Irrigation of steppe soils in the south of Russia: Problems and solutions (Analysis of Irrigation Practices in 1950-1990)

Science.gov (United States)

Minashina, N. G.

2009-07-01

Experience in irrigation of chernozems in the steppe zone of Russia for a period from 1950 to 1990 is analyzed. By the end of this period and in the subsequent years, the areas under irrigation reduced considerably, and the soil productivity worsened. This was caused by the improper design of irrigation systems, on the one hand, and by the low tolerance of chernozems toward increased moistening upon irrigation, on the other hand. The analysis of the factors and regimes of soil formation under irrigation conditions shows that irrigation-induced changes in the soil hydrology also lead to changes in the soil physicochemical, biochemical, and other properties. In particular, changes in the composition of exchangeable cations lead to the development of solonetzic process. In many areas, irrigation of chernozems was accompanied by the appearance of solonetzic, vertic, saline, and eroded soils. The development of soil degradation processes is described. In general, the deterioration of irrigated chernozems was related to the absence of adequate experience in irrigation of steppe soils, unskilled personnel, improper regime of irrigation, and excessively high rates of watering. In some cases, the poor quality of irrigation water resulted in the development of soil salinization and alkalization. To improve the situation, the training of personnel is necessary; the strategy of continuous irrigation should be replaced by the strategy of supplementary irrigation in the critical periods of crop development.

Matching soil salinization and cropping systems in communally managed irrigation schemes

Science.gov (United States)

Malota, Mphatso; Mchenga, Joshua

2018-03-01

Occurrence of soil salinization in irrigation schemes can be a good indicator to introduce high salt tolerant crops in irrigation schemes. This study assessed the level of soil salinization in a communally managed 233 ha Nkhate irrigation scheme in the Lower Shire Valley region of Malawi. Soil samples were collected within the 0-0.4 m soil depth from eight randomly selected irrigation blocks. Irrigation water samples were also collected from five randomly selected locations along the Nkhate River which supplies irrigation water to the scheme. Salinity of both the soil and the irrigation water samples was determined using an electrical conductivity (EC) meter. Analysis of the results indicated that even for very low salinity tolerant crops (ECi water was suitable for irrigation purposes. However, root-zone soil salinity profiles depicted that leaching of salts was not adequate and that the leaching requirement for the scheme needs to be relooked and always be adhered to during irrigation operation. The study concluded that the crop system at the scheme needs to be adjusted to match with prevailing soil and irrigation water salinity levels.

Converting Surface Irrigation to Pressurized Irrigation Systems and its Effecton Yield of OrangeTrees (Case Study:North of Khouzestan

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M. Khorramian

2017-01-01

Full Text Available Introduction: North of the Khouzestan is one of the most important citrus production center. Usually border irrigation is used to irrigate citrus in this area. This system has generally low application efficiency. Several investigations in other arid region have demonstrated in addition to improved irrigation efficiency with low-volume pressurized irrigation systems, citrus trees have adapted with these new irrigation systems. However limited information exists on the performance of mature orchards converted from border surface irrigation to pressurized irrigation systems. Therefore, the current research was conducted to evaluate the feasibility of converting surface irrigation to pressurized irrigation systems on mature citrus trees in climate conditions of North Khouzestan. Materials and Methods: This study was conducted during three years at Safiabad Agricultural Research Center to evaluate the yield of citrus trees and the quality of fruits for two Marss and Valencia varieties which grow 7 years previously with surface irrigation and converted to pressurized irrigation systems. The treatments consisted of six irrigation methods including Overhead sprinkle irrigation (OHSI, Under tree sprinkle irrigation(UTSI, Trickle irrigation(TI(six 8 L/h Netafim emitters, Microjet irrigation (MI(two 180 microjet were located under canopy near of the trunk at opposite sides of trunk,Bubbler irrigation(BI(a single located under the canopy of each treeandSurface irrigation(SI method.Soil texture was clay loam well drained without salinity(ECe=0.69ds m-1, with 1.25 percent organic carbon. The experimental design was completely randomized design. The trees were irrigated during spring and summer seasons. For calculating irrigation water depth in TI, MI and BI systems, daily evaporation from a class A evaporation pan of the Safiabad weather station (nearby the experimental field was collected, and evapotranspiration of the citrus trees was calculated applying a

Soil salinity under deficit drip irrigation of potato and millet in in an arid environment

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Kamel Nagaz

2017-06-01

Full Text Available The influence of deficit irrigation (DI with saline water on soil salinity in a drip-irrigated potato and millet fields was investigated. We had compared proportional soil salinity developed under Full and DI under drip irrigation. For both experiments, the treatments were (1 Full, control treatment where rooting zone soil water content was increased to field capacity at each irrigation; (2 DI80; (3 DI60 and DI40; 20, 40 and 60% deficit irrigation compared to Full treatment were applied, respectively. Soil salinity was assessed using the isosalinity maps constructed with grid soil sampling of plant root zone at harvest. Results show that high spatial variability was observed in salinity along soil profiles when applying saline water with drip irrigation for potato. For the DI40 and DI60 treatments, high soil salinity was recorded in the upper soil layer close to the emitter. Increase of soil salinity within soil depths of 30 cm or below was also observed under DI60 and DI40 treatments. The lowest increase was noted under the full treatment. Surface soil salinity was somewhat higher under DI60 and DI40 compared with that of full and DI80 irrigation treatments. The distribution of salts around the dripper changes during the crop season according to applied irrigation treatments, with overall higher concentrations between the drippers and towards the margin of wetted band. Iso-salinity maps at harvest of potato showed that the surface layer of 30 cm depth had the lowest salinity which gradually increased at deeper zones irrespective of the treatment. Salt accumulation essentially occurred at wetting front between the drippers and the plant row. Although salt accumulation was relatively highest along the row under DI treatments, the area of accumulation was relatively shifted toward the center between the rows and the drip line. The results also show the importance of the potato cropping season to benefit from the leaching of soluble salts with the

Drip irrigation and fertigation of potato under light-textured soils of cappadocia region

International Nuclear Information System (INIS)

Halitgil, M. B.; Onaran, H.; Munsuz, N.; Kislal, H.; Akin, A.; Unlenen, A. L.; Cayci, G.; Kutuk, C.

2002-01-01

In order to evaluate potato response to drip irrigation and N fertigation; and also to improve nitrogen and water use efficiencies of potato and eventually to obtain less nitrogen polluted surface and water, 10 field experiments were carried out at three different locations in Cappadocia Region of Turkey in 1997, 1998, 1999 and 2000 growing seasons. Nitrogen as ammonium sulphate ((NH 4 ) 2 So 4 ), was supplied by drip irrigation water (fertigation) at rates of 0, 30, 60 and 90 kg N/da. Also, soil N application treatment equivalent to the fertigation treatment of 60kg N/da was included. These five treatments were investigated in a completely randomized block design with four replicants. Agria potato variety was used in all experiments and potato was planted in mid May and harvested at the end of October.''1''5N-labelled ammonium sulphate fertilizer were applied in isotope-sub plots within the macroplots for each treatment, in order to determine the amount of nitrogen taken up by the plant, nitrogen use efficiency and the distribution of residual nitrogen at different depths in the soil profile. Each year, during the growth period, total 12 irrigations were done and 50 mm of water was applied at each irrigation. At harvest, plant samples (tuber and leaf+vein) and soil samples were taken from each plot and N%, ''1''5N% atom excess (''1''5N% a.e.) and Ndff% determinations were done. Soil water contents at differrent soil depths were determined by soil moisture neutron probe at plantingand at harvest period so that water contents at different soil layers and water use efficiencies were calculated for each treatment. The results obtained showed that 3350 kg/da mean total marketable tuber yield was obtained with application of 600 mm irrigation water. Also,it was found that water did not move below 90 cm of soil layer in drip irrigation-fertigation system, which showed clearly that no nitrogen movement occured beyond 90 cm soil depth. Tuber yields and %Ndff increased when

Sorption of pathogens during sub-surface drip irrigation with wastewater

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Levi, Laillach; Gillerman Gillerman, Leonid; Kalavrouziotis, Ioannis; Oron, Gideon

2017-04-01

Water scarcity continues to be one of the major threats to human survival in many regions worldwide, such as Africa, the Mediterranean Basin, the State of California in the US. Due to a mixture of factors such as population growth, reduction in water resources availability and higher demand for high quality waters in these regions these countries face water shortage issues that stem from overuse, extensive extraction of groundwater, and frequent drought events. In addition, there are increases in environmental and health awareness that have led to intensive efforts in the treatment and reuse of nonconventional water sources, mainly wastewater and greywater. One approach to water shortages issues is to use wastewater as means to close the gap between supply and demand. However, the need to treat wastewater and to disinfect it forces additional economic burden on the users, primarily for agricultural irrigation. A possible solution might be to use the soil as a sorbent for the contained pathogens. Under sub-surface drip irrigation, not allowing the wastewater to reach the soil surface, the pathogens will remain in the soil. It was as well shown in field experiments that the opening size of roots will not allow pathogens to penetrate into the plants. Additional advantages such as water saving, protection of the pipe systems and others are also important. Field experiments in commercial fields just emphasize the main advantages of sub-surface drip irrigation.

Horizontal distribution of phosphorus in soils of irrigation ditches ...

African Journals Online (AJOL)

Horizontal distribution of phosphorus in soils of irrigation ditches. ... correlations were found between soil P and stream water P on one hand, and between soil pH and stream water pH on the other, indicating that the irrigation water may indeed, have had little or no influence on the properties of the ditches' soils.

Heavy-metal contamination of agricultural soils irrigated with industrial effluents

International Nuclear Information System (INIS)

Nabi, G.; Ashraf, M.; Aslam, M. R.

2001-01-01

Pakistan is facing a thread of degradation of water and land-resources by industrial effluents. To evaluated the suitability of these effluents as a source of irrigation for agriculture and the study their effects on soil chemical properties, experiments were conducted in the industrial area of Sheikhupura, where effluent from Paper and Board Mill (PBM), Leather Industry (LI) and Fertilizer Industry (FI) were being used for irrigation. At each site, two fields were selected, one irrigated with industrial effluents and the other with tube-well/canal water. The soil samples were collected and analyzed for pH, ECe, SAR and for heavy metals, such as Cu, Cd, Cr, Zn, Pb, Mn, Fe, Al and Ni. Soil receiving effluent from LI showed higher ECe and SAR values, as compared to the soils receiving other effluents. The concentration of Al was high in the soil irrigated with LI effluent. The Mn and Fe contents were higher in soils irrigated with PBM effluent. Effluent from LI is not fit for irrigation, since its recipient soil showed high concentration of Cr and also high sodicity values. Except Cr, the heavy metals were not of environmental concern. (author)

Soil Suitability Classification of Tomas Irrigation Scheme for Irrigated ...

African Journals Online (AJOL)

The need for sustainable rice production in Nigeria cannot be over-emphasized. Since rice can be grown both under rain-fed and irrigated conditions, the need for soil suitability evaluation becomes very necessary in order for supply to meet up with demand. Six land qualities viz; climate, soil physical properties, drainage, ...

Sensor-Based Assessment of Soil Salinity during the First Years of Transition from Flood to Sprinkler Irrigation

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Mª Auxiliadora Casterad

2018-02-01

Full Text Available A key issue for agriculture in irrigated arid lands is the control of soil salinity, and this is one of the goals for irrigated districts when changing from flood to sprinkling irrigation. We combined soil sampling, proximal electromagnetic induction, and satellite data to appraise how soil salinity and its distribution along a previously flood-irrigated field evolved after its transformation to sprinkling. We also show that the relationship between NDVI (normalized difference vegetation index and ECe (electrical conductivity of the soil saturation extracts mimics the production function between yield and soil salinity. Under sprinkling, the field had a double crop of barley and then sunflower in 2009 and 2011. In both years, about 50% of the soil of the entire studied field—45 ha—had ECe < 8 dS m−1, i.e., allowing barley cultivation, while the percent of surface having ECe ≥ 16 dS m−1 increased from 8.4% in 2009 to 13.7% in 2011. Our methodology may help monitor the soil salinity oscillations associated with irrigation management. After quantifying and mapping the soil salinity in 2009 and 2011, we show that barley was stunted in places of the field where salinity was higher. Additionally, the areas of salinity persisted after the subsequent alfalfa cropping in 2013. Application of differential doses of water to the saline patches is a viable method to optimize irrigation water distribution and lessen soil salinity in sprinkler-irrigated agriculture.

Irrigation scheduling using soil moisture sensors

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Soil moisture sensors were evaluated and used for irrigation scheduling in humid region. Soil moisture sensors were installed in soil at depths of 15cm, 30cm, and 61cm belowground. Soil volumetric water content was automatically measured by the sensors in a time interval of an hour during the crop g...

Online decision support system for surface irrigation management

Science.gov (United States)

Wang, Wenchao; Cui, Yuanlai

2017-04-01

Irrigation has played an important role in agricultural production. Irrigation decision support system is developed for irrigation water management, which can raise irrigation efficiency with few added engineering services. An online irrigation decision support system (OIDSS), in consist of in-field sensors and central computer system, is designed for surface irrigation management in large irrigation district. Many functions have acquired in OIDSS, such as data acquisition and detection, real-time irrigation forecast, water allocation decision and irrigation information management. The OIDSS contains four parts: Data acquisition terminals, Web server, Client browser and Communication system. Data acquisition terminals are designed to measure paddy water level, soil water content in dry land, ponds water level, underground water level, and canals water level. A web server is responsible for collecting meteorological data, weather forecast data, the real-time field data, and manager's feedback data. Water allocation decisions are made in the web server. Client browser is responsible for friendly displaying, interacting with managers, and collecting managers' irrigation intention. Communication system includes internet and the GPRS network used by monitoring stations. The OIDSS's model is based on water balance approach for both lowland paddy and upland crops. Considering basic database of different crops water demands in the whole growth stages and irrigation system engineering information, the OIDSS can make efficient decision of water allocation with the help of real-time field water detection and weather forecast. This system uses technical methods to reduce requirements of user's specialized knowledge and can also take user's managerial experience into account. As the system is developed by the Browser/Server model, it is possible to make full use of the internet resources, to facilitate users at any place where internet exists. The OIDSS has been applied in

Effect of long-term irrigation patterns on phosphorus forms and distribution in the brown soil zone.

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Chang Liu

Full Text Available Continuous application of P fertilizers under different irrigation patterns can change soil phosphorus (P chemical behavior and increase soil P levels that are of environmental concern. To assess the effect of long-term different irrigation patterns on soil P fractions and availability, this study examined sequential changes in soil organic P and inorganic P from furrow irrigation (FI, surface drip irrigation (SUR, and subsurface drip irrigation (SDI in the brown soil zone (0-60 cm during 1998 to 2011. Analyses of soil P behavior showed that the levels of total P are frequently high on top soil layers. The total P (TP contents of the entire soil profiles under three irrigation treatments were 830.2-3180.1 mg/kg. The contents of available P (AP were 72.6-319.3 mg P/kg soil through soil profiles. The greatest TP and AP contents were obtained within the upper soil layers in FI. Results of Hedley's P fractionation indicate that HCl-P is a dominant form and the proportion to TP ranges from 29% to 43% in all three methods. The contents of various fractions of P were positively correlated with the levels of total carbon (TC, total inorganic carbon (TIC, and calcium (Ca, whereas the P fractions had negative correlation with pH in all soil samples. Regression models proved that NaHCO3-Po was an important factor in determining the amount of AP in FI. H2O-Po, NaHCO3-Po, and NaOH-Pi were related to available P values in SUR. NaHCO3-Po and NaOH-Po played important roles in SDI. The tomato yield under SUR was higher than SDI and FI. The difference of P availability was also controlled by the physicochemical soil properties under different irrigation schedule. SUR was a reasonable irrigation pattern to improve the utilization efficiency of water and fertilizer.

Effect of different levels of nitrogen fertilizer on yield and quality of sugar beet Beta vulgaris irrigated with saline groundwater (fertigation and surface irrigation) and grown under saline conditions

International Nuclear Information System (INIS)

Janat, M.

2009-07-01

In a field experiment Sugar beet Beta vulgaris was grown as a spring crop during the growing seasons of 2004 and 2006, in salt affected soil, previously planted with sesbania and barley (2005 and 2003) to evaluate the response of sugar beet to two irrigation methods, (drip fertigation and surface irrigation), different levels of nitrogen fertilizer and its effect on yield and quality. Different rates of nitrogen fertilizers (0, 50, 100, 150 and 200 kg N/ ha) as urea (46% N) were injected for drip irrigation or broadcasted for the surface-irrigated treatments in four equally split applications. The 15 N labelled urea was applied to sub-plots of 1.0 m 2 in each experimental unit in a manner similar to that of unlabeled urea. Irrigation scheduling was carried out using the direct method of neutron scattering technique. Sugar beet was irrigated when soil moisture in the upper 25 cm was 80% of the field capacity (FC) and such practice continued until the six leaf stage. From the latter stage until harvest, sugar beet was irrigated when soil moisture in the upper 50 cm reached 80% of the FC. The amount of irrigation water applied, electrical conductivity of the soil paste, dry matter and fresh roots yield, total nitrogen uptake and N derived from fertilizer were also determined. Furthermore, Nitrogen use as well as water use-efficiencies for dry matter and roots yield were also calculated. Results revealed that sugar beets and dry matter yield increased with increasing N input up to 100-150 kg N/ha which was indicated by the higher dry matter yield, and sugar beet yield. Sugar percentage was also increased relative to the average percentage recorded in Syria. Crop water use efficiencies, for both the drip-fertigated and surface-irrigated treatments were increased in most cases with increasing rate of nitrogen fertilizer. During the course of this study, small increases in soil salinity under both irrigation methods were observed. Higher increases in soil salinity was

[Study on soil enzyme activities and microbial biomass carbon in greenland irrigated with reclaimed water].

Science.gov (United States)

Pan, Neng; Hou, Zhen-An; Chen, Wei-Ping; Jiao, Wen-Tao; Peng, Chi; Liu, Wen

2012-12-01

The physicochemical properties of soils might be changed under the long-term reclaimed water irrigation. Its effects on soil biological activities have received great attentions. We collected surface soil samples from urban green spaces and suburban farmlands of Beijing. Soil microbial biomass carbon (SMBC), five types of soil enzyme activities (urease, alkaline phosphatase, invertase, dehydrogenase and catalase) and physicochemical indicators in soils were measured subsequently. SMBC and enzyme activities from green land soils irrigated with reclaimed water were higher than that of control treatments using drinking water, but the difference is not significant in farmland. The SMBC increased by 60.1% and 14.2% than those control treatments in 0-20 cm soil layer of green land and farmland, respectively. Compared with their respective controls, the activities of enzymes in 0-20 cm soil layer of green land and farmland were enhanced by an average of 36.7% and 7.4%, respectively. Investigation of SMBC and enzyme activities decreased with increasing of soil depth. Significantly difference was found between 0-10 cm and 10-20 cm soil layer in green land. Soil biological activities were improved with long-term reclaimed water irrigation in Beijing.

Irrigation effects on soil attributes and grapevine performance in a 'Godello' vineyard of NW Spain

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Fandiño, María; Trigo-Córdoba, Emiliano; Martínez, Emma M.; Bouzas-Cid, Yolanda; Rey, Benjamín J.; Cancela, Javier J.; Mirás-Avalos, Jose M.

2014-05-01

Irrigation systems are increasingly being used in Galician vineyards. However, a lack of information about irrigation management can cause a bad use of these systems and, consequently, reductions in berry quality and loss of water resources. In this context, experiences with Galician cultivars may provide useful information. A field experiment was carried out over two seasons (2012-2013) on Vitis vinifera (L.) cv. 'Godello' in order to assess the effects of irrigation on soil attributes, grapevine performance and berry composition. The field site was a commercial vineyard located in A Rúa (Ourense-NW Spain). Rain-fed vines (R) were compared with two irrigation systems: surface drip irrigation (DI) and subsurface drip irrigation (SDI). Physical and chemical characteristics of soil were analyzed after installing irrigation systems at the beginning of each season, in order to assess the effects that irrigation might have on soil attributes. Soil water content, leaf and stem water potentials and stomatal conductance were periodically measured over the two seasons. Yield components including number of clusters, yield per plant and cluster average weight were taken. Soluble solids, pH, total acidity and amino acids contents were measured on the grapes at harvest. Pruning weight was also recorded. Soil attributes did not significantly vary due to the irrigation treatments. Stem water potentials were significantly lower for R plants on certain dates through the season, whereas stomatal conductance was similar for the three treatments in 2013, while in 2012 SDI plants showed greater stomatal conductance values. SDI plants yielded more than those R due to both a greater number of clusters per plant and to heavier clusters. Pruning weight was significantly higher in SI plants. Berry composition was similar for the three treatments except for the amino acids content, which was higher under SDI conditions. These results may be helpful for a sustainable management of irrigation

[Effects of brackish water irrigation on soil enzyme activity, soil CO2 flux and organic matter decomposition].

Science.gov (United States)

Zhang, Qian-qian; Wang, Fei; Liu, Tao; Chu, Gui-xin

2015-09-01

Brackish water irrigation utilization is an important way to alleviate water resource shortage in arid region. A field-plot experiment was set up to study the impact of the salinity level (0.31, 3.0 or 5.0 g · L(-1) NaCl) of irrigated water on activities of soil catalase, invertase, β-glucosidase, cellulase and polyphenoloxidase in drip irrigation condition, and the responses of soil CO2 flux and organic matter decomposition were also determined by soil carbon dioxide flux instrument (LI-8100) and nylon net bag method. The results showed that in contrast with fresh water irrigation treatment (CK), the activities of invertase, β-glucosidase and cellulase in the brackish water (3.0 g · L(-1)) irrigation treatment declined by 31.7%-32.4%, 29.7%-31.6%, 20.8%-24.3%, respectively, while soil polyphenoloxidase activity was obviously enhanced with increasing the salinity level of irrigated water. Compared to CK, polyphenoloxidase activity increased by 2.4% and 20.5%, respectively, in the brackish water and saline water irrigation treatments. Both soil microbial biomass carbon and microbial quotient decreased with increasing the salinity level, whereas, microbial metabolic quotient showed an increasing tendency with increasing the salinity level. Soil CO2 fluxes in the different treatments were in the order of CK (0.31 g · L(-1)) > brackish water irrigation (3.0 g · L(-1)) ≥ saline water irrigation (5.0 g · L(-1)). Moreover, CO2 flux from plastic film mulched soil was always much higher than that from no plastic film mulched soil, regardless the salinity of irrigated water. Compared with CK, soil CO2 fluxes in the saline water and brackish water treatments decreased by 29.8% and 28.2% respectively in the boll opening period. The decomposition of either cotton straw or alfalfa straw in the different treatments was in the sequence of CK (0.31 g · L(-1)) > brackish water irrigation (3.0 g · L(-1)) > saline water treatment (5.0 g · L(-1)). The organic matter

Monitoring of Lead (Pb) Pollution in Soils and Plants Irrigated with Untreated Sewage Water in Some Industrialized Cities of Punjab, India.

Science.gov (United States)

Sikka, R; Nayyar, V K

2016-04-01

Soil and plant samples were collected from sewage and tubewell irrigated sites from three industrially different cities of Punjab (India) viz. Ludhiana, Jalandhar and Malerkotla. The extent of lead (Pb) pollution was assessed with respect to background concentration of tubewell irrigation. In sewage irrigated surface soil layer (0-15 cm), the extent of Pb accumulation was 4.61, 4.20 and 2.26 times higher than those receiving tubewell irrigation sites in Ludhiana, Jalandhar and Malerkotla, respectively. Multiple regression analysis showed that soil pH, organic carbon, calcium carbonate and clay were significant soil parameters explaining the variation in available soil Pb. The mean Pb content in plants receiving sewage irrigation was 4.56, 5.48 and 2.72 times higher than tubewell irrigation in Ludhiana, Jalandhar and Malerkotla, respectively. The content of Pb in plants receiving sewage irrigation revealed that, assuming a weekly consumption of 500-1000 g of vegetables grown on sewage irrigated soils by an adult of 70 kg body weight, the Pb intake may far exceed the World Health Organization proposed tolerable weekly intake of Pb.

An overview of soil water sensors for salinity & irrigation management

Science.gov (United States)

Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands while protecting the soil and water resources from degradation. Accurate irrigation management is even more important in salt affected soils ...

Soil salinisation and irrigation management of date palms in a Saharan environment.

Science.gov (United States)

Haj-Amor, Zied; Ibrahimi, Mohamed-Khaled; Feki, Nissma; Lhomme, Jean-Paul; Bouri, Salem

2016-08-01

The continuance of agricultural production in regions of the world with chronic water shortages depends upon understanding how soil salinity is impacted by irrigation practises such as water salinity, irrigation frequency and amount of irrigation. A two-year field study was conducted in a Saharan oasis of Tunisia (Lazala Oasis) to determine how the soil electrical conductivity was affected by irrigation of date palms with high saline water. The study area lacked a saline shallow water table. Field results indicate that, under current irrigation practises, soil electrical conductivity can build up to levels which exceed the salt tolerance of date palm trees. The effects of irrigation practises on the soil electrical conductivity were also evaluated using model simulations (HYDRUS-1D) of various irrigation regimes with different frequencies, different amounts of added water and different water salinities. The comparison between the simulated and observed results demonstrated that the model gave an acceptable estimation of water and salt dynamics in the soil profile, as indicated by the small values of root mean square error (RMSE) and the high values of the Nash-Sutcliffe model efficiency coefficient (NSE). The simulations demonstrated that, under field conditions without saline shallow groundwater, saline irrigation water can be used to maintain soil electrical conductivity and soil water content at safe levels (soil electrical conductivity soil water content >0.04 cm(3) cm(-3)) if frequent irrigations with small amounts of water (90 % of the evapotranspiration requirements) were applied throughout the year.

Soil nitrate testing supports nitrogen management in irrigated annual crops

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Patricia A. Lazicki

2016-12-01

Full Text Available Soil nitrate (NO3− tests are an integral part of nutrient management in annual crops. They help growers make field-specific nitrogen (N fertilization decisions, use N more efficiently and, if necessary, comply with California's Irrigated Lands Regulatory Program, which requires an N management plan and an estimate of soil NO3− from most growers. As NO3− is easily leached into deeper soil layers and groundwater by rain and excess irrigation water, precipitation and irrigation schedules need to be taken into account when sampling soil and interpreting test results. We reviewed current knowledge on best practices for taking and using soil NO3− tests in California irrigated annual crops, including how sampling for soil NO3− differs from sampling for other nutrients, how tests performed at different times of the year are interpreted and some of the special challenges associated with NO3− testing in organic systems.

Biodegradability of pharmaceutical compounds in agricultural soils irrigated with treated wastewater

International Nuclear Information System (INIS)

Grossberger, Amnon; Hadar, Yitzhak; Borch, Thomas; Chefetz, Benny

2014-01-01

Pharmaceutical compounds (PCs) are introduced into agricultural soils via irrigation with treated wastewater (TWW). Our data show that carbamazepine, lamotrigine, caffeine, metoprolol, sulfamethoxazole and sildenafil are persistent in soils when introduced via TWW. However, other PCs, namely diclofenac, ibuprofen, bezafibrate, gemfibrozil and naproxen were not detected in soils when introduced via TWW. This is likely due to rapid degradation as confirmed in our microcosm studies where they exhibited half-lives (t 1/2 ) between 0.2–9.5 days when soils were spiked at 50 ng/g soil and between 3 and 68 days when soils were spiked at 5000 ng/g soil. The degradation rate and extent of PCs observed in microcosm studies were similar in soils that had been previously irrigated with TWW or fresh water. This suggests that pre-exposure of the soils to PCs via irrigation with TWW does not enhance their biodegradation. This suggests that PCs are probably degraded in soils via co-metabolism. Highlights: • Some pharmaceuticals are highly persistent in arable soils. • Weak acid pharmaceuticals are readily degradable in agricultural soils. • Irrigation with treated wastewater does not enhance degradation of pharmaceuticals. • Degradation of pharmaceuticals in soil is probably occurred via co-metabolism. -- Some pharmaceutical compounds are persistent in arable soils when introduced via irrigation with treated wastewater

Environmental assessment of water-salt regime of irrigated soils in the Central-Chernozem Region of Russia

Science.gov (United States)

Alaeva, Liliia; Negrobova, Elena; Jablonskikh, Lidiia; Rumyantseva, Irina

2016-04-01

A large part of Central Chernozem Region is located in the zone of risky agriculture. This led to intensive use of soil in the irrigation system. Therefore, a detailed analysis of water-salt regime of irrigated soils required for ecological state assessment of soils for irrigation. In the investigated area the fone component of the soil cover on the levelled plateau are chernozems. On the slopes formed a meadow-chernozem soils. Parent material is a cover loess-like calcareous non-saline clay. In these soils, our studies found component-quantitative composition of the aqueous extract, the chemism of salinity, which allowed us to make conclusions about the direction of the salinisation process in soils when used in the system of irrigated agriculture. By quantity water extract chernozems are non-saline, the ratio of anions and cations are chloride-sulphate magnesium-calcium salinization. In the composition of easily soluble salts dominated by Ca(HCO3)2. On sum of toxic salts in the soils are non-saline. This type and chemism of salinity deep brackish groundwater (more than 5 m) can be actively used in the system of rational irrigation. The meadow-chernozem soils formed under conditions of increased surface and soil moisture in the shallow brackish water at a depth of 3-5 m. These soils by quantity water extract are non-saline, anionic-cationic ratio - chloride-sulphate magnesium-calcium salinization. Permanent components of salt associations are Ca(HCO3)2, MgCl2, Na2SO4. On sum of toxic salts in the soil is not saline throughout the profile. The chemism of salinity and the proximity of groundwater at irregular watering can lead to the rise of groundwater level, the development of gleyed and sodium alkalinization. Thus, the introduction of intensive irrigated agriculture on chernozems and hydromorphic analogues may lead to the development in them of negative consequences. The most dynamic indicator is the water-salt regime, the systematic monitoring and control which

Irrigated cotton grown on sierozem soils in South Kazakhstan

Science.gov (United States)

The Gloldnaya steppe has large areas of fertile sierozem soils that are important for crop production and its accompanying economic development. The soils are fertile loams but because of the steppe’s dry environment, they need to be irrigated. Our objective was to study irrigation management of cot...

Soil properties evolution after irrigation with reclaimed water

Science.gov (United States)

Leal, M.; González-Naranjo, V.; de Miguel, A.; Martínez-Hernández, V.; Lillo, J.

2012-04-01

Many arid and semi-arid countries are forced to look for new and alternative water sources. The availability of suitable quality water for agriculture in these regions often is threatened. In this context of water scarcity, the reuse of treated wastewater for crop irrigation could represent a feasible solution. Through rigorous planning and management, irrigation with reclaimed water presents some advantages such as saving freshwater, reducing wastewater discharges into freshwater bodies and decreasing the amount of added fertilizers due to the extra supply of nutrients by reclaimed water. The current study, which involves wastewater reuse in agriculture, has been carried out in the Experimental Plant of Carrión de los Céspedes (Sevile, Spain). Here, two survey parcels equally designed have been cultivated with Jatropha curcas L, a bioenergetic plant and a non-interfering food security crop. The only difference between the two parcels lies on the irrigation water quality: one is irrigated with groundwater and another one with reclaimed water. The main aim of this study focuses on analysing the outstanding differences in soil properties derived from irrigation with two water qualities, due to their implications for plant growth. To control and monitor the soil variables, soil samples were collected before and after irrigation in the two parcels. pH, electrical conductivity, cation exchange capacity, exchangeable cations (Ca2+, Mg2+, Na+ and K+), kjeldahl nitrogen, organic matter content and nutrients (boron, phosphorus, nitrogen, potassium) were measured. Data were statistically analyzed using the R package. To evaluate the variance ANOVA test was used and to obtain the relations between water quality and soil parameters, Pearson correlation coefficient was computed. According to other authors, a decrease in the organic matter content and an increase of parameters such as pH, electrical conductivity and some exchangeable cations were expected. To date and after

Near-surface distributions of soil water and water repellency under three effluent irrigation scemes in a blue gum (Eucalyptus globulus) plantation

NARCIS (Netherlands)

Thwaites, L.A.; Rooij, de G.H.; Salzman, S.; Allinson, G.; Stagnitti, F.; Carr, R.; Versace, V.; Struck, S.; March, T.

2006-01-01

Water repellent soils are difficult to irrigate and susceptible to preferential flow, which enhances the potential for accelerated leaching to groundwater of hazardous substances. Over 5 Mha of Australian soil is water repellent, while treated municipal sewage is increasingly used for irrigation.

Scenario Studies on Effects of Soil Infiltration Rates, Land Slope, and Furrow Irrigation Characteristics on Furrow Irrigation-Induced Erosion.

Science.gov (United States)

Dibal, Jibrin M; Ramalan, A A; Mudiare, O J; Igbadun, H E

2014-01-01

Furrow irrigation proceeds under several soil-water-furrow hydraulics interaction dynamics. The soil erosion consequences from such interactions in furrow irrigation in Samaru had remained uncertain. A furrow irrigation-induced erosion (FIIE) model was used to simulate the potential severity of soil erosion in irrigated furrows due to interactive effects of infiltration rates, land slope, and some furrow irrigation characteristics under different scenarios. The furrow irrigation characteristics considered were furrow lengths, widths, and stream sizes. The model itself was developed using the dimensional analysis approach. The scenarios studied were the interactive effects of furrow lengths, furrow widths, and slopes steepness; infiltration rates and furrow lengths; and stream sizes, furrow lengths, and slopes steepness on potential furrow irrigation-induced erosion, respectively. The severity of FIIE was found to relate somewhat linearly with slope and stream size, and inversely with furrow lengths and furrow width. The worst soil erosion (378.05 t/ha/yr) was found as a result of the interactive effects of 0.65 m furrow width, 50 m furrow length, and 0.25% slope steepness; and the least soil erosion (0.013 t/ha/yr) was induced by the combined effects of 0.5 l/s, 200 m furrow length, and 0.05% slope steepness. Evidently considering longer furrows in furrow irrigation designs would be a better alternative of averting excessive FIIE.

Accumulation of Cd in agricultural soil under long-term reclaimed water irrigation

International Nuclear Information System (INIS)

Chen, Weiping; Lu, Sidan; Peng, Chi; Jiao, Wentao; Wang, Meie

2013-01-01

Safety of agricultural irrigation with reclaimed water is of great concern as some potential hazardous compounds like heavy metals may be accumulated in soils over time. Impacts of long-term reclaimed water on soil Cd pollution were evaluated based on the field investigation in two main crop areas in Beijing with long irrigation history and on simulation results of STEM-profile model. Under long-term reclaimed water, Cd content in the top 20 cm soil layer was greatly elevated and was more than 2 times higher than that in the deep soil layer. There was very small differences between the field measured and model simulated Cd content in the plow layer (top 20 cm) and entire soil layer. Long-term model prediction showed that reclaimed water irrigation had a low environmental risk of soil Cd pollution, but the risk would be aggravated when there were high metal loading from other sources. The risk is also depending on the soil and plant properties. -- Highlights: •Root zone soil Cd content was elevated by one time under long-term reclaimed water irrigation. •The STEM-profile model can well track the Cd balance in the soil profile. •Reclaimed water irrigation plays a limited role on soil Cd accumulation in Beijing croplands. -- There was a low risk of soil Cd pollution under long-term reclaimed water irrigation

Infiltration into cropped soils: effect of rain and sodium adsorption ratio-impacted irrigation water.

Science.gov (United States)

Suarez, Donald L; Wood, James D; Lesch, Scott M

2008-01-01

The sodium adsorption ratio (SAR) and salinity criteria for water suitability for irrigation have been developed for conditions where irrigation water is the only water source. It is not clear that these criteria are applicable to environments where there is a combination of rain and irrigation during the growing season. The interaction of rainfall with irrigation water is expected to result in increased sodicity hazard because of the low electrical conductivity of rain. In this study we examined the effects of irrigation waters of SAR 2, 4, 6, 8, and 10 mmol(1/2) L(-1/2) and electrical conductivities of 1 and 2 dS m(-1) on the infiltration rate of two soils with alternating cycles of rain (simulated with a rainfall sprinkler) and irrigation water, separated by drying cycles. The infiltration rate of surface samples from two soils, Kobase silty clay (fine, smectitic, frigid, Torrertic Haplustept) and Glendive very fine sandy loam (coarse-loamy, mixed superactive, calcareous, frigid Aridic Ustifluvent) were evaluated under alfalfa (Medicago sativa) cropped conditions for over 140 d and under full canopy cover. Reductions in infiltration were observed for both soils for SAR above 2, and the reductions became more severe with increasing SAR. Saturated hydraulic conductivity measurements taken from undisturbed cores at the end of the experiment were highly variable, suggesting that in situ infiltration measurements may be preferred when evaluating SAR effects.

Evaluation of soil and water salinity for irrigation in North-eastern ...

African Journals Online (AJOL)

For sound land use and water management in irrigated area, knowledge of the chemical composition of soils, water, climate, drainage condition and irrigation methods before action are crucial for sustainability of irrigation projects. The study aimed to evaluate the physicochemical properties of soils and water for intended ...

Continuous measurement of soil evaporation in a drip-irrigated wine vineyard in a desert area

Science.gov (United States)

Evaporation from the soil surface (E) can be a significant source of water loss in arid areas. In sparsely vegetated systems, E is expected to be a function of soil, climate, irrigation regime, precipitation patterns, and plant canopy development, and will therefore change dynamically at both daily ...

Uptake and Accumulation of Pharmaceuticals in Lettuce Under Surface and Overhead Irrigations

Science.gov (United States)

Bhalsod, G.; Chuang, Y. H.; Jeon, S.; Gui, W.; Li, H.; Guber, A.; Zhang, W.

2015-12-01

Pharmaceuticals and personal care products are being widely detected in wastewater and surface waters. As fresh water becomes scarcer, interests in using reclaimed water for crop irrigation is intensified. Since reclaimed waters often carry trace levels of pharmaceuticals, accumulation of pharmaceuticals in food crops could increase the risk of human exposure. This study aims to investigate uptake and accumulations of pharmaceuticals in greenhouse-grown lettuce under contrasting irrigation practices (i.e., overhead and surface irrigations). Lettuce was irrigated with water spiked with 11 commonly used pharmaceuticals (acetaminophen, caffeine, carbamazepine, sulfadiazine, sulfamethoxazole, carbadox, trimethoprim, lincomycin hydrochloride, oxytetracycline hydrochloride, monensin sodium, and tylosin). Weekly sampling of lettuce roots, shoots, and soils were continued for 5 weeks, and the samples were freeze dried, extracted for pharmaceuticals and analyzed by LC-MS/MS. Preliminary results indicate that higher concentrations of pharmaceuticals were found in overhead irrigated lettuce compared to surface irrigated lettuce. For carbamezapine, sulfadiazine, trimethoprim, oxytetracycline, and monensin sodium, their concentrations generally increased in lettuce shoots in the overhead treatment over time. However, acetaminophen was found at higher concentrations in both shoots and roots, indicating that acetaminophen can be easily transported in the plant system. This study provides insight on developing better strategies for using reclaimed water for crop irrigations, while minimizing the potential risks of pharmaceutical contamination of vegetables.

Simulated optimization of crop yield through irrigation system design and operation based on the spatial variability of soil hydrodynamic properties

International Nuclear Information System (INIS)

Gurovich, L.; Stern, J.; Ramos, R.

1983-01-01

Spatial autocorrelation and kriging techniques were applied to soil infiltrability data from a 20 hectare field, to separate homogeneous irrigation units. Border irrigation systems were designed for each unit and combinations of units by using DESIGN, a computer model based on soil infiltrability and hydraulics of surface water flow, which enables optimal irrigation systems to be designed. Water depths effectively infiltrated at different points along the irrigation run were determined, and the agronomic irrigation efficiency of the unit evaluated. A modification of Hanks' evapotranspiration model, PLANTGRO, was used to evaluate plant growth, relative crop yield and soil-water economy throughout the growing season, at several points along each irrigation unit. The effect of different irrigation designs on total field yield and total water used for irrigation was evaluated by integrating yield values corresponding to each point, volume and inflow time during each irrigation. For relevant data from winter wheat grown in the central area of Chile during 1981, simulation by an interactive and sequentially recurrent use of DESIGN and PLANTGRO models, was carried out. The results obtained indicate that, when a field is separated into homogeneous irrigation units on the basis of the spatial variability of soil infiltrability and the border irrigation systems are designed according to soil characteristics, both a significant yield increase and less water use can be obtained by comparison with other criteria of field zonification for irrigation management. The use of neutrometric determinations to assess soil-water content during the growing season, as a validation of the results obtained in this work, is discussed. (author)

Approaches and challenges of soil water monitoring in an irrigated vineyard

Science.gov (United States)

Nolz, Reinhard; Loiskandl, Willibald

2016-04-01

Monitoring of water content is an approved method to quantify certain components of the soil water balance, for example as basis for hydrological studies and soil water management. Temporal soil water data also allow controlling water status by means of demand-oriented irrigation. Regarding spatial variability of water content due to soil characteristics, plant water uptake and other non-uniformities, it is a great challenge to select a location that is most likely representing soil water status of a larger area (e.g. an irrigated field). Although such an approach might not satisfy the requirements of precision farming - which becomes more and more related to industrial agriculture - it can help improving water use efficiency of small-scale farming. In this regard, specific conditions can be found in typical vineyards in the eastern part of Austria, where grapes are grown for high quality wine production. Generally, the local dry-subhumid climate supports grape development. However, irrigation is temporarily essential in order to guarantee stable yields and high quality. As the local winegrowers traditionally control irrigation based on their experience, there is a potential to improve irrigation management by means of soil water data. In order to gain experience with regard to irrigation management, soil water status was determined in a small vineyard in Austria (47°48'16'' N, 17°01'57'' E, 118 m elevation). The vineyard was equipped with a subsurface drip irrigation system and access tubes for measuring water content in soil profiles. The latter was measured using a portable device as well as permanently installed multi-sensor capacitance probes. Soil samples were taken at chosen dates and gravimetrically analyzed in the laboratory. Water content data were analyzed using simple statistical procedures and the temporal stability concept. Soil water content was interpreted considering different environmental conditions, including rainfall and irrigation periods

Changes of soil organic matter and microbial activity in irrigated and non irrigated olive groves

Science.gov (United States)

Kavvadias, Victor; Papadopoulou, Maria; Theocharopoulos, Sideris; Vavoulidou, Evagelia; Doula, Maria; Reppas, Spiros

2014-05-01

The implementation of olive cultivation techniques in Greece has not been systematically tested under the prevailing Mediterranean conditions. A LIFE+ project was initiated (oLIVE-CLIMA; LIFE 11/ENV/000942) aiming to introduce new management practices in olive tree crops that lead to increased carbon dioxide uptake by plants as well as carbon sequestration from the atmosphere and reverse the trend of soil organic matter decline, erosion and desertification. This paper presents data on soil organic matter and microbial activity from a soil campaign in a pilot region in Greece, and particularly in the area of Chora, prefecture of Messinia, South west Peloponnese. The soil campaign took place during the period December 2012-February 2013. Twelve soil parcels of olive groves were selected (6 irrigated and 6 rainfed) and in each soil parcel six composite soil samples were taken from 0-10 cm depth at equal intervals along a straight line of the trunk of the tree to the middle of the distance from the nearest tree of the next tree series. The first three samples were under olive tree canopy. An additional composite sample was taken at depth of 10-40 cm. Soil samples were analyzed for soil physicochemical and biological properties. In this study results for total organic carbon (TOC), soil basal microbial respiration (BR), microbial biomass C (MB-C) from the region of Messinia, are presented. Organic matter was determined by dichromate oxidation. The microbial activity was measured by the amount of CO2 evolution, while microbial biomass C was determined by substrate-induced respiration, after the addition of glucose. The results showed considerable differences in TOC, BR and MB-C associated with the sampling position and soil depth. The higher TOC, BR and MB-C values, in most cases, were determined in samples taken from points under the canopy, but not close to the tree trunk compared to the sampling points outside the canopy. This indicates the positive effect of

Phosphorus distribution in sandy soil profile under drip irrigation system

International Nuclear Information System (INIS)

El-Gendy, R.W.; Rizk, M.A.; Abd El Moniem, M.; Abdel-Aziz, H.A.; Fahmi, A.E.

2009-01-01

This work aims at to studying the impact of irrigation water applied using drip irrigation system in sandy soil with snap bean on phosphorus distribution. This experiment was carried out in soils and water research department farm, nuclear research center, atomic energy authority, cairo, Egypt. Snap bean was cultivated in sandy soil and irrigated with 50,37.5 and 25 cm water in three water treatments represented 100, 75 and 50% ETc. Phosphorus distribution and direction of soil water movement had been detected in three sites on the dripper line (S1,S2 and S3 at 0,12.5 and 25 cm distance from dripper). Phosphorus fertilizer (super phosphate, 15.5% P 2 O 5 in rate 300 kg/fed)was added before cultivation. Neutron probe was used to detect the water distribution and movement at the three site along soil profile. Soil samples were collected before p-addition, at end developing, mid, and late growth stages to determine residual available phosphorus. The obtained data showed that using 50 cm water for irrigation caused an increase in P-concentration till 75 cm depth in the three sites of 100% etc treatment, and covered P-requirements of snap bean for all growth stages. As for 37.5 and 25 cm irrigation water cannot cover all growth stages for P-requirements of snap bean. It could be concluded that applied irrigation water could drive the residual P-levels till 75 cm depth in the three sites. Yield of the crop had been taken as an indicator as an indicator profile. Yield showed good response according to water quantities and P-transportation within the soil profile

Assessing the fate of antibiotic contaminants in metal contaminated soils four years after cessation of long-term waste water irrigation

International Nuclear Information System (INIS)

Tamtam, Fatima; Oort, Folkert van; Le Bot, Barbara; Dinh, Tuc; Mompelat, Sophie; Chevreuil, Marc; Lamy, Isabelle; Thiry, Medard

2011-01-01

Spreading of urban wastewater on agricultural land may lead to concomitant input of organic and inorganic pollutants. Such multiple pollution sites offer unique opportunities to study the fate of both heavy metals and pharmaceuticals. We examined the occurrence and fate of selected antibiotics in sandy-textured soils, sampled four years after cessation of 100 years irrigation with urban wastewater from the Paris agglomeration. Previous studies on heavy metal contamination of these soils guided our sampling strategy. Six antibiotics were studied, including quinolones, with a strong affinity for organic and mineral soil components, and sulfonamides, a group of more mobile molecules. Bulk samples were collected from surface horizons in different irrigation fields, but also in subsurface horizons in two selected profiles. In surface horizons, three quinolones (oxolinic acid, nalidixic acid, and flumequine) were present in eight samples out of nine. Their contents varied spatially, but were well-correlated one to another. Their distributions showed great similarities regarding spatial distribution of total organic carbon and heavy metal contents, consistent with a common origin by wastewater irrigation. Highest concentrations were observed for sampling sites close to irrigation water outlets, reaching 22 μg kg -1 for nalidixic acid. Within soil profiles, the two antibiotic groups demonstrated an opposite behavior: quinolones, found only in surface horizons; sulfamethoxazole, detected in clay-rich subsurface horizons, concomitant with Zn accumulation. Such distribution patterns are consistent with chemical adsorption properties of the two antibiotic groups: immobilization of quinolones in the surface horizons ascribed to strong affinity for organic matter (OM), migration of sulfamethoxazole due to a lower affinity for OM and its interception and retention in electronegative charged clay-rich horizons. Our work suggests that antibiotics may represent a durable

Behaviour Of Saline Irrigation Water Components In Pakistani Barley And Calcareous Soil Under Scheduling Irrigation Using Neutron Scattering Technique

International Nuclear Information System (INIS)

RIZK, M.A.

