roncin, Philippe, E-mail: philippe.roncin@u-psud.fr

    2016-09-01

    Grazing incidence fast atom diffraction (GIFAD, or FAD) has developed as a surface sensitive technique. Compared with thermal energies helium diffraction (TEAS or HAS), GIFAD is less sensitive to thermal decoherence but also more demanding in terms of surface coherence, the mean distance between defects. Such high quality surfaces can be obtained from freshly cleaved crystals or in a molecular beam epitaxy (MBE) chamber where a GIFAD setup has been installed allowing in situ operation. Based on recent publications by Atkinson et al. (2014) and Debiossac et al. (2014), the paper describes in detail the basic steps needed to measure the relative intensities of the diffraction spots. Care is taken to outline the underlying physical assumptions.

  8. A model of ammonia volatilization from a grazing livestock farm

    Science.gov (United States)

    Hutchings, N. J.; Sommer, S. G.; Jarvis, S. C.

    A dynamic model was developed to predict the ammonia volatilization from grazing livestock farms and to allow potential control measures to be evaluated. The relationships within the model were based on the underlying physical and chemical processes but empirically based factors were used to reduce the demand for input data and where the understanding of the underlying processes was inadequate. On a daily basis, the model simulates the partitioning of dietary nitrogen into dung and urine and its subsequent fate within the pasture or the slurry handling system. The fate of dry matter and water added in dung, urine and from other sources is also predicted. The model illustrates the indirect interactions between ammonia sources, highlights the influence of slurry management on ammonia losses, stresses the need for integrated, whole farm measurements and demonstrates that assessments of the impact of control measures may be misleading unless considered at the scale of the whole farm.

  9. Bilaterian burrows and grazing behavior at >585 million years ago.

    Science.gov (United States)

    Pecoits, Ernesto; Konhauser, Kurt O; Aubet, Natalie R; Heaman, Larry M; Veroslavsky, Gerardo; Stern, Richard A; Gingras, Murray K

    2012-06-29

    Based on molecular clocks and biomarker studies, it is possible that bilaterian life emerged early in the Ediacaran, but at present, no fossils or trace fossils from this time have been reported. Here we report the discovery of the oldest bilaterian burrows in shallow-water glaciomarine sediments from the Tacuarí Formation, Uruguay. Uranium-lead dating of zircons in cross-cutting granite dykes constrains the age of these burrows to be at least 585 million years old. Their features indicate infaunal grazing activity by early eumetazoans. Active backfill within the burrow, an ability to wander upward and downward to exploit shallowly situated sedimentary laminae, and sinuous meandering suggest advanced behavioral adaptations. These findings unite the paleontological and molecular data pertaining to the evolution of bilaterians, and link bilaterian origins to the environmental changes that took place during the Neoproterozoic glaciations.

  10. The Extreme-ultraviolet Emission from Sun-grazing Comets

    Science.gov (United States)

    Bryans, Paul; Pesnell, William D.

    2012-01-01

    The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory has observed two Sun-grazing comets as they passed through the solar atmosphere. Both passages resulted in a measurable enhancement of extreme-ultraviolet (EUV) radiance in several of the AIA bandpasses.We explain this EUV emission by considering the evolution of the cometary atmosphere as it interacts with the ambient solar atmosphere. Molecules in the comet rapidly sublimate as it approaches the Sun. They are then photodissociated by the solar radiation field to create atomic species. Subsequent ionization of these atoms produces a higher abundance of ions than normally present in the corona and results in EUV emission in the wavelength ranges of the AIA telescope passbands.

  11. GRAZING BEHAVIOUR OF DAIRY COWS ON MOUNTAIN FARM

    Directory of Open Access Journals (Sweden)

    J. VOŘÍŠKOVÁ

    2009-10-01

    Full Text Available The etological observation was provided on a dairy herd (65 Czech Fleckvieh and 51 Holstein cows on a low-input mountain farm during the pasture season (April – October 2008. The milking was provided two-times a day in the stalls. The 24-hours observations were made four-times: in June, July, September and October, in 10- minutes intervals. The cows spent 25 to 38 % of a day on average by feeding and 18 to 22 % on average by moving (stalls – pasture movements took about half of this period. The resting time consisting of chewing was found unsufficient and took 29 % to 40 % of a day on average. Better comfort of cows given by an improved milking technology and a more effective grazing management connected with longer time spent by resting is suggested to achieve higher milk yields on the farm.