2010-01-01

This study aims to investigate the behaviour of cation uptake by Pakistani barley (genotype PK-30163) as affected by saline irrigation water, as well as cation distribution within the soil profile. This experiment was carried out at Soil and Water Research Department, Nuclear Research Centre, Atomic Energy Authority, Inshas, Egypt. The soil was transferred from Wadi Sudr (South Sinai, Egypt). It is salted affected soil (calcareous soil, EC = 4.3 dS/m) and was irrigated using ground water irrigation (12.5 dS/m). Nine used lysimeters were irrigated with three artificial saline water (0.3, 4 and 8 dS/m) using drip irrigation system. The irrigation schedule was carried out using neutron scattering technique according to the hydro physical properties of the soil. Pakistani barley (halophytic plant) was used to remove salts from the soil especially sodium cations. The cation uptake and cation distribution (Na, K, Ca, Mg) within the soil profile were studied.The data indicated that roots of barley collected within 0-15 cm layer showed high cation uptake that made the salt concentrations in this layer low. Sodium uptake ratio was 43, 37 and 47% from total cation uptake by using fresh water (0.3 dS/m), 4 and 8 dS/m, respectively. The maximum uptake for Na, K, Ca and Mg was 20.51, 19.13, 3.98 and 12.81 g/lys at 5.69, 3.05, 6.56 and 4.15 dS/m, respectively. It was found that Pakistani barley preferred Mg uptake rather than Ca uptake.

Arsenic accumulation in irrigated agricultural soils in Northern Greece.

Science.gov (United States)

Casentini, B; Hug, S J; Nikolaidis, N P

2011-10-15

The accumulation of arsenic in soils and food crops due to the use of arsenic contaminated groundwater for irrigation has created worldwide concern. In the Chalkidiki prefecture in Northern Greece, groundwater As reach levels above 1000μg/L within the Nea Triglia geothermal area. While this groundwater is no longer used for drinking, it represents the sole source for irrigation. This paper provides a first assessment of the spatial extent of As accumulation and of As mobility during rainfall and irrigation periods. Arsenic content in sampled soils ranged from 20 to 513mg/kg inside to 5-66mg/kg outside the geothermal area. Around irrigation sprinklers, high As concentrations extended horizontally to distances of at least 1.5m, and to 50cm in depth. During simulated rain events in soil columns (pH=5, 0μg As/L), accumulated As was quite mobile, resulting in porewater As concentrations of 500-1500μg/L and exposing plant roots to high As(V) concentrations. In experiments with irrigation water (pH=7.5, 1500μg As/L), As was strongly retained (50.5-99.5%) by the majority of the soils. Uncontaminated soils (500mg/kg) could not retain any of the added As. Invoked mechanisms affecting As mobility in those soils were adsorption on solid phases such as Fe/Mn-phases and As co-precipitation with Ca. Low As accumulation was found in collected olives (0.3-25μg/kg in flesh and 0.3-5.6μg/kg in pits). However, soil arsenic concentrations are frequently elevated to far above recommended levels and arsenic uptake in faster growing plants has to be assessed. Copyright © 2011 Elsevier B.V. All rights reserved.

Impacts of deficit irrigation and altered rooting patterns on soil structure and associated soil properties

Science.gov (United States)

A better understanding of belowground systems and overall management impacts on soil health is needed to improve crop production and long-term sustainability under deficit irrigation. This study investigates effects of deficit irrigation on rooting patterns in maize and subsequent impacts on soil pr...

Impacts of irrigation regimes with saline water on carrot productivity and soil salinity

Directory of Open Access Journals (Sweden)

Kamel Nagaz

2012-01-01

Full Text Available A three-year study was conducted to evaluate the effects of different irrigation regimes with saline water on soil salinity, yield and water productivity of carrot as a fall-winter crop under actual commercial-farming conditions in the arid region of Tunisia. Carrot was grown on a sandy soil and surface-irrigated with a water having an ECi of 3.6 dS/m. For the three years, a complete randomized block design with four replicates was used to evaluate five irrigation regimes. Four irrigation methods were based on the use of soil water balance (SWB to estimate irrigation amounts and timing while the fifth consisted of using traditional farmers practices. SWB methods consisted in replacement of cumulated ETc when readily available water is depleted with levels of 100% (FI-100, 80% (DI-80 and 60% (DI-60. FI-100 was considered as full irrigation while DI-80 and DI-60 were considered as deficit irrigation regimes. Regulated deficit irrigation regime where 40% reduction is applied only during ripening stage (FI-DI60 was also used. Farmer method (Farmer consisted in giving fixed amounts of water (25 mm every 7 days from planting till harvest. Results on carrot production and soil salinization are globally consistent between the three-year experiments and shows significant difference between irrigation regimes. Higher soil salinity in the root zone is observed at harvest under DI-60 (3.1, 3.4, 3.9 dS/m, respectively, for the three years and farmer irrigation (3.3, 3.6, 3.9 dS/m treatments compared to FI-100 treatment (2.3, 2.6 and 3.1 dS/m. Relatively low ECe values were also observed under FI-DI60 and DI-80 treatments with respectively (2.7, 3, 3.5 dS/m and (2.5, 2.9, 3.3 dS/m. ECe values under the different irrigation treatments were generally lower than or equal to the EC of irrigation water used. Rainfall received during fall and/or winter periods (57, 26 and 29 mm, respectively, during the three years contributed probably to leaching soluble

Soils and irrigation of three areas in the Lower Tana Region, Kenya : a comparative study of soil conditions and irrigation suitability

NARCIS (Netherlands)

Muchena, F.N.

1987-01-01

The soils and soil conditions of three areas situated in different physiographic positions in the Lower Tana Region of Kenya were investigated in respect of their suitability for irrigated agriculture. The soils vary widely in both physical and chemical properties. Most of the soils have an

Cokriging of Electromagnetic Induction Soil Electrical Conductivity Measurements and Soil Textural Properties to Demarcate Sub-field Management Zones for Precision Irrigation.

Science.gov (United States)

Ding, R.; Cruz, L.; Whitney, J.; Telenko, D.; Oware, E. K.

2017-12-01

There is the growing need for the development of efficient irrigation management practices due to increasing irrigation water scarcity as a result of growing population and changing climate. Soil texture primarily controls the water-holding capacity of soils, which determines the amount of irrigation water that will be available to the plant. However, while there are significant variabilities in the textural properties of the soil across a field, conventional irrigation practices ignore the underlying variability in the soil properties, resulting in over- or under-irrigation. Over-irrigation leaches plant nutrients beyond the root-zone leading to fertilizer, energy, and water wastages with dire environmental consequences. Under-irrigation, in contrast, causes water stress of the plant, thereby reducing plant quality and yield. The goal of this project is to leverage soil textural map of a field to create water management zones (MZs) to guide site-specific precision irrigation. There is increasing application of electromagnetic induction methods to rapidly and inexpensively map spatially continuous soil properties in terms of the apparent electrical conductivity (ECa) of the soil. ECa is a measure of the bulk soil properties, including soil texture, moisture, salinity, and cation exchange capacity, making an ECa map a pseudo-soil map. Data for the project were collected from a farm site at Eden, NY. The objective is to leverage high-resolution ECa map to predict spatially dense soil textural properties from limited measurements of soil texture. Thus, after performing ECa mapping, we conducted particle-size analysis of soil samples to determine the textural properties of soils at selected locations across the field. We cokriged the high-resolution ECa measurements with the sparse soil textural data to estimate a soil texture map for the field. We conducted irrigation experiments at selected locations to calibrate representative water-holding capacities of each

A comparative analysis of the impacts of climate change and irrigation on land surface and subsurface hydrology in the North China Plain

Energy Technology Data Exchange (ETDEWEB)

Leng, Guoyong; Tang, Qiuhong; Huang, Maoyi; Leung, Lai-Yung R.

2015-02-01

The Community Land Model 4.0 (CLM4) was used to investigate and compare the effects of climate change and irrigation on terrestrial water cycle. Three climate change scenarios and one irrigation scenario (IRRIG) were simulated in the North China Plain (NCP), which is one of the most vulnerable regions to climate change and human perturbations in China. The climate change scenarios consist of (1) HOT (i.e. temperature increase by 2oC); (2) HOTWET (same with HOT but with an increase of precipitation by 15%); (3) HOTDRY (same with HOT but with a decrease of precipitation by 15%). In the IRRIG scenario, the irrigation scheme was calibrated to simulate irrigation amounts that match the actual irrigation amounts and irrigation was divided between surface water and groundwater withdrawals based on census data. Our results show that the impacts of climate change were more widespread while those of irrigation were concentrated only over the agricultural regions. Specifically, the mean water table depth was simulated to decline persistently by over 1 m annually due to groundwater exploitation during the period of 1980-2000, while much smaller effects were induced by climate change. Although irrigation has comparable effects on surface fluxes and surface soil moisture as climate change, it has much greater effects on water table depth and groundwater storage. Moreover, irrigation has much larger effects on the top layer soil moisture whereas increase in precipitation associated with climate change exerts more influence on lower layer soil moisture. This study emphasizes the need to accurately account for irrigation impacts in adapting to climate change.

Soil Chemistry after Irrigation with Treated Wastewater in Semiarid Climate

Directory of Open Access Journals (Sweden)

Pedro Carlos Pacheco de Oliveira

2016-01-01

Full Text Available ABSTRACT Soil irrigation using treated wastewater in the Brazilian semiarid region is a promising practice as this area currently faces water scarcity and pollution of water resources by domestic sewage. The aim of this study was to evaluate the use of treated wastewater in drip irrigation and its effect on the chemistry of soil cultivated with squash (Cucurbita maxima Duch. Coroa IAC and to verify whether there was an increase in soil salinity under a semiarid climate. The experiment was conducted for 123 days on a farm close to the sewage treatment plant, in a randomized block design with five treatments and four replications. The treatments consisted of two irrigation water depths (100 and 150 % of the evapotranspiration, two applications of gypsum to attenuate wastewater sodicity (0 and 5.51 g per plant, and a control treatment with no application of wastewater or gypsum. During the experiment, treated wastewater and soil gravitational water, at a depth of 0.40 m, were collected for measurement of Na+, K+, Ca2+, Mg2+, NO−3, NH4+, Cl− , alkalinity, electrical conductivity, pH and sodium adsorption ratio. At the end of the experiment, soil samples were collected at depths of 0.00-0.10, 0.10-0.20, and 0.20-0.40 m; and pH, total N, organic C, exchangeable cations and electrical conductivity of the saturation extract (CEs were analyzed. Besides an increase in pH and a reduction in total N, the irrigation with wastewater reduces soil salinity of the naturally salt-rich soils of the semiarid climate. It also led to soil sodification, in spite of the added gypsum, which indicates that irrigation with wastewater might require the addition of greater quantities of gypsum to prevent physical degradation of the soil.

A New Soil Water and Bulk Electrical Conductivity Sensor Technology for Irrigation and Salinity Management

Energy Technology Data Exchange (ETDEWEB)

Evett, Steve; Schwartz, Robert; Casanova, Joaquin [Soil and Water Management Research Unit, Conservation and Production Research Laboratory, USDA-ARS, Bushland, Texas (United States); Anderson, Scott [Acclima, Inc., 2260 East Commercial Street, Meridian, Idaho 83642 (United States)

2014-01-15

Existing soil water content sensing systems based on electromagnetic (EM) properties of soils often over estimate and sometimes underestimate water content in saline and salt-affected soils due to severe interference from the soil bulk electrical conductivity (BEC), which varies strongly with temperature and which can vary greatly throughout an irrigation season and across a field. Many soil water sensors, especially those based on capacitance measurements, have been shown to be unsuitable in salt-affected or clayey soils (Evett et al., 2012a). The ability to measure both soil water content and BEC can be helpful for the management of irrigation and leaching regimes. Neutron probe is capable of accurately sensing water content in salt-affected soils but has the disadvantages of being: (1) labour-intensive, (2) not able to be left unattended in the field, (3) subject to onerous regulations, and (4) not able to sense salinity. The Waveguide-On-Access-Tube (WOAT) system based on time domain reflectometry (TDR) principles, recently developed by Evett et al. (2012) is a new promising technology. This system can be installed at below 3 m in 20-cm sensor segments to cover as much of the crop root zone as needed for irrigation management. It can also be installed to measure the complete soil profile from the surface to below the root zone, allowing the measurement of crop water use and water use efficiency - knowledge of which is key for irrigation and farm management, and for the development of new drought tolerant and water efficient crop varieties and hybrids, as well as watershed and environmental management.

Influence of Microsprinkler Irrigation Amount on Water, Soil, and pH Profiles in a Coastal Saline Soil

Directory of Open Access Journals (Sweden)

Linlin Chu

2014-01-01

Full Text Available Microsprinkler irrigation is a potential method to alleviate soil salinization. After conducting a homogeneous, highly saline, clayey, and coastal soil from the Bohai Gulf in northern China in a column experiment, the results show that the depth of the wetting front increased as the water amount applied increased, low-salinity and low-SAR enlarged after irrigation and water redistribution, and the soil pH increased with an increase in irrigation amount. We concluded that a water amount of 207 mm could be used to reclaim the coastal saline soil in northern China.

Irrigation Scheduling for Green Bell Peppers Using Capacitance Soil Moisture Sensors

NARCIS (Netherlands)

Zotarelli, L.; Dukes, M.D.; Scholberg, J.M.S.; Femminella, K.; Munoz-Carpena, R.

2011-01-01

Vegetable production areas are intensively managed with high inputs of fertilizer and irrigation. The objectives of this study were to evaluate the interaction between N-fertilizer rates and irrigation scheduling using soil moisture sensor irrigation controllers (SMS) on yield, irrigation water use

Changes in soil aggregate stability under different irrigation doses of waste water

Science.gov (United States)

Morugán, Alicia; García-Orenes, Fuensanta; Mataix-Solera, Jorge; Arcenegui, Victoria; Bárcenas, Gema

2010-05-01

Freshwater availability and soil degradation are two of the most important environmental problems in the Mediterranean area acerbated by incorrect agricultural use of irrigation in which organic matter is not correctly managed, the use of low quality water for irrigation, and the inefficiency of dose irrigation. For these reasons strategies for saving water and for the restoration of the mean properties of soil are necessary. The use of treated waste water for the irrigation of agricultural land could be a good solution to these problems, as it reduces the utilization of fresh water and could potentially improve key soil properties. In this work we have been studying, for more than three years, the effects on soil properties of different doses of irrigation with waste water. Here we show the results on aggregate stability. The study is located in an agricultural area at Biar (Alicante, SE of Spain), with a crop of grape (Vitis labrusca). Three types of waters are being used in the irrigation of the soil: fresh water (control) (TC), and treated waste water from secondary (T2) and tertiary treatment (T3). Three different doses of irrigation have been applied to fit the efficiency of the irrigation to the crop and soil type: D10 (10 L m-2 every week during 17 months), D50 (50 L m-2 every fifteen days during 14 moths) and D30 (30 L m-2 every week during 6 months up to present day). The results showed a clear decrease of aggregate stability during the period we used the second dose (D50) independent of the type of water used. That dose of irrigation and frequency produced strong wetting and drying cycles (WD) in the soil, and this is suspected to be the main factor responsible for the results. When we changed the dose of irrigation to D30, reducing the quantity per event and increasing the frequency, the soil aggregate stability started to improve. This dose avoids strong drying periods between irrigation events and the aggregate stability is confirmed to be slowly

An example of treated waste water use for soil irrigation in the SAFIR project.

Science.gov (United States)

Cary, L.; Jovanovic, Z.; Stikic, R.; Blagojevic, S.; Kloppmann, W.

2009-04-01

The safe use of treated domestic wastewater for irrigation needs to address the risks for humans (workers, exposed via contact with irrigation water, soil, crops and food, consumers, exposed via ingestion of fresh and processed food), for animals (via ingestion of crops on soil), for the crops and agricultural productivity (via salinity and trace element uptake), for soil (via accumulation or release of pollutants) as well as for surface, groundwaters and the associated ecosystems (via runoff and infiltration, Kass et al., 2005, Bouwer, 2000). In this context, the European FP6 SAFIR project (Safe and High Quality Food Production using Low Quality Waters and Improved Irrigation Systems and Management) investigates the geochemical quality of the root zone soil, knowing it is the main transit and storage compartment for pollutants. The type of reaction (sorption, co-precipitation…) and the reactive mineral phases also determine the availability of trace elements for the plant and determine the passage towards crops and products. Reactions of the infiltrating water with the soil solid phase are important for the solute cycling, temporary fixation and remobilisation of trace pollutants. Therefore the soil water quality was directly or indirectly assessed. Direct measurements of soil water were made through porous cups. The experiments were carried out during the growing season of 2006, 2007 and 2008 in a vegetable commercial farm, located at 10 km north of Belgrade. The soil is silty clayey, and developed on alluvial deposits. It was classified as humogley according to USDA Soil Classification. The climate of the field side is a continental type with hot and dry summers and cold and rainy winters. As in the rest of Serbia, farm suffers from water deficits during the main growing season. The initial soil quality was assessed through a sampling campaign before the onset of first year irrigation; the soil quality was then monitored throughout three years. Soil sampling

Residue and soil carbon sequestration in relation to crop yield as affected by irrigation, tillage, cropping system and nitrogen fertilization

Science.gov (United States)

Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

Tracking antibiotic resistance genes in soil irrigated with dairy wastewater

Science.gov (United States)

In southern Idaho, the application of dairy wastewater to agricultural soils is a widely used practice to irrigate crops and recycle nutrients. In this study, small-scale field plots were irrigated monthly (6 times) with dairy wastewater (100%), wastewater diluted to 50% with irrigation (canal) wate...

Using soil water sensors to improve irrigation management

Science.gov (United States)

Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands while protecting the soil and water resources from degradation. In this regard, sensors can be used to monitor the soil water status; and som...

Use of small scale electrical resistivity tomography to identify soil-root interactions during deficit irrigation

Science.gov (United States)

Vanella, D.; Cassiani, G.; Busato, L.; Boaga, J.; Barbagallo, S.; Binley, A.; Consoli, S.

2018-01-01

Plant roots activity affect the exchanges of mass and energy between the soil and atmosphere. However, it is challenging to monitor the activity of the root-zone because roots are not visible from the soil surface, and root systems undergo spatial and temporal variations in response to internal and external conditions. Therefore, measurements of the activity of root systems are interesting to ecohydrologists in general, and are especially important for specific applications, such as irrigation water management. This study demonstrates the use of small scale three-dimensional (3-D) electrical resistivity tomography (ERT) to monitor the root-zone of orange trees irrigated by two different regimes: (i) full rate, in which 100% of the crop evapotranspiration (ETc) is provided; and (ii) partial root-zone drying (PRD), in which 50% of ETc is supplied to alternate sides of the tree. We performed time-lapse 3-D ERT measurements on these trees from 5 June to 24 September 2015, and compared the long-term and short-term changes before, during, and after irrigation events. Given the small changes in soil temperature and pore water electrical conductivity, we interpreted changes of soil electrical resistivity from 3-D ERT data as proxies for changes in soil water content. The ERT results are consistent with measurements of transpiration flux and soil temperature. The changes in electrical resistivity obtained from ERT measurements in this case study indicate that root water uptake (RWU) processes occur at the 0.1 m scale, and highlight the impact of different irrigation schemes.

Soil physical criteria for evaluating irrigation suitability of Okija ...

African Journals Online (AJOL)

Suitability of upland soils of Anigbo Okija for irrigation was assessed using soil physical criteria of texture, depth, pore type, slope percent colour and soil structure for the purpose of estimating season farming and rainy season drought. Soils were classified using Soil Taxonomy and FAO/UNESCO legend. Mapping was ...

Use of the food-chain model FOOD III and the soil model SCEMR to assess irrigation as a biosphere pathway

International Nuclear Information System (INIS)

Sheppard, S.C.

1985-02-01

Irrigation of contaminated water onto crop land is a relatively direct pathway for radionuclides to deliver a radiation dose to man. Irrigation was not originally included in the SYVAC assessment model for the Precambrian Shield because no irrigation is currently practised in the region. This report re-evaluates this decision. An analysis of meteorological data shows that crop yield in northern Ontario would benefit from irrigation. Thus, incentives are present for subsistence-scale, and perhaps commercial-scale, irrigation of surface or well water. A food-chain analysis indicated that irrigation with contaminated water could deliver a dose comparable to direct consumption (drinking) of the same water, for some radionuclides. Long-term contamination of soil through irrigation was predicted to be a substantial hazard, even when soil leaching was incorporated into the food-chain model. This report presents parameter estimates that could be used to incorporate irrigation as a pathway in the SYVAC code and will constitute the basis for further decisions concerning this pathway

HEAVY METALS AND MICRONUTRIENTS IN THE SOIL AND GRAPEVINE UNDER DIFFERENT IRRIGATION STRATEGIES

Directory of Open Access Journals (Sweden)

Vanessa de Souza Oliveira

2015-02-01

Full Text Available Soils under natural conditions have heavy metals in variable concentrations and there may be an increase in these elements as a result of the agricultural practices adopted. Transport of heavy metals in soil mainly occurs in forms dissolved in the soil solution or associated with solid particles, water being their main means of transport. In this context, the aim of this study was to evaluate the heavy metal and micronutrient content in the soil and in the grapevine plant and fruit under different irrigation strategies. The experiment was carried out in Petrolina, PE, Brazil. The treatments consisted of three irrigation strategies: full irrigation (FI, regulated deficit irrigation (RDI, and deficit irrigation (DI. During the period of grape maturation, soil samples were collected at the depths of 0-10, 10-20, 20-40, 40-60, and 60-80 cm. In addition, leaves were collected at the time of ripening of the bunches, and berries were collected at harvest. Thus, the heavy metal and micronutrient contents were determined in the soil, leaves, and berries. The heavy metal and micronutrient contents in the soil showed a stochastic pattern in relation to the different irrigation strategies. The different irrigation strategies did not affect the heavy metal and micronutrient contents in the vine leaves, and they were below the contents considered toxic to the plant. In contrast, the greater availability of water in the FI treatment favored a greater Cu content in the grape, which may be a risk to vines, causing instability and turbidity. Thus, adoption of deficit irrigation is recommended so as to avoid compromising the stability of tropical wines of the Brazilian Northeast.

Irrigation with saline-sodic water: effects on two clay soils

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Giovanna Cucci

2013-05-01

Full Text Available The results of a 4-year experiment aimed at evaluating the effect of irrigation with saline-sodic water on the soil are reported. The research was carried out at the Campus of the Agricultural Faculty of Bari University (Italy on 2 clay soils (Bologna – T1 and Locorotondo – T2. The soils were cropped to borlotto bean (Phaseolus vulgaris L., capsicum (Capsicum annuum L., sunflower (Helianthus annuus L., wheat (Triticum durum Desf grown in succession; the crops were irrigated with 9 saline-sodic types of water and subjected to two different leaching fractions (10% and 20% of the watering volume. The 9 solutions were obtained dissolving in de-ionised water weighted amounts of sodium chloride (NaCl and calcium chloride (CaCl2, deriving from the combination of 3 saline concentrations and 3 sodicity levels. The crops were irrigated whenever the water lost by evapotranspiration from the soil contained in the pots was equal to 30% of the soil maximum available water. The results showed that, though the soils were leached during the watering period, they showed a high salt accumulation. Consequently, the saturated soil extract electrical conductivity increased from initial values of 0.65 and 0.68 dS m-1 to 11.24 and 13.61 dS m-1 at the end of the experiment, for the soils T1 and T2, respectively. The saline concentration increase in irrigation water caused in both soils a progressive increase in exchangeable sodium, and a decrease in exchangeable calcium and non-significant variations in exchangeable potassium (K and magnesium (Mg.

Drip Irrigation for Commercial Vegetable and Fruit Production

OpenAIRE

Maughn, Tiffany; Allen, Niel; Drost, Dan

2017-01-01

Drip irrigation is a highly efficient irrigation method well suited to many fruit and vegetable row crops. Drip tubing or tape discharges water to the soil through emitters positioned close to the plant. The drip tubing can be placed uncovered on the soil surface, under plastic mulch, buried in the soil, or suspended above the ground (e.g., on a trellis system). Water application rate is relatively low and irrigations are usually frequent. Properly designed and maintained drip-irrigation syst...

Effects of wastewater irrigation on soil sodicity and nutrient leaching in calcareous soils

NARCIS (Netherlands)

Jalali, M.; Merikhpour, H.; Kaledhonkar, M.J.; Zee, van der S.E.A.T.M.

2008-01-01

Soil column studies were conducted with two soils to assess the effects of irrigation with wastewater on soil and groundwater quality. Upon the application of wastewater, exchange occurred between solution sodium (Na+) and exchangeable cations (Ca2+, Mg2+, K+), whereby these cations were released

Monitoring of the humus status of soils of the Ingulets irrigation system

Science.gov (United States)

Lozovitsii, P. S.

2012-03-01

The results of long-term studies (1957-2007) of the changes in the morphology of soil profiles and in the reserves and fractional composition of the humus in the soils of the Ingulets irrigation system are discussed. After 50 years of irrigation, the boundaries of the genetic horizons shifted downward by 15-30 cm. The redistribution of the humus took place: its content decreased to a low level in the plow layer of the irrigated and rainfed soils and significantly increased in the layer of 60-100 cm so that the reserves of humus in the layer of 0-100 cm somewhat increased and corresponded to a moderate level. The distribution of humus in the soil profiles was characterized by the gradual lowering down the soil profile. The concentration of nitrogen in the humus of the irrigated southern chernozems was very low. The degree of humification of the soil organic matter was high. The humus was of the humate type in the upper horizons and of the fulvate-humate type in the lower horizons.

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

Science.gov (United States)

Pla-Sentís, Ildefonso

2014-05-01

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

Soil quality improvement through conversion to sprinkler irrigation

Science.gov (United States)

Conversion from furrow to sprinkler irrigation is a recommended conservation practice for improved water use efficiency (and/or erosion control), but effects on soil quality indicators were unknown. Several soil quality indicators were therefore quantified within a northwestern U.S. Conservation Eff...

Soil Salt Distribution and Tomato Response to Saline Water Irrigation under Straw Mulching.

Directory of Open Access Journals (Sweden)

Yaming Zhai

Full Text Available To investigate better saline water irrigation scheme for tomatoes that scheduling with the compromise among yield (Yt, quality, irrigation water use efficiency (IWUE and soil salt residual, an experiment with three irrigation quotas and three salinities of irrigation water was conducted under straw mulching in northern China. The irrigation quota levels were 280 mm (W1, 320 mm (W2 and 360 mm (W3, and the salinity levels were 1.0 dS/m (F, 3.0 dS/m (S1 and 5.0 dS/m (S2. Compared to freshwater, saline water irrigations decreased the maximum leaf area index (LAIm of tomatoes, and the LAIm presented a decline tendency with higher salinity and lower irrigation quota. The best overall quality of tomato was obtained by S2W1, with the comprehensive quality index of 3.61. A higher salinity and lower irrigation quota resulted in a decrease of individual fruit weight and an increase of the blossom-end rot incidence, finally led to a reduction in the tomato Yt and marketable yield (Ym. After one growth season of tomato, the mass fraction of soil salt in plough layer under S2W1 treatment was the highest, and which presented a decline trend with an increasing irrigation quota. Moreover, compared to W1, soil salts had a tendency to move to the deeper soil layer when using W2 and W3 irrigation quota. According to the calculation results of projection pursuit model, S1W3 was the optimal treatment that possessed the best comprehensive benefit (tomato overall quality, Yt, Ym, IWUE and soil salt residual, and was recommended as the saline water irrigation scheme for tomatoes in northern China.

Soil Salt Distribution and Tomato Response to Saline Water Irrigation under Straw Mulching.

Science.gov (United States)

Zhai, Yaming; Yang, Qian; Wu, Yunyu

2016-01-01

To investigate better saline water irrigation scheme for tomatoes that scheduling with the compromise among yield (Yt), quality, irrigation water use efficiency (IWUE) and soil salt residual, an experiment with three irrigation quotas and three salinities of irrigation water was conducted under straw mulching in northern China. The irrigation quota levels were 280 mm (W1), 320 mm (W2) and 360 mm (W3), and the salinity levels were 1.0 dS/m (F), 3.0 dS/m (S1) and 5.0 dS/m (S2). Compared to freshwater, saline water irrigations decreased the maximum leaf area index (LAIm) of tomatoes, and the LAIm presented a decline tendency with higher salinity and lower irrigation quota. The best overall quality of tomato was obtained by S2W1, with the comprehensive quality index of 3.61. A higher salinity and lower irrigation quota resulted in a decrease of individual fruit weight and an increase of the blossom-end rot incidence, finally led to a reduction in the tomato Yt and marketable yield (Ym). After one growth season of tomato, the mass fraction of soil salt in plough layer under S2W1 treatment was the highest, and which presented a decline trend with an increasing irrigation quota. Moreover, compared to W1, soil salts had a tendency to move to the deeper soil layer when using W2 and W3 irrigation quota. According to the calculation results of projection pursuit model, S1W3 was the optimal treatment that possessed the best comprehensive benefit (tomato overall quality, Yt, Ym, IWUE and soil salt residual), and was recommended as the saline water irrigation scheme for tomatoes in northern China.

Treated wastewater irrigation effects on soil hydraulic conductivity and aggregate stability of loamy soils in Israel

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Schacht Karsten

2015-03-01

Full Text Available The use of treated wastewater (TWW for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC and soil aggregate stability (SAS. To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm were collected for analyzing SAS and determination of selected soil chemical and physical characteristics.

Correlation among fluoride and metals in irrigation water and soils of ...

African Journals Online (AJOL)

Correlation among fluoride and metals in irrigation water and soils of Ethiopian Rift Valley. ... The fluoride concentrations in water samples were found in the range of 0.14-8.0 mg/L which is below the WHO limit of fluoride concentration for irrigation (less than 10 mg/L). ... KEY WORDS: Fluoride, Metals, Water, Soil, Ethiopia.

Regulated deficit irrigation can decrease soil CO2 emissions in fruit orchards

Science.gov (United States)

Zornoza, Raul; Acosta, José Alberto; Martínez-Martínez, Silvia; De la Rosa, Jose M.°; Faz, Angel; Pérez-Pastor, Alejandro

2016-04-01

Irrigation water restrictions in the Mediterranean area have created a growing interest in water conservation. Apart from environmental and economic benefits by water savings, regulated deficit irrigation (RDI) may contribute to reduce soil CO2 emissions and enhance C sequestration in soils, by decreasing microbial and root activity in response to decreased soil moisture levels. An experiment was established in four orchards (peach, apricot, Saturn peach and grape) to investigate the effects of regulated deficit irrigation (RDI) on soil CO2 emissions. Two irrigation treatments were assayed: full irrigation (FI), and RDI, irrigated as FI except for postharvest period (peach, apricot, Saturn peach) or post-veraison period (grape) were 50% of FI was applied. The application of deficit caused a significant decrease in CO2 emission rates, with rates in average of 90 mg CO2-C m-2 h-1, 120 mg CO2-C m-2 h-1, 60 mg CO2-C m-2 h-1 and 60 mg CO2-C m-2 h-1 lower than FI during the period when deficit was applied for peach, apricot, Saturn peach and grape. This confirms the high effectiveness of the RDI strategies not only to save water consumption but also to decrease soil CO2 emissions. However, monitoring during longer periods is needed to verify that this trend is long-term maintained, and assess if soil carbon stocks are increase or most CO2 emissions derive from root respiration. Acknowledgements This work has been funded by the European Union LIFE+ project IRRIMAN (LIFE13 ENV/ES/000539).

Spatial distribution of Cd and Cu in soils in Shenyang Zhangshi Irrigation Area (SZIA), China*

Science.gov (United States)

Sun, Li-na; Yang, Xiao-bo; Wang, Wen-qing; Ma, Li; Chen, Su

2008-01-01

Heavy metal contamination of soils, derived from sewage irrigation, mining and inappropriate utilization of various agrochemicals and pesticides, and so on, has been of wide concern in the last several decades. The Shenyang Zhangshi Irrigation Area (SZIA) in China is a representative area of heavy metal contamination of soils resulting from sewage irrigation for about 30 years. This study investigated the spatial distribution and temporal variation of soil cadmium (Cd) and copper (Cu) contamination in the SZIA. The soil samples were collected from the SZIA in 1990 and 2004; Cd and Cu in soils was analyzed and then the spatial distribution and temporal variation of Cd and Cu in soils were modeled using Kriging methods. The results show that long-term sewage irrigation had caused serious Cd and Cu contamination in soils. The mean and the maximum of soil Cd are markedly higher than the levels in second grade standard soil (LSGSS) in China, and the maximum of soil Cu is close to the LSGSS in China in 2004 and is more than the LSGSS in China in 1990. The contamination magnitude of soil Cd and the soil extent of Cd contamination had evidently increased since sewage irrigation ceased in 1992. The contamination magnitude of soil Cu and the soil extent of Cu contamination had evidently increased in topsoil, but obviously decresed in subsoil. The soil contamination of Cd and Cu was mainly related to Cd and Cu reactivation of contaminated sediments in Shenyang Xi River and the import of Cd and Cu during irrigation. The eluviation of Cd and Cu in contaminated topsoil with rainfall and irrigation water was another factor of temporal-spatial variability of Cd and Cu contamination in soils. PMID:18357631

Status and Causes of Soil Salinization of Irrigated Agricultural Lands in Southern Baja California,Mexico

International Nuclear Information System (INIS)

Endo, T.; Yamamoto, S.; Fujiyama, H.; Honna, T.; Larrinaga, J.A.

2011-01-01

Selected farmlands in southern Baja California, Mexico, were surveyed to determine the levels and the causes of salinization/sodication in irrigated agricultural soil. The salt dynamics observed in profiles differed from farm to farm. Low EC and high ph levels were observed in the profiles of sandy fields, because the salt composition of these soils can easily change when salts are leached by irrigation water that contains carbonates of sodium. On the other hand, high levels of salinity and sodicity were observed in the soils of clayey fields. Soil salinization/sodication is complexly interrelated with soil characteristics, the amount and composition of salts in the soil, the quantity and quality of irrigation water applied, and the irrigation methods used. Our findings indicate that irrigation water in Baja California should be supplied at a rate that is sufficient to meet crop requirements without exacerbating salt accumulation.

Effects of ten years treated wastewater drip irrigation on soil ...

African Journals Online (AJOL)

SWEET

soil contamination and the cumulative impact of wastewater, we compared two plots, all under orange- ... A slight increase in the concentration of soil enteric bacteria and soil fungal densities was ..... could be used for fruit tree irrigation.

On-irrigator pasture soil moisture sensor

International Nuclear Information System (INIS)

Tan, Adrian Eng-Choon; Richards, Sean; Platt, Ian; Woodhead, Ian

2017-01-01

In this paper, we presented the development of a proximal soil moisture sensor that measured the soil moisture content of dairy pasture directly from the boom of an irrigator. The proposed sensor was capable of soil moisture measurements at an accuracy of  ±5% volumetric moisture content, and at meter scale ground area resolutions. The sensor adopted techniques from the ultra-wideband radar to enable measurements of ground reflection at resolutions that are smaller than the antenna beamwidth of the sensor. An experimental prototype was developed for field measurements. Extensive field measurements using the developed prototype were conducted on grass pasture at different ground conditions to validate the accuracy of the sensor in performing soil moisture measurements. (paper)

Leaching of N-nitrosodimethylamine (NDMA) in turfgrass soils during wastewater irrigation.

Science.gov (United States)

Gan, J; Bondarenko, S; Ernst, F; Yang, W; Ries, S B; Sedlak, D L

2006-01-01

N-nitrosodimethylamine (NDMA) is a carcinogenic by-product of chlorination that is frequently found in municipal wastewater effluent. NDMA is miscible in water and negligibly adsorbed to soil, and therefore may pose a threat to ground water when treated wastewater is used for landscape irrigation. A field study was performed in the summer months under arid Southern California weather conditions to evaluate the leaching potential of NDMA in turfgrass soils during wastewater irrigation. Wastewater was used to irrigate multiple turfgrass plots at 110 to 160% evapotranspiration rate for about 4 mo, and leachate was continuously collected and analyzed for NDMA. The treated wastewater contained relatively high levels of NDMA (114-1820 ng L(-1); mean 930 ng L(-1)). NDMA was detected infrequently in the leachate regardless of the soil type or irrigation schedule. At a method detection limit of 2 ng L(-1), NDMA was only detected in 9 out of 400 leachate samples and when it was detected, the NDMA concentration was less than 5 ng L(-1). NDMA was relatively persistent in the turfgrass soils during laboratory incubation, indicating that mechanisms other than biotransformation, likely volatilization and/or plant uptake, contributed to the rapid dissipation. Under conditions typical of turfgrass irrigation with wastewater effluent it is unlikely that NDMA will contaminate ground water.

Distribution and accumulation of endocrine-disrupting chemicals and pharmaceuticals in wastewater irrigated soils in Hebei, China

International Nuclear Information System (INIS)

Chen Feng; Ying Guangguo; Kong Lingxiao; Wang Li; Zhao Jianliang; Zhou Lijun; Zhang Lijuan

2011-01-01

This study investigated the occurrence of 43 emerging contaminants including 9 endocrine-disrupting chemicals and 34 pharmaceuticals in three sites in Hebei Province, north China. Each site has a wastewater irrigated plot and a separate groundwater irrigated plot for comparison purpose. The results showed that the concentrations of the target compounds in the wastewater irrigated soils were in most cases higher than those in the groundwater irrigated soils. Among the 43 target compounds, nine compounds bisphenol-A, triclocarban, triclosan, 4-nonylphenol, salicylic acid, oxytetracycline, tetracycline, trimethoprim and primidone were detected at least once in the soils. Preliminary environmental risk assessment showed that triclocarban might pose high risks to terrestrial organisms while the other detected compounds posed minimal risks. Irrigation with wastewater could lead to presence or accumulation of some emerging contaminants to some extent in irrigated soils. - Highlights: → Some EDCs and PPCPs were detected in the wastewater irrigated soils. → Application of reclaimed water could lead to accumulation of some compounds. → Groundwater has been contaminated by some compounds. → Triclocarban posed high risks to soil organisms. - Application of reclaimed wastewater on agricultural land could lead to the presence or accumulation of wastewater-related contaminants in soils.

Distribution and accumulation of endocrine-disrupting chemicals and pharmaceuticals in wastewater irrigated soils in Hebei, China

Energy Technology Data Exchange (ETDEWEB)

Feng, Chen [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.com [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Lingxiao, Kong [Institute of Plant Protection, Hebei Academy of Agriculture and Forestry Science, Baoding 07100 (China); Li, Wang; Jianliang, Zhao; Lijun, Zhou; Lijuan, Zhang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2011-06-15

This study investigated the occurrence of 43 emerging contaminants including 9 endocrine-disrupting chemicals and 34 pharmaceuticals in three sites in Hebei Province, north China. Each site has a wastewater irrigated plot and a separate groundwater irrigated plot for comparison purpose. The results showed that the concentrations of the target compounds in the wastewater irrigated soils were in most cases higher than those in the groundwater irrigated soils. Among the 43 target compounds, nine compounds bisphenol-A, triclocarban, triclosan, 4-nonylphenol, salicylic acid, oxytetracycline, tetracycline, trimethoprim and primidone were detected at least once in the soils. Preliminary environmental risk assessment showed that triclocarban might pose high risks to terrestrial organisms while the other detected compounds posed minimal risks. Irrigation with wastewater could lead to presence or accumulation of some emerging contaminants to some extent in irrigated soils. - Highlights: > Some EDCs and PPCPs were detected in the wastewater irrigated soils. > Application of reclaimed water could lead to accumulation of some compounds. > Groundwater has been contaminated by some compounds. > Triclocarban posed high risks to soil organisms. - Application of reclaimed wastewater on agricultural land could lead to the presence or accumulation of wastewater-related contaminants in soils.

Effect of Treated Wastewater Irrigation on Heavy Metals Distribution in a Tunisian Soil

Directory of Open Access Journals (Sweden)

K. Khaskhoussy

2015-06-01

Full Text Available Treated wastewater (TWW may contain toxic chemical constituents that pose negative environmental and health impacts. In this study, soil samples under treated wastewater irrigation were studied. For this purpose, six plots were made in an irrigated area in north of Tunisia and treated with two water qualities: fresh water (FW and treated wastewater (TWW. Five soil depths were used: 0-30, 30-60, 60-90, 90-120 and 120-150 cm. The TWW irrigation increased significantly (P≤0.05 the soils’ EC, Na, K, Ca, Mg, Cl, SAR, Cu, Cd and Ni and had no significant (P ≤0.05 effect on the soils’ pH, Zn, Co and Pb contents. EC, Na, Cl, SAR, Zn and Co increased significantly with soil depth. The results for K, Ca, Mg, Cd, Pb and Ni exhibited similar repartition in different layers of soil. It was also shown that the amount of different elements in soil irrigated with fresh water (FW were less compared with the control soil

Mapping Soil hydrologic features in a semi-arid irrigated area in Spain

Science.gov (United States)

Jiménez-Aguirre, M.° Teresa; Isidoro, Daniel; Usón, Asunción

2016-04-01

The lack of soil information is a managerial problem in irrigated areas in Spain. The Violada Irrigation District (VID; 5234 ha) is a gypsic, semi-arid region in the Middle Ebro River Basin, northeast Spain. VID is under irrigation since the 1940's. The implementation of the flood irrigation system gave rise to waterlogging problems, solved along the years with the installation of an artificial drainage network. Aggregated water balances have been performed in VID since the early 1980's considering average soil properties and aggregated irrigation data for the calculations (crop evapotranspiration, canal seepage, and soil drainage). In 2008-2009, 91% of the VID was modernized to sprinkler irrigation. This new system provides detailed irrigation management information that together with detailed soil information would allow for disaggregated water balances for a better understanding of the system. Our goal was to draw a semi-detailed soil map of VID presenting the main soil characteristics related to irrigation management. A second step of the work was to set up pedotransfer functions (PTF) to estimate the water content and saturated hydraulic conductivity (Ks) from easily measurable parameters. Thirty four pits were opened, described and sampled for chemical and physical properties. Thirty three additional auger holes were sampled for water holding capacity (WHC; down to 60 cm), helping to draw the soil units boundaries. And 15 Ks tests (inverse auger hole method) were made. The WHC was determined as the difference between the field capacity (FC) and wilting point (WP) measured in samples dried at 40°C during 5 days. The comparison with old values dried at 105°C for 2 days highlighted the importance of the method when gypsum is present in order to avoid water removal from gypsum molecules. The soil map was drawn down to family level. Thirteen soil units were defined by the combination of five subgroups [Typic Calcixerept (A), Petrocalcic Calcixerept (B), Gypsic

Accumulation of oil and grease in soils irrigated with greywater and their potential role in soil water repellency.

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Travis, Micheal J; Weisbrod, Noam; Gross, Amit

2008-05-01

The potential impact of oil and grease (O and G) to soils irrigated with greywater (GW) was investigated. Greywater streams were sampled and analyzed for O and G content, along with corresponding GW-irrigated soils. Untreated kitchen GW averaged 200 mg L(-1) O and G, over an order of magnitude more than other GW streams. GW-irrigated soils showed O and G accumulation of up to 200 mg kg(-l) within the first 20-cm of depth. To determine the potential effects of such O and G accumulation on water movement in soil, capillary rise and water drop penetration time (WDPT) experiments were conducted. The results showed up to 60% decrease in capillary rise when sand containing 250 mg kg(-1) O and G was used. Interestingly, no additional reduction in capillary rise was observed at concentrations above 250 mg kg(-1). WDPT was observed to increase linearly with increased O and G content, up to 1000 mg kg(-1). This work demonstrated that O and G in GW used for irrigation can accumulate in soil and may lead to a significant reduction in the soils ability to transmit water.

Arsenic transport in irrigation water across rice-field soils in Bangladesh

International Nuclear Information System (INIS)

Polizzotto, Matthew L.; Lineberger, Ethan M.; Matteson, Audrey R.; Neumann, Rebecca B.; Badruzzaman, A. Borhan M.; Ashraf Ali, M.

2013-01-01

Experiments were conducted to analyze processes impacting arsenic transport in irrigation water flowing over bare rice-field soils in Bangladesh. Dissolved concentrations of As, Fe, P, and Si varied over space and time, according to whether irrigation water was flowing or static. Initially, under flowing conditions, arsenic concentrations in irrigation water were below well-water levels and showed little spatial variability across fields. As flowing-water levels rose, arsenic concentrations were elevated at field inlets and decreased with distance across fields, but under subsequent static conditions, concentrations dropped and were less variable. Laboratory experiments revealed that over half of the initial well-water arsenic was removed from solution by oxidative interaction with other water-column components. Introduction of small quantities of soil further decreased arsenic concentrations in solution. At higher soil-solution ratios, however, soil contributed arsenic to solution via abiotic and biotic desorption. Collectively, these results suggest careful design is required for land-based arsenic-removal schemes. -- Highlights: •We analyzed the processes impacting arsenic transport in flowing irrigation water. •Arsenic in Bangladesh rice-field irrigation water varied over space and time. •Arsenic was correlated with Fe, P, and Si in flowing and static water. •Oxidation, adsorption and desorption reactions controlled arsenic concentrations. •Land-based arsenic removal from water will be impacted by hydraulic conditions. -- Arsenic concentrations in flowing and static irrigation water in Bangladesh varied over space and time, suggesting careful design is required for land-based pre-treatment schemes that aim to remove As from solution

Soil Water Balance and Irrigation Strategies in an Agricultural District of Southern Italy

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Domenico Ventrella

2010-06-01

Full Text Available An efficient management of water resources is considered very important for Mediterranean regions of Italy in order to improve the economical and environmental sustainability of the agricultural activity. The purpose of this study is to analyze the components of soil water balance in an important district included in the regions of Basilicata and Puglia and situated in the Jonical coastal area of Southern Italy and mainly cropped with horticultural crops. The study was performed by using the spatially distributed and physically based model SIMODIS in order to individuate the best irrigation management maximizing the water use efficiency and minimizing water losses by deep percolation and soil evaporation. SIMODIS was applied taking in to account the soil spatial variability and localization of cadastral units for two crops, durum wheat and water melon. For water melon recognition in 2007 a remote sensed image, from SPOT5 satellite, at the spatial resolution of 10 m, has been used. In 2008, a multi-temporal data set was available, from SPOT5 satellite to produce a land cover map for the classes water melon and durum wheat. Water melon cultivation was simulated adopting different water supply managements: rainfed and four irrigation strategies based on (i soil water availability and (ii plant water status adopting a threshold daily stress value. For each management, several water management indicators were calculated and mapped in GIS environment. For seasonal irrigation depth, actual evapotranspiration and irrigation efficiency were also determined. The analysis allowed to individuate the areas particularly sensitive to water losses by deep percolation because of their hydraulic functions characterized by low water retention and large values of saturated hydraulic conductivity. For these areas, the irrigation based on plant water status caused very high water losses by drainage. On the contrary, the irrigation scheduled on soil base allowed to

Effects of bleaching wastewater irrigation on soil quality of constructed reed wetlands

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Cheng Ding

2016-10-01

Full Text Available Constructed reed wetland microcosms (CRWs in a lab of east China have been irrigated with bleaching wastewater per month for a reed growth season. The soil physicochemical properties, enzyme activities (i.e. urease, invertase, polyphenol oxidase, alkaline phosphatase and cellulase and soil microbial diversity were assayed before and after the exposure experiment. Compared to the river water irrigated controls (CKs, bleaching wastewater application has no marked influence on soil pH, but significantly increased soil Na+, total halogen and absorbable organic halogen (AOX contents, which induced the increasing of soil electrical conductivity. Furthermore, soil enzyme activities displayed significant variation (except for polyphenol oxidase. Bleaching wastewater irrigation decreased Sorenson’s pairwise similarity coefficient (Cs, which indicated the changes of the structure of bacterial and fungal communities. However, only the diversity of bacterial community was inhibited and has no effect on the diversity of fungal community, as evidenced by the calculated Shannon–Wiener index (H.

Impact of long-term wastewater irrigation on sorption and transport of atrazine in Mexican agricultural soils.

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Müller, K; Duwig, C; Prado, B; Siebe, C; Hidalgo, C; Etchevers, J

2012-01-01

In the Mezquital Valley, Mexico, crops have been irrigated with untreated municipal wastewater for more than a century. Atrazine has been applied to maize and alfalfa grown in the area for weed control for 15 years. Our objectives were to analyse (i) how wastewater irrigation affects the filtering of atrazine, and (ii) if the length of irrigation has a significant impact. We compared atrazine sorption to Phaeozems that have been irrigated with raw wastewater for 35 (P35) and 85 (P85) years with sorption to a non-irrigated (P0) Phaeozem soil under rainfed agriculture. The use of bromide as an inert water tracer in column experiments and the subsequent analysis of the tracers' breakthrough curves allowed the calibration of the hydrodynamic parameters of a two-site non equilibrium convection-dispersion model. The quality of the irrigation water significantly altered the soils' hydrodynamic properties (hydraulic conductivity, dispersivity and the size of pores that are hydraulically active). The impacts on soil chemical properties (total organic carbon content and pH) were not significant, while the sodium adsorption ratio was significantly increased. Sorption and desorption isotherms, determined in batch and column experiments, showed enhanced atrazine sorption and reduced and slower desorption in wastewater-irrigated soils. These effects increased with the length of irrigation. The intensified sorption-desorption hysteresis in wastewater-irrigated soils indicated that the soil organic matter developed in these soils had fewer high-energy, easily accessible sorption sites available, leading to lower and slower atrazine desorption rates. This study leads to the conclusion that wastewater irrigation decreases atrazine mobility in the Mezquital valley Phaeozems by decreasing the hydraulic conductivity and increasing the soil's sorption capacity.

Observation and Modelling of Soil Water Content Towards Improved Performance Indicators of Large Irrigation Schemes

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Labbassi, Kamal; Akdim, Nadia; Alfieri, Silvia Maria; Menenti, Massimo

2014-05-01

-Monteith equation with reflectance-based estimates of canopy biophysical variables, such as surface albedo (r), leaf area index (LAI) and crop height (hc). The validation of spatial results using the dual crop coefficient approach (kcb) showed that the satellite-based estimates of ETc corresponded well with ground-based ETc i.e, R²=0.75 and RMSE=0.79 versus R²=0.73 and RMSE=0.89 for respectively kc-NDVI and analytical approach. To monitor IP3 (x, y, t) with the SWAP model we mapped soil hydrological properties combining soil maps with grain size analysis of a number of samples, and agricultural crops using multi-temporal classification of NDVI time series. The assessment of irrigation performance in term of adequacy between requirement and allocation showed that CWR are much larger than water supply for entire area, this mismatch is improved in the beginning of the growing season by means of Irrigation water requirement (IWR) and even more using the net irrigation water requirement (NIWR) estimated using SWAP model. We expect that the availability of SMAP data products will significantly improve the reliability and temporal sampling of our indicators.

Towards Global Simulation of Irrigation in a Land Surface Model: Multiple Cropping and Rice Paddy in Southeast Asia

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Beaudoing, Hiroko Kato; Rodell, Matthew; Ozdogan, Mutlu

2010-01-01

Agricultural land use significantly influences the surface water and energy balances. Effects of irrigation on land surface states and fluxes include repartitioning of latent and sensible heat fluxes, an increase in net radiation, and an increase in soil moisture and runoff. We are working on representing irrigation practices in continental- to global-scale land surface simulation in NASA's Global Land Data Assimilation System (GLDAS). Because agricultural practices across the nations are diverse, and complex, we are attempting to capture the first-order reality of the regional practices before achieving a global implementation. This study focuses on two issues in Southeast Asia: multiple cropping and rice paddy irrigation systems. We first characterize agricultural practices in the region (i.e., crop types, growing seasons, and irrigation) using the Global data set of monthly irrigated and rainfed crop areas around the year 2000 (MIRCA2000) dataset. Rice paddy extent is identified using remote sensing products. Whether irrigated or rainfed, flooded fields need to be represented and treated explicitly. By incorporating these properties and processes into a physically based land surface model, we are able to quantify the impacts on the simulated states and fluxes.

Root Development of Transplanted Cotton and Simulation of Soil Water Movement under Different Irrigation Methods

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Hao Zhang

2017-07-01

Full Text Available Winter wheat and cotton are the main crops grown on the North China Plain (NCP. Cotton is often transplanted after the winter wheat harvest to solve the competition for cultivated land between winter wheat and cotton, and to ensure that both crops can be harvested on the NCP. However, the root system of transplanted cotton is distorted due to the restrictions of the seedling aperture disk before transplanting. Therefore, the investigation of the deformed root distribution and water uptake in transplanted cotton is essential for simulating soil water movement under different irrigation methods. Thus, a field experiment and a simulation study were conducted during 2013–2015 to explore the deformed roots of transplanted cotton and soil water movement using border irrigation (BI and surface drip irrigation (SDI. The results showed that SDI was conducive to root growth in the shallow root zone (0–30 cm, and that BI was conducive to root growth in the deeper root zone (below 30 cm. SDI is well suited for producing the optimal soil water distribution pattern for the deformed root system of transplanted cotton, and the root system was more developed under SDI than under BI. Comparisons between experimental data and model simulations showed that the HYDRUS-2D model described the soil water content (SWC under different irrigation methods well, with root mean square errors (RMSEs of 0.023 and 0.029 cm3 cm−3 and model efficiencies (EFs of 0.68 and 0.59 for BI and SDI, respectively. Our findings will be very useful for designing an optimal irrigation plan for BI and SDI in transplanted cotton fields, and for promoting the wider use of this planting pattern for cotton transplantation.

A dynamic model of soil salinity and drainage generation in irrigated agriculture: A framework for policy analysis

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Dinar, Ariel; Aillery, Marcel P.; Moore, Michael R.

1993-06-01

This paper presents a dynamic model of irrigated agriculture that accounts for drainage generation and salinity accumulation. Critical model relationships involving crop production, soil salinity, and irrigation drainage are based on newly estimated functions derived from lysimeter field tests. The model allocates land and water inputs over time based on an intertemporal profit maximization objective function and soil salinity accumulation process. The model is applied to conditions in the San Joaquin Valley of California, where environmental degradation from irrigation drainage has become a policy issue. Findings indicate that in the absence of regulation, drainage volumes increase over time before reaching a steady state as increased quantities of water are allocated to leaching soil salts. The model is used to evaluate alternative drainage abatement scenarios involving drainage quotas and taxes, water supply quotas and taxes, and irrigation technology subsidies. In our example, direct drainage policies are more cost-effective in reducing drainage than policies operating indirectly through surface water use, although differences in cost efficiency are relatively small. In some cases, efforts to control drainage may result in increased soil salinity accumulation, with implications for long-term cropland productivity. While policy adjustments may alter the direction and duration of convergence to a steady state, findings suggest that a dynamic model specification may not be necessary due to rapid convergence to a comon steady state under selected scenarios.

Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

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Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.

2013-10-04

Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (~3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO{sub 4} salts more soluble than gypsum. Irrigation with high SAR (24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

Science.gov (United States)

Bern, Carleton R.; Boehlke, Adam R.; Engle, Mark A.; Geboy, Nicholas J.; Schroeder, K.T.; Zupancic, J.W.

2013-01-01

Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (∼3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO4 salts more soluble than gypsum. Irrigation with high SAR (∼24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

Effect of irrigation on soil salinity profiles along the Lower Vaal River ...

African Journals Online (AJOL)

The impact of long-term irrigation on semi-arid soils along the Lower Vaal River in central South Africa was assessed. Irrigated sandy and clayey soils representative of relatively homogeneous agro-ecosystems were sampled at 200 mm intervals to a depth of 2 m wherever possible. To serve as a reference, adjacent virgin ...

EFFECT OF IRRIGATION INTERVAL AND SOIL AMENDMENTS ON SOIL ORGANIC C, NITROGEN AND POTASSIUM OF SANDY SOIL AND GROWTH OF Jatropha curcas L.

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Djajadi

2013-06-01

Full Text Available Inherently, sandy soil is the unfertile soil with low in all aspects of soil fertility and has a low capacity to retain water applied nutrients. To improve the fertility of sandy soil as media growth of Jatropha curcas, clay and organic matter may have important role when they are incorporated to the sandy soil. This study investigated the effect of irrigation interval and incorporation of clay together with organic matter to sandy soil on soil organic C, N, and K and growth of J. curcas. The rates of clay and organic matter incorporated to top sandy soil were 5% clay + 0.8% organic matter and 10% clay + 1.6% organic matter. Two irrigation intervals tested were 10 day and 20 day. The results found that incorporation of 10% clay + 1.6% organic matter to sandy soil increased soil C organic, N total and exchangeable K which in turn increased number of leaves and number of lateral branches of J curcas. Irrigation intervals had no effect on all parameters observed.

Assessing the ecological long-term impact of wastewater irrigation on soil and water based on bioassays and chemical analyses.

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Richter, Elisabeth; Hecht, Fabian; Schnellbacher, Nadine; Ternes, Thomas A; Wick, Arne; Wode, Florian; Coors, Anja

2015-11-01

The reuse of treated wastewater for irrigation and groundwater recharge can counteract water scarcity and reduce pollution of surface waters, but assessing its environmental risk should likewise consider effects associated to the soil. The present study therefore aimed at determining the impact of wastewater irrigation on the habitat quality of water after soil passage and of soil after percolation by applying bioassays and chemical analysis. Lab-scale columns of four different soils encompassing standard European soil and three field soils of varying characteristics and pre-contamination were continuously percolated with treated wastewater to simulate long-term irrigation. Wastewater and its percolates were tested for immobilization of Daphnia magna and growth inhibition of green algae (Pseudokirchneriella subcapitata) and water lentils (Lemna minor). The observed phytotoxicity of the treated wastewater was mostly reduced by soil passage, but in some percolates also increased for green algae. Chemical analysis covering an extensive set of wastewater-born organic pollutants demonstrated that many of them were considerably reduced by soil passage, particularly through peaty soils. Taken together, these results indicated that wastewater-born phytotoxic substances may be removed by soil passage, while existing soil pollutants (e.g. metals) may leach and impair percolate quality. Soils with and without wastewater irrigation were tested for growth of plants (Avena sativa, Brassica napus) and soil bacteria (Arthrobacter globiformis) and reproduction of collembolans (Folsomia candida) and oligochaetes (Enchytraeus crypticus, Eisenia fetida). The habitat quality of the standard and two field soils appeared to be deteriorated by wastewater percolation for at least one organism (enchytraeids, plants or bacteria), while for two pre-contaminated field soils it also was improved (for plants and/or enchytraeids). Wastewater percolation did not seem to raise soil concentrations

Reactive transport modelling to infer changes in soil hydraulic properties induced by non-conventional water irrigation

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Valdes-Abellan, Javier; Jiménez-Martínez, Joaquín; Candela, Lucila; Jacques, Diederik; Kohfahl, Claus; Tamoh, Karim

2017-06-01

The use of non-conventional water (e.g., treated wastewater, desalinated water) for different purposes is increasing in many water scarce regions of the world. Its use for irrigation may have potential drawbacks, because of mineral dissolution/precipitation processes, such as changes in soil physical and hydraulic properties (e.g., porosity, permeability), modifying infiltration and aquifer recharge processes or blocking root growth. Prediction of soil and groundwater impacts is essential for achieving sustainable agricultural practices. A numerical model to solve unsaturated water flow and non-isothermal multicomponent reactive transport has been modified implementing the spatio-temporal evolution of soil physical and hydraulic properties. A long-term process simulation (30 years) of agricultural irrigation with desalinated water, based on a calibrated/validated 1D numerical model in a semi-arid region, is presented. Different scenarios conditioning reactive transport (i.e., rainwater irrigation, lack of gypsum in the soil profile, and lower partial pressure of CO2 (pCO2)) have also been considered. Results show that although boundary conditions and mineral soil composition highly influence the reactive processes, dissolution/precipitation of carbonate species is triggered mainly by pCO2, closely related to plant roots. Calcite dissolution occurs in the root zone, precipitation takes place under it and at the soil surface, which will lead a root growth blockage and a direct soil evaporation decrease, respectively. For the studied soil, a gypsum dissolution up to 40 cm depth is expected at long-term, with a general increase of porosity and hydraulic conductivity.

Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas

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Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

Evaluation of soil and water salinity for irrigation in North-eastern ...

African Journals Online (AJOL)

GREG

2013-05-08

May 8, 2013 ... For sound land use and water management in irrigated area, knowledge of the chemical ... Nowadays, soil salinity has become important problem in irrigated ... hoe, shovel, plastic bags, hard paper or labeling, markers, rope,.

Soil water sensors for irrigation management-What works, what doesn't, and why

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Irrigation scheduling can be greatly improved if accurate soil water content data are available. There are a plethora of available soil water sensing systems, but those that are practical for irrigation scheduling are divided into two major types: the frequency domain (capacitance) sensors and the t...

Use of neutron scattering meter to detect soil moisture distribution under trickle irrigation system in sandy soil of inshas, Egypt

International Nuclear Information System (INIS)

Abd El-moniem, M.; El-gendy, R.W.; Gadalla, A.M.; Hamdy, A.; Zeedan, A.

2006-01-01

This study aims to investigate the soil moisture distribution under different quantities of irrigation water in cultivated sandy soil with squash, using drip irrigation system. This study was carried out in Inshas sandy soil at the farm of Soil and Water Research Department, Nuclear Research Centre, Atomic Energy Authority, Egypt. Three rates of applied irrigation water (100, 75 and 50 % ETc) were used. Three sites (0, 12.5 and 25 cm distances from the emitter between drippers and laterals lines) were chosen to measure soil moisture contents (horizontal and vertical directions within the soil depths). The obtained data pointed out that the maximum width, in onion shape of water distribution under drip irrigation system, was at 45 cm depth at 0 site. From the study of soil moisture distribution, the overlapping between each two neighbor drippers played a good role in increasing soil moisture content at the 25 site rather than the rest sites. Water distribution was affected with plant location within the wet area as well as the used irrigation water quantities. Water distribution between drippers and laterals did not differ much approximately. The highest soil moisture depletion was at 12.5 site (between drippers) for 100 and 75 % ETc rather than the rest treatments. 100 % ETc treatment introduced the highest soil moisture depletion in the first stage of plant growth season for the three sites (between drippers and laterals). In the last stage of plant growth season, water re-distribution phenomena resulted from the changeable total hydraulic potential, which played important role for interpretation of results

New soil water sensors for irrigation management

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Effective irrigation management is key to obtaining the most crop production per unit of water applied and increasing production in the face of competing demands on water resources. Management methods have included calculating crop water needs based on weather station measurements, calculating soil ...

The impact of informal irrigation practices on soil drainage condition, soil pollution and land suitability for agriculture in El Saf area of El Giza Governorate

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Hanan E.M. El Azab

2015-12-01

Full Text Available The study area was selected in El Saf District of El Giza Governorate in Egypt, covering 21461.4 ha of Nile sediments and their outskirts of alluvial higher and lower terraces. The aim of this study was to assess the impact of informal irrigation practices on drainage deterioration, soil pollution and land suitability for agricultural use using the satellite LDCM data 2013. From the lower alluvial terraces (partly cultivated using wastewater, the drainage flows westward via descending slopes resulting in land deterioration in both the alluvial lower terraces and alluvial plain of River Nile. The drainage conditions are excessively drained soils in the alluvial upper terraces within soils of Typic Haplocalcids, sandy skeletal, but in the lower terraces it partly occurred within soils of Typic Torriorthents, sandy skeletal. Moderately well drained soils occurred in soils of Typic Torriorthents, sandy in the alluvial lower terraces, while in the alluvial plain of Nile sediments are Sodic Haplotorrerts, fine. Poorly drained soils in the lower alluvial terraces have soils of Typic Epiaquents, sandy associated with Sodic Psammaquents and Aquic Haplocalcids, coarse loamy, while in the alluvial plain of River Nile the soils are Halic Epiaquerts, fine. Very poorly drained soils (submerged areas are scattered spots in both the lower alluvial terraces and the alluvial plain. In the alluvial plain of River Nile, 1967.1 ha become not suitable for the traditional cultivated crops, while in the alluvial terraces 3251.0 ha are not suitable for the proposed cultivation of Jojoba plants. Heavy metals of Cadmium (Cd, Cobalt (Co, Lead (Pb and Nickel (Ni were added to the soil surface and sub-surface in the irrigated areas by wastewater in the lower alluvial terraces (moderately well drained soils, but Cd and Co exceeded the standards of permissible total concentrations in these soils. The same metals were added to soil sub-surface layers in the alluvial plain

Heavy metal input to agricultural soils from irrigation with treated wastewater: Insight from Pb isotopes

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Kloppmann, Wolfram; Cary, Lise; Psarras, Georgios; Surdyk, Nicolas; Chartzoulakis, Kostas; Pettenati, Marie; Maton, Laure

2010-05-01

A major objective of the EU FP6 project SAFIR was to overcome certain drawbacks of wastewater reuse through the development of a new irrigation technology combining small-scale modular water treatment plants on farm level and improved irrigation hardware, in the aim to lower the risks related to low quality water and to increase water use efficiency. This innovative technology was tested in several hydro-climatic contexts (Crete, Italy, Serbia, China) on experimental irrigated tomato and potato fields. Here we present the heavy metal variations in soil after medium-term (3 irrigation seasons from 2006-2008) use of treated municipal wastewater with a special focus on lead and lead isotope signatures. The experimental site is located in Chania, Crete. A matrix of plots were irrigated, combining different water qualities (secondary, primary treated wastewater, tap water, partially spiked with heavy metals, going through newly developed tertiary treatment systems) with different irrigation strategies (surface and subsurface drip irrigation combined with full irrigation and partial root drying). In order to assess small scale heavy metal distribution around a drip emitter, Pb isotope tracing was used, combined with selective extraction. The sampling for Pb isotope fingerprinting was performed after the 3rd season of ww-irrigation on a lateral profile from a drip irrigator (half distance between drip lines, i.e. 50cm) and three depth intervals (0-10, 10-20, 20-40 cm). These samples were lixiviated through a 3 step selective extraction procedure giving rise to the bio-accessible, mobile and residual fraction: CaCl2/NaNO3 (bio-accessible fraction), DPTA (mobile fraction), total acid attack (residual fraction). Those samples were analysed for trace elements (including heavy metals) and major inorganic compounds by ICP-MS. The extracted fractions were then analysed by Thermal Ionisation Mass Spectrometry (TIMS) for their lead isotope fingerprints (204Pb, 206Pb, 207Pb, 208Pb

Soil water sensors for irrigation scheduling:Can they deliver a management allowed depletion?

Science.gov (United States)

Soil water sensors are widely marketed in the farming sector as aids for irrigation scheduling. Sensors report either volumetric water content (theta-v, m**3 m**-3) or soil water potential, with theta-v sensors being by far the most common. To obtain yield and quality goals, irrigations are schedule...

Soil surface moisture estimation over a semi-arid region using ENVISAT ASAR radar data for soil evaporation evaluation

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M. Zribi

2011-01-01

Full Text Available The present paper proposes a method for the evaluation of soil evaporation, using soil moisture estimations based on radar satellite measurements. We present firstly an approach for the estimation and monitoring of soil moisture in a semi-arid region in North Africa, using ENVISAT ASAR images, over two types of vegetation covers. The first mapping process is dedicated solely to the monitoring of moisture variability related to rainfall events, over areas in the "non-irrigated olive tree" class of land use. The developed approach is based on a simple linear relationship between soil moisture and the backscattered radar signal normalised at a reference incidence angle. The second process is proposed over wheat fields, using an analysis of moisture variability due to both rainfall and irrigation. A semi-empirical model, based on the water-cloud model for vegetation correction, is used to retrieve soil moisture from the radar signal. Moisture mapping is carried out over wheat fields, showing high variability between irrigated and non-irrigated wheat covers. This analysis is based on a large database, including both ENVISAT ASAR and simultaneously acquired ground-truth measurements (moisture, vegetation, roughness, during the 2008–2009 vegetation cycle. Finally, a semi-empirical approach is proposed in order to relate surface moisture to the difference between soil evaporation and the climate demand, as defined by the potential evaporation. Mapping of the soil evaporation is proposed.

Integrated water-crop-soil-management system for evaluating the quality of irrigation water

International Nuclear Information System (INIS)

Pla-Sentis, I.

1983-01-01

The authors make use of an independent balance of the salts and ions present in the water available for irrigation, based on the residence times in the soil solution that are allowed by solubility limits and drainage conditions, to develop an efficient system for evaluating the quality of such water which combines the factors: water, crop, soil and management. The system is based on the principle that such quality depends not only on the concentration and composition of the salts dissolved in the water, but also on existing possibilities and limitations in using and managing it in respect of the soil and crops, with allowance for the crop's tolerance of salinity, drainage conditions and hydrological properties of the soils, climate and current or potential practices for the management of the irrigation. If this system is used to quantify approximately the time behaviour of the concentration and composition of the salts in the soil solution, it is possible not only to predict the effects on soil, crops and drainage water, but also to evaluate the various combinations of irrigation water, soil, crops and management and to select the most suitable. It is also useful for fairly accurately diagnosing current problems of salinity and for identifying alternatives and possibilities for reclamation. Examples of its use for these purposes in Venezuela are presented with particular reference to the diagnosis of the present and future development of ''salino-sodic'' and ''sodic'' soils by means of low-salt irrigation water spread over agricultural soils with very poor drainage in a sub-humid or semi-arid tropical climate. The authors also describe the use of radiation techniques for gaining an understanding of the relations between the factors making up the system and for improving the quantitative evaluations required to diagnose problems and to select the best management methods for the available irrigation water. (author)

Soil water sensors:Problems, advances and potential for irrigation scheduling

Science.gov (United States)

Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands, while protecting the soil and water resources from degradation. In this regard, sensors can be used to monitor the soil water status; and so...

Heavy metal accumulation in soils, plants, and hair samples: an assessment of heavy metal exposure risks from the consumption of vegetables grown on soils previously irrigated with wastewater.

Science.gov (United States)

Massaquoi, Lamin Daddy; Ma, Hui; Liu, Xue Hui; Han, Peng Yu; Zuo, Shu-Mei; Hua, Zhong-Xian; Liu, Dian-Wu

2015-12-01

It is common knowledge that soils irrigated with wastewater accumulate heavy metals more than those irrigated with cleaner water sources. However, little is known on metal concentrations in soils and cultivars after the cessation of wastewater use. This study assessed the accumulation and health risk of heavy metals 3 years post-wastewater irrigation in soils, vegetables, and farmers' hair. Soils, vegetables, and hair samples were collected from villages previously irrigating with wastewater (experimental villages) and villages with no history of wastewater irrigation (control villages). Soil samples were digested in a mixture of HCL/HNO3/HCLO4/HF. Plants and hair samples were digested in HNO3/HCLO4 mixture. Inductive coupled plasma-optical emission spectrometer (ICP-OES) was used to determine metal concentrations of digested extracts. Study results indicate a persistence of heavy metal concentration in soils and plants from farms previously irrigated with wastewater. In addition, soils previously irrigated with wastewater were severely contaminated with cadmium. Hair metal concentrations of farmers previously irrigating with wastewater were significantly higher (P metal concentrations in hair samples of farmers previously irrigating with wastewater were not associated with current soil metal concentrations. The study concludes that there is a persistence of heavy metals in soils and plants previously irrigated with wastewater, but high metal concentrations in hair samples of farmers cannot be associated with current soil metal concentrations.

Soil Fertility Assessment of The Lugu Main Canal Of Wurno Irrigation ...

African Journals Online (AJOL)

acer

Sokoto State, Nigeria, Five Years After Rehabilitation. A.U. Dikko* ... the soil fertility. Key words: Soil fertility, Soil chemical properties, Wurno Irrigation Project, Lugu main canal. .... 17oC recorded in December/January to 40oC in. April/May.

Influence of sustainable irrigation regimes and agricultural practices on the soil CO2 fluxes from olive groves in SE Spain

Science.gov (United States)

Marañón-Jiménez, Sara; Serrano-Ortíz, Penelope; Vicente-Vicente, Jose Luis; Chamizo, Sonia; Kowalski, Andrew S.

2017-04-01

Olive (Olea europaea) is the dominant agriculture plantation in Spain and its main product, olive oil, is vital to the economy of Mediterranean countries. Given the extensive surface dedicated to olive plantations, olive groves can potentially sequester large amounts of carbon and contribute to mitigate climate change. Their potential for carbon sequestration will, however, largely depend on the management and irrigation practices in the olive grove. Although soil respiration is the main path of C release from the terrestrial ecosystems to the atmosphere and a suitable indicator of soil health and fertility, the interaction of agricultural management practices with irrigation regimes on soil CO2 fluxes have not been assessed yet. Here we investigate the influence of the presence of herbaceous cover, use of artificial fertilizers and their interaction with the irrigation regime on the CO2 emission from the soil to the atmosphere. For this, the three agricultural management treatments were established in replicated plots in an olive grove in the SE of Spain: presence of herbaceous cover ("H"), exclusion of herbaceous cover by using herbicides ("NH"), and exclusion of herbaceous cover along with addition of artificial fertilizers (0.55 kg m-2 year-1 of N, P, K solid fertilizer in the proportion 20:10:10, "NHF"). Within each management treatment, three irrigation regimes were also implemented in a randomized design: no-irrigation ("NO") or rain fed, full irrigation (224 l week-1 per olive tree, "MAX"), and a 50% restriction (112 l week-1 per olive tree, "MED"). Soil respiration was measured every 2-3 weeks at 1, 3, and 5 meters from each olive tree together with soil temperature and soil moisture in order to account for the spatial and seasonal variability over the year. Soil respiration was higher when herbaceous cover was present compared to the herbaceous exclusion, whereas the addition of fertilizer did not exert any significant effect. Although the different

Produced water irrigation changes the soil mesofauna community in a semiarid agroecosystem.

Science.gov (United States)

Ferreira, Raimundo Nonato Costa; Weber, Olmar Baller; Crisóstomo, Lindbergue Araujo

2015-08-01

The scarcity of water in semiarid regions requires alternative sources for irrigation to improve agricultural production. Here, we aimed to evaluate the effects of produced water from oil exploration on the structure of soil mesofauna during the dry and rainy seasons in irrigated sunflower and castor bean fields in a Brazilian semiarid region. Three irrigation treatments were applied on plots cultivated with castor beans and sunflowers: produced water treated by filtration (filtrated) or treated by reverse osmosis (reverse osmosis) and groundwater. The mesofauna under the biofuel crops was collected and identified during the dry and rainy seasons. Although the abundance and richness of the total fauna did not differ between seasons in sunflower plots, the community was altered. In castor beans, the abundance, richness, and community of mesofauna observed in plots irrigated with produced water differed from the groundwater treatment. Irrigation with produced water promotes important changes in soil fauna community that justify their assessment for the maintenance and monitoring of agroecosystems.

Effect of Irrigation with Wastewater on Certain Soil Physical and Chemical properties

Directory of Open Access Journals (Sweden)

Farzad Rohani Shahraki

2005-03-01

Full Text Available Depending on effluent characteristics, irrigation with wastewater plant effluent can be either beneficial or harmful. To investigate the effects of nine years of irrigation with North Isfahan Wastewater Treatment Plant effluent on physical and chemical properties of soil, a study was carried out using a randomized complete block design with three replications. Treatments included: 1 raw wastewater; 2 effluent from primary settling basin; 3 final plant effluent and 4 well water. To investigate soil physical and chemical properties, samples were taken from depths of 0-5 cm and 5-10 cm from each plot. The results showed that raw wastewater COD and SS were higher than the Iranian Standard limits for use in irrigation. So were BOD5 and turbidity of effluent from primary sedimentation tanks. From the results obtained, the raw wastewater may be considered to be of medium quality. However, regarding other parameters such as EC, SAR, Na and Pb, the quality of the raw wastewater was considerably higher than that of well water. All treatments showed medium infiltrability with respect to chloride concentration. The concentration of lead in well water was higher than in treated wastewater. It should be noted that lead concentration in all samples was less than the standard limits. The average soil bulk density and percentage of moisture in FC did not follow any specific trend. The results indicate that the soil irrigated with effluent over the nine years had a lower bulk density, a higher percentage of moisture, and a lower infiltration compared to adjacent soil not irrigated with wastewater. Analysis of variance for all results did not confirm any significant differences among treatments.

Impact of reclaimed water irrigation on soil salinity, hydraulic conductivity, cation exchange capacity and macro-nutrients

Directory of Open Access Journals (Sweden)

Saif A. Al-Khamisi

2016-01-01

Full Text Available Field studies were conducted at Agriculture Research Center, Oman during the year 2010/2011 to monitor the impact of reclaimed water irrigation on soil physical and chemical properties after wheat, cowpea and maize cultivation (in rotation. Three different water sources (Groundwater (GW, desalinized water (DW, and Reclaimed Water (RW were used as the treatments in Randomized Completely Block Design (RCBD with 3 blocks (replicates. Samples were taken from four depths (30, 45, 60 and 90 cm after harvesting time of the three crops. Soil salinity (ECe in all soil depths decreased with time. Organic carbon did not show significant difference between harvest timings of wheat and cowpea. Organic carbon increased with time in soil irrigated with reclaimed water. The saturated hydraulic conductivity of the soil, Ksat didn’t show significant difference among the water types and their interaction with soil depths. Total nitrogen was the highest after cowpea harvest in reclaimed water irrigation. The soil phosphorus and potassium were not affected by any of the three water irrigation types. The highest concentrations of phosphorus and potassium were found to be in the upper soil layers. Overall, no adverse impacts of reclaimed water irrigation were observed after growing three crops of rotation.

Arsenic contamination of soils and agricultural plants through irrigation water in Nepal

International Nuclear Information System (INIS)

Dahal, B.M.; Fuerhacker, M.; Mentler, A.; Karki, K.B.; Shrestha, R.R.; Blum, W.E.H.

2008-01-01

This study monitored the influence of arsenic-contaminated irrigation water on alkaline soils and arsenic uptake in agricultural plants at field level. The arsenic concentrations in irrigation water ranges from -1 where the arsenic concentrations in the soils were measured from 6.1 to 16.7 mg As kg -1 . The arsenic content in different parts of plants are found in the order of roots > shoots > leaves > edible parts. The mean arsenic content of edible plant material (dry weight) were found in the order of onion leaves (0.55 mg As kg -1 ) > onion bulb (0.45 mg As kg -1 ) > cauliflower (0.33 mg As kg -1 ) > rice (0.18 mg As kg -1 ) > brinjal (0.09 mg As kg -1 ) > potato ( -1 ). - The arsenic content in soil and plants is influenced by the degree of arsenic amount in irrigated water

Decision support system for surface irrigation design

OpenAIRE

Gonçalves, José M.; Pereira, L.S.

2009-01-01

The SADREG decision support system was developed to help decision makers in the process of design and selection of farm surface irrigation systems to respond to requirements of modernization of surface irrigation—furrow, basin, and border irrigation. It includes a database, simulation models, user-friendly interfaces, and multicriteria analysis models. SADREG is comprised of two components: design and selection. The first component applies database information, and through several si...

Ecological estimation of the irrigated soils in Qarabagh plain

International Nuclear Information System (INIS)

Mammadov, Q.S.; Nuriyeva, K.Q.

2009-01-01

Contemporary agricultural science improved the known adaptive approaches in the past, for it accounting natural peccularities of the concrete region is offered with the assistance of agroecological estimation of soil. Using of collecting materials of the soil esological parameters of soil cover of the studying territory and applying the system of the private scales of the soil estimation on degree of display of their separate signs, the ecological estimation of the irrigated soils of Qarabagh steppe where the highest ecological marks have been got such as grey-brown dark (94 marks) and ordinary soils (93 marks) has been carried out

Capacitive Sensors and Breakthrough Curves in Automated Irrigation for Water and Soil Conservation

Science.gov (United States)

Fahmy Hussein, Mohamed

2016-04-01

Shortness of water resources is the dominant criterion that dampens agricultural expansion in Egypt. Ten times population increase was recorded versus twice increase in the cultivated area during the last 100 years. Significant increase in freshwater supply is not expected in the near future. Consequently, a great deal of water-conservation is required to ameliorate water-use efficiency and to protect soils against sodicity under the prevailing arid-zone conditions. Modern irrigation (pivot, drip and sprinkling) was introduced during the last three decades in newly cultivated lands. However, this was done without automated watering. Moreover, dynamic chemical profile data is lacking in the cultivated lands. These current water conditions are behind this work. Two experimental procedures were used for a conjunctive goal of water and soil conservation. The first procedure used the resonance of analog-oscillators (relative permittivity sensors) based on capacitive Frequency Domain Reflectometry, FDR. Commercially available FDR sensors were calibrated for three soil textures, and solenoids were used to automatically turn on and off irrigation pipes in three experimental plots (via low power AC latching-valves on relay solid-state boards connected to sensors; the valve got closed when soil became sufficiently moist near saturation and opened before reaching wilting point as the relay contacts were defined by variable-resistor on board after sensor calibration). This article reports the results of sensor mV readings versus soil-moisture in the linear parts of calibration diagrams, for known moisture contents from wilting point to saturation, fitted as "power-law of dielectric mixing". The results showed close to optimum watering at soil-surface in the nursery beds when the sensors were sampled every 10 minutes to update the relays. This work is planned to extend to different sensors and drippers for soils with field crops / fruit trees to account for aspects of concern

Irrigation and Nitrogen Regimes Promote the Use of Soil Water and Nitrate Nitrogen from Deep Soil Layers by Regulating Root Growth in Wheat.

Science.gov (United States)

Liu, Weixing; Ma, Geng; Wang, Chenyang; Wang, Jiarui; Lu, Hongfang; Li, Shasha; Feng, Wei; Xie, Yingxin; Ma, Dongyun; Kang, Guozhang

2018-01-01

Unreasonably high irrigation levels and excessive nitrogen (N) supplementation are common occurrences in the North China Plain that affect winter wheat production. Therefore, a 6-yr-long stationary field experiment was conducted to investigate the effects of irrigation and N regimes on root development and their relationship with soil water and N use in different soil layers. Compared to the non-irrigated treatment (W0), a single irrigation at jointing (W1) significantly increased yield by 3.6-45.6%. With increases in water (W2, a second irrigation at flowering), grain yield was significantly improved by 14.1-45.3% compared to the W1 treatments during the drier growing seasons (2010-2011, 2012-2013, and 2015-2016). However, under sufficient pre-sowing soil moisture conditions, grain yield was not increased, and water use efficiency (WUE) decreased significantly in the W2 treatments during normal precipitation seasons (2011-2012, 2013-2014, and 2014-2015). Irrigating the soil twice inhibited root growth into the deeper soil depth profiles and thus weakened the utilization of soil water and NO 3 -N from the deep soil layers. N applications increased yield by 19.1-64.5%, with a corresponding increase in WUE of 66.9-83.9% compared to the no-N treatment (N0). However, there was no further increase in grain yield and the WUE response when N rates exceeded 240 and 180 kg N ha -1 , respectively. A N application rate of 240 kg ha -1 facilitated root growth in the deep soil layers, which was conducive to utilization of soil water and NO 3 -N and also in reducing the residual NO 3 -N. Correlation analysis indicated that the grain yield was significantly positively correlated with soil water storage (SWS) and nitrate nitrogen accumulation (SNA) prior to sowing. Therefore, N rates of 180-240 kg ha -1 with two irrigations can reduce the risk of yield loss that occurs due to reduced precipitation during the wheat growing seasons, while under better soil moisture conditions, a

Soil capacitance sensors and stem dendrometers. Useful tools for irrigation scheduling of commercial orchards?

Energy Technology Data Exchange (ETDEWEB)

Bonet, L.; Ferrer, P.; Castel, J. R.; Intrigliolo, D. S.

2010-07-01

Irrigation scheduling is often performed based on a soil water balance, where orchard evapotranspiration is estimated using the reference evapotranspiration (ETo) times the crop coefficient (Kc). This procedure, despite being widely spread, has some uncertainties. Because of this, plant and soil water status monitoring could be alternatively or complementarity used to schedule irrigation. The usefulness of capacitance probes was evaluated during several seasons in large irrigation districts where irrigation practices were changed over years from the ETo * Kc model to the analysis of soil water status trend. This area corresponds to drip irrigated orchards planted with citrus, peach, nectarine and persimmon. Around 25% less irrigation was applied with no substantial yield penalty when the information provided by capacitance probes was correctly applied for irrigation management. On the other hand, the usefulness of stem dendrometers for continuously monitoring plant water status was evaluated in a young plum experimental orchard. Over two years, irrigation was scheduled using exclusively trunk shrinkage via the signal intensity approach by means of a baseline equation previously obtained in the orchard. Results showed that it was not always possible to schedule irrigation based on the trunk shrinkage signal intensity due to the temporal changes in the reference values that occurred as trees aged. Overall, results obtained are discussed in terms of the possible extrapolation at field level of both capacitance probes and stem dendrometers. Advantages and drawbacks of each technique are analyzed and discussed. (Author) 34 refs.

Soil-pit Method for Distribution and Leaching Loss of Nitrogen in Winter Wheat’s Soil, Weishan Irrigation District

Science.gov (United States)

Zhao, Erni; Xu, Lirong; Wang, Rongzhen

2018-01-01

Unreasonable application of irrigation and fertilizer will cause the waste of water and nitrogen and environmental pollution. In this paper, a series of soil-pit experiments were carried out to study the distribution and leaching loss of nitrogen in winter wheat’s soil. The results showed that NO3 - concentration at 20-80cm depth mainly responded to fertilizer application at the beginning of field experiment, but the amount of irrigation became the dominant factor with the growth of winter wheat. It is noteworthy that the distribution of NO3 - was mainly affected by the amount of fertilizer applied at the depth of 120-160cm in the whole period of growth of winter wheat. The accumulation position of NH4 + was deepened as the amount of irrigation increased, however, the maximum aggregation depth of ammonium nitrogen was no more than 80cm owing to its poor migration. It can be concluded that the influence of irrigation amount on the concentration of NH4 + in soil solution was more obvious than that of fertilizer. Compared with fertilizer, the amount of irrigation played a leading role in the utilization ratio of nitrogen and the yield of winter wheat. In summary, the best water and fertilizer treatment occurred in No.3 soil-pit, which meant that the middle amount of water and fertilizer could get higher wheat yield and less nitrogen leaching losses in the study area.

Potential impacts of wintertime soil moisture anomalies from agricultural irrigation at low latitudes on regional and global climates

Science.gov (United States)

Wey, Hao-Wei; Lo, Min-Hui; Lee, Shih-Yu; Yu, Jin-Yi; Hsu, Huang-Hsiung

2015-10-01

Anthropogenic water management can change surface energy budgets and the water cycle. In this study, we focused on impacts of Asian low-latitude irrigation on regional and global climates during boreal wintertime. A state-of-the-art Earth system model is used to simulate the land-air interaction processes affected by irrigation and the consequent responses in atmospheric circulation. Perturbed experiments show that wet soil moisture anomalies at low latitudes can reduce the surface temperature on a continental scale through atmospheric feedback. The intensity of prevailing monsoon circulation becomes stronger because of larger land-sea thermal contrast. Furthermore, anomalous upper level convergence over South Asia and midlatitude climatic changes indicate tropical-extratropical teleconnections. The wintertime Aleutian low is deepened and an anomalous warm surface temperature is found in North America. Previous studies have noted this warming but left it unexplained, and we provide plausible mechanisms for these remote impacts coming from the irrigation over Asian low-latitude regions.

Design of a pot experiment to study the effect of irrigation with ...

African Journals Online (AJOL)

Municipal water was used to irrigate the control treatment of each soil. .... experiment. RESULTS AND DISCUSSION. Since only ... deeper horizons were considered to be irrelevant. With the ... irrigation water uniformly over the soil surface, the four micro- .... of selected vineyard soils and a critical assessment of methods to.

Effects of waste water irrigation on soil properties and soil fauna of spinach fields in a West African urban vegetable production system.

Science.gov (United States)

Stenchly, Kathrin; Dao, Juliane; Lompo, Désiré Jean-Pascal; Buerkert, Andreas

2017-03-01

The usage of inadequately processed industrial waste water (WW) can lead to strong soil alkalinity and soil salinization of agricultural fields with negative consequences on soil properties and biota. Gypsum as a soil amendment to saline-sodic soils is widely used in agricultural fields to improve their soil physical, chemical and hence biological properties. This study aimed at analysing the effects of intensive WW irrigation on the structure and composition of soil-dwelling arthropods on spinach fields (Spinacia oleracea L.) in a West African urban vegetable production system. We used gypsum as a soil amendment with the potential to alleviate soil chemical stress resulting in a potentially positive impact on soil arthropods. A total of 32 plots were established that showed a gradient in soil pH ranging from slight to strong soil alkalinity and that were irrigated with WW (n = 12) or clean water (CW; n = 20), including eight plots into which gypsum was incorporated. Our study revealed a high tolerance of soil-dwelling arthropods for alkaline soils, but spinach fields with increased soil electrical conductivity (EC) showed a reduced abundance of Hymenoptera, Diptera and Auchenorrhyncha. Arthropod abundance was positively related to a dense spinach cover that in turn was not affected by WW irrigation or soil properties. Gypsum application reduced soil pH but increased soil EC. WW irrigation and related soil pH affected arthropod composition in the investigated spinach fields which may lead to negative effects on agronomical important arthropod groups such as pollinators and predators. Copyright © 2017 Elsevier Ltd. All rights reserved.

Management of sierozem soils for irrigated cotton production in South Kazakhstan

Science.gov (United States)

Because cotton is an important crop in South Kazakhstan, it is irrigated to get economically viable yields. Irrigation management is challenging because water and soils are saline and because water must be conserved so that some of it can refill the Aral Sea. From 2006 to 2008, we grew furrow-irriga...

Soil Fertility Assessment of The Lugu Main Canal Of Wurno Irrigation ...

African Journals Online (AJOL)

Soil Fertility Assessment of The Lugu Main Canal Of Wurno Irrigation Project, Sokoto State, ... Nigerian Journal of Basic and Applied Sciences ... Soil chemical properties such as pH, total N, available P, CEC and exchangeable bases were

Health risks of heavy metals in contaminated soils and food crops irrigated with wastewater in Beijing, China

International Nuclear Information System (INIS)

Khan, S.; Cao, Q.; Zheng, Y.M.; Huang, Y.Z.; Zhu, Y.G.

2008-01-01

Consumption of food crops contaminated with heavy metals is a major food chain route for human exposure. We studied the health risks of heavy metals in contaminated food crops irrigated with wastewater. Results indicate that there is a substantial buildup of heavy metals in wastewater-irrigated soils, collected from Beijing, China. Heavy metal concentrations in plants grown in wastewater-irrigated soils were significantly higher (P ≤ 0.001) than in plants grown in the reference soil, and exceeded the permissible limits set by the State Environmental Protection Administration (SEPA) in China and the World Health Organization (WHO). Furthermore, this study highlights that both adults and children consuming food crops grown in wastewater-irrigated soils ingest significant amount of the metals studied. However, health risk index values of less than 1 indicate a relative absence of health risks associated with the ingestion of contaminated vegetables. - Long-term wastewater irrigation leads to buildup of heavy metals in soils and food crops

Effects of surface and subsurface drip irrigation regimes with saline water on yield and water use efficiency of potato in arid conditions of Tunisia

Directory of Open Access Journals (Sweden)

Fathia El Mokh

2014-12-01

Full Text Available Field experiments were conducted on a sandy soil during spring of 2009 and autumn of 2010 in southern Tunisia for evaluating the effects of two drip irrigation methods and three irrigation regimes on soil moisture and salinity, yield and water use efficiency of potato (Solanum tuberosum L.. The surface drip (SDI and subsurface drip (SSDI irrigation methods were used. Irrigation regimes consisted in replacement of cumulated ETc when readily available water is depleted with levels of 100% (FI100, 60% (DI60 and 30% (DI30. FI100 was considered as full irrigation while DI60 and DI30 were considered as deficit irrigation regimes. Well water with an ECi of 7.0 dS/m was used for irrigation. Findings are globally consistent between the two experiments. Results show that soil moisture content and salinity were significantly affected by irrigation treatments and methods. Higher soil moisture content and lower soil salinity were maintained with SSDI than SDI for all irrigation treatments. For both irrigation methods, higher salinity and lower moisture content in the root zone are observed under DI60 and DI30 treatments compared to FI100. Potato yields were highest over two cropping periods for the SSDI method although no significant differences were observed with the SDI. Irrigation regimes resulted in significant difference in both irrigation methods on yield and its components. Yields were highest under FI100. Compared to FI100, considerable reductions in potato yields were observed under DI60 and DI30 deficit treatments resulting from a reduction in tubers number/m² and average tuber weight and size. Water use efficiency (WUE was found to vary significantly among irrigation methods and treatments and varied between 5.9 and 20.5 kg/m3. WUE of SSDI method had generally higher values than SDI. The lowest WUE values were observed for the FI100 treatment, while the highest values were obtained under DI30 treatment for both methods. SSDI method provides

Using Automation to Improve Surface Irrigation Management

Science.gov (United States)

In the Lower Mississippi Water Resource Area (WRA 08), also called the Mid-South, 2 million ha of cropland (80% of the irrigated farmland) employ surface irrigation, almost equally divided between furrow (52%) and controlled flooding (48%). Because Mid-South farmers experience less-than-optimal surf...