  12. Exploration of agro-ecological options for improving maize-based farming systems in Costa Chica, Guerrero, Mexico

    NARCIS (Netherlands)

    Flores Sanchez, D.

    2013-01-01

    Keywords: farm diagnosis, farming systems, soil degradation, intercropping, maize, roselle, legumes, nutrient management, vermicompost, crop residues, decomposition, explorations.

    In the Costa Chica, a region of Southwest Mexico, farming systems are organized in

  13. Methods and software tools for agro-ecological evaluation at farm level: the livestock component within the SIPEAA project

    Directory of Open Access Journals (Sweden)

    E. Basile

    2010-01-01

    Full Text Available Livestock farms need to adapt to social and economics changes. Often, farmers must take decision in order to: - remain competitive, meanwhile market and public aids change; - reduce impact on environment. Improvement of efficiency seems to be the only way to conciliate these two different needs. Livestock farm are very complex systems involving physical and biologic components.

  14. Morpho-physiological Traits and Mineral Composition on Local Maize Population Growing in Agro Ecological Conditions in Kosova

    Directory of Open Access Journals (Sweden)

    Sali ALIU

    2013-05-01

    Full Text Available Twelve local maize populations were evaluated at the experimental farm, University of Prishtina, Kosovo. The study was conducted to assess the magnitude of genetic variation in local maize populations for different morphological-physiological and chemical composition under field and laboratory conditions. Randomized complete block design (RCBD with three replications was used for laying out the experiment. The results showed that there were significant differences for most morphological and physiological traits under study. The mean grain yield of all populations was 102.96 g plant-1. The protein and oil contents ranged between 11.53 to 9.43% and 4.23 to 4.87% respectively. The cellulose content varied from 6.03 to 6.37%. There were also big differences regarding phenotypic correlations. The present study revealed considerable amount of diversity among the local maize populations which could be manipulated for further improvement in maize breeding.

  15. Agricultural Policies and Soil Degradation in Western Canada: An Agro-Ecological Economic Assessment, Report 1: Conceptual Framework

    OpenAIRE

    Aziz Bouzaher; Philip W. Gassman; Derald Holtkamp; David Archer; Alicia L. Carriquiry; Jason F. Shogren; Randall Reese; P. G. Lakshminarayan; William H. Furtan; R. César Izaurralde; James Kiniry

    1993-01-01

    The trade-off between agricultural production stability and environmental sustainability is a growing concern. The two major Canadian farm income stabilization programs of 1991, GRIP (Gross Revenue Insurance Plan) and NISA (Net Income Stabilization Account), are being considered for their resource neutrality impacts. This report presents a conceptual framework designed to evaluate the environmental impacts of GRIP and NISA, focusing on land use, technology, and soil degradation shifts. The ap...

  16. Tropical forest-transition landscapes: a portfolio for studying people, tree crops and agro-ecological change in context

    NARCIS (Netherlands)

    Dewi, S.; Noordwijk, van M.; Zulkarnain, Muhammad Thoha; Dwiputra, Adrian; Hyman, Glenn; Prabhu, R.; Gitz, V.; Nasi, Robert

    2017-01-01

    Nudging the development trajectory of tropical landscapes towards sustainability requires a global commitment and policies that take diverse contexts and forest transitions into account. Out-scaling and upscaling landscape-level actions to achieve sustainable development goals globally need to be

  17. Exploration of agro-ecological options for improving maize-based farming systems in Costa Chica, Guerrero, Mexico

    NARCIS (Netherlands)

    Flores Sanchez, D.