Irrigation in dose assessments models

Energy Technology Data Exchange (ETDEWEB)

Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

2004-05-01

SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

Irrigation in dose assessments models

International Nuclear Information System (INIS)

Bergstroem, Ulla; Barkefors, Catarina

2004-05-01

SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

The effect of irrigation time and type of irrigation fluid on cartilage surface friction.

Science.gov (United States)

Stärke, F; Awiszus, F; Lohmann, C H; Stärke, C

2018-01-01

It is known that fluid irrigation used during arthroscopic procedures causes a wash-out of lubricating substances from the articular cartilage surface and leads to increased friction. It was the goal of this study to investigate whether this effect depends on the time of irrigation and type of fluid used. Rabbit hind legs were used for the tests. The knees were dissected and the friction coefficient of the femoral cartilage measured against glass in a boundary lubrication state. To determine the influence of irrigation time and fluid, groups of 12 knees received either no irrigation (control), 15, 60 or 120min of irrigation with lactated Ringer's solution or 60min of irrigation with normal saline or a sorbitol/mannitol solution. The time of irrigation had a significant effect on the static and kinetic coefficient of friction (CoF), as had the type of fluid. Longer irrigation time with Ringer's solution was associated with increased friction coefficients (relative increase of the kinetic CoF compared to the control after 15, 60 and 120min: 16%, 76% and 88% respectively). The sorbitol/mannitol solution affected the static and kinetic CoF significantly less than either Ringer's or normal saline. The washout of lubricating glycoproteins from the cartilage surface and the associated increase of friction can be effectively influenced by controlling the time of irrigation and type of fluid used. The time of exposure to the irrigation fluid should be as short as possible and monosaccharide solutions might offer a benefit compared to salt solutions in terms of the resultant friction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of different irrigation practices using treated wastewater on tomato yields, quality, water productivity, and soil and fruit mineral contents.

Science.gov (United States)

Demir, Azize Dogan; Sahin, Ustun

2017-11-01

Wastewater use in agricultural irrigation is becoming a common practice in order to meet the rising water demands in arid and semi-arid regions. The study was conducted to determine the effects of the full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation practices using treated municipal wastewater (TWW) and freshwater (FW) on tomato yield, water use, fruit quality, and soil and fruit heavy metal concentrations. The TWW significantly increased marketable yield compared to the FW, as well as decreased water consumption. Therefore, water use efficiency (WUE) in the TWW was significantly higher than in the FW. Although the DI and the PRD practices caused less yields, these practices significantly increased WUE values due to less irrigation water applied. The water-yield linear relationships were statistically significant. TWW significantly increased titratable acidity and vitamin C contents. Reduced irrigation provided significantly lower titratable acidity, vitamin C, and lycopene contents. TWW increased the surface soil and fruit mineral contents in response to FW. Greater increases were observed under FI, and mineral contents declined with reduction in irrigation water. Heavy metal accumulation in soils was within safe limits. However, Cd and Pb contents in fruits exceeded standard limits given by FAO/WHO. Higher metal pollution index values determined for fruits also indicated that TWW application, especially under FI, might cause health risks in long term.

Soil salinity assessment through satellite thermography for different irrigated and rainfed crops

Science.gov (United States)

Ivushkin, Konstantin; Bartholomeus, Harm; Bregt, Arnold K.; Pulatov, Alim; Bui, Elisabeth N.; Wilford, John

2018-06-01

The use of canopy thermography is an innovative approach for salinity stress detection in plants. But its applicability for landscape scale studies using satellite sensors is still not well investigated. The aim of this research is to test the satellite thermography soil salinity assessment approach on a study area with different crops, grown both in irrigated and rainfed conditions, to evaluate whether the approach has general applicability. Four study areas in four different states of Australia were selected to give broad representation of different crops cultivated under irrigated and rainfed conditions. The soil salinity map was prepared by the staff of Geoscience Australia and CSIRO Land and Water and it is based on thorough soil sampling together with environmental modelling. Remote sensing data was captured by the Landsat 5 TM satellite. In the analysis we used vegetation indices and brightness temperature as an indicator for canopy temperature. Applying analysis of variance and time series we have investigated the applicability of satellite remote sensing of canopy temperature as an approach of soil salinity assessment for different crops grown under irrigated and rainfed conditions. We concluded that in all cases average canopy temperatures were significantly correlated with soil salinity of the area. This relation is valid for all investigated crops, grown both irrigated and rainfed. Nevertheless, crop type does influence the strength of the relations. In our case cotton shows only minor temperature difference compared to other vegetation classes. The strongest relations between canopy temperature and soil salinity were observed at the moment of a maximum green biomass of the crops which is thus considered to be the best time for application of the approach.

Salinity effect of irrigation with treated wastewater in basal soil respiration in SE of Spain

Science.gov (United States)

Morugan, A.; Garcia-Orenes, F.; Mataix-Solera, J.

2012-04-01

The use of treated wastewater for the irrigation of agricultural soils is an alternative to utilizing better-quality water, especially in semiarid regions where water shortage is a very serious problem. Wastewater use in agriculture is not a new practice, all over the world this reuse has been common practice for a long time, but the concept is of greater importance currently because of the global water crisis. Replacement of freshwater by treated wastewater is seen as an important conservation strategy contributing to agricultural production, substantial benefits can derive from using this nutrient-rich waste water but there can also be a negative impact. For this reason it is necessary to know precisely the composition of water before applying it to the soil in order to guarantee minimal impact in terms of contamination and salinization. In this work we have been studying, for more than three years, different parameters in calcareous soils irrigated with treated wastewater in an agricultural Mediterranean area located at Biar (Alicante, SE Spain), with a crop of grape (Vitis labrusca). Three types of waters were used for the irrigation of the soil: fresh water (control) (TC), and treated wastewater from secondary (T2) and tertiary treatment (T3). Three different doses of irrigation have been applied to fit the efficiency of the irrigation to the crop and soil type during the study period. A soil sampling was carried out every four months. We show the results of the evolution of basal soil respiration (BSR), and its relationship with other parameters. We observed a similar pattern of behavior for BSR between treatments, a decrease at the first eighteen months of irrigation and an increase at the end of study. In our study case, the variations of BSR obtained for all the treatments seem to be closely related to the dose and frequency of irrigation and the related soil wetting and drying cycles. However, the results showed a negative correlation between BSR and

EVALUATION OF RADIONUCLIDE ACCUMULATION IN SOIL DUE TO LONG-TERM IRRIGATION

International Nuclear Information System (INIS)

De Wesley Wu

2006-01-01

Radionuclide accumulation in soil due to long-term irrigation is an important part of the model for predicting radiation dose in a long period of time. The model usually assumes an equilibrium condition in soil with a constant irrigation rate, so that radionuclide concentration in soil does not change with time and can be analytically solved. This method is currently being used for the dose assessment in the Yucca Mountain project, which requires evaluating radiation dose for a period of 10,000 years. There are several issues associated with the method: (1) time required for the equilibrium condition, (2) validity of constant irrigation rate, (3) agricultural land use for a long period of time, and (4) variation of a radionuclide concentration in water. These issues are evaluated using a numerical method with a simple model built in the GoldSim software. Some key radionuclides, Tc-99, Np-237, Pu-239, and Am-241 are selected as representative radionuclides. The results indicate that the equilibrium model is acceptable except for a radionuclide that requires long time to accumulate in soil and that its concentration in water changes dramatically with time (i.e. a sharp peak). Then the calculated dose for that radionuclide could be overestimated using the current equilibrium method

In-Soil and Down-Hole Soil Water Sensors: Characteristics for Irrigation Management

Science.gov (United States)

The past use of soil water sensors for irrigation management was variously hampered by high cost, onerous regulations in the case of the neutron probe (NP), difficulty of installation or maintenance, and poor accuracy. Although many sensors are now available, questions of their utility still abound....

Arsenic contamination of soils and agricultural plants through irrigation water in Nepal

Energy Technology Data Exchange (ETDEWEB)

Dahal, B.M. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria); Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Applied Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna (Austria); Environment and Public Health Organization (ENPHO), P.O. Box 4102, Kathmandu (Nepal); Fuerhacker, M. [Institute of Sanitary Engineering and Water Pollution Control, University of Natural Resources and Applied Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna (Austria); Mentler, A. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria); Karki, K.B. [Soil Science Division, Nepal Agricultural Research Council, Khumaltar, Lalitpur (Nepal); Shrestha, R.R. [UN Habitat-Nepal, UN House, Pulchwok, P.O. Box 107, Kathmandu (Nepal); Blum, W.E.H. [Institute of Soil Research, University of Natural Resources and Applied Life Sciences (BOKU), Peter Jordan Strasse 82, A-1190 Vienna (Austria)], E-mail: winfried.blum@boku.ac.at

2008-09-15

This study monitored the influence of arsenic-contaminated irrigation water on alkaline soils and arsenic uptake in agricultural plants at field level. The arsenic concentrations in irrigation water ranges from <0.005 to 1.014 mg L{sup -1} where the arsenic concentrations in the soils were measured from 6.1 to 16.7 mg As kg{sup -1}. The arsenic content in different parts of plants are found in the order of roots > shoots > leaves > edible parts. The mean arsenic content of edible plant material (dry weight) were found in the order of onion leaves (0.55 mg As kg{sup -1}) > onion bulb (0.45 mg As kg{sup -1}) > cauliflower (0.33 mg As kg{sup -1}) > rice (0.18 mg As kg{sup -1}) > brinjal (0.09 mg As kg{sup -1}) > potato (<0.01 mg As kg{sup -1}). - The arsenic content in soil and plants is influenced by the degree of arsenic amount in irrigated water.

Fate and distribution of nitrogen in soil and plants irrigated with landfill leachate.

Science.gov (United States)

Cheng, C Y; Chu, L M

2011-06-01

Landfill leachate contains a high concentration of ammoniacal substances which can be a potential supply of N for plants. A bioassay was conducted using seeds of Brassica chinensis and Lolium perenne to evaluate the phytotoxicity of the leachate sample. A soil column experiment was then carried out in a greenhouse to study the effect of leachate on plant growth. Two grasses (Paspalum notatum and Vetiver zizanioides) and two trees (Hibiscus tiliaceus and Litsea glutinosa) were irrigated with leachate at the EC50 levels for 12 weeks. Their growth performance and the distribution of N were examined and compared with columns applied with chemical fertilizer. With the exception of P. notatum, plants receiving leachate and fertilizer grew better than those receiving water alone. The growth of L. glutinosa and V. zizanioides with leachate irrigation did not differ significantly from plants treated with fertilizer. Leachate irrigation significantly increased the levels of NH(x)-N in soil. Although NO(x)-N was below 1 mg NL(-1) in the leachate sample, the soil NO(x)-N content increased by 9-fold after leachate irrigation, possibly as a result of nitrification. Leachate irrigation at EC50 provided an N input of 1920 kg N ha(-1) over the experimental period, during which up to 1050 kg N ha(-1) was retained in the soil and biomass, depending on the type of vegetation. The amount of nutrient added seems to exceed beyond the assimilative capability. Practitioners should be aware of the possible consequence of N saturation when deciding the application rate if leachate irrigation is aimed for water reuse. Copyright © 2011 Elsevier Ltd. All rights reserved.

Root-Zone Redox Dynamics - In Search for the Cause of Damage to Treated-Wastewater Irrigated Orchards in Clay Soils

Science.gov (United States)

Yalin, David; Shenker, Moshe; Schwartz, Amnon; Assouline, Shmuel; Tarchitzky, Jorge

2016-04-01

Treated wastewater (TW) has become a common source of water for agriculture. However recent findings raise concern regarding its use: a marked decrease (up to 40%) in yield appeared in orchards irrigated with TW compared with fresh water (FW) irrigated orchards. These detrimental effects appeared predominantly in orchards cultivated in clay soils. The association of the damage with clay soils rather than sandy soils led us to hypothesize that the damage is linked to soil aeration problems. We suspected that in clay soils, high sodium adsorption ratio (SAR) and high levels of organic material, both typical of TW, may jointly lead to an extreme decrease in soil oxygen levels, so as to shift soil reduction-oxidation (redox) state down to levels that are known to damage plants. Two-year continuous measurement of redox potential, pH, water tension, and oxygen were conducted in the root-zone (20-35 cm depth) of avocado trees planted in clay soil and irrigated with either TW or FW. Soil solution composition was sampled periodically in-situ and mineral composition was sampled in tree leaves and woody organs biannually. In dry periods the pe+pH values indicated oxic conditions (pe+pH>14), and the fluctuations in redox values were small in both TW and FW plots. Decreases in soil water tension following irrigation or rain were followed by drops in soil oxygen and pe+pH values. TW irrigated plots had significantly lower minimum pe+pH values compared with FW-irrigated plots, the most significant differences occurred during the irrigation season rather than the rain season. A linear correlation appeared between irrigation volume and reduction severity in TW-irrigated plots, but not in the FW plots, indicating a direct link to the irrigation regime in TW-irrigated plots. The minimum pe+pH values measured in the TW plots are indicative of suboxic conditions (9water tension and oxygen concentration levels. The consequences of our findings to plant health will be discussed, and

Modeling the effects of different irrigation water salinity on soil water movement, uptake and multicomponent solute transport

Science.gov (United States)

Lekakis, E. H.; Antonopoulos, V. Z.

2015-11-01

Simulation models can be important tools for analyzing and managing irrigation, soil salinization or crop production problems. In this study a mathematical model that describes the water movement and mass transport of individual ions (Ca2+, Mg2+ and Na+) and overall soil salinity by means of the soil solution electrical conductivity, is used. The mass transport equations of Ca2+, Mg2+ and Na+ have been incorporated as part of the integrated model WANISIM and the soil salinity was computed as the sum of individual ions. The model was calibrated and validated against field data, collected during a three year experiment in plots of maize, irrigated with three different irrigation water qualities, at Thessaloniki area in Northern Greece. The model was also used to evaluate salinization and sodification hazards by the use of irrigation water with increasing electrical conductivity of 0.8, 3.2 and 6.4 dS m-1, while maintaining a ratio of Ca2+:Mg2+:Na+ equal to 3:3:2. The qualitative and quantitative procedures for results evaluation showed that there was good agreement between the simulated and measured values of the water content, overall salinity and the concentration of individual soluble cations, at two soil layers (0-35 and 35-75 cm). Nutrient uptake was also taken into account. Locally available irrigation water (ECiw = 0.8 dS m-1) did not cause soil salinization or sodification. On the other hand, irrigation water with ECiw equal to 3.2 and 6.4 dS m-1 caused severe soil salinization, but not sodification. The rainfall water during the winter seasons was not sufficient to leach salts below the soil profile of 110 cm. The modified version of model WANISIM is able to predict the effects of irrigation with saline waters on soil and plant growth and it is suitable for irrigation management in areas with scarce and low quality water resources.

The Response and Repairing of Three Kinds of Crops on Xi’an’s Sewage Irrigation Area Soil

Science.gov (United States)

Xin, H.; Zhimei, Z.; Lei, H.; Huan, L.; Tian, Z.

2017-10-01

This paper focuses on the XiChaZhai village’s vegetable soil which is located in the northern suburbs of Xi’an and on its vegetables, thus analyzes the quality of sewage irrigation region soil and its influence on vegetables through the measurement of Cu, Zn, Pb, Cd’s content in samples. The results show that the research area soil contains apparently excessive heavy metals, and there exists significant differences of different elements’ integrated intensity in soil, the content declines in sequence from Cd, Zn, Pb to Cu. The four heavy metals’ contents in sewage irrigation region soil vary greatly from that in non-sewage irrigation region soil(Prepairing effects on Xi’an sewage irrigation region soil are Raphanus sativus, Ottelia acuminate and Brassica chinensis, in that order. Different crop tissues differ in the accumulation of heavy metal, the order according as roots, stem and leaves, fruits. Therefore, based on differences of various crops on heavy metals’ absorption and translocation, appropriate crops should be scientifically planted in heavy metal contaminated area soil.

Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

Science.gov (United States)

Stietiya, Mohammed Hashem; Duqqah, Mohammad; Udeigwe, Theophilus; Zubi, Ruba; Ammari, Tarek

2014-01-01

Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO) amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1) soil was higher than Wadi Dhuleil (WD1) soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective. PMID:24723833

Fate and Distribution of Heavy Metals in Wastewater Irrigated Calcareous Soils

Directory of Open Access Journals (Sweden)

Mohammed Hashem Stietiya

2014-01-01

Full Text Available Accumulation of heavy metals in Jordanian soils irrigated with treated wastewater threatens agricultural sustainability. This study was carried out to investigate the environmental fate of Zn, Ni, and Cd in calcareous soils irrigated with treated wastewater and to elucidate the impact of hydrous ferric oxide (HFO amendment on metal redistribution among soil fractions. Results showed that sorption capacity for Zarqa River (ZR1 soil was higher than Wadi Dhuleil (WD1 soil for all metals. The order of sorption affinity for WD1 was in the decreasing order of Ni > Zn > Cd, consistent with electrostatic attraction and indication of weak association with soil constituents. Following metal addition, Zn and Ni were distributed among the carbonate and Fe/Mn oxide fractions, while Cd was distributed among the exchangeable and carbonate fractions in both soils. Amending soils with 3% HFO did not increase the concentration of metals associated with the Fe/Mn oxide fraction or impact metal redistribution. The study suggests that carbonates control the mobility and bioavailability of Zn, Ni, and Cd in these calcareous soils, even in presence of a strong adsorbent such as HFO. Thus, it can be inferred that in situ heavy metal remediation of these highly calcareous soils using iron oxide compounds could be ineffective.

Effect of dry land transformation and quality of water use for crop irrigation on the soil bacterial community in the Mezquital Valley, Mexico

Science.gov (United States)

Lüneberg, Kathia; Schneider, Dominik; Daniel, Rolf; Siebe, Christina

2017-04-01

Soil bacteria are important determinants of soil fertility and ecosystem services as they participate in all biogeochemical cycles. Until now the comprehension of compositional and functional response that bacterial communities have to land use change and management, specifically in dry land its limited. Dry lands cover 40% of the world's land surface and its crop production supports one third of the global population. In this regions soil moisture is limited constraining farming to the rainy season or oblige to irrigate, as fresh water resources become scarce, to maintain productivity, treated or untreated wastewater for field irrigation is used. In this study the transformation of semiarid shrubland to agriculture under different land systems regarding quantity and quality of water use for crop irrigation on bacterial communities was investigated. The land systems included maize rain-fed plantations and irrigation systems with freshwater, untreated wastewater stored in a dam and untreated wastewater during dry and rainy season. Bacterial community structure and function was heavily affected by land use system and soil properties, whereas seasonality had a slighter effect. A soil moisture, nutrient and contaminant-content increasing gradient among the land use systems, going from rain fed plantation over fresh water, dam wastewater to untreated wastewater irrigated plantations was detected, this gradient diminished the abundance of Actinobacteria and Cyanobacteria, but enhanced the one from Bacteroidetes and Proteobacteria. Discernible clustering of the dry land soil communities coincides with the moisture, nutrient and contaminant gradient, being shrubland soil communities closer to the rain-fed's system and farer to the one from untreated wastewater irrigated soil. Soil moisture together with sodium content and pH were the strongest drivers of the community structure. Seasonality promoted shifts in the composition of soil bacteria under irrigation with

Soil Nutrient Availability, Plant Nutrient Uptake, and Wild Blueberry (Vaccinium angustifolium Ait. Yield in Response to N-Viro Biosolids and Irrigation Applications

Directory of Open Access Journals (Sweden)

Aitazaz A. Farooque

2012-01-01

Full Text Available We compared the impact of surface broadcasted N-Viro biosolids and inorganic fertilizer (16.5% Ammonium sulphate, 34.5% Diammonium phosphate, 4.5% Potash, and 44.5% s and/or clay filler applications on soil properties and nutrients, leaf nutrient concentration, and the fruit yield of lowbush blueberry under irrigated and nonirrigated conditions during 2008-2009 at Debert, NS, Canada. Application rates of N-Viro biosolids were more than double of inorganic fertilizer applied at a recommended N rate of 32 kg ha−1. The experimental treatments NI: N-Viro with irrigation, FI: inorganic fertilizer with irrigation, N: N-Viro without irrigation, and F: inorganic fertilizer without irrigation (control were replicated four times under a randomized complete block design. The NI treatment had the highest OM (6.68% followed by FI (6.32%, N (6.18%, and F (4.43% treatments during the year 2008. Similar trends were observed during 2009 with the highest soil OM values (5.50% for NI treatment. Supplemental irrigation resulted in a 21% increase in the ripe fruit yield. Nonsignificant effect of fertilizer treatments on most of the nutrient concentrations in soil and plant leaves, and on ripe fruits yield reflects that the performance of N-Viro was comparable with that of the inorganic fertilizer used in this study.

Effect of organic matter, irrigation and soil mulching on the nutritional ...

African Journals Online (AJOL)

Rukevwe S. Abraka

2016-11-30

Nov 30, 2016 ... necessary for the soil humidity to be in an adequate amount (Danso ... clay, with soil and particle density of: 1.51 and 2.76 g cm-3, respectively ..... fertilization and irrigation methods on nitrogen uptake, intercepted ŷ = 2373.4 + ...

Drip and Surface Irrigation Water Use Efficiency of Tomato Crop Using Nuclear Techniques

International Nuclear Information System (INIS)

Mellouli, H.J.; Askri, H.; Mougou, R.

2003-01-01

Nations in the arid and semi-arid regions, especially the Arab countries, will have to take up an important challenge at the beginning of the 21 st century: increasing food production in order to realise food security for growing population, wile optimising the use of limited water resources. Using and adapting management techniques like the drip irrigation system could obtain the later. This would allow reduction in water losses by bare soil evaporation and deep percolation. Consequently improved water use efficiency could be realised. In this way, this work was conducted as a contribution on the Tunisian national programs on the optimisation of the water use. By mean a field study at Cherfech Experimental Station (30 km from Tunis), the effect of the irrigation system on the water use efficiency (WUE)-by a season tomato crop-was monitored by comparing three treatments receiving equivalent quantities of fertiliser: Fertigation, Drip irrigation and Furrow irrigation. Irrigation was scheduled by mean calculation of the water requirement based on the agro meteorological data, the plant physiological stage and the soil water characteristics (Clay Loam). The plant water consumption (ETR) was determined by using soil water balance method, where rainfall and amount of irrigation water readily measured

Coastal surface water suitability analysis for irrigation in Bangladesh

Science.gov (United States)

Mahtab, Mohammad Hossain; Zahid, Anwar

2018-03-01

Water with adequate quality and quantity is very important for irrigation to ensure the crop yields. Salinity is common problem in the coastal waters in Bangladesh. The intensity of salinity in the coastal zone in Bangladesh is not same. It fluctuates over the year. Sodium is another hazard which may hamper permeability and ultimately affects the fertility. It can reduce the crop yields. Although surface water is available in the coastal zone of Bangladesh, but its quality for irrigation needs to be monitored over the year. This paper will investigate the overall quality of coastal surface waters. Thirty-three water samples from different rivers were collected both in wet period (October-December) and in dry period (February-April). Different physical and chemical parameters are considered for investigation of the adequacy of water with respect to international irrigation water quality standards and Bangladesh standards. A comparison between the dry and wet period coastal surface water quality in Bangladesh will also be drawn here. The analysis shows that coastal surface water in Bangladesh is overall suitable for irrigation during wet period, while it needs treatment (which will increase the irrigation cost) for using for irrigation during dry period. Adaptation to this situation can improve the scenario. An integrated plan should be taken to increase the water storing capacity in the coastal area to harvest water during wet period.

Summary of Inorganic Compositional Data for Groundwater, Soil-Water, and Surface-Water Samples at the Headgate Draw Subsurface Drip Irrigation Site

Energy Technology Data Exchange (ETDEWEB)

Geboy, Nicholas J.; Engle, Mark A.; Schroeder, Karl T.; Zupanic, John W.

2007-01-01

As part of a 5-year project on the impact of subsurface drip irrigation (SDI) application of coalbed-methane (CBM) produced waters, water samples were collected from the Headgate Draw SDI site in the Powder River Basin, Wyoming, USA. This research is part of a larger study to understand short- and long-term impacts on both soil and water quality from the beneficial use of CBM waters to grow forage crops through use of SDI. This document provides a summary of the context, sampling methodology, and quality assurance and quality control documentation of samples collected prior to and over the first year of SDI operation at the site (May 2008-October 2009). This report contains an associated database containing inorganic compositional data, water-quality criteria parameters, and calculated geochemical parameters for samples of groundwater, soil water, surface water, treated CBM waters, and as-received CBM waters collected at the Headgate Draw SDI site.

Nitrogen dynamics in the soil-plant system under deficit and partial root-zone drying irrigation strategies in potatoes

DEFF Research Database (Denmark)

Shahnazari, Ali; Ahmadi, Seyed Hamid; Lærke, Poul Erik

2008-01-01

Experiments were conducted in lysimeters with sandy soil under an automatic rain-out shelter to study the effects of subsurface drip irrigation treatments, full irrigation (FI), deficit irrigation (DI) and partial root-zone drying (PRD), on nitrogen (N) dynamics in the soil-plant system of potatoes...

The effect of irrigated rice cropping on the alkalinity of two alkaline rice soils in the Sahel

NARCIS (Netherlands)

Asten, van P.J.A.; Zelfde, van 't J.A.; Zee, van der S.E.A.T.M.; Hammecker, C.

2004-01-01

Irrigated rice cropping is practiced to reclaim alkaline-sodic soils in many parts of the world. This practice is in apparent contrast with earlier studies in the Sahel, which suggests that irrigated rice cropping may lead to the formation of alkaline-sodic soils. Soil column experiments were done

Distribution Of 15N Fertilizer Added To Sandy Soil Under Drip Irrigation System As Affected By Irrigation Frequencies

International Nuclear Information System (INIS)

GADALLA, A.M.; GALAL, Y.G.M.; EL-GENDY, R.W.; ISMAIL, M.M.; EL-DEGWY, S.M.; KASSAB, M.F.

2009-01-01

Neutron moisture meter and stable nitrogen isotope ( 15 N) were used to follow horizontal and vertical water movement and N-fertilizer added to soil before and after irrigation. The data indicated that soil moisture distribution and values of total hydraulic potential depend on soil moisture content. Characterization of nitrogen in soil for all sites around the emitter indicated spatial variability with different soil depths due to leaching and volatilization processes. Moreover, water movement and flow direction greatly were characterized by active evaporation depth which was 30 cm.

Distribuição de água no solo aplicado por gotejamento enterrado e superficial Soil water distribution for subsurface and surface drip irrigation

Directory of Open Access Journals (Sweden)

Allan C. Barros

2009-12-01

Full Text Available Devido à falta de estudos sobre o movimento da água quando aplicada abaixo da superfície, realizou-se este trabalho com o objetivo de avaliar a distribuição de água aplicada pelo sistema de gotejamento enterrado e convencional. O experimento de campo foi conduzido na área experimental do Departamento de Engenharia Rural da ESALQ/USP - Piracicaba, SP. Para o estudo, trincheiras foram abertas e instaladas sondas de TDR, dispostas a 0,05; 0,15; 0,25; 0,35 e 0,45 m profundidade, e a 0,05; 0,15; 0,25; 0,35 m comprimento, totalizando 17 sondas por trincheira. Os tratamentos foram baseados na profundidade de aplicação (0,0 e 0,10 m e vazão aplicada (2 e 4 L h-1: ENT2; ENT4; SUP2 e SUP4. A cada hora era aplicado 1 L de água (total de 10 L, seguida de leituras com o TDR. Medições do disco úmido e saturado foram feitas com régua milimetrada; além disso, estabeleceu-se um volume controle onde foi avaliada a uniformidade de aplicação; assim, foi possível verificar, em relação aos sistemas superficiais, que os sistemas enterrados apresentaram menor área superficial molhada e atingiram maior largura e profundidade; já as maiores concentrações foram obtidas próximas ao ponto de emissão.Studies of sub-surface water movement is an interesting topic in irrigation but, in spite of the its importance, there is little literature. One of the purposes of this study was to contribute to this subject and evaluate the distribution of water applied by both subsurface drip irrigation (SDI and conventional irrigation. Experiments were conducted at the Department of Rural Engineering (ESALQ/USP, located at Piracicaba, SP. Trenches were opened and 17 three-rod TDR probes were installed, placed at 0.05, 0.15, 0.25, 0.35 and 0.45 m depths, and to 0.05, 0.15, 0.25, 0.35 m intervals. This procedure was repeated using a dripper buried at 0 and 0.10 m for each discharge rate of 2 and 4 L h-1 tested. Wetted soil volume was observed with 1 L of water

Effect of sequential surface irrigations on field-scale emissions of 1,3-dichloropropene.

Science.gov (United States)

Yates, S R; Knuteson, J; Ernst, F F; Zheng, W; Wang, Q

2008-12-01

A field experiment was conducted to measure subsurface movement and volatilization of 1,3-dichloropropene (1,3-D) after shank injection to an agricultural soil. The goal of this study was to evaluate the effect of sprinkler irrigation on the emissions of 1,3-D to the atmosphere and is based on recent research that has shown that saturating the soil pore space reduces gas-phase diffusion and leads to reduced volatilization rates. Aerodynamic, integrated horizontal flux, and theoretical profile shape methods were used to estimate fumigant volatilization rates and total emission losses. These methods provide estimates of the volatilization rate based on measurements of wind speed, temperature, and 1,3-D concentration in the atmosphere. The volatilization rate was measured continuously for 16 days, and the daily peak volatilization rates for the three methods ranged from 18 to 60 microg m(-2) s(-1). The total 13-D mass entering the atmosphere was approximately 44-68 kg ha(-1), or 10-15% of the applied active ingredient This represents approximately 30-50% reduction in the total emission losses compared to conventional fumigant applications in field and field-plot studies. Significant reduction in volatilization of 1,3-D was observed when five surface irrigations were applied to the field, one immediately after fumigation followed by daily irrigations.

Distribution of heavy metals in plants cultivated with wastewater irrigated soils during different periods of time

International Nuclear Information System (INIS)

Solis, C.; Andrade, E.; Mireles, A.; Reyes-Solis, I.E.; Garcia-Calderon, N.; Lagunas-Solar, M.C.; Pina, C.U.; Flocchini, R.G.

2005-01-01

The Mezquital valley is a vast area near Mexico city that has been irrigated with wastewater from Mexico city for more than 50 years. At present, this water source continues to be used while new irrigation areas are being incorporated according to rural demand. This research study was conducted to evaluate the relationship between the accumulation of metals in soils and plants and the physicochemical properties of soils irrigated in this manner for 50 and 100 years, respectively. Soil properties such as pH and total organic carbon (TOC) were determined by conventional methods. Plant and soil total trace metals Fe, Co, Ni, Cu, Zn and Pb were determined using particle induced X-ray emission (PIXE). Lower pH and TOC contents were obtained for soils irrigated during 100 years, indicating a higher metal bioavailability. This is not reflected in plant content for most of the reported elements, but Zn and Pb show a higher absorption in 100 years old plots (26-79%) than in 50-year-olds plots, indicating a pH dependence

Soil phosphorus dynamics and availability and irrigated coffee yield

Directory of Open Access Journals (Sweden)

Thiago Henrique Pereira Reis

2011-04-01

Full Text Available Research data have demonstrated that the P demand of coffee (Coffea arabica L. is similar to that of short-cycle crops. In this context, the objective of this study was to evaluate the influence of annual P fertilization on the soil P status by the quantification of labile, moderately labile, low-labile, and total P fractions, associating them to coffee yield. The experiment was installed in a typical dystrophic Red Latosol (Oxisol cultivated with irrigated coffee annually fertilized with triple superphosphate at rates of 0, 50, 100, 200, and 400 kg ha-1 P2O5. Phosphorus fractions were determined in two soil layers: 0-10 and 10-20 cm. The P leaf contents and coffee yield in 2008 were also evaluated. The irrigated coffee responded to phosphate fertilization in the production phase with gains of up to 138 % in coffee yield by the application of 400 kg ha-1 P2O5. Coffee leaf P contents increased with P applications and stabilized around 1.98 g kg-1, at rates of 270 kg ha-1 P2O5 and higher. Soil P application caused, in general, an increase in bioavailable P fractions, which constitute the main soil P reservoir.

Crop and irrigation management strategies for saline-sodic soils and waters aimed at environmentally sustainable agriculture.

Science.gov (United States)

Qadir, M; Oster, J D

2004-05-05

Irrigation has long played a key role in feeding the expanding world population and is expected to play a still greater role in the future. As supplies of good-quality irrigation water are expected to decrease in several regions due to increased municipal-industrial-agricultural competition, available freshwater supplies need to be used more efficiently. In addition, reliance on the use and reuse of saline and/or sodic drainage waters, generated by irrigated agriculture, seems inevitable for irrigation. The same applies to salt-affected soils, which occupy more than 20% of the irrigated lands, and warrant attention for efficient, inexpensive and environmentally acceptable management. Technologically and from a management perspective, a couple of strategies have shown the potential to improve crop production under irrigated agriculture while minimizing the adverse environmental impacts. The first strategy, vegetative bioremediation--a plant-assisted reclamation approach--relies on growing appropriate plant species that can tolerate ambient soil salinity and sodicity levels during reclamation of salt-affected soils. A variety of plant species of agricultural significance have been found to be effective in sustainable reclamation of calcareous and moderately sodic and saline-sodic soils. The second strategy fosters dedicating soils to crop production systems where saline and/or sodic waters predominate and their disposal options are limited. Production systems based on salt-tolerant plant species using drainage waters may be sustainable with the potential of transforming such waters from an environmental burden into an economic asset. Such a strategy would encourage the disposal of drainage waters within the irrigated regions where they are generated rather than exporting these waters to other regions via discharge into main irrigation canals, local streams, or rivers. Being economically and environmentally sustainable, these strategies could be the key to future

Management systems in irrigated rice affect physical and chemical soil properties

NARCIS (Netherlands)

Rodrigues de Lima, A.C.; Hoogmoed, W.B.; Pauletto, E.A.; Pinto, L.F.S.

2009-01-01

Lowland soils are commonly found in the state of Rio Grande do Sul, Southern of Brazil, where they represent around 20% of the total area. Deficient drainage is the most important natural characteristic of these soils which therefore are mainly in use for irrigated rice (Oriza sativa). Degradation

Red cabbage yield, heavy metal content, water use and soil chemical characteristics under wastewater irrigation.

Science.gov (United States)

Tunc, Talip; Sahin, Ustun

2016-04-01

The objective of this 2-year field study was to evaluate the effects of drip irrigation with urban wastewaters reclaimed using primary (filtration) and secondary (filtration and aeration) processes on red cabbage growth and fresh yield, heavy metal content, water use and efficiency and soil chemical properties. Filtered wastewater (WW1), filtered and aerated wastewater (WW2), freshwater and filtered wastewater mix (1:1 by volume) (WW3) and freshwater (FW) were investigated as irrigation water treatments. Crop evapotranspiration decreased significantly, while water use efficiency increased under wastewater treatments compared to FW. WW1 treatment had the lowest value (474.2 mm), while FW treatments had the highest value (556.7 mm). The highest water use efficiency was found in the WW1 treatment as 8.41 kg m(-3), and there was a twofold increase with regard to the FW. Wastewater irrigation increased soil fertility and therefore red cabbage yield. WW2 treatment produced the highest total fresh yield (40.02 Mg ha(-1)). However, wastewater irrigation increased the heavy metal content in crops and soil. Cd content in red cabbage heads was above the safe limit, and WW1 treatment had the highest value (0.168 mg kg(-1)). WW3 treatment among wastewater treatments is less risky in terms of soil and crop heavy metal pollution and faecal coliform contamination. Therefore, WW3 wastewater irrigation for red cabbage could be recommended for higher yield and water efficiency with regard to freshwater irrigation.

Accumulation of pharmaceuticals, Enterococcus, and resistance genes in soils irrigated with wastewater for zero to 100 years in central Mexico.

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Philipp Dalkmann

Full Text Available Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin, 4.3 µg/kg (sulfamethoxazole, and 5.4 µg/kg (carbamazepine in soils irrigated for 19-28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15 × 10(-3 ± 0.22 × 10(-3 copies/16S rDNA than in non-irrigated soils (4.35 × 10(-5± 1.00 × 10(-5 copies/16S rDNA, while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61 × 10(-4 ± 0.59 × 10(-4 versus 2.99 × 10(-5 ± 0.26 × 10(-5 copies/16S rDNA. Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a

Effect of Post-Infiltration Soil Aeration at Different Growth Stages on Growth and Fruit Quality of Drip-Irrigated Potted Tomato Plants (Solanum lycopersicum).

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Li, Yuan; Jia, Zongxia; Niu, Wenquan; Wang, Jingwei; Zhang, Mingzhi

2015-01-01

Soil hydraulic principles suggest that post-infiltration hypoxic conditions would be induced in the plant root-zone for drip-irrigated tomato production in small pots filled with natural soil. No previous study specifically examined the response of tomato plants (Solanum lycopersicum) at different growth stages to low soil aeration under these conditions. A 2 × 6 factorial experiment was conducted to quantify effects of no post-infiltration soil aeration versus aeration during 5 different periods (namely 27-33, 34-57, 58-85, 86-99, and 27-99 days after sowing), on growth and fruit quality of potted single tomato plants that were sub-surface trickle-irrigated every 2 days at 2 levels. Soil was aerated by injecting 2.5 liters of air into each pot through the drip tubing immediately after irrigation. Results showed that post-infiltration aeration, especially during the fruit setting (34-57 DAS) and enlargement (58-85 DAS) growth stages, can positively influence the yield, root dry weight and activity, and the nutritional (soluble solids and vitamin C content), taste (titratable acidity), and market quality (shape and firmness) of the tomato fruits. Interactions between irrigation level and post-infiltration aeration on some of these fruit quality parameters indicated a need for further study on the dynamic interplay of air and water in the root zone of the plants under the conditions of this experiment.

Effect of Post-Infiltration Soil Aeration at Different Growth Stages on Growth and Fruit Quality of Drip-Irrigated Potted Tomato Plants (Solanum lycopersicum.

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Yuan Li

Full Text Available Soil hydraulic principles suggest that post-infiltration hypoxic conditions would be induced in the plant root-zone for drip-irrigated tomato production in small pots filled with natural soil. No previous study specifically examined the response of tomato plants (Solanum lycopersicum at different growth stages to low soil aeration under these conditions. A 2 × 6 factorial experiment was conducted to quantify effects of no post-infiltration soil aeration versus aeration during 5 different periods (namely 27-33, 34-57, 58-85, 86-99, and 27-99 days after sowing, on growth and fruit quality of potted single tomato plants that were sub-surface trickle-irrigated every 2 days at 2 levels. Soil was aerated by injecting 2.5 liters of air into each pot through the drip tubing immediately after irrigation. Results showed that post-infiltration aeration, especially during the fruit setting (34-57 DAS and enlargement (58-85 DAS growth stages, can positively influence the yield, root dry weight and activity, and the nutritional (soluble solids and vitamin C content, taste (titratable acidity, and market quality (shape and firmness of the tomato fruits. Interactions between irrigation level and post-infiltration aeration on some of these fruit quality parameters indicated a need for further study on the dynamic interplay of air and water in the root zone of the plants under the conditions of this experiment.

Estimating irrigated areas from satellite and model soil moisture data over the contiguous US

Science.gov (United States)

Zaussinger, Felix; Dorigo, Wouter; Gruber, Alexander

2017-04-01

Information about irrigation is crucial for a number of applications such as drought- and yield management and contributes to a better understanding of the water-cycle, land-atmosphere interactions as well as climate projections. Currently, irrigation is mainly quantified by national agricultural statistics, which do not include spatial information. The digital Global Map of Irrigated Areas (GMIA) has been the first effort to quantify irrigation at the global scale by merging these statistics with remote sensing data. Also, the MODIS-Irrigated Agriculture Dataset (MirAD-US) was created by merging annual peak MODIS-NDVI with US county level irrigation statistics. In this study we aim to map irrigated areas by confronting time series of various satellite soil moisture products with soil moisture from the ERA-Interim/Land reanalysis product. We follow the assumption that irrigation signals are not modelled in the reanalysis product, nor contributing to its forcing data, but affecting the spatially continuous remote sensing observations. Based on this assumption, spatial patterns of irrigation are derived from differences between the temporal slopes of the modelled and remotely sensed time series during the irrigation season. Results show that a combination of ASCAT and ERA-Interim/Land show spatial patterns which are in good agreement with the MIrAD-US, particularly within the Mississippi Delta, Texas and eastern Nebraska. In contrast, AMSRE shows weak agreements, plausibly due to a higher vegetation dependency of the soil moisture signal. There is no significant agreement to the MIrAD-US in California, which is possibly related to higher crop-diversity and lower field sizes. Also, a strong signal in the region of the Great Corn Belt is observed, which is generally not outlined as an irrigated area. It is not yet clear to what extent the signal obtained in the Mississippi Delta is related to re-reflection effects caused by standing water due to flood or furrow

Soil water sensing: Implications of sensor capabilities for variable rate irrigation management

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Irrigation scheduling using soil water sensors aims at maintaining the soil water content in the crop root zone above a lower limit defined by the management allowed depletion (MAD) for that soil and crop, but not so wet that too much water is lost to deep percolation, evaporation and runoff or that...

Smart Irrigation From Soil Moisture Forecast Using Satellite And Hydro -Meteorological Modelling

Science.gov (United States)

Corbari, Chiara; Mancini, Marco; Ravazzani, Giovanni; Ceppi, Alessandro; Salerno, Raffaele; Sobrino, Josè

2017-04-01

Increased water demand and climate change impacts have recently enhanced the need to improve water resources management, even in those areas which traditionally have an abundant supply of water. The highest consumption of water is devoted to irrigation for agricultural production, and so it is in this area that efforts have to be focused to study possible interventions. The SIM project funded by EU in the framework of the WaterWorks2014 - Water Joint Programming Initiative aims at developing an operational tool for real-time forecast of crops irrigation water requirements to support parsimonious water management and to optimize irrigation scheduling providing real-time and forecasted soil moisture behavior at high spatial and temporal resolutions with forecast horizons from few up to thirty days. This study discusses advances in coupling satellite driven soil water balance model and meteorological forecast as support for precision irrigation use comparing different case studies in Italy, in the Netherlands, in China and Spain, characterized by different climatic conditions, water availability, crop types and irrigation techniques and water distribution rules. Herein, the applications in two operative farms in vegetables production in the South of Italy where semi-arid climatic conditions holds, two maize fields in Northern Italy in a more water reach environment with flood irrigation will be presented. This system combines state of the art mathematical models and new technologies for environmental monitoring, merging ground observed data with Earth observations. Discussion on the methodology approach is presented, comparing for a reanalysis periods the forecast system outputs with observed soil moisture and crop water needs proving the reliability of the forecasting system and its benefits. The real-time visualization of the implemented system is also presented through web-dashboards.

Transfer mechanisms in cultivated soils of waste radionuclides from electronuclear power plants in the system river--irrigated soil--underground water level

Energy Technology Data Exchange (ETDEWEB)

Saas, A; Grauby, A

1974-12-31

From symposinm on environmentl behavior of radionuclides released in the nuclear industry; Aix-en-Provence, France (14 May 1973). The location of nuclear power plants by rivers whose waters are used for irrigation and industrial and domestic consumption necessities a profound study of the river-irrigated soil- ground water system. Mechanisms of radionuclide transport in cultivated soil are considered under three principal aspects: the effect of the quality of the river water, of the irrigation channels, and of the ground water level on the mobility of the radionuclides in the soil; the influence of the type of soil (the four types of soils considered are acid brown soil, calcic brown soil, chalky brown soil, and chalky alluvial soil); and the distribution of radionuclides in the soil (hydrosoluble forms can contminate the ground water level and these are the forms in which they are taken up by plants. A study was made on the following nuclides: /sup 22/Na, /sup 137/Cs, /sup 85/Sr, /Sup 54/Mn, /Sup 59/Fe, /Sup 60/ Co, /sup 65/Zn, /sup 124/Sb, /sup 141 in the cultivated soils permit the evaluation of the risks of contmination of the food chain and of the underground water. This study also showed new perspectives of the behavior of radionuclides as a function of their contmination of the organo-mineral wastes of industrial and domestic origin. This pollution interfers largely with the formation of stble complexes carried by the river to irrigated soils. The quality of the water determines the distribution of the radionuclides in the profile. The hydrosoluble complex persists in the soil and migrates toward the underground water level if they are not biodegradable. The stability of these forms as a function of the soil pH and of its physicochemical characteristics, as well as that of the radionuclides considered, permit the formulation of a new balance of the radionuclides in soils. The formulation of new proposals for the contml of nuclear sites is discussed. (tr-auth)

Experimental study on soluble chemical transfer to surface runoff from soil.

Science.gov (United States)

Tong, Juxiu; Yang, Jinzhong; Hu, Bill X; Sun, Huaiwei

2016-10-01

Prevention of chemical transfer from soil to surface runoff, under condition of irrigation and subsurface drainage, would improve surface water quality. In this paper, a series of laboratory experiments were conducted to assess the effects of various soil and hydraulic factors on chemical transfer from soil to surface runoff. The factors include maximum depth of ponding water on soil surface, initial volumetric water content of soil, depth of soil with low porosity, type or texture of soil and condition of drainage. In the experiments, two soils, sand and loam, mixed with different quantities of soluble KCl were filled in the sandboxes and prepared under different initial saturated conditions. Simulated rainfall induced surface runoff are operated in the soils, and various ponding water depths on soil surface are simulated. Flow rates and KCl concentration of surface runoff are measured during the experiments. The following conclusions are made from the study results: (1) KCl concentration in surface runoff water would decrease with the increase of the maximum depth of ponding water on soil surface; (2) KCl concentration in surface runoff water would increase with the increase of initial volumetric water content in the soil; (3) smaller depth of soil with less porosity or deeper depth of soil with larger porosity leads to less KCl transfer to surface runoff; (4) the soil with finer texture, such as loam, could keep more fertilizer in soil, which will result in more KCl concentration in surface runoff; and (5) good subsurface drainage condition will increase the infiltration and drainage rates during rainfall event and will decrease KCl concentration in surface runoff. Therefore, it is necessary to reuse drained fertile water effectively during rainfall, without polluting groundwater. These study results should be considered in agriculture management to reduce soluble chemical transfer from soil to surface runoff for reducing non-point sources pollution.

Nutrition of Tithonia diversifolia and attributes of the soil fertilized with biofertilizer in irrigated system

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Matheus M. Reis

Full Text Available ABSTRACT The fertilization with biofertilizer associated with the use of irrigation favors nutrient uptake by plants and soil chemical properties; however, these effects are little studied in Tithonia diversifolia in semiarid regions. This study evaluated the effect of doses of bovine biofertilizer and irrigation on accumulation of nutrients in the leaves of Tithonia diversifolia plants and on soil chemical attributes. The study was carried out from December 3, 2014 to November 28, 2015, and arranged in a 2 x 5 factorial scheme, consisting of five doses of bovine biofertilizer (0, 40, 80, 120 and 160 m3 ha-1, combined with and without irrigation. The experiment was set in a randomized block design, using three replicates. Irrigation promoted increased accumulation of N, P, K, Ca, Mg, S, Zn, Fe, Mn, Cu and B in leaves of Tithonia diversifolia in the first cutting. However, the high bicarbonate concentration in the irrigation water and the occurrence of rainfall during the second crop increased the accumulation of Cu in the leaves of Tithonia diversifolia under rainfed condition, compared with irrigated plants. The increase in biofertilizer doses contributed to the increment of base saturation and the contents of organic matter, P and K in soil.

Long-term effects of irrigation with waste water on soil AM fungi diversity and microbial activities: the implications for agro-ecosystem resilience.

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Maria del Mar Alguacil

Full Text Available The effects of irrigation with treated urban wastewater (WW on the arbuscular mycorrhizal fungi (AMF diversity and soil microbial activities were assayed on a long-term basis in a semiarid orange-tree orchard. After 43 years, the soil irrigated with fresh water (FW had higher AMF diversity than soils irrigated with WW. Microbial activities were significantly higher in the soils irrigated with WW than in those irrigated with FW. Therefore, as no negative effects were observed on crop vitality and productivity, it seems that the ecosystem resilience gave rise to the selection of AMF species better able to thrive in soils with higher microbial activity and, thus, to higher soil fertility.

Detecting the Spatio-temporal Distribution of Soil Salinity and Its Relationship to Crop Growth in a Large-scale Arid Irrigation District Based on Sampling Experiment and Remote Sensing

Science.gov (United States)

Ren, D.; Huang, G., Sr.; Xu, X.; Huang, Q., Sr.; Xiong, Y.

2016-12-01

Soil salinity analysis on a regional scale is of great significance for protecting agriculture production and maintaining eco-environmental health in arid and semi-arid irrigated areas. In this study, the Hetao Irrigation District (Hetao) in Inner Mongolia Autonomous Region, with suffering long-term soil salinization problems, was selected as the case study area. Field sampling experiments and investigations related to soil salt contents, crop growth and yields were carried out across the whole area, during April to August in 2015. Soil salinity characteristics in space and time were systematically analyzed for Hetao as well as the corresponding impacts on crops. Remotely sensed map of soil salinity distribution for surface soil was also derived based on the Landsat OLI data with a 30 m resolution. The results elaborated the temporal and spatial dynamics of soil salinity and the relationships with irrigation, groundwater depth and crop water consumption in Hetao. In addition, the strong spatial variability of salinization was clearly presented by the remotely sensed map of soil salinity. Further, the relationship between soil salinity and crop growth was analyzed, and then the impact degrees of soil salinization on cropping pattern, leaf area index, plant height and crop yield were preliminarily revealed. Overall, this study can provide very useful information for salinization control and guide the future agricultural production and soil-water management for the arid irrigation districts analogous to Hetao.

Short-term effects of irrigation with treated domestic wastewater on microbiological activity of a Vertic xerofluvent soil under Mediterranean conditions.

Science.gov (United States)

Kayikcioglu, Huseyin Husnu

2012-07-15

Approximately 70% of the world water use, including all the water diverted from rivers and pumped from underground, is used for agricultural irrigation, so the reuse of treated domestic wastewater (TWW) for purposes such as agricultural and landscape irrigation reduces the amount of water that needs to be extracted from natural water sources as well as reducing discharge of wastewater to the environment. Thus, TWW is a valuable water source for recycling and reusing in arid and semi-arid regions which are frequently confronting water shortages. In this regard, this study was planned to reveal the short-term effects of advanced-TWW irrigation on microbial parameters of Vertic xerofluvent soil. For this purpose, certain parameters were measured in the study, including soil total organic carbon (C(org)), N-mineralization (N(min)), microbial biomass carbon (C(mic)), soil microbial quotient (C(mic)/C(org)) and the activities of the enzymes dehydrogenase (DHG), urease (UA), alkaline phosphatase (ALKPA), β-glucosidase (GLU) and aryl sulphatase (ArSA) in soils irrigated with TWW and fresh water (FW). All of the microbial parameters were negatively affected by TWW irrigation. Microbial parameters decreased by 10.1%-54.1% in comparison with the FW plots. This decrease especially in enzymatic activities of soil irrigated with TWW, presumably due to some heavy metals inhibited their activity associated with the soil types and the concentrations of heavy metals in wastewater. In contrast, C(mic)/C(org) was found higher in the plots irrigated with TWW at the end of the experiment. The addition of organic matter to soil by irrigation with TWW is cause for the increase in this ratio. The dose of irrigation should be modified to reduce the quantity and to increase the frequency of application to avoid the loss of aggregation and salt accumulation. TWW irrigation is a strategy with many benefits to agricultural land management; however, long-term studies should be implemented to

Methodological approach for evaluating the response of soil hydrological behavior to irrigation with treated municipal wastewater

Science.gov (United States)

Coppola, A.; Santini, A.; Botti, P.; Vacca, S.; Comegna, V.; Severino, G.

2004-06-01

This paper aims mainly to provide experimental evidence of the consequences of urban wastewater reuse in irrigation practices on the hydrological behavior of soils. The effects on both the hydraulic and dispersive properties of representative soils in southern Sardinia are illustrated. Ten undisturbed soil monoliths, 120 cm in height and 40 cm in diameter, were collected from plots previously selected through a soil survey. Soil hydraulic and solute transport properties were determined before and after application of wastewater using transient water infiltration and steady state-solute transport column experiments. Detailed spatial-temporal information on the propagation of water and solute through the soil profiles were obtained by monitoring soil water contents, θ, pressure heads, h, and solute concentrations, C, measured by a network of time domain reflectometry probes, tensiometers and solution samplers horizontally inserted in each column at different depths. A disturbed layer at the soil surface, which expands in depth with time, was observed, characterized by reduced soil porosity, translation of pore size distribution towards narrower pores and consequent decrease in water retention, hydraulic conductivity and hydrodynamic dispersion. It is shown that these changes occurring in the disturbed soil layer, although local by nature, affect the hydrological behavior of the whole soil profile. Due to the disturbed layer formation, the soil beneath never saturates. Such behavior has important consequences on the solute transport in soils, as unsaturated conditions mean higher residence times of solutes, even of those normally characterized by considerable mobility (e.g. boron), which may accumulate along the profile. The results mainly provide experimental evidence that knowledge of the chemical and microbiological composition of the water is not sufficient to evaluate its suitability for irrigation. Other factors, mainly soil physical and hydrological

Soil water movement in the unsaturated zone of an inland arid region: Mulched drip irrigation experiment

Science.gov (United States)

Han, Dongmei; Zhou, Tiantian

2018-04-01

Agricultural irrigation with trans-basin water diversion can effectively relieve the water paucity in arid and semi-arid regions, however, this may be accompanied by eco-environmental problems (e.g., saline soils, rising groundwater levels, water quality problems). The mechanism of soil water movement under irrigation in the unsaturated zone of arid regions is a key scientific problem that should be solved in order to evaluate agricultural water management and further improve current irrigation practices. This study investigated the impact of drip irrigation on soil water movement in the unsaturated zone of a cotton field in an inland arid region (the Karamay Agricultural Development Area), northwest China. Combining in situ observational physical data with temporal variation in stable isotopic compositions of soil water, we described the soil water flow system and mechanism in severe (Plot 1) and mild (Plot 2) saline-alkali cotton fields. The infiltration depths are 0-150 cm for both plots. Drip irrigation scheduling makes no significant contribution to local groundwater recharge, however, groundwater can move into the unsaturated zone through capillary rise during cotton flowering and boll periods. Plot 2 is less prone to having secondary soil salinization than Plot 1 due to the existence of a middle layer (approximately 100 cm thick), which elongated the distance between the root zone and aquifer. Rise in the water table (approximately 60 cm for Plot 1 and 50 cm for Plot 2) could be caused by lateral groundwater flow instead of vertical infiltration. We estimated the soil water storage changes in the unsaturated zone and proposed a conceptual model for deciphering the movement process of soil water. This study provides a scientific basis for determining the rise of groundwater levels and potential development of saline soils and improving agricultural water management in arid regions.

Spatial Variation of Arsenic in Soil, Irrigation Water, and Plant Parts: A Microlevel Study

OpenAIRE

Kabir, M. S.; Salam, M. A.; Paul, D. N. R.; Hossain, M. I.; Rahman, N. M. F.; Aziz, Abdullah; Latif, M. A.

2016-01-01

Arsenic pollution became a great problem in the recent past in different countries including Bangladesh. The microlevel studies were conducted to see the spatial variation of arsenic in soils and plant parts contaminated through ground water irrigation. The study was performed in shallow tube well command areas in Sadar Upazila (subdistrict), Faridpur, Bangladesh, where both soil and irrigation water arsenic are high. Semivariogram models were computed to determine the spatial dependency of s...

Biological soil attributes in oilseed crops irrigated with oilfield produced water in the semi-arid region

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Ana Clarice Melo Azevedo de Meneses

Full Text Available ABSTRACT Wastewater from oil is the main residue of the oil industry. Studies have shown that wastewater, or produced water, can be treated and used as an alternative source for the irrigation of oilseed crops. The aim of this work was to evaluate the effect of treated produced water on the biological properties of soil cultivated with the castor bean cv. BRS Energy and the sunflower cv. BRS 321 respectively, for two and three successive cycles of grain production. The first cycle in the sunflower and castor bean corresponds to the dry season and the second cycle to the rainy season. The third crop cycle in the sunflower relates to the dry season. The research was carried out from August 2012 to October 2013, in the town of Aracati, in the State of Ceará (Brazil, where both crops were submitted to irrigation with filtered produced water (FPW, produced water treated by reverse osmosis (OPW, or groundwater water from the Açu aquifer (ACW, and to no irrigation (RFD. The treatments, with three replications, were evaluated during the periods of pre-cultivation and plant reproduction for soil respiration (Rs, total organic carbon (TOC and the population density of bacteria (Bact and filamentous fungi (Fung in the soil. In the sunflower crop, these soil attributes are sensitive to the irrigation water used. Irrigation of the castor bean affects soil respiration. Under the conditions of this study, irrigation with FPW may be a short-term alternative in the castor bean and sunflower crops.

Comparison of traditional and ET-based irrigation scheduling of surface-irrigated cotton in the arid southwestern USA

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The use of irrigation scheduling tools to produce cotton under-surface irrigation in the arid southwesternUSA is minimal. In the State of Arizona, where traditional irrigation scheduling is the norm, producersuse an average of 1460 mm annually to grow a cotton crop. The purpose of this paper was to ...

Effect of addition of organic materials and irrigation conditions on soil quality in olive groves in the region of Messinia, Greece.

Science.gov (United States)

Kavvadias, Victor; Papadopoulou, Maria; Vavoulidou, Evangelia; Theocharopoulos, Sideris; Repas, Spiros; Koubouris, Georgos; Psaras, Georgios

2017-04-01

Intensive cultivation practices are associated to soil degradation mainly due to low soil organic matter content. The application of organic materials to land is a common practice in sustainable agriculture in the last years. However, its implementation in olive groves under different irrigation regimes has not been systematically tested under the prevailing Mediterranean conditions. The aim of this work was to study the effect of alternative carbon input techniques (i.e. wood shredded, pruning residues, returning of olive mill wastes the field with compost) and irrigation conditions (irrigated and rainfed olive orchards) on spatial distribution of soil chemical (pH, EC, total organic carbon, total nitrogen, inorganic nitrogen, humic and fulvic acids, available P, and exchangeable K) and microbial properties (soil basal microbial respiration and microbial biomass carbon) in two soil depths (0-10 cm and 10-40 cm). The study took place in the region of Messinia, South western Peloponnese, Greece during three year soil campaigns. Forty soil plots of olive groves were selected (20 rainfed and 20 irrigated) and carbon input practices were applied on the half of the irrigated and rainfed soil parcels (10 rainfed and 10 irrigated), while the remaining ones were used as controls. The results showed significant changes of chemical and biological properties of soil in olive orchards due to carbon treatments. However, these changes were depended on irrigation conditions. Microbial parameters appeared to be reliable indicators of changes in soil management. Proper management of alternative soil carbon inputs in olive orchards can positively affect soil fertility.

Control of soil moisture with radio frequency in a photovoltaic-powered drip irrigation system

OpenAIRE

DURSUN, Mahir; ÖZDEN, Semih

2015-01-01

Solar-powered irrigation systems are becoming increasingly widespread. However, the initial setup costs of these systems are very high. To reduce these costs, both the energy usage and the prevention of losses from irrigation systems are very important. In this study, a drip irrigation control system of 1000 dwarf cherry trees was controlled using soil moisture sensors in order to prevent excessive water consumption and energy losses in a solar-powered irrigation system. The control sys...

Regulations of irrigation on regional climate in the Heihe watershed, China, and its implications to water budget

Science.gov (United States)

Zhang, X.

2015-12-01

In the arid area, such as the Heihe watershed in Northwest China, agriculture is heavily dependent on the irrigation. Irrigation suggests human-induced hydro process, which modifies the local climate and water budget. In this study, we simulated the irrigation-induced changes in surface energy/moisture budgets and modifications on regional climate, using the WRF-NoahMP modle with an irrigation scheme. The irrigation scheme was implemented following the roles that soil moisture is assigned a saturated value once the mean soil moisture of all root layers is lower than 70% of fileld capacity. Across the growth season refering from May to September, the simulated mean irrigation amount of the 1181 cropland gridcells is ~900 mm, wihch is close to the field measurments of around 1000 mm. Such an irrigation largely modified the surface energy budget. Due to irrigation, the surface net solar radiation increased by ~76.7 MJ (~11 Wm-2) accouting for ~2.3%, surface latent and senbile heat flux increased by 97.7 Wm-2 and decreased by ~79.7 Wm-2 respectively; and local daily mean surface air temperature was thereby cooling by ~1.1°C. Corresponding to the surface energy changes, wind and circulation were also modified and regional water budget is therefore regulated. The total rainfall in the irrigation area increased due to more moisture from surface. However, the increased rainfall is only ~6.5mm (accounting for ~5% of background rainfall) which is much less than the increased evaporation of ~521.5mm from surface. The ~515mm of water accounting for 57% of total irrigation was transported outward by wind. The other ~385 mm accounting for 43% of total irrigation was transformed to be runoff and soil water. These results suggest that in the Heihe watershed irrigation largely modify local energy budget and cooling surface. This study also implicate that the existing irrigation may waste a large number of water. It is thereby valuable to develope effective irrigation scheme to

Accumulation of Pharmaceuticals, Enterococcus, and Resistance Genes in Soils Irrigated with Wastewater for Zero to 100 Years in Central Mexico

Science.gov (United States)

Siebe, Christina; Willaschek, Elisha; Sakinc, Tuerkan; Huebner, Johannes; Amelung, Wulf; Grohmann, Elisabeth; Siemens, Jan

2012-01-01

Irrigation with wastewater releases pharmaceuticals, pathogenic bacteria, and resistance genes, but little is known about the accumulation of these contaminants in the environment when wastewater is applied for decades. We sampled a chronosequence of soils that were variously irrigated with wastewater from zero up to 100 years in the Mezquital Valley, Mexico, and investigated the accumulation of ciprofloxacin, enrofloxacin, sulfamethoxazole, trimethoprim, clarithromycin, carbamazepine, bezafibrate, naproxen, diclofenac, as well as the occurrence of Enterococcus spp., and sul and qnr resistance genes. Total concentrations of ciprofloxacin, sulfamethoxazole, and carbamazepine increased with irrigation duration reaching 95% of their upper limit of 1.4 µg/kg (ciprofloxacin), 4.3 µg/kg (sulfamethoxazole), and 5.4 µg/kg (carbamazepine) in soils irrigated for 19–28 years. Accumulation was soil-type-specific, with largest accumulation rates in Leptosols and no time-trend in Vertisols. Acidic pharmaceuticals (diclofenac, naproxen, bezafibrate) were not retained and thus did not accumulate in soils. We did not detect qnrA genes, but qnrS and qnrB genes were found in two of the irrigated soils. Relative concentrations of sul1 genes in irrigated soils were two orders of magnitude larger (3.15×10−3±0.22×10−3 copies/16S rDNA) than in non-irrigated soils (4.35×10−5±1.00×10−5 copies/16S rDNA), while those of sul2 exceeded the ones in non-irrigated soils still by a factor of 22 (6.61×10–4±0.59×10−4 versus 2.99×10−5±0.26×10−5 copies/16S rDNA). Absolute numbers of sul genes continued to increase with prolonging irrigation together with Enterococcus spp. 23S rDNA and total 16S rDNA contents. Increasing total concentrations of antibiotics in soil are not accompanied by increasing relative abundances of resistance genes. Nevertheless, wastewater irrigation enlarges the absolute concentration of resistance genes in soils due to a long-term increase in

Monitoring soil moisture dynamics via ground-penetrating radar survey of agriculture fields after irrigation

Science.gov (United States)

Muro, G.

2015-12-01

It is possible to examine the quality of ground-penetrating radar (GPR) as a measure of soil moisture content in the shallow vadose zone, where roots are most abundant and water conservation best management practices are critical in active agricultural fields. By analyzing temporal samplings of 100 Mhz reflection profiles and common-midpoint (CMP) soundings over a full growing season, the variability of vertical soil moisture distribution directly after irrigation events are characterized throughout the lifecycle of a production crop. Reflection profiles produce high-resolution travel time data and summed results of CMP sounding data provide sampling depth estimates for the weak, but coherent reflections amid strong point scatterers. The high ratio of clay in the soil limits the resolution of downward propagation of infiltrating moisture after irrigation; synthetic data analysis compared against soil moisture lysimeter logs throughout the profile allow identification of the discrete soil moisture content variation in the measured GPR data. The nature of short duration irrigation events, evapotranspiration, and drainage behavior in relation to root depths observed in the GPR temporal data allow further examination and comparison with the variable saturation model HYDRUS-1D. After retrieving soil hydraulic properties derived from laboratory measured soil samples and simplified assumptions about boundary conditions, the project aims to achieve good agreement between simulated and measured soil moisture profiles without the need for excessive model calibration for GPR-derived soil moisture estimates in an agricultural setting.

Soil moisture and plant canopy temperature sensing for irrigation application in cotton

Science.gov (United States)

A wireless sensor network was deployed in a cotton field to monitor soil water status for irrigation. The network included two systems, a Decagon system and a microcontroller-based system. The Decagon system consists of soil volumetric water-content sensors, wireless data loggers, and a central data...

Water saving at the field scale with Irrig-OH, an open-hardware environment device for soil water potential monitoring and irrigation management

Science.gov (United States)

Masseroni, Daniele; Facchi, Arianna; Gandolfi, Claudio

2015-04-01

Sustainability of irrigation practices is an important objective which should be pursued in many countries, especially in areas where water scarcity causes strong conflicts among the different water uses. The efficient use of water is a key factor in coping with the food demand of an increasing world population and with the negative effects of the climate change on water resources availability in many areas. In this complex context, it is important that farmers adopt instruments and practices that enable a better management of water at the field scale, whatever the irrigation method they adopt. This work presents the hardware structure and the functioning of an open-hardware microstation based on the Arduino technology, called Irrig-OH, which allows the continuous and low-cost monitoring of the soil water potential (SWP) in the root zone for supporting the irrigation scheduling at the field scale. In order to test the microstation, an experiment was carried out during the agricultural season 2014 at Lodi (Italy), with the purpose of comparing the farmers' traditional management of irrigation of a peach variety and the scheduling based on the SWP measurements provided by the microstation. Additional measurements of leaf water potential (LWP), stomatal resistance, transpiration (T), crop water stress index (CWSI) and fruit size evolution were performed respectively on leafs and fruits for verifying the plant physiological responses on different SWP levels in soil. At the harvesting time, the peach production in term of quantity and quality (sucrose content was measured by a rifractometer over a sample of one hundred fruits) of the two rows were compared. Irrigation criteria was changed with respect to three macro-periods: up to the endocarp hardening phase (begin of May) soil was kept well watered fixing the SWP threshold in the first 35 cm of the soil profile at -20 kPa, during the pit hardening period (about the entire month of May) the allowed SWP threshold was

Chemical properties of a Haplustalf soil under irrigation with treated wastewater and nitrogen fertilization

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Leda V. B. D. Silva

2016-04-01

Full Text Available ABSTRACT The objective of this research was to investigate the effects of irrigation with treated wastewater and nitrogen (N fertilization on the chemical characteristics of a Haplustalf soil cultivated with cotton. An experiment was conducted in a greenhouse in a completely randomized design with four replicates, and arranged in a 5 x 4 factorial. Five doses of N fertilization (0, 45, 90, 135 and 180 kg ha-1 and four sources of irrigation water (freshwater, wastewater treated by an anaerobic reactor, wastewater treated by an anaerobic reactor and post-treated by intermittent sand filter in series, wastewater treated in a septic tank and post-treated by an intermittent sand filter were tested. Irrigation was daily performed from July 2011 to January 2012 according to the water demand of cotton resulting in a water depth of 620 mm. It was found that, compared with the conventional management with freshwater irrigation, treated wastewater provides greater accumulation of micronutrient, potassium and sodium in the soil, increasing the risk of sodification in irrigated areas.

Impact of treated wastewater for irrigation on soil microbial communities.

Science.gov (United States)

Ibekwe, A M; Gonzalez-Rubio, A; Suarez, D L

2018-05-01

The use of treated wastewater (TWW) for irrigation has been suggested as an alternative to use of fresh water because of the increasing scarcity of fresh water in arid and semiarid regions of the world. However, significant barriers exist to widespread adoption due to some potential contaminants that may have adverse effects on soil quality and or public health. In this study, we investigated the abundance and diversity of bacterial communities and the presence of potential pathogenic bacterial sequences in TWW in comparison to synthetic fresh water (SFW) using pyrosequencing. The results were analyzed using UniFrac coupled with principal coordinate analysis (PCoA) to compare diversity and abundance of different bacterial groups in TWW irrigated soils to soils treated with SFW. Shannon diversity index values (H') suggest that microbial diversity was not significantly different (P<0.086) between soils with TWW and SFW. Pyrosequencing detected sequences of 17 bacterial phyla with Proteobacteria (32.1%) followed by Firmicutes (26.5%) and Actinobacteria (14.3%). Most of the sequences associated with nitrifying bacteria, nitrogen-fixing bacteria, carbon degraders, denitrifying bacteria, potential pathogens, and fecal indicator bacteria were more abundant in TWW than in SFW. Therefore, TWW effluent may contain bacterial that may be very active in many soil functions as well as some potential pathogens. Published by Elsevier B.V.

Soil Compressibility under Irrigated Perennial and Annual Crops in a Semi-Arid Environment

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Rafaela Watanabe

Full Text Available ABSTRACT In irrigated soils, a continuous state of high moisture reduces resistance of the soil to applied external forces, favouring compaction. The aim of this study was to evaluate the susceptibility to compaction of developed calcareous soils in irrigated annual and perennial cropping systems of the Apodi Plateau, located in the Brazilian semi-arid region. Four areas of irrigated crops were evaluated: banana after two (B2 and 15 (B15 years cultivation, pasture (P, and a corn and beans succession (MB, as well as the reference areas for soil quality and corresponding natural vegetation (NVB2, NVB15, NVP and NVMB. Samples were collected at layers of 0.00-0.10 and 0.20-0.30 m; and for B2 and B15, samples were collected in the row and inter-row spaces. The following properties were determined: degree of compactness (DC, preconsolidation pressure (σp, compression index (Cc, maximum density (ρmax, critical water content (WCcrit, total organic carbon (TOC and carbon of light organic matter (Clom. Mean values were compared by the t-test at 5, 10, 15 and 20 % probability. An increase was seen in DC at a layer of 0.20-0.30 m in MB (p<0.15, showing the deleterious effects of preparing the soil by ploughing and chiselling, together with the cumulative traffic of heavy machinery. The TOC had a greater influence on ρmax than the stocks of Clom. Irrigation caused a reduction in Cc, and there was no effect on σp at field capacity. The planting rows showed different behaviour for Cc, ρmax, and WCcrit,, and in general the physical properties displayed better conditions than the inter-row spaces. Values for σp and Cc showed that agricultural soils display greater load-bearing capacity and are less susceptible to compaction in relation to soils under natural vegetation.

Effects of Biochar on the Net Greenhouse Gas Emissions under Continuous Flooding and Water-Saving Irrigation Conditions in Paddy Soils

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Le Qi

2018-05-01

Full Text Available In this study, we investigated the greenhouse gas emission under different application of biochar in the conditions of continuous flooding and water-saving irrigation in paddy fields, whereas, plant and soil carbon sequestration were considered in the calculation of net greenhouse gas emissions. The emission rates of methane (CH4, carbon dioxide (CO2, and nitrous oxide (N2O gases were simultaneously monitored once every 7–10 days using the closed-chamber method. As a whole, the net greenhouse gas emission in the water-saving irrigation was more than that of the continuous flooding irrigation conditions. Compared with the water-saving irrigation, the continuous flooding irrigation significantly increased the CH4 in the control (CK and chemical fertilizer treatments (NPK. The CO2 emissions increased in each treatment of the water-saving irrigation condition, especially in the chemical fertilizer treatments (NPKFW. Similarly, the soil N2O emission was very sensitive to the water-saving irrigation condition. An interesting finding is that the biochar application in soils cut down the soil N2O emission more significantly than NPKFW in the water-saving irrigation condition while the effect of biochar increased under the continuous flooding irrigation condition.

Effects Of Irrigation With Saline Water, And Soil Type On Germination And Seedling Growth Of Sweet Maize (Zea Mays L.)

International Nuclear Information System (INIS)

Mostafa, A.Z.; Amato, M.; Hamdi, A.; Mostafa, A.Z.; Galal, Y.G.M.; Lotfy, S.M.

2012-01-01

Germination and early growth of maize Sweet Maize (Zea mays L.), var. (SEL. CONETA) under irrigation with saline water were investigated in a pot experiment with different soil types. Seven salinity levels of irrigation water up to 12 dS/m were used on a Clay soil (C) and a Sandy-Loam (SL). Emergence of maize was delayed under irrigation with saline water, and the final percentage of germination was reduced only at 8 dS/m or above. Seedling shoot and root growth were reduced starting at 4 dS/m of irrigation water. Salts accumulated more in the C soil but reductions in final germination rate and seedling growth were larger in the SL soil, although differences were not always significant. Data indicate that germination is rather tolerant to salinity level in var. SEL. CONETA whereas seedling growth is reduced at moderate salinity levels, and that soil type affects plant performance under irrigation with saline water

Where Does the Irrigation Water Go? An Estimate of the Contribution of Irrigation to Precipitation Using MERRA

Science.gov (United States)

Wei, Jiangfeng; Dirmeyer, Paul A.; Wisser, Dominik; Bosilovich, Michael G.; Mocko, David M.

2013-01-01

Irrigation is an important human activity that may impact local and regional climate, but current climate model simulations and data assimilation systems generally do not explicitly include it. The European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) shows more irrigation signal in surface evapotranspiration (ET) than the Modern-Era Retrospective Analysis for Research and Applications (MERRA) because ERA-Interim adjusts soil moisture according to the observed surface temperature and humidity while MERRA has no explicit consideration of irrigation at the surface. But, when compared with the results from a hydrological model with detailed considerations of agriculture, the ET from both reanalyses show large deficiencies in capturing the impact of irrigation. Here, a back-trajectory method is used to estimate the contribution of irrigation to precipitation over local and surrounding regions, using MERRA with observation-based corrections and added irrigation-caused ET increase from the hydrological model. Results show substantial contributions of irrigation to precipitation over heavily irrigated regions in Asia, but the precipitation increase is much less than the ET increase over most areas, indicating that irrigation could lead to water deficits over these regions. For the same increase in ET, precipitation increases are larger over wetter areas where convection is more easily triggered, but the percentage increase in precipitation is similar for different areas. There are substantial regional differences in the patterns of irrigation impact, but, for all the studied regions, the highest percentage contribution to precipitation is over local land.

Simulation of Salinity Distribution in Soil Under Drip Irrigation Tape with Saline Water Using SWAP Model

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M. Tabei

2016-02-01

Full Text Available Introduction: The to be limited available water amount from one side and to be increased needs of world population from the other side have caused increase of cultivation for products. For this reason, employing new irrigation ways and using new water resources like using the uncommon water (salty water, water drainage are two main strategies for regulating water shortage conditions. On the other side, accumulation of salts on the soil surface in dry regions having low rainfall and much evaporation, i.e. an avoidable case. As doing experiment for determining moisture distribution form demands needs a lot of time and conducting desert experiments are costly, stimulator models are suitable alternatives in answering the problem concerning moving and saltiness distribution. Materials and Methods: In this research, simulation of soil saltiness under drip irrigation was done by the SWAP model and potency of the above model was done in comparison with evaluated relevant results. SWAP model was performed based on measured data in a corn field equipped with drip irrigation system in the farming year 1391-92 in the number one research field in the engineering faculty of water science, ShahidChamran university of Ahvaz and hydraulic parameters of soil obtained from RETC . Statistical model in the form of a random full base plan with four attendants for irrigating water saltiness including salinity S1 (Karoon River water with salinity 3 ds/m as a control treatment, S2 (S1 +0/5, S3 (S1 +1 and S4 (S1 +1/5 dS/m, in 3 repetition and in 3 intervals of 10 cm emitter, 20 cm emitters on the stack, at a depth of 0-90 cm (instead of each 30 cm from soil surface and intervals of 30, 60 and 90 days after modeling cultiviation was done. The cultivation way was done handheld in plots including four rows of 3 m in distance of 75 cm rows and with denseness of 80 bushes in a hectar. Drip irrigation system was of type strip with space of 20 cm pores. Results and Discussion

Assessing the Sodium Exchange Capacity in Rainfed and Irrigated Soils in the Mediterranean Basin Using GIS

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Luís Loures

2017-03-01

Full Text Available The soil exchange complex consists of colloidal materials on which ion exchange phenomena occur allowing it to attract, retain, and exchange elements that have opposite electric charges. Since their mineral constituents (clay and organic components (humus are mainly of a negative nature retained or exchanged ion are predominantly cations. Historically, failing to monitor parameters like the exchange sodium percentage (ESP has led to the permanent deterioration of soils which have become completely unproductive, largely reducing the sustainability of the agricultural systems. This study assesses how the sodium exchange capacity in irrigated soils differs from the rainfed ones through a sample survey that was carried out in the 15,031 ha of the Caia Irrigation Perimeter and adjacent areas, located in the municipalities of Elvas and Campo Maior, Portalegre District, Portugal where 14,280 georeferenced samples were collected from the top soil layer (0–20 cm, which were mixed 10 at a time so that each composite sample representing 11.1 ha. Then the samples were analyzed regarding the most relevant parameters for characterizing the soil exchange complex including the concentrations of exchanged bases and Cation Exchange Capacity (CEC. The results were arranged in a georeferenced grid with 1451 entries. Using classical statistical analysis and Geographic Information Systems (GIS software, it was possible to relate the individual soil samples analyzed with the cultural system practiced (irrigated or rainfed and the present soil group which permitted us to analyze the influence of the cultural system in the soil exchange complex. The distribution chart of the exchange sodium and CEC were created. The obtained results confirm a general decrease of CEC values and an increase of the exchangeable sodium content of irrigated explored soils when compared to the rainfed ones, putting forward noteworthy ideas not only regarding the necessary changes towards

Pollution of intensively managed greenhouse soils by nutrients and heavy metals in the Yellow River Irrigation Region, Northwest China.

Science.gov (United States)

Kong, Xiaole; Cao, Jing; Tang, Rangyun; Zhang, Shengqiang; Dong, Fang

2014-11-01

The present study aimed to assess the potential ecological risk of heavy metals and nutrient accumulation in polytunnel greenhouse soils in the Yellow River irrigation region (YRIR), Northwest China, and to identify the potential sources of these heavy metals using principal component analysis. Contents of available nitrogen (AN), phosphorus (AP), and potassium (AK) in the surface polytunnel greenhouse soils (0-20 cm) varied from 13.42 to 486.78, from 39.10 to 566.97, and from 21.64 to 1,156.40 mg kg(-1), respectively, as well as AP, soil organic matter (SOM) and AK contents tended to increase significantly at the 0-20- and 20-40-cm soil layers. Heavy metal accumulations occurred in the polytunnel greenhouse soils as compared to arable soils, especially at a depth of 20 cm where Cd, Zn and Cu contents were significantly higher than arable soil. Cd and As were found to be the two main polluting elements in the greenhouse soils because their contents exceeded the thresholds established for greenhouse vegetable production HJ333-2006 in China and the background of Gansu province. It has been shown that Cd, Cu, Pb and Zn at the 0-20-cm soil layer were derived mainly from agricultural production activities, whereas contents of Cr and Ni at the same soil layer were determined by 'natural' factors and As originated from natural sources, deposition and irrigation water.

Actual and potential salt-related soil degradation in an irrigated rice scheme in the Sahelian zone of Mauritania

NARCIS (Netherlands)

Asten, van P.J.A.; Barbi'ro, L.; Wopereis, M.C.S.; Maeght, J.L.; Zee, van der S.E.A.T.M.

2003-01-01

Salt-related soil degradation due to irrigation activities is considered a major threat to the sustainability of rice cropping under semi-arid conditions in West Africa. Rice productivity problems related to soil salinity, alkalinity and topographic position were observed in an irrigated rice scheme

Irrigation of Castor Bean (Ricinus communis L. and Sunflower (Helianthus annus L. Plant Species with Municipal Wastewater Effluent: Impacts on Soil Properties and Seed Yield

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Vasileios A. Tzanakakis

2011-11-01

Full Text Available The effects of plant species (castor bean (Ricinus communis L. versus sunflower (Helianthus annus L. and irrigation regime (freshwater versus secondary treated municipal wastewater on soil properties and on seed and biodiesel yield were studied in a three year pot trial. Plant species were irrigated at rates according to their water requirements with either freshwater or wastewater effluent. Pots irrigated with freshwater received commercial fertilizer, containing N, P, and K, applied at the beginning of each irrigation period. The results obtained in this study showed that irrigation with effluent did not result in significant changes in soil pH, soil organic matter (SOM, total kjeldahl nitrogen (TKN, and dehydrogenase activity, whereas soil available P was found to increase in the upper soil layer. Soil salinity varied slightly throughout the experiment in effluent irrigated pots but no change was detected at the end of the experiment compared to the initial value, suggesting sufficient salt leaching. Pots irrigated with effluent had higher soil salinity, P, and dehydrogenase activity but lower SOM and TKN than freshwater irrigated pots. Sunflower showed greater SOM and TKN values than castor bean suggesting differences between plant species in the microorganisms carrying out C and N mineralization in the soil. Plant species irrigated with freshwater achieved higher seed yield compared to those irrigated with effluent probably reflecting the lower level of soil salinity in freshwater irrigated pots. Castor bean achieved greater seed yield than sunflower. Biodiesel production followed the pattern of seed yield. The findings of this study suggest that wastewater effluent can constitute an important source of irrigation water and nutrients for bioenergy crop cultivations with minor adverse impacts on soil properties and seed yield. Plant species play an important role with regard to the changes in soil properties and to the related factors of

Effect of Different Alternate Irrigation Strategies using Saline and Non-Saline Water on Corn Yield, Salinity and Moisture Distribution in Soil Profile

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Ali Reza Kiani

2017-01-01

-saline water in every other row, respectively; T5 and T6= fixed and variable deficit irrigation with non-saline water in every other rows, respectively and T7= full irrigation with saline water. To create the desired water salinity (8 dS/m, non-saline well water (1.5 dS/m and drainage water (20–35 dS/m were blended in different proportions. A T-tape drip irrigation system (20 m in length was used in the field experiment. Results and Discussion: In general, corn yield in 2013 was about 1270 kg ha-1 higher than in 2012. From the weather records it can be seen that the second year was drier than the first year. Yield analysis showed that deficit irrigation treatments (T2, T5 & T6 and also alternate salinity treatments (T3 & T4 did not significantly difference. In other words, the deficit irrigation management had no effect on yield. Corn yield in T3 and T4 with 50% of saved fresh water was just reduced to 7 and 1 % of T1, respectively. As a result, comparing treatments T3 and T4 with full irrigation have shown that treatments T3 and T4 are the best option. Comparison of moisture distribution in deficit irrigation treatments showed the highest water content in surface and deep layers was related to the treatments T6 and T2, respectively. The distribution of salinity in the soil profile for treatments T3 and T4 showed that after two years of irrigation with saline water, there is the possibility of use saline water for corn production, but drainage and leaching of soil will need to maintain sustainability. Conclusion: Naturally, in water scarce areas that use some strategic management such as deficit irrigation or saline water use, there is available arable farmland to further develop the irrigated area, and thereby increase total production. According to the results of the two-years where there was a shortage of water to meet crop water requirement and saline water was not available, the use of deficit irrigation managements as described in this study can save fresh water

Increase globe artichoke cropping sustainability using sub-surface drip-irrigation systems in a Mediterranean coastal area for reducing groundwater withdrawal

Science.gov (United States)

Mantino, Alberto; Marchina, Chiara; Bonari, Enrico; Fabbrizzi, Alessandro; Rossetto, Rudy

2017-04-01

During the last decades in coastal areas of the Mediterranean basin, human growth posed severe stresses on freshwater resources due to increasing demand by agricultural, industrial and civil activities, in particular on groundwater. This in turn led to worsening of water quality, loss/reduction of wetlands, up to soil salinization and abandonment of agricultural areas. Within the EU LIFE REWAT project a number of demonstration measures will take place in the lower Cornia valley (Livorno, Italy), both structural (pilot) and non-structural (education, dissemination and capacity building), aiming at achieving sustainable and participated water management. In particular, the five demonstration actions are related to: (1) set up of a managed aquifer recharge facility, (2) restoration of a Cornia river reach, (3) water saving in the civil water supply sector, (4) water saving in agriculture, (5) reuse of treated wastewater for irrigation purposes. Thus, the REWAT project general objective is to develop a new model of governance for sustainable development of the lower Cornia valley based on the water asset at its core. As per water use in agriculture, the lower Cornia valley is well known for the horticultural production. In this regard, globe artichoke (Cynara cardunculus L. var. scolymus L. (Fiori)) crops, a perennial cool-season vegetable, cover a surface of about 600 ha. In order to increase stability and productivity of the crop, about 2000 - 4000 m3 ha-1 yr-1 of irrigation water is required. Recent studies demonstrated that yield of different crops increases using Sub-surface Drip-Irrigation (SDI) system under high frequency irrigation management enhancing water use efficiency. In the SDI systems, the irrigation water is delivered to the plant root zone, below the soil surface by buried plastic tubes containing embedded emitters located at regular spacing. Within the LIFE REWAT, the specific objectives of the pilot on irrigation efficiency is to (i) demonstrate the

Water stress indices for the sugarcane crop on different irrigated surfaces

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Rodrigo G. Brunini

Full Text Available ABSTRACT Sugarcane (Saccharum officinarum L. is a crop of vital importance to Brazil, in the production of sugar and ethanol, power generation and raw materials for various purposes. Strategic information such as topography and canopy temperature can provide management technologies accessible to farmers. The objective of this study was to determine water stress indices for sugarcane in irrigated areas, with different exposures and slopes. The daily water stress index of the plants and the water potential in the soil were evaluated and the production system was analyzed. The experiment was carried out in an “Experimental Watershed”, using six surfaces, two horizontal and the other ones with 20 and 40% North and South exposure slopes. Water stress level was determined by measuring the temperatures of the vegetation cover and the ambient air. Watering was carried out using a drip irrigation system. The results showed that water stress index of sugarcane varies according to exposure and slope of the terrain, while areas whose water stress index was above 5.0 oC had lower yield values.

Monitoring of water in soil in asparagus irrigated culture in Vale do Sao Francisco, Pernambuco, Brazil

International Nuclear Information System (INIS)

Antonino, Antonio C. Dantas; Sampaio, Everardo V.S.B.; Dall' Ollio, Attilio; Bernardo, Ana L. Alves; Audry, Pierre

1996-08-01

For many years the brazilian government has inactivated the implantation of irrigated areas in the Sao Francisco valley, obtaining high productivity.After the most appropriated areas having been occupied, the irrigation of second choice soils, usually more shallower and more clay is been tried. In one of these areas, the productivity of asparagus is less than the expected. trying to improve productivity by optimization of irrigation, the movement of water on soil and plants is being monitored far the last year and a half. the main results are shown with emphasis on the raining season, the most problematic

Prospects for Improving Gravity-Fed Surface Irrigation Systems in Mediterranean European Contexts

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Daniele Masseroni

2017-01-01

Full Text Available Traditionally, most irrigation practices in Southern Europe have been based on gravity-fed surface irrigation systems. Currently, these systems remain a relevant typology in the European Union (EU member states of the Mediterranean areas, where it is often the only sustainable method for farmers due to the small size of agricultural holdings, their reduced capacity and readiness to invest and the low ratio between yield profits and irrigation costs. In the last several years, in response to European and national directives, surface irrigation has garnered increasing attention at the political and bureaucratic levels due to frequent criticisms of its postulated low efficiency and high water wastage. However, these systems commonly provide a number of ecosystem services and nature-based solutions that increase the positive externalities in different rural socio-ecological contexts and often have the potential to extend these services and provide solutions that are compatible with economical sustainability. This study aims to discuss the prospects for new practices and for the rehabilitation and modernization of the gravity-fed surface irrigation systems in EU Mediterranean areas to enhance water efficiency, thus gaining both economic advantages and environmental benefits. The difficulties, stimuli for improvements and peculiarities of the irrigation water management of four rural environments located in Italy, Spain and Portugal were analyzed and compared to the current state of the gravity-fed surface irrigation systems with hypothetical future improvements achievable by innovative technologies and practices. In these different case studies, the current gravity-fed surface irrigation systems have an obsolete regulatory structure; water-use efficiency is not a driving criterion for the management of the conveyance and distribution canal network, and farmers are not yet adequately encouraged to adopt more efficient gravity-fed irrigation practices

Impacts of Irrigation on the Heat Fluxes and Near-Surface Temperature in an Inland Irrigation Area of Northern China

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Li Jiang

2014-03-01

Full Text Available Irrigated agriculture has the potential to alter regional to global climate significantly. We investigate how irrigation will affect regional climate in the future in an inland irrigation area of northern China, focusing on its effects on heat fluxes and near-surface temperature. Using the Weather Research and Forecasting (WRF model, we compare simulations among three land cover scenarios: the control scenario (CON, the irrigation scenario (IRR, and the irrigated cropland expansion scenario (ICE. Our results show that the surface energy budgets and temperature are sensitive to changes in the extent and spatial pattern of irrigated land. Conversion to irrigated agriculture at the contemporary scale leads to an increase in annual mean latent heat fluxes of 12.10 W m−2, a decrease in annual mean sensible heat fluxes of 8.85 W m−2, and a decrease in annual mean temperature of 1.3 °C across the study region. Further expansion of irrigated land increases annual mean latent heat fluxes by 18.08 W m−2, decreases annual mean sensible heat fluxes by 12.31 W m−2, and decreases annual mean temperature by 1.7 °C. Our simulated effects of irrigation show that changes in land use management such as irrigation can be an important component of climate change and need to be considered together with greenhouse forcing in climate change assessments.

Production of mungbean under reclaimed sandy soil and irrigation levels using N-15 labeled

International Nuclear Information System (INIS)

Abdallah, A.A.G.; Thabet, E.M.A.

2000-01-01

Field experiment were performed at the Atomic Energy Authority, Experimental farm, Inshas, Egypt. During 1998 growing season. In tafla and sand mixture soil (1:7 Wt./Wt.). The treatments were laid out using a single line source sprinkler irrigation system which allows a gradual variation of irrigation from excess to little irrigation in which the calculated amount of irrigation water levels were 2241, 1562 and 1093 m 3 / feddan (W 1 , W 2 and W 3 ). The obtained results indicated that, there was a clear relationship between adequate amount of irrigation water and both total seed yield and total green pods/plot as well as there were significant increase in both characters due to irrigation W 1 and W 2 compared with W 3 . The results also indicated that W 2 irrigation level could be used in irrigation under the same conditions. Water use efficiency was significantly increased with middle irrigation level than with other two irrigation treatments. The result concerned fertilizer use efficiency using N 15 labeled fertilizers and total seed protein content were increased with decreasing irrigation level

Deep subsurface drip irrigation using coal-bed sodic water: part II. geochemistry

Science.gov (United States)

Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.

2013-01-01

Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm-1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation(SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5-1.2) are only slightly increased over non-irrigated soils (0.1-0.5). Only 8-15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values >12, measured by 1:1 water-soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (-1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1-1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to 14 and decreasing EC in soil water to 3.2 mS cm-1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters.

Heavy metal displacement in chelate-irrigated soil during phytoremediation

Science.gov (United States)

Madrid, F.; Liphadzi, M. S.; Kirkham, M. B.