    2013-01-01

    Keywords: farm diagnosis, farming systems, soil degradation, intercropping, maize, roselle, legumes, nutrient management, vermicompost, crop residues, decomposition, explorations.   In the Costa Chica, a region of Southwest Mexico, farming systems are organized in smallholder

  18. Need for agro-ecological intelligence to limit trade-offs between global food, feed and fuel

    NARCIS (Netherlands)

    Bindraban, P.S.

    2009-01-01

    Hopefully the quality of life for billions of people will improve considerably during the coming decades. This implies that the production of virtually every commodity will have to increase dramatically. Agriculture related activities ought to provide food, feed and non-edible plant-based products.

  19. Environmental impacts and nutrient recycling on pastures grazed by cattle

    Directory of Open Access Journals (Sweden)

    J.M.B. Vendramini

    2007-07-01

    Full Text Available Grasslands are being replaced by urbanization and more profitable agricultural activities around the world. Producers may be faced with land constraints and need to consider intensification of the remaining grasslands as a means of maintaining overall production on a decreasing land resource. However, intensification of the grazing system is usually associated with greater nutrient inputs, including those from commercial fertilizers and supplement fed to animals. Excessive loading of nutrients in intensive grazing systems via fertilizer and animal wastes can cause nutrient buildup in the soil and subsequent water quality problems. Surface runoff and leaching of nutrients are the two major process affecting water quality. Nitrogen and P represent major nutrient concerns as related to water quality. Increased nitrate concentrations render groundwater unsuitable for drinking and can cause serious health issues for humans. Excessive N and P concentrations may contribute to eutrophication of streams and lakes. Maximizing efficiency of nutrient recycling through the soil-forage-animal system minimizes off-site nutrient transport and decreases production costs by reducing the quantity of commercial fertilizer needed. Management strategies to reduce soil and water contamination include refining the balance of nutrient inputs from feeds and fertilizers as well as accounting for the nutrients recycled through the decomposition of plant litter and animal wastes. Current interest in the development and adoption of efficient and sustainable agriculture systems has led forage researchers to amplify the scope of grasslands research by increasing multidisciplinary efforts. There is an increased interest in quantifying the impacts of forage-animal management strategies on the environment, with the goal of developing economically viable best management practices that result in optimum forage production and profitability, while protecting the environment

  20. Sympatric cattle grazing and desert bighorn sheep foraging

    Science.gov (United States)

    Garrison, Kyle R.; Cain, James W.; Rominger, Eric M.; Goldstein, Elise J.

    2015-01-01

    Foraging behavior affects animal fitness and is largely dictated by the resources available to an animal. Understanding factors that affect forage resources is important for conservation and management of wildlife. Cattle sympatry is proposed to limit desert bighorn population performance, but few studies have quantified the effect of cattle foraging on bighorn forage resources or foraging behavior by desert bighorn. We estimated forage biomass for desert bighorn sheep in 2 mountain ranges: the cattle-grazed Caballo Mountains and the ungrazed San Andres Mountains, New Mexico. We recorded foraging bout efficiency of adult females by recording feeding time/step while foraging, and activity budgets of 3 age-sex classes (i.e., adult males, adult females, yearlings). We also estimated forage biomass at sites where bighorn were observed foraging. We expected lower forage biomass in the cattle-grazed Caballo range than in the ungrazed San Andres range and lower biomass at cattle-accessible versus inaccessible areas within the Caballo range. We predicted bighorn would be less efficient foragers in the Caballo range. Groundcover forage biomass was low in both ranges throughout the study (Jun 2012–Nov 2013). Browse biomass, however, was 4.7 times lower in the Caballo range versus the San Andres range. Bighorn in the Caballo range exhibited greater overall daily travel time, presumably to locate areas of higher forage abundance. By selecting areas with greater forage abundance, adult females in the Caballo range exhibited foraging bout efficiency similar to their San Andres counterparts but lower overall daily browsing time. We did not find a significant reduction in forage biomass at cattle-accessible areas in the Caballo range. Only the most rugged areas in the Caballo range had abundant forage, potentially a result of intensive historical livestock use in less rugged areas. Forage conditions in the Caballo range apparently force bighorn to increase foraging effort by