2003-03-01

Heavy metals in wastewater sewage sludge (biosolids), applied to land, contaminate soils. Phytoremediation, the use of plants to clean up toxic heavy metals, might remove them. Chelating agents are added to soil to solubilize the metals for enhanced phytoextraction. Yet no studies follow the displacement and leaching of heavy metals in soil with and without roots following solubilization with chelates. The objective of this work was to determine the mobility of heavy metals in biosolids applied to the surface of soil columns (76 cm long; 17 cm diam.) with or without plants (barley; Hordeum vulgare L.). Three weeks after barley was planted, all columns were irrigated with the disodium salt of the chelating agent, EDTA (ethylenediamine tetraacetic acid) (0.5 g/kg soil). Drainage water, soil, and plants were analyzed for heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn). Total concentrations of the heavy metals in all columns at the end of the experiment generally were lower in the top 30 cm of soil with EDTA than without EDTA. The chelate increased concentrations of heavy metals in shoots. With or without plants, the EDTA mobilized Cd, Fe, Mn, Ni, Pb, and Zn, which leached to drainage water. Drainage water from columns without EDTA had concentrations of these heavy metals below detection limits. Only Cu did not leach in the presence of EDTA. Even though roots retarded the movement of Cd, Fe, Mn, Ni, Pb, and Zn through the EDTA-treated soil from 1 d (Cd) to 5 d (Fe), the drainage water from columns with EDTA had concentrations of Cd, Fe, Mn, and Pb that exceeded drinking water standards by 1.3, 500, 620, and 8.6 times, respectively. Because the chelate rendered Cd, Fe, Mn, Ni, Pb, and Zn mobile, it is suggested that the theory for leaching of soluble salts, put forward by Nielsen and associates in 1965, could be applied to control movement of the heavy metals for maximum uptake during chelate-assisted phytoremediation.

Vegetative growth and yield of strawberry under irrigation and soil mulches for different cultivation environments

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Pires Regina Célia de Matos

2006-01-01

Full Text Available The vegetative growth and yield of strawberry in relation to irrigation levels and soil mulches are still not well known, mainly for different environmental conditions. Two experiments were carried out in Atibaia, SP, Brazil, during 1995, one in a protected environment and the other in an open field, to evaluate the cultivar Campinas IAC-2712, under different irrigation levels and soil mulches (black and clear polyethylene. Three water potential levels in the soil were used in order to define irrigation time, corresponding to -0.010 (N1, -0.035 (N2, and -0.070 (N3 MPa, measured through tensiometers installed at the 10 cm depth. A 2 x 3 factorial arrangement was adopted, as randomized complete block, with 5 replicates. In the protected cultivation, the irrigation levels of -0.010 and -0.035 MPa and the clear plastic mulch favored the vegetative growth, evaluated through plant height, maximum horizontal dimension of the plant, leaf area index, as well as by total marketable fruit yield and its components (mean number and weight of fruits per plant. In the open field cultivation, no effect of treatments due to rainfall were observed.

Assessment of the soil water balance by the combination of cosmic ray neutron sensing and eddy covariance technique in an irrigated citrus orchard (Marrakesh, Morocco)

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Mroos, Katja; Baroni, Gabriele; Er-Raki, Salah; Francke, Till; Khabba, Said; Jarlan, Lionel; Hanich, Lahoucine; Oswald, Sascha E.

2014-05-01

Irrigation water requirement plays a crucial role in many agricultural areas and especially in arid and semi-arid landscapes. Improvements in the water management and the performance of the irrigation systems require a correct evaluation of the hydrological processes involved. However, some difficulties can arise due to the heterogeneity of the soil-plant system and of the irrigation scheme. To overcome these limitations, in this study, the soil water balance is analyzed by the combination of the Eddy Covariance technique (EC) and Cosmic Ray neutron Sensing (CRS). EC provides the measurement of the actual evapotranspiration over the area as it was presented in many field conditions. Moreover CRS showed to be a valuable approach to measure the root zone soil moisture integrated in a footprint of ~30 ha. In this way, the combination of the two methodologies should provide a better analysis of the soil water balance at field scale, as opposed to point observations, e.g. by TDR, evaporimeter and fluxmeter. Then, this could increase the capability to assess the irrigation efficiency and the agricultural water management. The study is conducted in a citrus orchard situated in a semi-arid region, 30 km southwest of Marrakesh (Morocco). The site is flat and planted with trees of same age growing in parallel rows with drip irrigation lines and application of fertilizer and pesticides. The original soil seems modified on the surface by the agricultural use, creating differences between trees, rows and lines. In addition, the drip irrigation creates also a spatial variability of the water flux distribution in the field, making this site an interesting area to test the methodology. Particular attention is given to the adaptation of the standard soil sampling campaign used for the calibration of the CRS and the introduction of a weighing function. Data were collected from June to December 2013, which corresponds to the high plant transpiration. Despite the intention of the

Effects of soil moisture conservation practice, irrigation and fertilization on Jatropha curcas

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Aran Phiwngam

2016-11-01

Full Text Available A field experiment was conducted on an Ultic Haplustalf at the Kanchanaburi Research Station, Muang district, Kanchanaburi province, western Thailand between July 2011 and June 2012. Split plots in a randomized complete block design with four replications were employed, having eight main plots (soil moisture conservation practice and irrigation, W1–W8 and 2 sub plots (fertilization, F1 and F2. Jatropha curcas (KUBP 78-9 Var., having been planted at 2 × 2 m spacing, was aged 2 yr when the experiment was commenced. The highly significantly heaviest 100-seed weight of 42 g was obtained 1 mth after water irrigation which had been applied at the rate of 16 L/plant, particularly in the treatment with crop residue mulching (W8 but there were no significant differences among the other treatments where irrigation had been applied (W5–W7. Fertilization and a combination between different fertilizers and soil moisture conservation schemes plus irrigation showed no different effect on the weight of 100 seeds throughout the year of measurement. Growing J. curcas with drip-irrigated water at the rate of 16 L/plant applied every 2 d and crop residue mulching (W8 significantly gave the highest seed yield of 1301.3 kg/ha at 15% moisture content. There were no significant differences among the seed yields from the plots applied with the same amount of irrigated water but with no mulching (W7 and half that amount of irrigated water with crop residue mulching (W6, producing yields of 1112.0 kg/ha and 1236.3 kg/ha, respectively. Three-year-old J. curcas gave inferior seed yield when grown with no irrigated water supply (W1–W4. The application of 50–150–150 kg/ha of N–P2O5–K2O significantly induced a higher amount of seed yield (933.9 kg/ha than did the addition of 93.75–93.75–93.75 kg/ha of N–P2O5–K2O (786.3 kg/ha. The interaction between soil moisture conservation plus irrigation and fertilizer was clear. Applying 50–150�

Effect of irrigation regimes on mobilization of nonreactive tracers and dissolved and particulate phosphorus in slurry-injected soils

DEFF Research Database (Denmark)

Glæsner, Nadia; Kjærgaard, Charlotte; Rubæk, Gitte Holton

2011-01-01

affected by the irrigation regime. These results highlight that nonequilibrium exchange dynamics are important when evaluating processes affecting mobilization and transport in structured soils. Leaching experiments, including cycles of irrigation interruptions and gravitational drainage, thus, adds......Understanding the mobilization processes of phosphorus (P) in the plow layer are essential to quantify potential P losses and suggest management strategies to reduce P losses. This study is aimed at examining nonequilibrium exchange dynamics on the mobilization of slurry-amended Br−, and dissolved...... and particulate P in slurry-injected soils. We compared leaching from intact soil columns (20 cm diam., 20 cm high) under unsaturated flow (suction at the lower boundary of 5 hPa) subjected to continuous irrigation at 2 mm hr−1, and intermittent irrigation at 2 mm hr−1 and 10 mm hr−1 to with interruptions of 10 h...

Impact of Potentially Contaminated River Water on Agricultural Irrigated Soils in an Equatorial Climate

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Juan M. Trujillo-González

2017-06-01

Full Text Available Globally, it is estimated that 20 million hectares of arable land are irrigated with water that contains residual contributions from domestic liquids. This potentially poses risks to public health and ecosystems, especially due to heavy metals, which are considered dangerous because of their potential toxicity and persistence in the environment. The Villavicencio region (Colombia is an equatorial area where rainfall (near 3000 mm/year and temperature (average 25.6 °C are high. Soil processes in tropical conditions are fast and react quickly to changing conditions. Soil properties from agricultural fields irrigated with river water polluted by a variety of sources were analysed and compared to non-irrigated control soils. In this study, no physico-chemical alterations were found that gave evidence of a change due to the constant use of river water that contained wastes. This fact may be associated with the climatic factors (temperature and precipitation, which contribute to fast degradation of organic matter and nutrient and contaminants (such as heavy metals leaching, or to dilution of wastes by the river.

Using Hydrus 2-D to assess the emitters optimal position for Eggplants under surface and subsurface drip irrigation

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Ghazouani, Hiba; Autovino, Dario; Douh, Boutheina; Boujelben, Abdel Hamid; Provenznao, Giuseppe; Rallo, Giovanni

2014-05-01

The main objective of the work is to assess the emitters optimal position for Eggplant crop (Solanum melongena L.) in a sandy loam soil irrigated with surface or subsurface drip irrigation systems, by means of field measurements and simulations carried out with Hydrus-2D model. Initially, the performance of the model is evaluated on the basis of the comparison between simulated soil water contents (SWC) and the corresponding measured in two plots, in which laterals with coextruded emitters are laid on the soil surface (T0) and at 20 cm depth (T20), respectively. In order to choose the best position of the lateral, the results of different simulation runs, carried out by changing the installation depth of the lateral (5 cm, 15 cm and 45 cm) were compared in terms of ratio between actual transpiration and total amount of water provided during the entire growing season (WUE). Experiments were carried out, from April to June 2007, at Institut Supérieur Agronomique de Chott Mériem (Sousse, Tunisia). In the two plots, plants were spaced 0.40 m along the row and 1.2 m between the rows. Each plot was irrigated by means of laterals with coextruded emitters spaced 0.40 m and discharging a flow rate equal to 4.0 l h-1 at a nominal pressure of 100 kPa. In each plot, spatial and temporal variability of SWCs were acquired with a Time Domain Reflectometry probe (Trime-FM3), on a total of four 70 cm long access tubes, installed along the direction perpendicular to the plant row, at distances of 0, 20, 40 and 60 cm from the emitter. Irrigation water was supplied, accounting for the rainfall, every 7-10 days at the beginning of the crop cycle (March-April) and approximately once a week during the following stages till the harvesting (May-June), for a total of 15 one-hour watering. To run the model, soil evaporation, Ep, and crop transpiration, Tp were determined according to the modified FAO Penman-Monteith equation and the dual crop coefficient approach, whereas soil hydraulics

Stover removal effects on seasonal soil water availability under full and deficit irrigation

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Removing corn (Zea mays L.) stover for livestock feed or bioenergy feedstock may impact water availability in the soil profile to support crop growth. The role of stover in affecting soil profile water availability will depend on annual rainfall inputs as well as irrigation level. To assess how res...

Economic analysis of irrigated melon cultivated in greenhouse with and without soil plastic mulching

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Elvis M. de C. Lima

Full Text Available ABSTRACT The objective of this study was to analyze technically and economically the irrigated ‘Gália’ melon (Hybrid Nectar, cultivated in greenhouse with and without using plastic mulch covering on the soil. Simultaneously, two experiments were conducted using a completely randomized design (CRD, in which melon plants were submitted to five water availability levels, defined by 50, 75, 100, 125, and 150% of crop evapotranspiration, with four replicates. The difference between experiments were only about the soil covering with plastic mulch: with (CC or without (SC plastic mulch. The economically optimal irrigation depths were 208.83 and 186.88 mm, resulting in yields of 50.85 and 44.51 t ha-1 for the experiments with and without mulching, respectively. The results showing the economically optimal irrigation depths were very close to those that produced the highest yield.

Irrigating poplar energy crops with landfill leachate negatively affects soil micro- and meso-fauna.

Science.gov (United States)

Coyle, David R; Zalesny, Jill A; Zalesny, Ronald S; Wiese, Adam H

2011-10-01

Increased municipal solid waste generated worldwide combined with substantial demand for renewable energy has prompted testing and deployment of woody feedstock production systems that reuse and recycle wastewaters as irrigation and fertilization. Populus selections are ideal for such systems given their fast growth, extensive root systems, and high water usage rates. Maintaining ecological sustainability (i.e., the capacity for an ecosystem to maintain its function and retain its biodiversity over time) during tree establishment and development is an important component of plantation success, especially for belowground faunal populations. To determine the impact of solid waste leachate on soil micro- and meso-fauna, we compared soilfrom eight different Populus clones receiving municipal solid waste landfill leachate irrigation with clones receiving fertilized (N, P K) well water irrigation. Microfauna (i.e., nematodes) communities were more diverse in control soils. Mesofauna (i.e., insects) were associated with all clones; however, they were four times more abundant around trees found within the control plot than those that received leachate treatments. Nematode and insect abundance varied among Populus clones yet insect diversity was greater in the leachate-treated soils. Phytotechnologies must allow for soil faunal sustainability, as upsetting this balance could lead to great reductions in phytotechnology efficacy.

Comparison and analysis of empirical equations for soil heat flux for different cropping systems and irrigation methods

Science.gov (United States)

Irmak, A.; Singh, Ramesh K.; Walter-Shea, Elizabeth; Verma, S.B.; Suyker, A.E.

2011-01-01

We evaluated the performance of four models for estimating soil heat flux density (G) in maize (Zea mays L.) and soybean (Glycine max L.) fields under different irrigation methods (center-pivot irrigated fields at Mead, Nebraska, and subsurface drip irrigated field at Clay Center, Nebraska) and rainfed conditions at Mead. The model estimates were compared against measurements made during growing seasons of 2003, 2004, and 2005 at Mead and during 2005, 2006, and 2007 at Clay Center. We observed a strong relationship between the G and net radiation (Rn) ratio (G/Rn) and the normalized difference vegetation index (NDVI). When a significant portion of the ground was bare soil, G/Rn ranged from 0.15 to 0.30 and decreased with increasing NDVI. In contrast to the NDVI progression, the G/Rn ratio decreased with crop growth and development. The G/Rn ratio for subsurface drip irrigated crops was smaller than for the center-pivot irrigated crops. The seasonal average G was 13.1%, 15.2%, 10.9%, and 12.8% of Rn for irrigated maize, rainfed maize, irrigated soybean, and rainfed soybean, respectively. Statistical analyses of the performance of the four models showed a wide range of variation in G estimation. The root mean square error (RMSE) of predictions ranged from 15 to 81.3 W m-2. Based on the wide range of RMSE, it is recommended that local calibration of the models should be carried out for remote estimation of soil heat flux.

Heavy metals contamination of soils in response to wastewater irrigation in Rawalpindi region

International Nuclear Information System (INIS)

Mushtaq, N.; Khan, K.S.

2010-01-01

The study was conducted to evaluate the quality of effluents/ waste water samples from Rawalpindi region for irrigation purpose and to elucidate effects of their application on heavy metal contents in soils of area. Results indicated that the EC, SAR, RSC and TDS of most effluent/ waste water samples were above the critical limits. Cadmium and Cr were above the critical limits in almost all the effluent samples, whereas Ni was high in 14, Pb was high in 10, Cu was high in 5 and the Fe was high in 3 effluent samples as compared to critical limits. Regarding heavy metals contents of soils irrigated by these effluents/ waste water, total Fe, total Cd and total Ni were higher in almost all the sampled sites, whereas total Cr was high at 7 sampled sites. AB-DTPA extractable Fe and Zn were higher at all the sampled sites, while the extractable Cd was higher at 2 sampled sites. Overall, the effluent samples collected from Adiala showed high concentrations of heavy metals, whereas soils of Wah factory and Islamabad area had higher heavy metal contents (total and AB-DTPA extractable). On the basis of results it is concluded that quality of effluents/ waste water samples collected from different locations of Rawalpindi is not good for irrigation and the long term use of these effluents for crop production caused accumulation of some toxic metals in soils above critical limits which is harmful for soil health and may lead to elevated levels of heavy metals in crop plants. (author)

Using SWAT-MODFLOW to simulate groundwater flow and groundwater-surface water interactions in an intensively irrigated stream-aquifer system

Science.gov (United States)

Wei, X.; Bailey, R. T.

2017-12-01

Agricultural irrigated watersheds in semi-arid regions face challenges such as waterlogging, high soil salinity, reduced crop yield, and leaching of chemical species due to extreme shallow water tables resulting from long-term intensive irrigation. Hydrologic models can be used to evaluate the impact of land management practices on water yields and groundwater-surface water interactions in such regions. In this study, the newly developed SWAT-MODFLOW, a coupled surface/subsurface hydrologic model, is applied to a 950 km2 watershed in the Lower Arkansas River Valley (southeastern Colorado). The model accounts for the influence of canal diversions, irrigation applications, groundwater pumping, and earth canal seepage losses. The model provides a detailed description of surface and subsurface flow processes, thereby enabling detailed description of watershed processes such as runoff, infiltration, in-streamflow, three-dimensional groundwater flow in a heterogeneous aquifer system with sources and sinks (e.g. pumping, seepage to subsurface drains), and spatially-variable surface and groundwater exchange. The model was calibrated and tested against stream discharge from 5 stream gauges in the Arkansas River and its tributaries, groundwater levels from 70 observation wells, and evapotranspiration (ET) data estimated from satellite (ReSET) data during the 1999 to 2007 period. Since the water-use patterns within the study area are typical of many other irrigated river valleys in the United States and elsewhere, this modeling approach is transferable to other regions.

Microbial indicators of fecal contamination in soils under different wastewater irrigation patterns

International Nuclear Information System (INIS)

Contreras-Godinez, C. A.; Palacios-Lopez, O. A.; Munoz-Castellanos, L. N.; Saucedo-Teran, R.; Rubio-Arias, H.; Nevarez-Moorillon, G. V.

2009-01-01

The use of wastewater to irrigate produce was a common practice in some suburban areas in Mexico. The continuous use of wastewater can increase the chance of fecal soil contamination, which can percolate in soil and finally cause groundwater contamination. A suburban area in Chihuahua, mexico, has been traditionally irradiated with wastewater for production of agriculture goods, including produce and animal foodstuffs. (Author)

Irrigation management and phosphorus addition alter the abundance of carbon dioxide-fixing autotrophs in phosphorus-limited paddy soil.

Science.gov (United States)

Wu, Xiaohong; Ge, Tida; Yan, Wende; Zhou, Juan; Wei, Xiaomeng; Chen, Liang; Chen, Xiangbi; Nannipieri, Paolo; Wu, Jinshui

2017-12-01

In this study, we assessed the interactive effects of phosphorus (P) application and irrigation methods on the abundances of marker genes (cbbL, cbbM, accA and aclB) of CO2-fixing autotrophs. We conducted rice-microcosm experiments using a P-limited paddy soil, with and without the addition of P fertiliser (P-treated-pot (P) versus control pot (CK)), and using two irrigation methods, namely alternate wetting and drying (AWD) and continuous flooding (CF). The abundances of bacterial 16S rRNA, archaeal 16S rRNA, cbbL, cbbM, accA and aclB genes in the rhizosphere soil (RS) and bulk soil (BS) were quantified. The application of P significantly altered the soil properties and stimulated the abundances of Bacteria, Archaea and CO2-fixation genes under CF treatment, but negatively influenced the abundances of Bacteria and marker genes of CO2-fixing autotrophs in BS soils under AWD treatment. The response of CO2-fixing autotrophs to P fertiliser depended on the irrigation management method. The redundancy analysis revealed that 54% of the variation in the functional marker gene abundances could be explained by the irrigation method, P fertiliser and the Olsen-P content; however, the rhizosphere effect did not have any significant influence. P fertiliser application under CF was more beneficial in improving the abundance of CO2-fixing autotrophs compared to the AWD treatment; thus, it is an ideal irrigation management method to increase soil carbon fixation. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Assessment of soil moisture dynamics on an irrigated maize field using cosmic ray neutron sensing

Science.gov (United States)

Scheiffele, Lena Maria; Baroni, Gabriele; Oswald, Sascha E.

2015-04-01

In recent years cosmic ray neutron sensing (CRS) developed as a valuable, indirect and non-invasive method to estimate soil moisture at a scale of tens of hectares, covering the gap between point scale measurements and large scale remote sensing techniques. The method is particularly promising in cropped and irrigated fields where invasive installation of belowground measurement devices could conflict with the agricultural management. However, CRS is affected by all hydrogen pools in the measurement footprint and a fast growing biomass provides some challenges for the interpretation of the signal and application of the method for detecting soil moisture. For this aim, in this study a cosmic ray probe was installed on a field near Braunschweig (Germany) during one maize growing season (2014). The field was irrigated in stripes of 50 m width using sprinkler devices for a total of seven events. Three soil sampling campaigns were conducted throughout the growing season to assess the effect of different hydrogen pools on calibration results. Additionally, leaf area index and biomass measurements were collected to provide the relative contribution of the biomass on the CRS signal. Calibration results obtained with the different soil sampling campaigns showed some discrepancy well correlated with the biomass growth. However, after the calibration function was adjusted to account also for lattice water and soil organic carbon, thus representing an equivalent water content of the soil, the differences decreased. Soil moisture estimated with CRS responded well to precipitation and irrigation events, confirming also the effective footprint of the method (i.e., radius 300 m) and showing occurring water stress for the crop. Thus, the dynamics are in agreement with the soil moisture determined with point scale measurements but they are less affected by the heterogeneous moisture conditions within the field. For this reason, by applying a detailed calibration, CRS proves to be a

Similarity index between irrigation water and soil saturation extract in the experimental field of Yachay University, Ecuador

Science.gov (United States)

Carrera-Villacrés, D. V.; Sánchez-Gómez, V. P.; Portilla-Bravo, O. A.; Bolaños-Guerrón, D. R.

2017-08-01

Soil monitoring is a job that demands a lot of time and money. therefore, measuring the same parameters in the water becomes simple because it can be done in situ. The objective of this work was to find a similarity index for the validation of mathematical correlation models based on physicochemical parameters to verify if there is a balance between irrigation water and soil saturation extract in the experimental field Yachay that is known as the city of knowledge that is located in Imbabura province, Ecuador, for which, the sampling of water was carried out in two representative periods (dry and rainy). Sampling of 10 soil profiles was also performed, covering the total area; these samples were obtained results of Electrical Conductivity (EC), pH and total dissolved salts (TDS). With correlation models between soils and water, it is possible to predict concentrations of elements in the irrigation water. It was concluded that there is a balance between soil and water, so that the salts present in the soil are highly soluble, in addition, there is a high probability that the elements in the irrigation water are in the soil. In sample water, the same concentrations were found in the soil, at their saturation point, and very close to the field capacity.

Longevity of shallow subsurface drip irrigation tubing under three tillage practices

Science.gov (United States)

Shallow Sub-Surface drip irrigation (S3DI) has drip tubing buried about 2-in below the soil surface. It is unknown how long drip tubing would be viable at this shallow soil depth using strip- or no-tillage systems. The objectives were to determine drip tube longevity, resultant crop yield, and parti...

Effect of irrigation on heavy metals content of wastewater irrigated ...

African Journals Online (AJOL)

There is an urgent need to educate farmers on the dangers of the presence of heavy metals in soils as well as the quality of irrigation water especially if it comes from tanning industries for increased crop production. Accordingly, soil and irrigation wastewater study was conducted to assess the concentrations of heavy ...

Contribution of Wastewater Irrigation to Soil Transmitted Helminths Infection among Vegetable Farmers in Kumasi, Ghana.

Directory of Open Access Journals (Sweden)

Isaac Dennis Amoah

2016-12-01

Full Text Available Wastewater irrigation is associated with several benefits but can also lead to significant health risks. The health risk for contracting infections from Soil Transmitted Helminths (STHs among farmers has mainly been assessed indirectly through measured quantities in the wastewater or on the crops alone and only on a limited scale through epidemiological assessments. In this study we broadened the concept of infection risks in the exposure assessments by measurements of the concentration of STHs both in wastewater used for irrigation and the soil, as well as the actual load of STHs ova in the stool of farmers and their family members (165 and 127 in the wet and dry seasons respectively and a control group of non-farmers (100 and 52 in the wet and dry seasons, respectively. Odds ratios were calculated for exposure and non-exposure to wastewater irrigation. The results obtained indicate positive correlation between STH concentrations in irrigation water/soil and STHs ova as measured in the stool of the exposed farmer population. The correlations are based on reinfection during a 3 months period after prior confirmed deworming. Farmers and family members exposed to irrigation water were three times more likely as compared to the control group of non-farmers to be infected with Ascaris (OR = 3.9, 95% CI, 1.15-13.86 and hookworm (OR = 3.07, 95% CI, 0.87-10.82. This study therefore contributes to the evidence-based conclusion that wastewater irrigation contributes to a higher incidence of STHs infection for farmers exposed annually, with higher odds of infection in the wet season.

Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes

DEFF Research Database (Denmark)

Ahmadi, S.H.; Andersen, M.N.; Lærke, P.E.

2011-01-01

received 65% of FI after tuber bulking and lasted for six weeks until final harvest. Results showed that the irrigation treatments were not significantly different in terms of N uptake in the tubers, shoot, and whole crop. However, there was a statistical difference between the soil textures where plants...... in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could...... potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96...

[Effects of soil wetting pattern on the soil water-thermal environment and cotton root water consumption under mulched drip irrigation].

Science.gov (United States)

Li, Dong-wei; Li, Ming-si; Liu, Dong; Lyu, Mou-chao; Jia, Yan-hui

2015-08-01

Abstract: To explore the effects of soil wetting pattern on soil water-thermal environment and water consumption of cotton root under mulched drip irrigation, a field experiment with three drip intensities (1.69, 3.46 and 6.33 L · h(-1)), was carried out in Shihezi, Xinjiang Autonomous Region. The soil matric potential, soil temperature, cotton root distribution and water consumption were measured during the growing period of cotton. The results showed that the main factor influencing the soil temperature of cotton under plastic mulch was sunlight. There was no significant difference in the soil temperature and root water uptake under different treatments. The distribution of soil matrix suction in cotton root zone under plastic mulch was more homogeneous under ' wide and shallow' soil wetting pattern (W633). Under the 'wide and shallow' soil wetting pattern, the average difference of cotton root water consumption between inner row and outer row was 0.67 mm · d(-1), which was favorable to the cotton growing trimly at both inner and outer rows; for the 'narrow and deep' soil wetting pattern (W169), the same index was 0.88 mm · d(-1), which was unfavorable to cotton growing uniformly at both inner and outer rows. So, we should select the broad-shallow type soil wetting pattern in the design of drip irrigation under mulch.

Potential microbial risk factors related to soil amendments and irrigation water of potato crops.

Science.gov (United States)

Selma, M V; Allende, A; López-Gálvez, F; Elizaquível, P; Aznar, R; Gil, M I

2007-12-01

This study assesses the potential microbial risk factors related to the use of soil amendments and irrigation water on potato crops, cultivated in one traditional and two intensive farms during two harvest seasons. The natural microbiota and potentially pathogenic micro-organisms were evaluated in the soil amendment, irrigation water, soil and produce. Uncomposted amendments and residual and creek water samples showed the highest microbial counts. The microbial load of potatoes harvested in spring was similar among the tested farms despite the diverse microbial levels of Listeria spp. and faecal coliforms in the potential risk sources. However, differences in total coliform load of potato were found between farms cultivated in the autumn. Immunochromatographic rapid tests and the BAM's reference method (Bacteriological Analytical Manual; AOAC International) were used to detect Escherichia coli O157:H7 from the potential risk sources and produce. Confirmation of the positive results by polymerase chain reaction procedures showed that the immunochromatographic assay was not reliable as it led to false-positive results. The potentially pathogenic micro-organisms of soil amendment, irrigation water and soil samples changed with the harvest seasons and the use of different agricultural practices. However, the microbial load of the produce was not always influenced by these risk sources. Improvements in environmental sample preparation are needed to avoid interferences in the use of immunochromatographic rapid tests. The potential microbial risk sources of fresh produce should be regularly controlled using reliable detection methods to guarantee their microbial safety.

Biological degradation of chernozems under irrigation

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Oksana Naydyonova

2014-12-01

Full Text Available We studied the changes in the state of microbial cenosis of Ukraine’s chernozems under irrigation. Considerable part of Ukraine’s chernozems is located in the areas where humidification is insufficient and unstable. Irrigation is a soil-reclamation measure for chernozems of Ukrainian Forest-steppe and Steppe which enables getting the assured yield, especially vegetable and fodder crops. At the same time, irrigation is a powerful anthropogenic factor that affects the soil, causes a significant transformation of many of its properties and regimes including biological ones. Often these changes are negative. The purpose of our investigation was to identify changes in the state of microbial cenoses of chernozem soils under irrigation which depend on such factors as the quality of irrigation water, the duration and intensity of irrigation, the initial properties of soil, the structure of crop rotation, usage of fertilizing systems and agroameliorative techniques. We identified direction and evaluated a degree of changes in biological properties of chernozems under influence of irrigation in different agro-irrigational and soil-climatic conditions. In the long-term stationary field experiments we identified the following biological indices of irrigated soils and their non-irrigated analogues: a number of microorganisms which belong to main ecological-trophic groups, activity of soil enzymes (dehydrogenase, invertase, phenol oxidase, soil phytotoxic activity, cellulose destroying capacity of soil, indices of oligotrophy and mineralization, summary biological index (SBI and index of biological degradation (BDI. Results of researches showed that irrigation unbalanced the soil ecosystem and stipulated the forming of microbial cenosis with new parameters. Long-term intensive irrigation of typical chernozem (Kharkiv Region with fresh water under condition of 4-fields vegetable crop rotation led to the degradation changes of its microbial cenosis such as

Projected irrigation requirements for upland crops using soil moisture model under climate change in South Korea

Science.gov (United States)

An increase in abnormal climate change patterns and unsustainable irrigation in uplands cause drought and affect agricultural water security, crop productivity, and price fluctuations. In this study, we developed a soil moisture model to project irrigation requirements (IR) for upland crops under cl...

Effects of reclaimed water irrigation on microbial diversity and composition of soil with reducing nitrogen fertilization

DEFF Research Database (Denmark)

Wei, Guo; Qi, Xuebin; Xiao, Yatao

2018-01-01

-dependent manner. RW irrigation increased the abundances of Gemmatimonadetes, Actinobacteria, Firmicutes, and Nitrospirae in soils. The Chao, ACE, and H indices revealed no significant difference under RW irrigation with varying levels of N fertilization. The tomato yield and partial factor productivity from...

Effect of irrigation techniques and strategies on water footprint of growing crops

Science.gov (United States)

Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y. Y.

2014-12-01

Reducing the water footprint (WF) of growing crops, the largest water user and a significant contributor to the WF of many consumer products, plays a significant role in integrated and sustainable water management. The water footprint for growing crop is accounted by relating the crop yield with the corresponding consumptive water use (CWU), which both can be adjusted by measures that affect the crop growth and root-zone soil water balance. This study explored the scope for reducing the water footprint of irrigated crops by experimenting set of field level technical and managerial measures: (i) irrigation technologies (Furrow, sprinkler, drip and sub-surface drip), (ii) irrigation strategies (full and a range of sustained and controlled deficit) and (iii) field management options (zero, organic and synthetic mulching). Ranges of cases were also considered: (a) Arid and semi-arid environment (b) Loam and Sandy-loam soil types and (c) for Potato, Wheat and Maize crops; under (c) wet, normal and dry years. AquaCrop, the water driven crop growth and soil water balance model, offered the opportunity to systematically experiment these measures on water consumption and yield. Further, the green and blue water footprints of growing crop corresponding to each measure were computed by separating the root zone fluxes of the AquaCrop output into the green and blue soil water stocks and their corresponding fluxes. Results showed that in arid environment reduction in irrigation supply, CWU and WF up to 300 mm, 80 mm and 75 m3/tonne respectively can be achieved for Maize by a combination of organic mulching and drip technology with controlled deficit irrigation strategies (10-20-30-40% deficit with reference to the full irrigation requirement). These reductions come with a yield drop of 0.54 tonne/ha. In the same environment under the absence of mulching practice, the sub-surface drip perform better in reducing CWU and WF of irrigated crops followed by drip and furrow irrigation

Interaction of different irrigation strategies and soil textures on the nitrogen uptake of field grown potatoes

DEFF Research Database (Denmark)

Ahmadi, S.H.; Andersen, Mathias Neumann; Lærke, Poul Erik

2011-01-01

Nitrogen (N) uptake (kg ha-1) of field-grown potatoes was measured in 4.32 m2 lysimeters that were filled with coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments...... in the loamy sand had the highest amount of N uptake. The interaction between irrigation treatments and soil textures was significant, and implied that under non-limiting water conditions, loamy sand is the suitable soil for potato production because plants can take up sufficient amounts of N and it could...... potentially lead to higher yield. However, under limited water conditions and applying water-saving irrigation strategies, sandy loam and coarse sand are better growth media because N is more available for the potatoes. The simple yield prediction model was developed that could explains ca. 96...

[Influence of water deficit and supplemental irrigation on nitrogen uptake by winter wheat and nitrogen residual in soil].

Science.gov (United States)

Wang, Zhaohui; Wang, Bing; Li, Shengxiu

2004-08-01

Pot experiment in greenhouse showed that water deficit at all growth stages and supplemental irrigation at tillering stage significantly decreased the nitrogen uptake by winter wheat and increased the mineral N residual (79.8-113.7 mg x kg(-1)) in soil. Supplemental irrigation at over-wintering, jointing or filling stage significantly increased the nitrogen uptake by plant and decreased the nitrogen residual (47.2-60.3 mg x kg(-1)) in soil. But, the increase of nitrogen uptake caused by supplemental irrigation did not always mean a high magnitude of efficient use of nitrogen by plants. Supplemental irrigation at over-wintering stage didn't induce any significant change in nitrogen content of grain, irrigation at filling stage increased the nitrogen content by 20.9%, and doing this at jointing stage decreased the nitrogen content by 19.6%, as compared to the control.

Nematode Community Composition under Various Irrigation Schemes in a Citrus Soil Ecosystem.

Science.gov (United States)

Porazinska, D L; McSorley, R; Duncan, L W; Graham, J H; Wheaton, T A; Parsons, L R

1998-06-01

Interest in the sustainability of farming practices has increased in response to environmental problems associated with conventional agricultural management often adopted for the production of herbaceous crops, ornamentals, and fruit crops. Availability of measures of the status of the soil ecosystem is of immediate importance, particularly for environmental assessment and monitoring programs. This study investigated the effects of various irrigation regimes (an example of an agricultural management practice) on the structure of the nematode fauna in a citrus orchard in the sandy ridge area of Central Florida. Ecological measures such as community structure indices, diversity indices, and maturity indices were assessed and related to irrigation intensity. Maturity index was an effective measure in distinguishing differences between irrigation regimes, whereas other indices of community structure were not. Of various nematode genera and trophic groups, only omnivores and the omnivore genera. Aporcelaimellus and Eudorylaimus responded to irrigation treatments.

Correlations of natural radionuclides in soil with those in sediment from the Danube and nearby irrigation channels

International Nuclear Information System (INIS)

Krmar, M.; Varga, E.; Slivka, J.

2013-01-01

The correlation between activity concentrations of some natural radionuclides ( 238 U, 226 Ra, 232 Th, 40 K) measured in soil and in sediment taken from the Danube River and nearby irrigation channels was studied. The soil samples were collected from the northern part of Serbia and the sediment from the Serbian part of the Danube River and from the surrounding irrigation channels. The correlation between 238 U and other natural radionuclides in irrigation channel sediments was not as good as in the Danube. One of the possible explanations for this weak correlation can be the different chemical dynamics of 238 U in the irrigation channel sediment or changes of the 238 U activity concentration in irrigation channel sediment due to some human activities. The evaluation of ratios of activity concentrations of some natural radionuclides could be a more sensitive method for the determination of contaminant, rather than the straightforward analysis of activity concentrations. -- Highlights: ► 238 U, 232 Th and 40 K were measured in soil, Danube and surrounding channel sediment. ► Correlation of activity concentrations were observed. ► In cannel sediment natural radionuclides are not well correlated as in Danube one. ► Ratios of 238 U, 232 Th and 40 K can be good indicator for TENORM monitoring

Comparative Study of Water and Nitrogen Fertilizer Application on Potato Crop under Fertigation and Surface Irrigating Systems by Using Labeled Nitrogen (15N)

International Nuclear Information System (INIS)

Abdullah Haidara, H. M.; Amin Alkirshi, A. H.; Saleh Husien, A.

2007-01-01

This research activity was conducted at Central Highland Research Station Farm-Dhamar, on potato Crop (Diamant cv.), during three seasons of 2000, 2001, and 2003.The objective of this activity was to study the Nitrogen Fertilizer Use Efficiency (WUE) which applied in different dosages with irrigation water (fertigation) and one dosage to the soil under surface irrigation, by using Labeled nitrogen fertilizer ( 15N ), comparing the quantity of irrigation water applied through Drip irrigation method and surface irrigation and its effect on WUE and yield of potato crop. The basic experiment was planted in randomized completely block design (RCBD) with five replications during 2000 season and six replication in 2001.and five treatments were tested (N1= 50kg N/ha, N2 =100kg N/ha, N3=150kg N/ha and N4=200kgN/ha as fertigated treatments under drip irrigation and Ns = 150kg N/ha as surface Nitrogen Application under surface irrigation. While in the 2003 season Verification trial was conducted with two replications, two treatments and RCB design. Results indicated that using Drip irrigation method in application of water saved 38% of irrigation water as compared to Surface irrigation. Fertigated treatments (N1, N2, N3 and N4) were, significantly superior to Surface Nitrogen Application treatment (NS), fertigated treatment (N3) gave the highest values of WUE which were 5.3, 6.4 and 6.1 kg/m3 for the three seasons (2000, 2001, 2003 respectively) with an average of 5.9 kg/m3 comparing to the surface Nitrogen Application treatment (NS) which gave the less yield per unit of water which was 3.8, 3.6 and 3.9 kg /m3 for the three seasons 2000, 2001 and 2003 respectively with an average of 3.7 kg/m3.The Average yield of potato tubers for (N3) treatment in the three seasons was 30 .3 t/ha comparing to the (NS) treatment, which gave an average of 29,5t/ha.The fertigatetd treatment (N1) recorded the highest efficient use of nitrogen Fertilizer followed by (N3) compare to the surface

Mapping soil moisture across an irrigated field using electromagnetic conductivity imaging

Science.gov (United States)

The ability to measure and map volumetric soil water theta quickly and accurately is important in irrigated agriculture. However, the traditional approach of using thermogravimetric moisture (w) and converting this to theta using measurements of bulk density (theta – cm3/cm3) is laborious and time c...

Effects of soil texture and drought stress on the uptake of antibiotics and the internalization of Salmonella in lettuce following wastewater irrigation.

Science.gov (United States)

Zhang, Yuping; Sallach, J Brett; Hodges, Laurie; Snow, Daniel D; Bartelt-Hunt, Shannon L; Eskridge, Kent M; Li, Xu

2016-01-01

Treated wastewater is expected to be increasingly used as an alternative source of irrigation water in areas facing fresh water scarcity. Understanding the behaviors of contaminants from wastewater in soil and plants following irrigation is critical to assess and manage the risks associated with wastewater irrigation. The objective of this study was to evaluate the effects of soil texture and drought stress on the uptake of antibiotics and the internalization of human pathogens into lettuce through root uptake following wastewater irrigation. Lettuce grown in three soils with variability in soil texture (loam, sandy loam, and sand) and under different levels of water stress (no drought control, mild drought, and severe drought) were irrigated with synthetic wastewater containing three antibiotics (sulfamethoxazole, lincomycin and oxytetracycline) and one Salmonella strain a single time prior to harvest. Antibiotic uptake in lettuce was compound-specific and generally low. Only sulfamethoxazole was detected in lettuce with increasing uptake corresponding to increasing sand content in soil. Increased drought stress resulted in increased uptake of lincomycin and decreased uptake of oxytetracycline and sulfamethoxazole. The internalization of Salmonella was highly dependent on the concentration of the pathogen in irrigation water. Irrigation water containing 5 Log CFU/mL Salmonella resulted in limited incidence of internalization. When irrigation water contained 8 Log CFU/mL Salmonella, the internalization frequency was significantly higher in lettuce grown in sand than in loam (p = 0.009), and was significantly higher in lettuce exposed to severe drought than in unstressed lettuce (p = 0.049). This work demonstrated how environmental factors affected the risk of contaminant uptake by food crops following wastewater irrigation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Imidacloprid soil movement under micro-sprinkler irrigation and soil-drench applications to control Asian citrus psyllid (ACP) and citrus leafminer (CLM).

Science.gov (United States)

Fletcher, Evelyn; Morgan, Kelly T; Qureshi, Jawwad A; Leiva, Jorge A; Nkedi-Kizza, Peter

2018-01-01

Imidacloprid (IM) is used to control the Asian Citrus Psyllid (ACP) and citrus leafminer (CLM), which are related to the spread of huanglongbing (HLB or citrus greening) and citrus canker diseases, respectively. In Florida citrus, imidacloprid is mainly soil-drenched around the trees for proper root uptake and translocation into plant canopy to impact ACP and CLM. The objective of this study was to determine the effect of imidacloprid rate, and irrigate amount on concentration of imidacloprid in the soil following drench application to citrus trees in three age classes. The plots were established at the Southwest Florida Research and Education Center, Immokalee, using a randomized complete-block design for three age classes of trees: one-year-old trees (B1), three to five-year-old trees (B2), and eight-year-old trees (B3). The treatments were a combination of two rates each of imidacloprid (1D, 2D) and micro-sprinkling irrigation (1I, 2I). Imidacloprid and bromide (Br-) used as tracer were applied simultaneously. Soil moisture and concentrations of imidacloprid and Br were monitored using soil cores from hand held augers. Soil moisture content (θV) did not differ under two irrigation rates at any given observation day or depth, except following heavy rainfall events. Br- was lost from the observation depths (0-45 cm) about two weeks after soil-drench. Contrarily, imidacloprid persisted for a much longer time (4-8 weeks) at all soil depths, regardless of treatment combinations. The higher retardation of imidacloprid was related to the predominantly unsaturated conditions of the soil (which in turn reduced soil hydraulic conductivities by orders of magnitude), the imidacloprid sorption on soil organic matter, and the citrus root uptake. Findings of this study are important for citrus growers coping with the citrus greening and citrus canker diseases because they suggest that imidacloprid soil drenches can still be an effective control measure of ACP and CLM, and the

Water and solute balances as a basis for sustainable irrigation agriculture

Science.gov (United States)

Pla-Sentís, Ildefonso

2015-04-01

The growing development of irrigated agriculture is necessary for the sustainable production of the food required by the increasing World's population. Such development is limited by the increasing scarcity and low quality of the available water resources and by the competitive use of the water for other purposes. There are also increasing problems of contamination of surface and ground waters to be used for other purposes by the drainage effluents of irrigated lands. Irrigation and drainage may cause drastic changes in the regime and balance of water and solutes (salts, sodium, contaminants) in the soil profile, resulting in problems of water supply to crops and problems of salinization, sodification and contamination of soils and ground waters. This is affected by climate, crops, soils, ground water depth, irrigation and groundwater composition, and by irrigation and drainage management. In order to predict and prevent such problems for a sustainable irrigated agriculture and increased efficiency in water use, under each particular set of conditions, there have to be considered both the hydrological, physical and chemical processes determining such water and solute balances in the soil profile. In this contribution there are proposed the new versions of two modeling approaches (SOMORE and SALSODIMAR) to predict those balances and to guide irrigation water use and management, integrating the different factors involved in such processes. Examples of their application under Mediterranean and tropical climate conditions are also presented.

Study of soil bacterial and crop quality irrigated with treated municipal wastewater

DEFF Research Database (Denmark)

Alinezhadian, A; Karim, A; Mohammadi, J

2014-01-01

Background and Objectives: In arid and semi-arid regions, wastewater reuse has become an important element in agriculture. However, irrigation with this resource can be either beneficial or harmful, depending on the wastewater characteristics. The aim of this research was to investigate the soil...... bacterial and crops quality irrigated with treated wastewater. Material and Methods: This research was conducted on a maize field near the wastewater treatment plant in Shahr-e-kord in summer,2011. Plots were arranged in a randomized complete block design in 3 replications and 2 treatments, well water (W1...

Effects of irrigation and plastic mulch on soil properties on semi-arid abandoned fields

NARCIS (Netherlands)

van der Meulen, E.S.; Nol, L.; Cammeraat, L.H.

2006-01-01

The Guadalentín Basin in Spain is one of the driest areas of Europe and has problems with high evaporation rates, and high risks of desertification exist including soil quality loss and soil erosion. Farmers in this semi-arid region use polyethylene covers on their irrigated croplands to reduce

Effects of water-saving irrigation on emissions of greenhouse gases and prokaryotic communities in rice paddy soil.

Science.gov (United States)

Ahn, Jae-Hyung; Choi, Min-Young; Kim, Byung-Yong; Lee, Jong-Sik; Song, Jaekyeong; Kim, Gun-Yeob; Weon, Hang-Yeon

2014-08-01

The effects of water-saving irrigation on emissions of greenhouse gases and soil prokaryotic communities were investigated in an experimental rice field. The water layer was kept at 1-2 cm in the water-saving (WS) irrigation treatment and at 6 cm in the continuous flooding (CF) irrigation treatment. WS irrigation decreased CH(4) emissions by 78 % and increased N(2)O emissions by 533 %, resulting in 78 % reduction of global warming potential compared to the CF irrigation. WS irrigation did not affect the abundance or phylogenetic distribution of bacterial/archaeal 16S rRNA genes and the abundance of bacterial/archaeal 16S rRNAs. The transcript abundance of CH(4) emission-related genes generally followed CH(4) emission patterns, but the difference in abundance between mcrA transcripts and amoA/pmoA transcripts best described the differences in CH(4) emissions between the two irrigation practices. WS irrigation increased the relative abundance of 16S rRNAs and functional gene transcripts associated with Anaeromyxobacter and Methylocystis spp., suggesting that their activities might be important in emissions of the greenhouse gases. The N(2)O emission patterns were not reflected in the abundance of N(2)O emission-related genes and transcripts. We showed that the alternative irrigation practice was effective for mitigating greenhouse gas emissions from rice fields and that it did not affect the overall size and structure of the soil prokaryotic community but did affect the activity of some groups.

Root growth, soil water variation, and grain yield response of winter wheat to supplemental irrigation

Directory of Open Access Journals (Sweden)

Jianguo Man

2016-04-01

Full Text Available Water shortage threatens agricultural sustainability in the Huang-Huai-Hai Plain of China. Thus, we investigated the effect of supplemental irrigation (SI on the root growth, soil water variation, and grain yield of winter wheat in this region by measuring the moisture content in different soil layers. Prior to SI, the soil water content (SWC at given soil depths was monitored to calculate amount of irritation water that can rehydrate the soil to target SWC. The SWC before SI was monitored to depths of 20, 40, and 60 cm in treatments of W20, W40, and W60, respectively. Rainfed treatment with no irrigation as the control (W0. The mean root weight density (RWD, triphenyl tetrazolium chloride reduction activity (TTC reduction activity, soluble protein (SP concentrations as well as catalase (CAT, and superoxide dismutase (SOD activities in W40 and W60 treatments were significantly higher than those in W20. The RWD in 60–100 cm soil layers and the root activity, SP concentrations, CAT and SOD activities in 40–60 cm soil layers in W40 treatment were significantly higher than those in W20 and W60. W40 treatment is characterized by higher SWC in the upper soil layers but lower SWC in the 60–100-cm soil layers during grain filling. The soil water consumption (SWU in the 60–100 cm soil layers from anthesis after SI to maturity was the highest in W40. The grain yield, water use efficiency (WUE, and irrigation water productivity were the highest in W40, with corresponding mean values of 9169 kg ha−1, 20.8 kg ha−1 mm−1, and 35.5 kg ha−1 mm−1. The RWD, root activities, SP concentrations, CAT and SOD activities, and SWU were strongly positively correlated with grain yield and WUE. Therefore, the optimum soil layer for SI of winter wheat after jointing is 0–40 cm.

Interaction between Soil Physicochemical Parameters and Earthworm Communities in Irrigated Areas with Natural Water and Wastewaters

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Kourtel Ghanem Nadra

2017-01-01

Full Text Available Our objective is to study interaction between physical and chemical properties of soils and their earthworm community characteristics in different areas irrigated by wastewaters and well waters. The fields have different topography and agricultural practices conditions and are located in two regions of Batna department (Eastern Algeria. Both regions are characterized by a semiarid climate with cold winters and Calcisol soils. Nine fields were subject of this study. Three of these fields are located in Ouled Si Slimane region whose irrigation is effectuated by natural waters of Kochbi effluent. The other six fields are located at edges of Wed El Gourzi, effluent from Batna city, and partially treated through water treatment station. The best rates of water saturation and infiltration as well as abundance of earthworms were recorded at sites characterized by irrigation with wastewaters downstream of El Gourzi effluent. PCA characterizes two major groups: a group of hydrodynamic infiltration parameters and structural index stability of soil, explained by fields irrigated with wastewaters downstream of El Gourzi effluent. This group includes chemical characteristics: pH and electric conductivity. The second group is the characteristics of earthworms and includes organic matter content, active limestone levels, and Shannon Biodiversity Index.

Village-level supply reliability of surface water irrigation in rural China: effects of climate change

Science.gov (United States)

Li, Yanrong; Wang, Jinxia

2018-06-01

Surface water, as the largest part of water resources, plays an important role on China's agricultural production and food security. And surface water is vulnerable to climate change. This paper aims to examine the status of the supply reliability of surface water irrigation, and discusses how it is affected by climate change in rural China. The field data we used in this study was collected from a nine-province field survey during 2012 and 2013. Climate data are offered by China's National Meteorological Information Center which contains temperature and precipitation in the past 30 years. A Tobit model (or censored regression model) was used to estimate the influence of climate change on supply reliability of surface water irrigation. Descriptive results showed that, surface water supply reliability was 74 % in the past 3 years. Econometric results revealed that climate variables significantly influenced the supply reliability of surface water irrigation. Specifically, temperature is negatively related with the supply reliability of surface water irrigation; but precipitation positively influences the supply reliability of surface water irrigation. Besides, climate influence differs by seasons. In a word, this paper improves our understanding of the impact of climate change on agriculture irrigation and water supply reliability in the micro scale, and provides a scientific basis for relevant policy making.

Impact of earthworm activity on the chemical fertility of irrigated soil ...

African Journals Online (AJOL)

Effluents analysis showed significant organic and particulate pollution, the latter contributed to earthworm abundance and increased the richness of irrigated soils with nutrients. The analysis of turricules revealed the role of earthworms through the activity of bioturbation in the increase of the rate of organic matter as well as ...

Evaluating the impact of irrigation on surface water - groundwater interaction and stream temperature in an agricultural watershed.

Science.gov (United States)

Essaid, Hedeff I; Caldwell, Rodney R

2017-12-01

Changes in groundwater discharge to streams caused by irrigation practices can influence stream temperature. Observations along two currently flood-irrigated reaches in the 640-square-kilometer upper Smith River watershed, an important agricultural and recreational fishing area in west-central Montana, showed a downstream temperature decrease resulting from groundwater discharge to the stream. A watershed-scale coupled surface water and groundwater flow model was used to examine changes in streamflow, groundwater discharge to the stream and stream temperature resulting from irrigation practices. The upper Smith River watershed was used to develop the model framework including watershed climate, topography, hydrography, vegetation, soil properties and current irrigation practices. Model results were used to compare watershed streamflow, groundwater recharge, and groundwater discharge to the stream for three scenarios: natural, pre-irrigation conditions (PreIrr); current irrigation practices involving mainly stream diversion for flood and sprinkler irrigation (IrrCurrent); and a hypothetical scenario with only groundwater supplying sprinkler irrigation (IrrGW). Irrigation increased groundwater recharge relative to natural PreIrr conditions because not all applied water was removed by crop evapotranspiration. Groundwater storage and groundwater discharge to the stream increased relative to natural PreIrr conditions when the source of irrigation water was mainly stream diversion as in the IrrCurrent scenario. The hypothetical IrrGW scenario, in which groundwater withdrawals were the sole source of irrigation water, resulted in widespread lowering of the water table and associated decreases in groundwater storage and groundwater discharge to the stream. A mixing analysis using model predicted groundwater discharge along the reaches suggests that stream diversion and flood irrigation, represented in the IrrCurrent scenario, has led to cooling of stream temperatures

Effects of compost on soil fertility in irrigated rice growing at Kou ...

African Journals Online (AJOL)

Effects of compost on soil fertility in irrigated rice growing at Kou Valley (Burkina Faso) : Amélioration de la fertilité du sol par utilisation du compost en riziculture irriguée dans la Vallée du Kou au Burkina Faso.

Water type and irrigation time effects on microbial metabolism of a soil cultivated with Bermuda-grass Tifton 85

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Sandra Furlan Nogueira

2011-06-01

Full Text Available This study investigated the microbial metabolism in Bermuda-grass Tifton 85 areas after potable-water and effluent irrigation treatments. The experiment was carried out in Lins/SP with samples taken in the rainy and dry seasons (2006 after one year and three years of irrigation management, and set up on an entirely randomized block design with four treatments: C (control, without irrigation or fertilization, PW (potable water + 520 kg of N ha-1 year-1; TE3 and TE0 (treated effluent + 520 kg of N ha-1 year-1 for three years and one year, respectively. The parameters determined were: microbial biomass carbon, microbial activity, and metabolic quotient. Irrigation with wastewater after three years indicated no alteration in soil quality for C and ET3; for PW, a negative impact on soil quality (microbial biomass decrease suggested that water-potable irrigation in Lins is not an adequate option. Microbial activity alterations observed in TE0 characterize a priming effect.

Response of Soil Mesofauna to Long-Term Application of Feedlot Manure on Irrigated Cropland.

Science.gov (United States)

Miller, Jim J; Battigelli, Jeff P; Beasley, Bruce W; Drury, Craig F

2017-01-01

Long-term application of feedlot manure to cropland may influence soil mesofauna. These organisms affect the health, structure, and fertility of soils, organic matter decomposition, and crop growth. The objective was to study the long-term (16-17 yr) influence of feedlot manure type and bedding on soil mesofauna over 2 yr (2014-2015). Stockpiled or composted feedlot manure with straw (ST) or wood-chip (WD) bedding (plus unamended control) was annually applied (13 Mg ha dry wt.) to an irrigated clay loam soil with continuous barley (). Intact cores were taken from surface (0-5 cm) soil in the fall, and the densities of Acari (mites) suborders and Collembola (springtails) families were determined. Manure type had no significant ( > 0.05) effect on soil mesofauna density. In contrast, there was a significant two- to sixfold increase in density with WD- compared with ST-amended soils of total Acari in 2014 and 2015, as well as total Collembola, total Acari and Collembola, oribatid mites, and entomobryid springtails in 2014. The bedding effect was attributed to significantly greater soil water content and lower bulk density for WD than ST. Density of soil mesofauna was not significantly greater in amended soils than in unamended soils. A shift by feedlot producers from stockpiled to composted feedlot manure application should have no effect on soil mesofauna density, whereas a shift from ST to WD bedding may increase the density of certain soil mesofauna, which may have a beneficial effect on soil. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Using ISBA model for partitioning evapotranspiration into soil evaporation and plant transpiration of irrigated crops under semi-arid climate

Science.gov (United States)

Aouade, Ghizlane; Jarlan, Lionel; Ezzahar, Jamal; Er-raki, Salah; Napoly, Adrien; Benkaddour, Abdelfettah; Khabba, Said; Boulet, Gilles; Chehbouni, Abdelghani; Boone, Aaron

2016-04-01

MEB version simulates more accurately the crop transpiration compared to the standard version. The RMSE and R² were about 0.79 mm and 0.67 for MEB and 1.37mm and 0.65 for standard version. An in-depth analysis of the results points out : (1) a deficiency of the standard version in simulating soil evaporation, in particular after an irrigation event, that directly impact the latent heat fluxes prediction because of two much energy reaching the soil and (2) a significant improvement of the surface temperature predictions with the double energy balance version; an interesting feature in the context of data assimilation; (3) a poor parameterization of the stomatal conductance in the A-gs photosynthetic module that is corrected thanks to a stochastic parameter identification approach. Results have direct implication for the prediction of evapotranspiration and its partition over irrigated crops in semi-arid areas of the South Mediterranean region.

Optimization of modern irrigation for biosaline agriculture

International Nuclear Information System (INIS)

Shahid, S.A.; Hasbini, B.

2007-01-01

Supplementation water is a must to offset the water requirement to produce profitable crops in most arid and semiarid zones, where fresh water resources are insufficient to meet the pressure of irrigated agriculture. This necessitates the use of poor quality water resources. These waters if not properly managed and used can cause serious soil related problems (salinity, sodicity, destruction of soil structure) in addition to decline in crop yields. Biosaline agriculture (using saline water on saline soils to grow salt-tolerant crops) becomes the only option for the farmer when both soil and water resources are saline and the water resource is scarce. In this regards key design considerations must be taken into account when irrigating with salty waters to optimize water uses and to reduce subsequent soil salinity development. Sprinkler irrigation systems are commonly used in irrigation of large-scale irrigational production systems. However they tend to concentrate salts on the leaves of plants. For this reason discharge and degree of overlap between consecutive sprinkler heads, are key design parameters when applying salty waters. Trickle irrigation is the most efficient system and is gaining importance in the GCC countries in the agriculture and landscape irrigation. The objective of this study was to optimize modern irrigation systems through development of design standards for drip (emitters spacing) and sprinkler irrigation systems (single head jet and overlapping) by applying saline water. The effect of emitter spacing (drip) and overlapping (sprinkler) were tested for the formation of salt contours in soil. The leaching ratio (LR) is the overall soil sanity within rhizosphere divided by the average irrigation water salinity. In this study LR is used to evaluate the effectiveness of irrigation systems in developing soil sanity. From the present investigations it is concluded that when using saline water for irrigation, the soil sanity development can be

Determination of optimal irrigation rates of agricultural crops under consideration of soil properties and climatic conditions

Directory of Open Access Journals (Sweden)

Irakli Kruashvili

2016-09-01

Full Text Available In conditions of increasing water shortage, further development of irrigated agriculture production is impossible without improving the methods of cultivation of agricultural crops, primarily irrigation technology. In 2015 the experiment have been conducted on the territory of irrigation farming area of village Tamarisi (Marneuli Municipality, according to which comprehensive study of local climatic and soil conditions were conducted. Received data were used for computation crop water requirements for tomato and melon under the different irrigation treatments. Obtained results have shown the possibility of water use efficiency and obtaining sufficiently high yields of crops that participated in the experiment that became possible in a case of usage of drip irrigation technology in combination with plastic mulch.

[Three-dimension temporal and spatial dynamics of soil water for the artificial vegetation in the center of Taklimakan desert under saline water drip-irrigation].

Science.gov (United States)

Ding, Xin-yuan; Zhou, Zhi-bin; Xu, Xin-wen; Lei, Jia-qiang; Lu, Jing-jing; Ma, Xue-xi; Feng, Xiao

2015-09-01

Three-dimension temporal and spatial dynamics of the soil water characteristics during four irrigating cycles of months from April to July for the artificial vegetation in the center of Taklimakan Desert under saline water drip-irrigation had been analyzed by timely measuring the soil water content in horizontal and vertical distances 60 cm and 120 cm away from the irrigating drips, respectively. Periodic spatial and temporal variations of soil water content were observed. When the precipitation effect was not considered, there were no significant differences in the characteristics of soil water among the irrigation intervals in different months, while discrepancies were obvious in the temporal and spatial changes of soil moisture content under the conditions of rainfall and non-rainfall. When it referred to the temporal changes of soil water, it was a little higher in April but a bit lower in July, and the soil water content in June was the highest among four months because some remarkable events of precipitation happened in this month. However, as a whole, the content of soil moisture was reduced as months (from April to July) went on and it took a decreasing tendency along with days (1-15 d) following a power function. Meanwhile, the characteristics of soil water content displayed three changeable stages in an irrigation interval. When it referred to the spatial distributions of soil water, the average content of soil moisture was reduced along with the horizontal distance following a linear regression function, and varied with double peaks along with the vertical distance. In addition, the spatial distribution characteristics of the soil water were not influenced by the factors of precipitation and irrigating time but the physical properties of soil.

Effects of deficit drip-irrigation scheduling regimes with saline water on pepper yield, water productivity and soil salinity under arid conditions of Tunisia

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Kamel Nagaz

2012-12-01

Full Text Available A two-year study was carried out in order to assess the effects of different irrigation scheduling regimes with saline water on soil salinity, yield and water productivity of pepper under actual commercial-farming conditions in the arid region of Tunisia. Pepper was grown on a sandy soil and drip-irrigated with water having an ECi of 3.6 dS/m. Irrigation treatments consisted in water replacements of accumulated ETc at levels of 100% (FI, full irrigation, 80% (DI-80, 60% (DI-60, when the readily available water in the control treatment (FI is depleted, deficit irrigation during ripening stage (FI-MDI60 and farmer method corresponding to irrigation practices implemented by the local farmers (FM. Results on pepper yield and soil salinity are globally consistent between the two-year experiments and shows significant difference between irrigation regimes. Higher soil salinity was maintained over the two seasons, 2008 and 2009, with DI-60 and FM treatments than FI. FI-MDI60 and DI-80 treatments resulted also in low ECe values. Highest yields for both years were obtained under FI (22.3 and 24.4 t/ha although we didn’t find significant differences with the regulated deficit irrigation treatment (FI-DI60. However, the DI-80 and DI-60 treatments caused significant reductions in pepper yields through a reduction in fruits number/m² and average fruit weight in comparison with FI treatment. The FM increased soil salinity and caused significant reductions in yield with 14 to 43%, 12 to 39% more irrigation water use than FI, FI-MDI60 and DI-80 treatments, respectively, in 2008 and 2009. Yields for all irrigation treatments were higher in the second year compared to the first year. Water productivity (WP values reflected this difference and varied between 2.31 and 5.49 kg/m3. The WP was found to vary significantly among treatments, where the highest and the lowest values were observed for DI-60 treatment and FM, respectively. FI treatment provides

Revegetation of coal mine soil with forest litter

Energy Technology Data Exchange (ETDEWEB)

Day, A.D.; Ludeke, K.L.; Thames, J.L.

1986-11-01

Forest litter, a good source of organic matter and seeds, was applied on undisturbed soil and on coal mine (spoils) in experiments conducted on the Black Mesa Coal Mine near Kayenta, Arizona over a 2-year period (1977-1978). Germination, seedling establishment, plant height and ground cover were evaluated for two seeding treatments (forest litter and no forest litter) and two soil moisture treatments (natural rainfall and natural rainfall plus irrigation). The forest litter was obtained at random from the Coconino National Forest, broadcast over the surface of the soil materials and incorporated into the surface 5 cm of each soil material. Germination, seedling establishment, plant height and ground cover on undisturbed soil and coal mine soil were higher when forest litter was applied than when it was not applied and when natural rainfall was supplemented with sprinkler irrigation than when rainfall was not supplemented with irrigation. Applications of forest litter and supplemental irrigation may ensure successful establishment of vegetation on areas disturbed by open-pit coal mining.

Estimation of soil salinity in a drip irrigation system by using joint inversion of multicoil electromagnetic induction measurements

KAUST Repository

Jadoon, Khan Zaib; Moghadas, Davood; Jadoon, Aurangzeb; Missimer, Thomas M.; Al-Mashharawi, Samir K.; McCabe, Matthew

2015-01-01

-Explorer) is used for subsurface characterization of soil salinity in a drip irrigation system via a joint inversion approach of multiconfiguration EMI measurements. EMI measurements were conducted across a farm where Acacia trees are irrigated with brackish water

Effects of soil texture and drought stress on the uptake of antibiotics and the internalization of Salmonella in lettuce following wastewater irrigation

International Nuclear Information System (INIS)

Zhang, Yuping; Sallach, J. Brett; Hodges, Laurie; Snow, Daniel D.; Bartelt-Hunt, Shannon L.; Eskridge, Kent M.; Li, Xu

2016-01-01

Treated wastewater is expected to be increasingly used as an alternative source of irrigation water in areas facing fresh water scarcity. Understanding the behaviors of contaminants from wastewater in soil and plants following irrigation is critical to assess and manage the risks associated with wastewater irrigation. The objective of this study was to evaluate the effects of soil texture and drought stress on the uptake of antibiotics and the internalization of human pathogens into lettuce through root uptake following wastewater irrigation. Lettuce grown in three soils with variability in soil texture (loam, sandy loam, and sand) and under different levels of water stress (no drought control, mild drought, and severe drought) were irrigated with synthetic wastewater containing three antibiotics (sulfamethoxazole, lincomycin and oxytetracycline) and one Salmonella strain a single time prior to harvest. Antibiotic uptake in lettuce was compound-specific and generally low. Only sulfamethoxazole was detected in lettuce with increasing uptake corresponding to increasing sand content in soil. Increased drought stress resulted in increased uptake of lincomycin and decreased uptake of oxytetracycline and sulfamethoxazole. The internalization of Salmonella was highly dependent on the concentration of the pathogen in irrigation water. Irrigation water containing 5 Log CFU/mL Salmonella resulted in limited incidence of internalization. When irrigation water contained 8 Log CFU/mL Salmonella, the internalization frequency was significantly higher in lettuce grown in sand than in loam (p = 0.009), and was significantly higher in lettuce exposed to severe drought than in unstressed lettuce (p = 0.049). This work demonstrated how environmental factors affected the risk of contaminant uptake by food crops following wastewater irrigation. - Highlights: • Higher sand content in soil caused higher internalization of sulfamethoxazole and Salmonella in lettuce. • Drought

Unsaturated flow dynamics during irrigation with wastewater: field and modelling study

Science.gov (United States)

Martinez-Hernandez, V.; de Miguel, A.; Meffe, R.; Leal, M.; González-Naranjo, V.; de Bustamante, I.

2012-04-01

To deal with water scarcity combined with a growing water demand, the reuse of wastewater effluents of wastewater treatment plants (WWTP) for industrial and agricultural purposes is considered as a technically and economically feasible solution. In agriculture, irrigation with wastewater emerges as a sustainable practice that should be considered in such scenarios. Water infiltration, soil moisture storage and evapotranspiration occurring in the unsaturated zone are fundamental processes that play an important role in soil water balance. An accurate estimation of unsaturated flow dynamics (during and after irrigation) is essential to improve wastewater management (i.e. estimating groundwater recharge or maximizing irrigation efficiency) and to avoid possible soil and groundwater affections (i.e. predicting contaminant transport). The study site is located in the Experimental Plant of Carrión de los Céspedes (Seville, Spain). Here, treated wastewater is irrigated over the soil to enhance plants growth. To obtain physical characteristics of the soil (granulometry, bulk density and water retention curve), soil samples were collected at different depths. A drain gauge passive capillary lysimeter was installed to determine the volume of water draining from the vadose zone. Volumetric water content of the soil was monitored by measuring the dielectric constant using capacitance/frequency domain technology. Three soil moisture probes were located at different depths (20, 50 and 70 cm below the ground surface) to control the variation of the volumetric water content during infiltration. The main aim of this study is to understand water flow dynamics through the unsaturated zone during irrigation by using the finite element model Hydrus-1D. The experimental conditions were simulated by a 90 cm long, one dimensional solution domain. Specific climatic conditions, wastewater irrigation rates and physical properties of the soil were introduced in the model as input parameters

TRANSPORT OF SOLUTES IN THE FIELD AS AFFECTED BY IRRIGATION

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Alessandro Comegna

2007-09-01

Full Text Available This study documents and compares the transport of a conservative solute in near saturated soil profiles under flood and sprinkler irrigation. The experiments were carried out on a clay Vertic-Usthortens soil located near Potenza (Italy. Two 2x2 m2 plots were clipped of their native grass vegetation. After spraying on the surface a Cl- pulse as KCl salt; water was applied in five increments over two months as flood irrigation on the first plot and as sprinkler irrigation on the second one. Chloride resident concentration Cr, was sampled by soil coring at four different days after chemical application. Cr(z,t profiles were analyzed by spatial moment method. The recovered mass of Cl- and location of center of mass were comparable for the two types of irrigation. The spread around the center of mass, however, was higher for the flood-irrigated plot. In the flood-irrigated plot, more mass leached below the depth of 90 cm. The velocity of the center of mass was consistently 10-20% larger than the piston displacement velocity. To evaluate the nature of transport, the Cr(z,t distributions were modelled using quasi-steady solution of convection-dispersion equation(CDE. At the scale of our experiments the profiles of Cl- resident concentration are well-simulated.

New Approaches to Irrigation Scheduling of Vegetables

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Michael D. Cahn

2017-04-01

Full Text Available Using evapotranspiration (ET data for scheduling irrigations on vegetable farms is challenging due to imprecise crop coefficients, time consuming computations, and the need to simultaneously manage many fields. Meanwhile, the adoption of soil moisture monitoring in vegetables has historically been limited by sensor accuracy and cost, as well as labor required for installation, removal, and collection of readings. With recent improvements in sensor technology, public weather-station networks, satellite and aerial imaging, wireless communications, and cloud computing, many of the difficulties in using ET data and soil moisture sensors for irrigation scheduling of vegetables can now be addressed. Web and smartphone applications have been developed that automate many of the calculations involved in ET-based irrigation scheduling. Soil moisture sensor data can be collected through wireless networks and accessed using web browser or smartphone apps. Energy balance methods of crop ET estimation, such as eddy covariance and Bowen ratio, provide research options for further developing and evaluating crop coefficient guidelines of vegetables, while recent advancements in surface renewal instrumentation have led to a relatively low-cost tool for monitoring crop water requirement in commercial farms. Remote sensing of crops using satellite, manned aircraft, and UAV platforms may also provide useful tools for vegetable growers to evaluate crop development, plant stress, water consumption, and irrigation system performance.

Assesing the suitability of water for irrigation theoretical and practical approach

International Nuclear Information System (INIS)

Hannan, A.; Javad, M.A.; Arif, M.; Rashid, A.

2006-01-01

Forced by the surface water shortage and prevalent drought like conditions in the country the farmers have started exploiting groundwater resource. On the other hand, seventy percent of the groundwater being marginal to unfit is a threat to the sustainability of irrigated agriculture. The judicious groundwater exploitation and application has also become imperative in context of ever increasing demographic pressure on soil, crop and water resources. Different classes of irrigation waters established by various research scientists / organizations within the country or abroad are not ultimate under all conditions but these serve as general guidelines. In some cases brackish water requires only minor modification under existing irrigation and ogronomic practices, while in most of the cases it requires major changes regarding type of crops grown, method of water application and the use of soil and water amendments. Therefore, before recommending water for irrigation. Soil characteristics, water management practices, drainage condition of the filed and climatic events must be taken into account as waters generally classified unsuitable for irrigation can be used successfully to grow crops without long term hazardous consequences to crops or soils. This can be attempted simply with the use of improved farming and management practices. Use of brackish water for irrigation may increase the resource base for irrigated agriculture in Pakistan. This article reviews various water classification schemes, salinity-crop yield interrelation with detailed discussion on brackish water application and associated problems. The article also covers a number of management options so as to mitigate the problem and sustain food security in the country. (author)

Safe and High Quality Food Production using Low Quality Waters and Improved Irrigation Systems and Management (SAFIR)

Science.gov (United States)

Cary, L.; Kloppmann, W.; Battilani, A.; Bertaki, M.; Blagojevic, S.; Chartzoulakis, K.; Dalsgaard, A.; Forslund, A.; Jovanovic, Z.; Kasapakis, I.

2009-04-01

The safe use of treated domestic wastewater for irrigation needs to address the risks for humans (workers, exposed via contact with irrigation water, soil, crops and food, consumers, exposed via ingestion of fresh and processed food), for animals (via ingestion of crops an soil), for the crops and agricultural productivity (via salinity and trace element uptake), for soil (via accumulation or release of pollutants) as well as for surface, groundwaters and the associated ecosystems (via runoff and infiltration, Kass et al., 2005, Bouwer, 2000). A work package in the EU FP5 project SAFIR is dedicated to study the impact of wastewater irrigation on the soil-water-plant-product system. Its monitoring program comprises pathogens and inorganic pollutants, including both geogenic and potentially anthropogenic trace elements in the aim to better understand soil-irrigation water interactions. The SAFIR field study sites are found in China, Italy, Crete, and Serbia. A performance evaluation of SAFIR-specific treatment technology through the monitoring of waste water and irrigation water quality was made through waste water chemical and microbiological qualities, which were investigated upstream and downstream of the SAFIR specific treatment three times per season. Irrigation water transits through the uppermost soil decimetres to the crop roots. The latter will become, in the course of the irrigation season, the major sink of percolating water, together with evaporation. The water saving irrigation techniques used in SAFIR are surface and subsurface drip irrigation. The investigation of the solid soil phase concentrates on the root zone as main transit and storage compartment for pollutants and, eventually, pathogens. The initial soil quality was assessed through a sampling campaign before the onset of the first year irrigation; the soil quality has been monitored throughout three years under cultivation of tomatoes or potatoes. The plot layout for each of the study sites

Uncertainties in modelling the climate impact of irrigation

Science.gov (United States)

de Vrese, Philipp; Hagemann, Stefan

2017-11-01

Irrigation-based agriculture constitutes an essential factor for food security as well as fresh water resources and has a distinct impact on regional and global climate. Many issues related to irrigation's climate impact are addressed in studies that apply a wide range of models. These involve substantial uncertainties related to differences in the model's structure and its parametrizations on the one hand and the need for simplifying assumptions for the representation of irrigation on the other hand. To address these uncertainties, we used the Max Planck Institute for Meteorology's Earth System model into which a simple irrigation scheme was implemented. In order to estimate possible uncertainties with regard to the model's more general structure, we compared the climate impact of irrigation between three simulations that use different schemes for the land-surface-atmosphere coupling. Here, it can be shown that the choice of coupling scheme does not only affect the magnitude of possible impacts but even their direction. For example, when using a scheme that does not explicitly resolve spatial subgrid scale heterogeneity at the surface, irrigation reduces the atmospheric water content, even in heavily irrigated regions. Contrarily, in simulations that use a coupling scheme that resolves heterogeneity at the surface or even within the lowest layers of the atmosphere, irrigation increases the average atmospheric specific humidity. A second experiment targeted possible uncertainties related to the representation of irrigation characteristics. Here, in four simulations the irrigation effectiveness (controlled by the target soil moisture and the non-vegetated fraction of the grid box that receives irrigation) and the timing of delivery were varied. The second experiment shows that uncertainties related to the modelled irrigation characteristics, especially the irrigation effectiveness, are also substantial. In general the impact of irrigation on the state of the land

Total Contents and Sequential Extraction of Heavy Metals in Soils Irrigated with Wastewater, Akaki, Ethiopia

Science.gov (United States)

Fitamo, Daniel; Itana, Fisseha; Olsson, Mats

2007-02-01

The Akaki River, laden with untreated wastes from domestic, industrial, and commercial sources, serves as a source of water for irrigating vegetable farms. The purpose of this study is to identify the impact of waste-water irrigation on the level of heavy metals and to predict their potential mobility and bioavailability. Zn and V had the highest, whereas Hg the lowest, concentrations observed in the soils. The average contents of As, Co, Cr, Cu, Ni, Zn, V, and Hg of both soils; and Pb and Se from Fluvisol surpassed the mean + 2 SD of the corresponding levels reported for their uncontaminated counterparts. Apparently, irrigation with waste water for the last few decades has contributed to the observed higher concentrations of the above elements in the study soils (Vertisol and Fluvisol) when compared to uncontaminated Vertisol and Fluvisol. On the other hand, Vertisol accommodated comparatively higher average levels of Cr, Cu, Ni, Zn, etc V, and Cd, whereas high contents of Pb and Se were observed in Fluvisol. Alternatively, comparable levels of Co and Hg were found in either soil. Except for Ni, Cr, and Cd in contaminated Vertisol, heavy metals in the soils were not significantly affected by the depth (0-20 and 30-50 cm). When the same element from the two soils was compared, the levels of Cr, Cu, Ni, Pb, Se, Zn, V, Cd at 0-20 cm; and Cr, Ni, Cu, Cd, and Zn at 30-50 cm were significantly different. Organic carbon (in both soils), CEC (Fluvisol), and clay (Vertisol) exhibited significant positive correspondences with the total heavy metal levels. Conversely, Se and Hg contents revealed perceptible associations with carbonate and pH. The exchangeable fraction was dominated by Hg and Cd, whereas the carbonate fraction was abounded with Cd, Pb, and Co. conversely, V and Pb displayed strong affinity to reducible fraction, where as Cr, Cu, Zn, and Ni dominated the oxidizable fraction. Cr, Hg, Se, and Zn (in both soils) showed preference to the residual fraction

Nutritional responses to soil drying and rewetting cycles under partial root-zone drying irrigation

DEFF Research Database (Denmark)

Wang, Yaosheng; Jensen, Christian Richardt; Liu, Fulai

2017-01-01

signaling that regulates stomatal aperture. PRI induced soil DRW cycles and more soil water dynamics in the root zone enhance soil nutrient mineralization process and thus increase the bioavailability of soil nutrients, resulting in improved nitrogen (N) and phosphorus (P) uptake, in which soil microbial...... processes play a key role. Studies investigating how soil DRW cycles and water dynamics under PRI on nutrient transport in soil solution, soil microbe mediated P transformation, interactions between phytohormones and nutrient uptake, root morphological and architectural traits for nutrient acquisition......Abstract Repeated soil drying and rewetting (DRW) cycles occur in rainfed and irrigated agriculture. The intensity and frequency of DRW cycles regulate both microbial physiology and soil physical processes, hereby affecting the mineralization and immobilization of soil nutrients...

Calibration Curve of Neutron Moisture Meter for Sandy Soil under Drip Irrigation System

International Nuclear Information System (INIS)

Mohammad, Abd El- Moniem M.; Gendy, R. W.; Bedaiwy, M. N.

2004-01-01

The aim of this work is to construct a neutron calibration curve in order to be able to use the neutron probe in sandy soils under drip irrigation systems. The experimental work was conducted at the Soil and Water Department of the Nuclear Research Center, Atomic Energy Authority. Three replicates were used along the lateral lines of the drip irrigation system. For each dripper, ten neutron access tubes were installed to 100-cm depth at distances of 5, 15 and 25 cm from the dripper location around the drippers on the lateral line, as well as between lateral lines. The neutron calibrations were determined at 30, 45, and 60-cm depths. Determining coefficients as well as t-test in pairs were employed to detect the accuracy of the calibrations. Results indicated that in order for the neutron calibration curve to express the whole wet area around the emitter; three-access tubes must be installed at distances of 5, 15, and 25 cm from the emitter. This calibration curve will be correlating the average count ratio (CR) at the studied soil depth of the three locations (5, 15, and 25-cm distances from the emitter) to the average moisture content (θ) for this soil depth of the entire wetted area. This procedure should be repeated at different times in order to obtain different θ and C.R values, so that the regression equation of calibration curve at this soil depth can be obtained. To determine the soil moisture content, the average CR of the three locations must be taken and substituted into the regression equation representing the neutron calibration curve. Results taken from access tubes placed at distances of 15 cm from the emitter, showed good agreement with the average calibration curve both for the 45- and the 60-cm depths, suggesting that the 15-cm distance may provide a suitable substitute for the simultaneous use of the three different distances of 5, 15 and 25 cm. However, the obtained results show also that the neutron calibration curves of the 30-cm depth for

Effects of arbuscular mycorrhizae on tomato yield, nutrient uptake, water relations, and soil carbon dynamics under deficit irrigation in field conditions.

Science.gov (United States)

Bowles, Timothy M; Barrios-Masias, Felipe H; Carlisle, Eli A; Cavagnaro, Timothy R; Jackson, Louise E

2016-10-01

Plant strategies to cope with future droughts may be enhanced by associations between roots and soil microorganisms, including arbuscular mycorrhizal (AM) fungi. But how AM fungi affect crop growth and yield, together with plant physiology and soil carbon (C) dynamics, under water stress in actual field conditions is not well understood. The well-characterized mycorrhizal tomato (Solanum lycopersicum L.) genotype 76R (referred to as MYC+) and the mutant nonmycorrhizal tomato genotype rmc were grown in an organic farm with a deficit irrigation regime and control regime that replaced evapotranspiration. AM increased marketable tomato yields by ~25% in both irrigation regimes but did not affect shoot biomass. In both irrigation regimes, MYC+ plants had higher plant nitrogen (N) and phosphorus (P) concentrations (e.g. 5 and 24% higher N and P concentrations in leaves at fruit set, respectively), 8% higher stomatal conductance (gs), 7% higher photosynthetic rates (Pn), and greater fruit set. Stem water potential and leaf relative water content were similar in both genotypes within each irrigation regime. Three-fold higher rates of root sap exudation in detopped MYC+ plants suggest greater capacity for water uptake through osmotic driven flow, especially in the deficit irrigation regime in which root sap exudation in rmc was nearly absent. Soil with MYC+ plants also had slightly higher soil extractable organic C and microbial biomass C at anthesis but no changes in soil CO2 emissions, although the latter were 23% lower under deficit irrigation. This study provides novel, field-based evidence for how indigenous AM fungi increase crop yield and crop water use efficiency during a season-long deficit irrigation and thus play an important role in coping with increasingly limited water availability in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

Physical-chemical effects of irrigation with treated wastewater on Dusky Red Latosol soil

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Vanessa Ribeiro Urbano

2015-11-01

Full Text Available The current water crisis underlines the importance of improving water management. The use of effluent from secondary treatment in agriculture can reduce the discharge of effluent into natural bodies and provide nutrients to crops. This study evaluated the physical and chemical properties of a Dusky Red Latosol soil that had been irrigated with treated wastewater. Conducted at the Center of Agricultural Sciences (CCA of Federal University of São Carlos (UFSCar, in Araras/São Paulo/Brazil, 18 undisturbed soil samples were collected and deposited on a constant-head permeameter in order to simulate the irrigation of five growth cycles of lettuce (Lactuca sativa L., organized in five different treatments and one control group. For each treatment 0.58 L, 1.16 L, 1.74 L, 2.32 L, and 2.90 L of treated wastewater and distilled water were applied . The treated wastewater came from a domestic waste treatment plant. After the water filtered through the soil, samples of treated wastewater were collected for analyses of electrical conductivity (EC, sodium adsorption ratio (SAR, turbidity, pH, Na, K, Mg, P and Ca and, in the soil the granulometry, complete fertility, exchangeable sodium percentage (ESP and saturated hydraulic conductivity (Ksat. The Ksat decreased, but did not alter the infiltration of water and nutrients in the soil. The concentration of nutrients in the soil increased, including Na, which raises the need for monitoring soil’s salinity. In conclusion, the application of wastewater did not cause damage to the physical properties of the soil, but resulted in a tendency towards salinization.

Field Comparison of Fertigation Vs. Surface Irrigation of Cotton Crop

International Nuclear Information System (INIS)

Janat, M.

2004-01-01

Based on previous results of the same nature, one nitrogen rate 180 kg N ha -1 was tested under two-irrigation methods, surface irrigation and drip fertigation of cotton (Cultivar Rakka-5) for two consecutive seasons 2000 and 2001. The study aimed to answer various questions regarding the applicability of drip fertigation at farm level and the effect of its employment on yield and growth parameters, compared to surface irrigation. Nitrogen fertilizer was either injected in eight equally split applications for the drip fertigated cotton or divided in four unequally split applications as recommend by Ministry of Agriculture (20% before planting, 40% at thinning, 20% after 60 days from planting and 20% after 75 days after planting). 15 N labeled urea was used to evaluate nitrogen fertilizer efficiency. The experimental design was randomized block design with seven replicates. Results showed that drip fertigation led to water saving exceeding 50% in some cases. Field germination percentage was highly increased under drip- fertigated cotton relative to surface-irrigated cotton. Dry matter and seed cotton yield of surface-irrigated cotton was slightly higher than that of drip-fertigated cotton in the first growing season. The reason for that was due to the hot spill that occurred in the region, which exposed the cotton crop to water stress and consequently pushed the cotton into early flowering. Lint properties were not affected by the introduction of drip-fertigation. Actually some properties were improved relative to the standard properties identified by the cotton Bureau.Nitrogen uptake was slightly increased under drip fertigation whereas nitrogen use efficiencies were not constant along the growing seasons. The reason for that could be lateral leaching and root proliferation into the labeled and unlabeled subplots. Field water use efficiency was highly increased for both growing seasons under drip fertigation practice. The rate of field water use efficiencies

Long-term fate of exogenous metals in a sandy Luvisol subjected to intensive irrigation with raw wastewater

International Nuclear Information System (INIS)

Dere, C.; Lamy, I.; Jaulin, A.; Cornu, S.

2007-01-01

From 1899 to 2002, sandy Luvisol in the Paris region has been intensively irrigated with raw wastewater, resulting in major soil pollution by metallic trace elements (MTE). To identify the soil phases implicated in retaining these metals, sequential extractions were performed on a solum irrigated with untreated wastewater and another reference solum. The endogenous and exogenous fractions of MTE in the contaminated soil were discriminated using correlations between MTE and major elements defined from unpolluted soils of the area. In the contaminated soil no exogenous lead and chromium are present below the surface horizon, whereas exogenous zinc and copper are found down to the base of the solum. The endogenous MTE are mainly found in the residual fraction. Exogenous MTE appear to be associated with organic matter in the surface horizon, and exogenous zinc seems to be readsorbed on iron and manganese oxyhydroxides in the underlying horizons. - After 100 years of intensive irrigation with wastewater, no exogenous Pb and Cr are found in the subsoil, while exogenous Zn and Cu are found down to the base of the solum, mostly readsorbed

Tritium dynamics in soils and plants grown under three irrigation regimes at a tritium processing facility in Canada

International Nuclear Information System (INIS)

Mihok, S.; Wilk, M.; Lapp, A.; St-Amant, N.; Kwamena, N.-O.A.; Clark, I.D.

2016-01-01

The dynamics of tritium released from nuclear facilities as tritiated water (HTO) have been studied extensively with results incorporated into regulatory assessment models. These models typically estimate organically bound tritium (OBT) for calculating public dose as OBT itself is rarely measured. Higher than expected OBT/HTO ratios in plants and soils are an emerging issue that is not well understood. To support the improvement of models, an experimental garden was set up in 2012 at a tritium processing facility in Pembroke, Ontario to characterize the circumstances under which high OBT/HTO ratios may arise. Soils and plants were sampled weekly to coincide with detailed air and stack monitoring. The design included a plot of native grass/soil, contrasted with sod and vegetables grown in barrels with commercial topsoil under natural rain and either low or high tritium irrigation water. Air monitoring indicated that the plume was present infrequently at concentrations of up to about 100 Bq/m"3 (the garden was not in a major wind sector). Mean air concentrations during the day on workdays (HTO 10.3 Bq/m"3, HT 5.8 Bq/m"3) were higher than at other times (0.7–2.6 Bq/m"3). Mean Tissue Free Water Tritium (TFWT) in plants and soils and OBT/HTO ratios were only very weakly or not at all correlated with releases on a weekly basis. TFWT was equal in soils and plants and in above and below ground parts of vegetables. OBT/HTO ratios in above ground parts of vegetables were above one when the main source of tritium was from high tritium irrigation water (1.5–1.8). Ratios were below one in below ground parts of vegetables when irrigated with high tritium water (0.4–0.6) and above one in vegetables rain-fed or irrigated with low tritium water (1.3–2.8). In contrast, OBT/HTO ratios were very high (9.0–13.5) when the source of tritium was mainly from the atmosphere. TFWT varied considerably through time as a result of SRBT's operations; OBT/HTO ratios showed no clear

Monitoring of soil chemical characteristics with time as affected by irrigation with saline water

International Nuclear Information System (INIS)

Mostafa, A. Z.; Galal, Y.G.M.; Lotfy, S.M.

2012-01-01

A lysimeter study was conducted to investigate the effect of irrigation with saline water on soil chemical characteristics at two depth (0-20) and (20-40 cm).Both fertilized (60, 120 KgN/ha) and unfertilized (0) soil were simulated in a total of 84 lysimeter. Data indicated that the electric conductivity (EC) values tended to increase with time intervals also EC-values as affected by soil depth after 105 days were high in 20 cm depth as compared to 40 cm depth. Chloride concentration did not reflect great variations as affected by time of nitrogen application where the values were nearly closed to each other. At the end of the experiment, much of Cl - content was occurred in the second layer of soil depth (20-40) as compared to depth of 0-20 cm. This was the case under all salinity levels. The irrigation with fresh water did not reflect any significant different in EC values between 120 KgN/ha , 60 KgN/ha or soil depth, however, it tend to increase with increasing water salinity levels. There were no much differences between the nitrogen application time (T1, T2 and T3). In contrast with Cl - , sodium was remained in the upper layer of 0-20 cm soil depth but still increase with increasing water salinity levels.

Heavy metal accumulation in soils and grains, and health risks associated with use of treated municipal wastewater in subsurface drip irrigation

Science.gov (United States)

Asgari, Kamran; Najafi, Payam; Cornelis, Wim M.

2014-05-01

Constant use of treated wastewater for irrigation over long periods may cause buildup of heavy metals up to toxic levels for plants, animals, and entails environmental hazards in different aspects. However, application of treated wastewater on agricultural land might be an effective and sustainable strategy in arid and semi-arid countries where fresh water resources are under great pressure, as long as potential harmful effects on the environment including soil, plants, and fresh water resources, and health risks to humans are minimized. The aim of this study was to assess the effect of using a deep emitter installation on lowering the potential heavy metal accumulation in soils and grains, and health risk under drip irrigation with treated municipal wastewater. A field experiment was conducted according to a split block design with two treatments (fresh and wastewater) and three sub treatments (0, 15 and 30 cm depth of emitters) in four replicates on a sandy loam soil, in Esfahan, Iran. The annual rainfall is about 123 mm, mean annual ETo is 1457 mm, and the elevation is 1590 m a.s.l.. A two-crop rotation of wheat [Triticum spp.] and corn [Zea mays]) was established on each plot with wheat growing from February to June and corn from July to September. Soil samples were collected before planting (initial value) and after harvesting (final value) for each crop in each year. Edible grain samples of corn and wheat were also collected. Elemental concentrations (Cu, Zn, Cd, Pb, Cr, Ni) in soil and grains were determined using an atomic absorption spectrophotometer. The concentrations of heavy metals in the wastewater-irrigated soils were not significantly different (P>0.05) compared with the freshwater-irrigated soils. The results showed no significant difference (P>0.05) of soil heavy metal content between different depths of emitters. A pollution load index PLI showed that there was not substantial buildup of heavy metals in the wastewater-irrigated soils compared to

Light Gray Surface-Gleyed Loamy Sandy Soils of the Northern Part of Tambov Plain: Agroecology, Properties, and Diagnostics

Science.gov (United States)

Zaidel'man, F. R.; Stepantsova, L. V.; Nikiforova, A. S.; Krasin, V. N.; Dautokov, I. M.; Krasina, T. V.

2018-04-01

Light gray soils of Tambov oblast mainly develop from sandy and loamy sandy parent materials; these are the least studied soils in this region. Despite their coarse texture, these soils are subjected to surface waterlogging. They are stronger affected by the agrogenic degradation in comparison with chernozems and dark gray soils. Morphology, major elements of water regime, physical properties, and productivity of loamy sandy light gray soils with different degrees of gleyzation have been studied in the northern part of Tambov Plain in order to substantiate the appropriate methods of their management. The texture of these soils changes at the depth of 70-100 cm. The upper part is enriched in silt particles (16-30%); in the lower part, the sand content reaches 80-85%. In the nongleyed variants, middle-profile horizons contain thin iron-cemented lamellae (pseudofibers); in surface-gleyed variants, iron nodules are present in the humus horizon. The removal of clay from the humus horizon and its accumulation at the lithological contact and in pseudofibers promote surface subsidence and formation of microlows in the years with moderate and intense winter precipitation. The low range of active moisture favors desiccation of the upper horizons to the wilting point in dry years. The yield of cereal crops reaches 3.5-4.5 t/ha in the years with high and moderate summer precipitation on nongleyed and slightly gleyed light gray soils and decreases by 20-50% on strongly gleyed light gray soils. On light gray soils without irrigation, crop yields are unstable, and productivity of pastures is low. High yields of cereals and vegetables can be obtained on irrigated soils. In this case, local drainage measures should be applied to microlows; liming can be recommended to improve soil productivity.

Deficit irrigation and fertilization strategies to improve soil quality and alfalfa yield in arid and semi-arid areas of northern China.

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Jia, Qianmin; Kamran, Muhammad; Ali, Shahzad; Sun, Lefeng; Zhang, Peng; Ren, Xiaolong; Jia, Zhikuan

2018-01-01

In the arid and semi-arid areas of northern China, overexploitation of fertilizers and extensive irrigation with brackish groundwater have led to soil degradation and large areas of farmland have been abandoned. In order to improve the soil quality of abandoned farmland and make reasonable use of brackish groundwater, we conducted field trials in 2013 and 2014. In our study, we used three fertilization modes (CF, chemical fertilizer; OM, organic manure and chemical fertilizer; NF, no fertilizer) and three deficit irrigation levels (I 0 : 0 mm; I 75 : 75 mm; I 150 : 150 mm). The results showed that the activities of soil urease, alkaline phosphatase, invertase, catalase, and dehydrogenase in the OM treatment were significantly improved compared with those in the CF and NF treatments under the three deficit irrigation levels. Compared with NF, the OM treatment significantly increased soil organic carbon (SOC), water-soluble carbon (WSC), total nitrogen, microbial biomass carbon and nitrogen (MBC and MBN), and soil respiration rate, and significantly decreased soil C:N and MBC:MBN ratios and the metabolic quotient, thus improving the soil quality of abandoned farmland. Furthermore, the OM treatment increased alfalfa plant height, leaf area index, leaf chlorophyll content, and biomass yield. Under the CF and OM fertilization modes, the activities of urease and catalase in I 150 were significantly higher than those in I 0 , whereas irrigating without fertilizer did not significantly increase the activity of these two enzymes. Regardless of fertilization, alkaline phosphatase activity increased with an increase in irrigation amount, whereas invertase activity decreased. The results showed that deficit irrigation with brackish groundwater under the OM treatment can improve soil quality. Over the two years of the study, maximum SOC, total nitrogen, WSC, MBC, and MBN were observed under the OM-I 150 treatment, and the alfalfa biomass yield of this treatment was also

Deficit irrigation and fertilization strategies to improve soil quality and alfalfa yield in arid and semi-arid areas of northern China

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Qianmin Jia

2018-02-01

Full Text Available Background In the arid and semi-arid areas of northern China, overexploitation of fertilizers and extensive irrigation with brackish groundwater have led to soil degradation and large areas of farmland have been abandoned. In order to improve the soil quality of abandoned farmland and make reasonable use of brackish groundwater, we conducted field trials in 2013 and 2014. Methods In our study, we used three fertilization modes (CF, chemical fertilizer; OM, organic manure and chemical fertilizer; NF, no fertilizer and three deficit irrigation levels (I0: 0 mm; I75: 75 mm; I150: 150 mm. Results The results showed that the activities of soil urease, alkaline phosphatase, invertase, catalase, and dehydrogenase in the OM treatment were significantly improved compared with those in the CF and NF treatments under the three deficit irrigation levels. Compared with NF, the OM treatment significantly increased soil organic carbon (SOC, water-soluble carbon (WSC, total nitrogen, microbial biomass carbon and nitrogen (MBC and MBN, and soil respiration rate, and significantly decreased soil C:N and MBC:MBN ratios and the metabolic quotient, thus improving the soil quality of abandoned farmland. Furthermore, the OM treatment increased alfalfa plant height, leaf area index, leaf chlorophyll content, and biomass yield. Under the CF and OM fertilization modes, the activities of urease and catalase in I150 were significantly higher than those in I0, whereas irrigating without fertilizer did not significantly increase the activity of these two enzymes. Regardless of fertilization, alkaline phosphatase activity increased with an increase in irrigation amount, whereas invertase activity decreased. Discussion The results showed that deficit irrigation with brackish groundwater under the OM treatment can improve soil quality. Over the two years of the study, maximum SOC, total nitrogen, WSC, MBC, and MBN were observed under the OM-I150 treatment, and the alfalfa

Nuclear techniques in flower production. Soil and irrigation fertility

International Nuclear Information System (INIS)

2001-01-01

Bad soil management; the nutrients and water used in ornamental cultivation are the cause for considerable reductions in productivity here in Ecuador. It's essential to take measures to reduce the accumulation of salts and the degeneration of soils to minimum, and to put back those nutrients that have been exported by the harvesting of ornamental crops. In this way we can maintain an ecologically, socially and economically sustainable flower industry. Nuclear techniques such as radioisotopes and stable isotopes are used to track the final destination of the fertilizers that have been applied to the soil and to determine the availability of these for plants. The Ecuadorian Atomic Energy Commission (CEEA) in collaboration with the Central University of Ecuador have carried out studies using the isotopic tracers Nitrogen 15 (N-15), Phosforus 32 (P-32), Rubide-85 (Rb-85) as tracers for Potassium (K). These studies have shown that only a part of the nigrogenized fertilizer applied to the soil is useful in the growing of roses, and a large part of the nitrogen escapes in the the environment thereby contaminating the water table in the form of nitrites, depending on he way and the time of year that the fertilizer has been applied. The best form of fertilizer in rose growing for example is with the nitrogen, phosphorus, potassium and other nutrients in fractioned from always using fertilized irrigation with a dose of 1300 kg of N, 200 Kg of P, 1600 kg of K per hectare/year. This differs form norm in plantations where a weekly-fertilized irrigation is used whilst on other days only watering is used. A 30% increase in production was achieved with a 50% increase in the absorption of nitrogen and a 40% increase in potassium. These studies have shown the tremendous cost saving in terms of the importing of fertilizers, as well as the decrease in the use of contaminating fertilizers. (The author)

Management of poor quality irrigation water

International Nuclear Information System (INIS)

Change, M.H.; Leghari, A.M.; Sipio, Q.A.

2000-01-01

The effect of poor quality drainage effluent on moderately saline sodic, medium textured soil at different growth stages of wheat and cotton is reported. The irrigation treatments were: I) All canal irrigations, II) one irrigation of 75 mm with saline drainage effluent (EC = 3 dS m1) after four weeks sowing of the crop, III) one irrigation of 75 mm with saline drainage effluent after seven weeks sowing of the crop, and IV) one irrigation of 75 mm with saline drainage effluent after ten weeks sowing of the crop. The treatments receiving saline water gave significant decrease in crop yields as compared to canal irrigation treatment. The higher yield of wheat and seed cotton was recorded T1 followed by T2, T3 and T4. The trend of produce was T1< T2< T3< T4 respectively. Electrical conductivity of the soil (Ece) in T1 was decreased and in other three treatments was increased, whereas, pH decreased in T1 and T2. The SAR of soil decreased in all the treatments as compared with initial values. Treatment receiving an irrigation with saline water after four weeks of sowing (T2) was better in reducing soil salinity as compared to treatments receiving such water after 7 or 10 weeks os sowing. Poor quality water (EC = 3 d Sm/sup -1/) can be managed for irrigation after four weeks of swing of crops provided certain soil and water management practices like good seed bed preparation and proper drainage measures are adopted. (author)

Impact of water quality and irrigation management on soil salinization in the Drâa valley of Morocco.

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Beff, L.; Descamps, C.; Dufey, J.; Bielders, C.

2009-04-01

Under the arid climatic conditions of the Drâa valley in southern Morocco, irrigation is essential for crop production. Two sources of water are available to farmers: (1) moderate salinity water from the Oued Drâa (classified as C3-S1 in the USDA irrigation water classification diagram) which is available only a few times per year following discrete releases from the Mansour Eddahbi dam, and (2) high salinity water from wells (C4-S2). Soil salinization is frequently observed, principally on plots irrigated with well water. As Oued water is available in insufficient amounts, strategies must be devised to use well and Oued water judiciously, without inducing severe salinization. The salinization risk under wheat production was evaluated using the HP1 program (Jacques and Šimůnek, 2005) for different combinations of the two main water sources, different irrigation frequencies and irrigation volumes. The soil was a sandy clay loam (topsoil) to sandy loam (40 cm depth). Soil hydrodynamic properties were derived from in situ measurements and lab measurements on undisturbed soil samples. The HP1 model was parameterized for wheat growth and 12 scenarios were run for 10 year periods using local climatic data. Water quality was measured or estimated on the basis of water samples in wells and various Oueds, and the soil chemical properties were determined. Depending on the scenario, soil salinity in the mean root zone increased from less than 1 meq/100g of soil to more than 5 meq/100g of soil over a ten year period. Salt accumulation was more pronounced at 45 cm soil depth, which is half of the maximum rooting depth, and when well water was preferentially used. Maximum crop yield (water transpired / potential water transpired) was achieved for five scenarios but this implied the use of well water to satisfy the crop water requirements. The usual Drâa Valley irrigation scenario, with five, 84 mm dam water applications per year, lead to a 25% yield loss. Adding the amount

Effects of irrigation regime and salinity on soil characteristics and yield of tomato

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Rita Leogrande

2012-03-01

Full Text Available A field experiment was conducted in Mediterranean conditions to evaluate the effects of different irrigation volumes and water quality on yield performance of tomato crop. The tomato crop was irrigated re-establishing 50 (I1, 75 (I2 and 100% (I3 of the crop evapotranspiration (ETc with two water quality: fresh water with EC 0.9 dS m-1 (FW and saline water with EC 6 dSm-1 (SW. At harvest, total and marketable yield, weight, number, , total soluble solids (TSS and dry matter of fruit were calculated, The results showed no statistical differences among the three different irrigation volumes on tomato yield and quality. The salinity treatment did not affect yield, probably because the soil salinity in the root zone on average remained below the threshold of tomato salt tolerance. Instead, salinity improved fruit quality parameters as dry matter and TSS by 13 and 8 %, respectively. After the first field application of saline water, soil saturated extract cations (SSEC, electrical conductivity of soil paste extract (ECe, sodium absorption ratio (SAR and exchangeable sodium percentage (ESP cations increased; the largest increase of cations, in particular of Na, occurred in the top layer. At the end of the experiment, the absolute value of SSEC, ECe and SAR, for all the effects studied, were lower than those recorded in 2007. This behavior was suitable to the reduced volumes of treatments administered in 2009 in respect to the 2007. Furthermore, the higher total rainfall recorded in 2009 increased the leaching and downward movement of salts out of the sampling depth.

Breakthrough of two pesticides into tile drain and shallow groundwater: comparison of tile drain reaction and soil profiles within a field scale irrigation experiment

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Klaus, Julian; Zehe, Erwin; Elsner, Martin; Palm, Juliane; Schneider, Dorothee; Schröder, Boris; Steinbeiss, Sibylle; West, Stephanie

2010-05-01

Preferential flow in macropores is a key process which strongly affects infiltration and may cause rapid transport of pesticides into depths of 80 to 150 cm. At these depths they experience a much slower degradation, may leach into shallow groundwater or enter a tile-drain and are transported into surface water bodies. Therefore, preferential transport might be an environmental problem, if the topsoil is bypassed, which has been originally thought to act as a filter to protect the subsoil and shallow groundwater. To investigate the behaviour of two pesticides with different chemical characteristics and to compare their transport behaviour in soil and into the tile drain an irrigation experiment was performed on a 400 m² field site. The experimental plot is located in the Weiherbach valley, south-west Germany, which basic geology consists of Loess and Keuper layers, the soil at the test site is a gleyic Colluvisol. The distance of the irrigation site to the Weiherbach brook is approximately 12 m, the field is drained with a tile-drain in about 1.2 m depth and shows discharge over the entire year. Three hours before the irrigation started, the farmer applied a pesticide solution consisting of Isoproturon (80 g) and Flufenacet (20 g) (IPU and FLU) according to conventional agricultural practice on the field plot. The irrigation took place in three time blocks (80 min, 60 min, 80 min) with in total 33.6 mm of precipitation. During the first block 1600 g of Bromide were mixed in the irrigation water. The drainage outlet was instrumented with a pressure probe. About 50 water samples ware taken during the experimental day, and several samples more the days after the experiment. They were analysed for the pesticides, bromide and water isotopes. In the two days after the experiment three soil profiles were excavated and soil samples were taken on a 10x10 cm² scheme. One week after the experiment two additional profiles were excavated. The soil was analysed for IPU, FLU

Effects of biochar, waste water irrigation and fertilization on soil properties in West African urban agriculture.

Science.gov (United States)

Häring, Volker; Manka'abusi, Delphine; Akoto-Danso, Edmund K; Werner, Steffen; Atiah, Kofi; Steiner, Christoph; Lompo, Désiré J P; Adiku, Samuel; Buerkert, Andreas; Marschner, Bernd

2017-09-06

In large areas of sub-Saharan Africa crop production must cope with low soil fertility. To increase soil fertility, the application of biochar (charred biomass) has been suggested. In urban areas, untreated waste water is widely used for irrigation because it is a nutrient-rich year-round water source. Uncertainty exists regarding the interactions between soil properties, biochar, waste water and fertilization over time. The aims of this study were to determine these interactions in two typical sandy, soil organic carbon (SOC) and nutrient depleted soils under urban vegetable production in Tamale (Ghana) and Ouagadougou (Burkina Faso) over two years. The addition of biochar at 2 kg m -2 made from rice husks and corn cobs initially doubled SOC stocks but SOC losses of 35% occurred thereafter. Both biochar types had no effect on soil pH, phosphorous availability and effective cation exchange capacity (CEC) but rice husk biochar retained nitrogen (N). Irrigation with domestic waste water increased soil pH and exchangeable sodium over time. Inorganic fertilization alone acidified soils, increased available phosphorous and decreased base saturation. Organic fertilization increased SOC, N and CEC. The results from both locations demonstrate that the effects of biochar and waste water were less pronounced than reported elsewhere.

Evaluating regional water scarcity: Irrigated crop water budgets for groundwater management in the Wisconsin Central Sands

Science.gov (United States)

Nocco, M. A.; Kucharik, C. J.; Kraft, G.

2013-12-01

Regional water scarcity dilemmas between agricultural and aquatic land users pervade the humid northern lake states of Wisconsin, Minnesota, and Michigan, where agricultural irrigation relies on groundwater drawn from shallow aquifers. As these aquifers have strong connectivity to surface waters, irrigation lowers water levels in lakes and wetlands and reduces stream discharges. Irrigation expansion has cultivated a 60-year water scarcity dilemma in The Wisconsin Central Sands, the largest irrigated region in the humid northern lake states, dedicated to potato, maize, and processing vegetable production. Irrigation has depleted Wisconsin Central Sands surface waters, lowering levels in some lakes by over 2 m and drying some coldwater trout streams. Aquatic ecosystems, property values, and recreational uses in some surface waters have been devastated. While the causal link between pumping and surface water stress is established, understanding crop-mediated processes, such as the timing and magnitude of groundwater consumption by evapotranspiration (ET) and groundwater recharge, will be useful in management of groundwater, irrigated cropping systems, and surface water health. Previous modeling and field efforts have compared irrigated crop water use to a natural reference condition on a net annual basis. As a result, we presently understand that for irrigated potatoes and maize, the average annual ET is greater and therefore, the average annual recharge is less than rainfed row crops, grasslands, and both coniferous and deciduous forests. However, we have a limited understanding of the magnitude and timing of ET and recharge from irrigated cropping systems on shorter time scales that proceed with the annual cropping cycle (i.e. planting, full canopy, harvest, residue cover). We seek to understand the spatiotemporal variability of crop water budgets and associated water scarcity in the Wisconsin Central Sands through detailed measurements of drainage (potential

Long-term no-till and stover retention each decrease the global warming potential of irrigated continuous corn.

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Jin, Virginia L; Schmer, Marty R; Stewart, Catherine E; Sindelar, Aaron J; Varvel, Gary E; Wienhold, Brian J

2017-07-01

Over the last 50 years, the most increase in cultivated land area globally has been due to a doubling of irrigated land. Long-term agronomic management impacts on soil organic carbon (SOC) stocks, soil greenhouse gas (GHG) emissions, and global warming potential (GWP) in irrigated systems, however, remain relatively unknown. Here, residue and tillage management effects were quantified by measuring soil nitrous oxide (N 2 O) and methane (CH 4 ) fluxes and SOC changes (ΔSOC) at a long-term, irrigated continuous corn (Zea mays L.) system in eastern Nebraska, United States. Management treatments began in 2002, and measured treatments included no or high stover removal (0 or 6.8 Mg DM ha -1  yr -1 , respectively) under no-till (NT) or conventional disk tillage (CT) with full irrigation (n = 4). Soil N 2 O and CH 4 fluxes were measured for five crop-years (2011-2015), and ΔSOC was determined on an equivalent mass basis to ~30 cm soil depth. Both area- and yield-scaled soil N 2 O emissions were greater with stover retention compared to removal and for CT compared to NT, with no interaction between stover and tillage practices. Methane comprised <1% of total emissions, with NT being CH 4 neutral and CT a CH 4 source. Surface SOC decreased with stover removal and with CT after 14 years of management. When ΔSOC, soil GHG emissions, and agronomic energy usage were used to calculate system GWP, all management systems were net GHG sources. Conservation practices (NT, stover retention) each decreased system GWP compared to conventional practices (CT, stover removal), but pairing conservation practices conferred no additional mitigation benefit. Although cropping system, management equipment/timing/history, soil type, location, weather, and the depth to which ΔSOC is measured affect the GWP outcomes of irrigated systems at large, this long-term irrigated study provides valuable empirical evidence of how management decisions can impact soil GHG emissions and surface

Tillage effects on soil quality after three years of irrigation in Northern Spain

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Irrigation is being initiated on large areas of traditionally rainfed land to meet increasing global demand for food, feed, fiber, and fuel. However, the consequences of this transition on soil quality (SQ) have scarcely been studied. Therefore, after previously identifying the most tillage-sensitiv...

On the control of irrigation through soil moisture measurement using a neutron depth probe in horizontal subsurface measuring circuits

International Nuclear Information System (INIS)

Schaecke, B.; Schaecke, E.

1977-01-01

An outline is given of the advantages inherent in soil moisture measurement by means of a neutron probe in horizontal subsurface measuring circuits for irrigation control. Preliminary experience for the setting up of a field calibration curve and for practical measurement are submitted. This technique includes the following advantages: almost complete covering of the upper soil range which is of interest to irrigation control; good measuring density; suitable distribution of measuring points per unit area; possibility of continuous probe passage; optimal repeatability of measurements; exploration of a unit area with but few measuring circuits; no obstacles to tillage, drilling, intercultivation and harvest operations; and complete conservation of crop and plot which is not reached with any other soil moisture measurement technique so far available. Making use of the above advantages, the new technique allows automatic irrigation control with only one neutron depth probe. (author)

Scheduling of Irrigation and Leaching Requirements

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Amer Hassan Al-haddad

2015-03-01

Full Text Available Iraq depends mainly on Tigris and Euphrates Rivers to provide high percentage of agricultural water use for thousands years. At last years, Iraq is suffering from shortage in water resources due to global climate changes and unfair water politics of the neighboring countries, which affected the future of agriculture plans for irrigation, added to that the lack of developed systems of water management in the irrigation projects and improper allocation of irrigation water, which reduces water use efficiency and lead to losing irrigation water and decreasing in agricultural yield. This study aims at studying the usability of irrigation and leaching scheduling within the irrigating projects and putting a complete annual or seasonal irrigation program as a solution for the scarcity of irrigation water, the increase of irrigation efficiency, lessening the salinity in the projects and preparing an integral irrigation calendar through field measurements of soil physical properties and chemical for project selected and compared to the results of the irrigation scheduling and leaching with what is proposed by the designers. The process is accomplished by using a computer program which was designed by Water Resources Department at the University of Baghdad, with some modification to generalize it and made it applicable to various climatic zone and different soil types. Study area represented by large project located at the Tigris River, and this project was (Al-Amara irrigation project. Sufficient samples of project's soil were collected so as to identify soil physical and chemical properties and the salinity of soil and water as well as identifying the agrarian cycles virtually applied to this project. Finally, a comparison was conducted between the calculated water quantities and the suggested ones by the designers. The research results showed that using this kind of scheduling (previously prepared irrigation and leaching scheduling with its properties

Comparison of Desertification Intensity in the Purified Wastewater Irrigated Lands with Normal Lands in Yazd Using of Soil Criterion of the IMDPA Model

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M. Yektafar

2016-09-01

the total study area. However, the intensity of desertifcation in the land irrigated with wastewater is lower than the desrtification intensity in the natural lands of the study area, but this issue caused by losing of large amounts of good quality purified wastewater and converting of a large part of the area to wetland which can craates numerous environmental problems in the region in future. Finally, it can be concluded that the natural land of the study area, are not suitable for afforestation and agriculture in present condition, and if the land is irrigatted, salinity of the soil depths transferred up to the surface and can be cause some environmental problems in thi region.

Monitoring soil coverage and yield of cowpea furrow irrigated with saline water

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Antonia Leila Rocha Neves

Full Text Available Abstract Cowpea crop is of great importance for northeast Brazil. The objective of this work was to evaluate the application of saline water in different developing stages on plant growth and changes in soil characteristics, measured by soil coverage, and on yield of cowpea plants. The experiment was conducted under field conditions, during the dry season in a completely randomized block design with five treatments and five replications. Each experimental unit consisted of 4 lines of plants with 5.0 m long. The treatments evaluated were: 1. irrigation with groundwater with electrical conductivity (ECw of 0.8 dS m-1 during the whole crop cycle; 2. saline water (5.0 dS m-1 during the whole crop cycle; 3, 4 and 5. saline water (5.0 dS m-1 up to 22nd, during 23rd to 42nd and from the 43rd to 62nd days after sowing, respectively, and groundwater in the remaining period. Soil coverage was evaluated by digital images using the software ENVI for image processing and classification. It was found that the continuous use of saline water inhibits plant growth, while irrigation with saline water during germination and initial growth stages caused retardation in plant development, but in this last case a recovery was observed in the final part of the experimental period. For treatments 2 and 3, a reduction was verified in the number of pods and in seed production, as compared to other treatments. Irrigation with saline water during 23 to 42 and 43 to 62 days after sowing did not affect reproductive and vegetative growth, but the saline water application in the pre-flowering (treatment 4 caused anticipation of the reproductive cycle.

Safety assessment of greenhouse hydroponic tomatoes irrigated with reclaimed and surface water.

Science.gov (United States)

Lopez-Galvez, Francisco; Allende, Ana; Pedrero-Salcedo, Francisco; Alarcon, Juan Jose; Gil, Maria Isabel

2014-11-17

The impact of reclaimed and surface water on the microbiological safety of hydroponic tomatoes was assessed. Greenhouse tomatoes were irrigated with reclaimed and surface water and grown on two hydroponic substrates (coconut fiber and rock wool). Water samples (n=208) were taken from irrigation water, with and without the addition of fertilizers and drainage water, and hydroponic tomatoes (n=72). Samples were analyzed for indicator microorganisms, generic Escherichia coli and Listeria spp., and pathogenic bacteria such as Salmonella spp. and Shiga-toxigenic E. coli (STEC), using multiplex real-time PCR (RT-PCR) after enrichment. The correlation between climatological parameters such as temperature and the levels of microorganisms in water samples was also determined. In irrigation water, generic E. coli counts were higher in reclaimed than in surface water whereas Listeria spp. numbers increased after adding the fertilizers in both water sources. In drainage water, no clear differences in E. coli and Listeria numbers were observed between reclaimed and surface water. No positive samples for STEC were found in irrigation water. Presumptive positives for Salmonella spp. were found in 7.7% of the water samples and 62.5% of these samples were reclaimed water. Salmonella-positive samples by RT-PCR could not be confirmed by conventional methods. Higher concentrations of E. coli were associated with Salmonella-presumptive positive samples. Climatological parameters, such as temperature, were not correlated with the E. coli and Listeria spp. counts. Tomato samples were negative for bacterial pathogens, while generic E. coli and Listeria spp. counts were below the detection limit. The prevalence of presumptive Salmonella spp. found in irrigation water (reclaimed and surface water) was high, which might present a risk of contamination. The absence of pathogens on greenhouse hydroponic tomatoes indicates that good agricultural practices (GAP) were in place, avoiding the

Compressibilidade de um solo sob sistemas de pastejo rotacionado intensivo irrigado e não irrigado Soil compressibility under non-irrigated and irrigated short duration grazing systems

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C. L. R. Lima

2004-12-01

Full Text Available O incremento da produtividade das pastagens tem sido associado ao comportamento à compressão dos solos. Os objetivos deste trabalho foram: quantificar as curvas de compressão e a pressão de preconsolidação em sistemas de pastejo intensivo rotacionado irrigado e não irrigado. Foram coletadas 96 amostras indeformadas de solo em quatro ciclos sucessivos de pastejo instalado com capim Tanzânia (Panicum maximum Jacq. em um Argissolo Vermelho. Após saturadas com água e equilibradas no potencial (psi: -10 kPa, as amostras foram pesadas e submetidas ao ensaio de compressão uniaxial com a aplicação sucessiva e contínua de pressões de 25, 50, 100, 200, 400, 600, 800, 1.000, 1.300 e 1.600 kPa. Os resultados comprovaram a hipótese de que houve diferença na compressibilidade do solo sob os sistemas de pastejo rotacionado intensivo irrigado e não irrigado. A maior compactação inicial verificada no sistema de pastejo rotacionado intensivo irrigado favoreceu o deslocamento das curvas de compressão uniaxial para valores superiores de densidade do solo. A pressão de preconsolidação foi significativamente superior no quarto ciclo de pastejo no sistema de pastejo rotacionado intensivo irrigado em relação ao sistema pastejo rotacionado intensivo não irrigado.Increment in pasture productivity has been associated with the understanding of the soil behavior under compression. The objective of this research was to quantify (a the compression curves and (b the preconsolidation pressure of the soils under non-irrigated and irrigated short duration grazing systems. Ninety-six undisturbed soil samples were taken from the four successive pasture cycles of Tanzania grass (Panicum maximum Jacq. in a Hapludalf. The samples were saturated in water and equilibrated at the matrix potential (psi: -10 kPa and then were weighed and submitted to an uniaxial compression test, applying the following pressures: 25, 50, 100, 200, 400, 600, 800, 1,000, 1,300, and

Organic fertilizer application increases the soil respiration and net ecosystem carbon dioxide absorption of paddy fields under water-saving irrigation.

Science.gov (United States)

Yang, Shihong; Xiao, Ya Nan; Xu, Junzeng

2018-04-01

Quantifying carbon sequestration in paddy soil is necessary to understand the effect of agricultural practices on carbon cycles. The objective of this study was to assess the effect of organic fertilizer addition (MF) on the soil respiration and net ecosystem carbon dioxide (CO 2 ) absorption of paddy fields under water-saving irrigation (CI) in the Taihu Lake Region of China during the 2014 and 2015 rice-growing seasons. Compared with the traditional fertilizer and water management (FC), the joint regulation of CI and MF (CM) significantly increased the rice yields and irrigation water use efficiencies of paddy fields by 4.02~5.08 and 83.54~109.97% (p < 0.05). The effects of organic fertilizer addition on soil respiration and net ecosystem CO 2 absorption rates showed inter-annual differences. CM paddy fields showed a higher soil respiration and net CO 2 absorption rates during some periods of the rice growth stage in the first year and during most periods of the rice growth stage in the second year. These fields also had significantly higher total CO 2 emission through soil respiration (total R soil ) and total net CO 2 absorption compared with FC paddy fields (p < 0.05). The total R soil and net ecosystem CO 2 absorption of CM paddy fields were 67.39~91.55 and 129.41~113.75 mol m -2 , which were 27.66~135.52 and 12.96~31.66% higher than those of FC paddy fields. The interaction between water and fertilizer management had significant effects on total net ecosystem CO 2 absorption. The frequent alternate wet-dry cycles of CI paddy fields increased the soil respiration and reduced the net CO 2 absorption. Organic fertilizer promoted the soil respiration of paddy soil but also increased its net CO 2 absorption and organic carbon content. Therefore, the joint regulation of water-saving irrigation and organic fertilizer is an effective measure for maintaining yield, increasing irrigation water use efficiency, mitigating CO 2 emission, and promoting paddy

12 years of irrigation in a drought stressed pine forest speeds up carbon cycling and alters the soil biome but has negligible effects on soil organic matter storage

Science.gov (United States)

Hagedorn, Frank; Hartmann, Martin; Brunner, Ivano; Rigling, Andreas; Herzog, Claude; Schaub, Marcus; Frey, Beat

2017-04-01

Inneralpine valleys are experiencing repeated summer droughts, which have caused a die-back of pine forests since the 1990s. Drought limits the metabolic activity and hence C cycling in the plant and soil system. The net effects of drought on soil organic matter (SOM) storage is, however, ambiguous as drought affects both C inputs and outputs. Moreover, in the long-term, water limitation is also altering above- and belowground diversity due to species-dependent resistance and adaptation to drought. In our study, we explored how ten years of irrigation of a water-limited pine forest in the central European Alps altered above- and belowground diversity and C cycling in the plant and soil systems. The decadal long irrigation during summer time strongly increased ecosystem productivity with litter fall and fine root biomass being increased by +50 and +40%, respectively. At the same time, soil CO2 efflux was stimulated by 60%, indicating that the removal of water limitation enhanced both the inputs and outputs of C into soils. The accelerated C cycling was also mirrored by compositional shifts in the soil microbiome. 454-pyrosequencing of ribosomal marker genes indicated that irrigation promoted bacteria and fungi with more copiotrophic life style strategies, that are typical for nutrient-rich conditions associated with a higher decomposition. Determination of SOM pools revealed a C loss in the organic layer under irrigation (-900 gC m-2) but a C gain in the mineral soil (+970 gC m-2), resulting in a negligible net effect. The likely mechanisms for the altered vertical SOM distribution might be (1) an accelerated mineralization of litter in conjunction with higher C inputs from the rhizosphere and/or (2) an increased incorporation of litter in the mineral soil as suggested by a litter bag experiment showing a stimulated activity of the macrofauna with a 5-fold increase of the earthworm density. In summary, our long-term irrigation experiment revealed that the removal of

Comparison of simulations of land-use specific water demand and irrigation water supply by MF-FMP and IWFM

Science.gov (United States)

Schmid, Wolfgang; Dogural, Emin; Hanson, Randall T.; Kadir, Tariq; Chung, Francis

2011-01-01

Two hydrologic models, MODFLOW with the Farm Process (MF-FMP) and the Integrated Water Flow Model (IWFM), are compared with respect to each model’s capabilities of simulating land-use hydrologic processes, surface-water routing, and groundwater flow. Of major concern among the land-use processes was the consumption of water through evaporation and transpiration by plants. The comparison of MF-FMP and IWFM was conducted and completed using a realistic hypothetical case study. Both models simulate the water demand for water-accounting units resulting from evapotranspiration and inefficiency losses and, for irrigated units, the supply from surface-water deliveries and groundwater pumpage. The MF-FMP simulates reductions in evapotranspiration owing to anoxia and wilting, and separately considers land-use-related evaporation and transpiration; IWFM simulates reductions in evapotranspiration related to the depletion of soil moisture. The models simulate inefficiency losses from precipitation and irrigation water applications to runoff and deep percolation differently. MF-FMP calculates the crop irrigation requirement and total farm delivery requirement, and then subtracts inefficiency losses from runoff and deep percolation. In IWFM, inefficiency losses to surface runoff from irrigation and precipitation are computed and subtracted from the total irrigation and precipitation before the crop irrigation requirement is estimated. Inefficiency losses in terms of deep percolation are computed simultaneously with the crop irrigation requirement. The seepage from streamflow routing also is computed differently and can affect certain hydrologic settings and magnitudes ofstreamflow infiltration. MF-FMP assumes steady-state conditions in the root zone; therefore, changes in soil moisture within the root zone are not calculated. IWFM simulates changes in the root zone in both irrigated and non-irrigated natural vegetation. Changes in soil moisture are more significant for non-irrigated

Spatiotemporal monitoring of soil salinization in irrigated Tadla Plain (Morocco) using satellite spectral indices

Science.gov (United States)

El Harti, Abderrazak; Lhissou, Rachid; Chokmani, Karem; Ouzemou, Jamal-eddine; Hassouna, Mohamed; Bachaoui, El Mostafa; El Ghmari, Abderrahmene

2016-08-01

Soil salinization is major environmental issue in irrigated agricultural production. Conventional methods for salinization monitoring are time and money consuming and limited by the high spatiotemporal variability of this phenomenon. This work aims to propose a spatiotemporal monitoring method of soil salinization in the Tadla plain in central Morocco using spectral indices derived from Thematic Mapper (TM) and Operational Land Imager (OLI) data. Six Landsat TM/OLI satellite images acquired during 13 years period (2000-2013) coupled with in-situ electrical conductivity (EC) measurements were used to develop the proposed method. After radiometric and atmospheric correction of TM/OLI images, a new soil salinity index (OLI-SI) is proposed for soil EC estimation. Validation shows that this index allowed a satisfactory EC estimation in the Tadla irrigated perimeter with coefficient of determination R2 varying from 0.55 to 0.77 and a Root Mean Square Error (RMSE) ranging between 1.02 dS/m and 2.35 dS/m. The times-series of salinity maps produced over the Tadla plain using the proposed method show that salinity is decreasing in intensity and progressively increasing in spatial extent, over the 2000-2013 period. This trend resulted in a decrease in agricultural activities in the southwestern part of the perimeter, located in the hydraulic downstream.

Water and nutrient productivity in melon crop by fertigation under subsurface drip irrigation and mulching in contrasting soils

Directory of Open Access Journals (Sweden)

Rodrigo Otávio Câmara Monteiro

2014-01-01

Full Text Available Cropping intensification and technical, economic and environmental issues require efficient application of production factors to maintain the soil productive capacity and produce good quality fruits and vegetables. The production factors, water and NPK nutrients, are the most frequent limiting factors to higher melon yields. The objective of the present study was to identify the influence of subsurface drip irrigation and mulching in a protected environment on the water and NPK nutrients productivity in melon cropped in two soil types: sandy loam and clay. The melon crop cultivated under environmental conditions with underground drip irrigation at 0.20m depth, with mulching on sandy loam soil increased water and N, P2O5 and K use efficiency.

Accumulation, mobility and plant availability of heavy metals in soils irrigated with untreated sewage effluent in Central Mexico

International Nuclear Information System (INIS)

Siebe-Grabach, C.

1994-01-01

In Irrigation District 03, Tula, Mexico, wastewater from Mexico City has been used for irrigating agricultural land since the beginning of this century. Today, approximately 85 000 ha are irrigated, alfalfa and maize being the main crops. The sewage effluent does not receive any treatment previous to its evacuation to this irrigation district, and only a part of the water is stored in the Endho Dam before being used, receiving in this way a kind or primary treatment through the sedimentation processes taking place. The reuse of wastewater for agricultural purposes represents an economic source of water and nutrients and has become an important disposal alternative for Mexico City. Nevertheless the contaminants and pathogens contained in the water represent a potential public health hazard and the production capacity of the soils. The aim of the present investigation is to determine the actual contamination levels of heavy metals (Pb, Cd, Cu, Zn) in soils, analysing the accumulation tendencies in time and space, and also to characterize their mobility and plant availability and thus their ecotoxicity. (orig.) [de

Changes in the persistence of two phenylurea herbicides in two Mediterranean soils under irrigation with low- and high-quality water: A laboratory approach.

Science.gov (United States)

ElGouzi, Siham; Draoui, Khalid; Chtoun, E H; Dolores Mingorance, M; Peña, Aránzazu

2015-12-15

The disappearance of two phenylurea herbicides, chlorotoluron (CHL) and isoproturon (IPU), in two Mediterranean soils, an agricultural calcareous soil (S5) and an organic forest soil (S2), was assessed under irrigation with high- and low-quality water. Irrigation with wastewater, as opposed to irrigation with high-quality water, increased the degradation rate of both herbicides in both soils. For each soil, the decay rate of IPU was always higher than that of CHL, and both pesticides disappeared more rapidly from S5 with lower clay and organic carbon content than from S2. The degradation rate was inversely related with pesticide sorption on soil, because increased sorption would reduce pesticide bioavailability for decomposition. In most cases the residual concentration in soil of both phenylurea herbicides was better fitted to a bi-exponential decay model than to first-order or first-order with plateau models. Dehydrogenase activity, used as an indication of microbial activity, was very high in S2 in comparison with S5, but was not related to pesticide disappearance. Copyright © 2015 Elsevier B.V. All rights reserved.

The impacts of irrigation with transferred and saline reclaimed water in the soil biological quality of two citrus species: Adaptations to low water availability

Science.gov (United States)

Bastida, Felipe; Abadía, Joaquín; García, Carlos; Torres, Irene; Ruiz Navarro, Antonio; José Alarcón, Juan; Nicolás, Emilio

2017-04-01

Mediterranean agroecosystems are limited by the availability of water and hence it is fundamental to find new water sources for sustainable agriculture in the face of climate change. Here, the effects of irrigation with water from different sources were analyzed in the soil microbial community and plant status of grapefruit and mandarin trees in a Mediterranean agro-ecosystem located in south-east of Spain. Four irrigation treatments were evaluated: i) water with an average electrical conductivity (EC) of 1.1 dS m-1 from the "Tagus-Segura" water-transfer canal (TW); ii) reclaimed water (EC = 3.21 dS m-1) from a wastewater-treatment-plant (RW); iii) irrigation with TW, except in the second stage of fruit development, when RW was applied (TWc); and iv) irrigation with RW except in the second stage, when TW was used (RWc). Phospholipid fatty acids indicated that microbial biomass was greater under grapefruit than under mandarin. In the case of grapefruit, TW showed a lower bacterial biomass than RW, RWc, and TWc, while RW showed the lowest values in the mandarin soil. In grapefruit soil, β-glucosidase and cellobiohydrolase activities, related to C cycling, were greater in RW and TWc than in TW and RWc. In mandarin soil, the greatest activity of these enzymes was found in TWc. The saline stress induced lower net photosynthesis (A) and stomatal conductance (gs) in plants of RW, RWc and TWc in comparison with TW. The annual use of reclaimed water or the combined irrigation with TWc positively influenced the soil biological quality of a grapefruit agro-ecosystem. Conversely, the mandarin soil community was more sensitive to the annual irrigation with RW.

ASPECTS OF DRIP IRRIGATION ON SLOPES

Directory of Open Access Journals (Sweden)

Oprea Radu

2010-01-01

Full Text Available Nowadays, water and its supply raise problems of strategic importance, of great complexity, being considered one of the keys to sustainable human development. Drip irrigation consists in the slow and controlled administration of water in the area of the root system of the plants for the purposes of fulfilling their physiological needs and is considered to be one of the variants of localized irrigation. Water is distributed in a uniform and slow manner, drop by drop, in a quantity and with a frequency that depend on the needs of the plant, thanks to the exact regulation of the water flow rate and pressure, as well as to the activation of the irrigation based on the information recorded by the tensiometer with regard to soil humidity. This method enables the exact dosage of the water quantity necessary in the various evolution stages of the plant, thus eliminating losses. By applying the irrigation with 5 liters of water per linear meter, at a 7 days interval, in the month of august, for a vine cultivated on a slope, in layers covered with black film and irrigated via dropping, soil humidity immediately after irrigation reaches its highest level, but within the limits of active humidity, on the line of the irrigation band. Three days later, the water content of the soil in the layer is relatively uniform, and, after this interval, it is higher in the points situated at the basis of the film. This technology of cultivation on slopes favors the accumulation, in the soil, of the water resulted from heavy rains and reduces soil losses as a result of erosion.

Assessment of Irrigation Water Quality and Suitability for Irrigation in ...

African Journals Online (AJOL)

A number of factors like geology, soil, effluents, sewage disposal and other environmental conditions in which the water stays or moves and interacts are among the factors that affect the quality of irrigation water. This study was conducted to determine the quality and suitability of different water sources for irrigation purpose ...

Mitigation of soil water repellency improves rootzone water status and yield in precision irrigated apples

Science.gov (United States)

Kostka, S.; Gadd, N.; Bell, D.

2009-04-01

Water repellent soils are documented to impact a range of hydrological properties, yet studies evaluating the consequences of soil water repellency (SWR) and its mitigation on crop yield and quality are conspicuously absent. With global concerns on drought and water availability and the projected impacts of climate change, development of novel strategies to optimize efficient rootzone delivery of water are required. Co-formulations of alkyl polyglycoside (APG) and ethylene oxide-propylene oxide (EO/PO) block copolymer surfactants have been shown to improve wetting synergistically. The objectives of this study were to determine if this surfactant technology: 1) increased soil water content and wetting front depth in mini-sprinkler irrigated, water repellent, Goulburn Valley clay loam soils and 2) assess the consequence of SWR mitigation on yield of Malus domestica Borkh. Three trials were conducted in the apple varieties 'Pink Lady' (2006/07 and 2007/08) and 'Gala' (2007/08) growing on Goulburn Valley clay loam soils in Victoria, AU. The test design was a randomized complete block with treatments replicated 5-6 times. Plot size varied by location. SWR was mitigated by applying surfactant at initial rates of 0, 5, or 10 L ha-1 in the spring, then at 0, 2.5, or 5 L ha-1 monthly for up to four months and compared to an untreated control. Treatments were applied to tree lines using a hand held small plot sprayer (118 liters of spray solution ha-1) followed by irrigation within 1-3 days of treatment applications. At each location, plots were irrigated by mini sprinklers and received the same irrigation volumes and management practices. Soil volumetric water content (VWC) was monitored at depths of 0-10 and 10-20 cm using a Theta probe (Delta-T Devices, Cambridge, UK). At harvest, fruit number and weights were measured and used for crop yield estimations. Data were analyzed using analysis of variance with mean values summarized and separated using Least Significant Test

Dual permeability soil water dynamics and water uptake by roots in irrigated potato fields

DEFF Research Database (Denmark)

Dolezal, Frantisek; Zumr, David; Vacek, Josef

2007-01-01

Water movement and uptake by roots in a drip-irrigated potato field was studied by combining field experiments, outputs of numerical simulations and summary results of an EU project (www.fertorganic.org). Detailed measurements of soil suction and weather conditions in the Bohemo-Moravian highland...

Evaluation of Populus and Salix continuously irrigated with landfill leachate II. soils and early tree development.

Science.gov (United States)

Zalesny, Ronald S; Bauer, Edmund O

2007-01-01

Soil contaminant levels and early tree growth data are helpful for assessing phytoremediation systems. Populus (DN17, DN182, DN34, NM2, and NM6) and Salix (94003, 94012, S287, S566, and SX61) genotypes were irrigated with landfill leachate or municipal water and tested for differences in (1) element concentrations (P, K, Ca, Mg, S, Zn, B, Mn, Fe, Cu, Al, and Na) of a topsoil layer and a layer of sand in tanks with a cover crop of trees or no trees and (2) height, diameter, volume, and dry mass of leaves, stems, and roots. Trees were irrigated with leachate or water during the final 12 wk of the 18-wk study. Differences in most soil element concentrations were negligible (P > 0.05) for irrigation treatments and cover main effects. Phosphorous, K, Mg, S, Zn, Mn, Fe, and Al concentrations were greater in topsoil than sand (P = 0.0011 for Mg; P tree yield. From a practical standpoint, these results may be used as a baseline for the development of future remediation systems.

Ancestral irrigation method by kanis in Bolivia

Science.gov (United States)

Roldán-Cañas, José; Chipana, René; Fátima Moreno-Pérez, María

2015-04-01

Irrigation in the Andean region is an ancient practice. For centuries, farmers were able to use the waters of rivers, lakes and springs to complement or supplement the scarce rainfall regime. The inter-Andean valleys of the Department of La Paz are the best areas for the study of traditional irrigation systems. This work has been carried out in the community of Jatichulaya located in te town of Charazani, 300 km from the city of La Paz, which lies 3250 meters above sea level. The annual rainfall ranges around 450 mm distributed mainly between the months of December to March. Therefore, water is needed to achieve adequate crop yields. The traditional irrigation system is done by the method of Kanis, consisting of a surface irrigation already developed by traditional Andean cultures of the country, in harmony with the ecological and productive characteristics of the area. Water enters the irrigation plot through a main channel (mama kani) from which the secondary channels (juchuy kanis) are derived. The fundamental characteristic of this irrigation is that these channels are open at the same time the water enters into the plot. The system works properly, adapting to the topography of the area. The irrigation method practiced in this community does not cause water erosion of soils because water management within the plot is based on the ancient knowledge of farmers following the contour lines. This practice allows good irrigation development and soil protection without causing any problems. However, it was evident a high use of labor in irrigation practice. Irrigation scheduling is done according to requests made by the irrigators in a given period. Delivering of water to the farmers is made by the so-called Water Agent (Agente de Aguas) or person in charge of the distribution of water. The Water Agent is elected annually and its functions include the maintenance and care of all system waterworks. The period between August and January is the highest water demand and

IRRIGATION USING SOLAR PUMP

OpenAIRE

Prof. Nitin P.Choudhary*1 & Ms. Komal Singne2

2017-01-01

In this report the described design of a PV and soil moisture sensor based automated irrigation system is introduced. This project aims to provide a human friendly, economical and automated water pumping system which eliminates the problems of over irrigation and helps in irrigation water optimization and manage it in accordance with the availability of water. Our project not only tries to modernize the irrigation practices and ensure the optimum yield by carefully fulfilling the requirements...

Effect of Irrigation Timing on Root Zone Soil Temperature, Root Growth and Grain Yield and Chemical Composition in Corn

Directory of Open Access Journals (Sweden)

Xuejun Dong

2016-05-01

Full Text Available High air temperatures during the crop growing season can reduce harvestable yields in major agronomic crops worldwide. Repeated and prolonged high night air temperature stress may compromise plant growth and yield. Crop varieties with improved heat tolerance traits as well as crop management strategies at the farm scale are thus needed for climate change mitigation. Crop yield is especially sensitive to night-time warming trends. Current studies are mostly directed to the elevated night-time air temperature and its impact on crop growth and yield, but less attention is given to the understanding of night-time soil temperature management. Delivering irrigation water through drip early evening may reduce soil temperature and thus improve plant growth. In addition, corn growers typically use high-stature varieties that inevitably incur excessive respiratory carbon loss from roots and transpiration water loss under high night temperature conditions. The main objective of this study was to see if root-zone soil temperature can be reduced through drip irrigation applied at night-time, vs. daytime, using three corn hybrids of different above-ground architecture in Uvalde, TX where day and night temperatures during corn growing season are above U.S. averages. The experiment was conducted in 2014. Our results suggested that delivering well-water at night-time through drip irrigation reduced root-zone soil temperature by 0.6 °C, increase root length five folds, plant height 2%, and marginally increased grain yield by 10%. However, irrigation timing did not significantly affect leaf chlorophyll level and kernel crude protein, phosphorous, fat and starch concentrations. Different from our hypothesis, the shorter, more compact corn hybrid did not exhibit a higher yield and growth as compared with taller hybrids. As adjusting irrigation timing would not incur an extra cost for farmers, the finding reported here had immediate practical implications for farm

Effects of different irrigation intervals and plant density on morphological characteristics, grain and oil yields of sesame (Sesamum indicum

Directory of Open Access Journals (Sweden)

parviz rezvani moghadam

2009-06-01

Full Text Available In order to study the effects of different irrigation intervals and plant density on morphological characteristics, grain and oil yields of sesame, an experiment was conducted at experimental station, college of agriculture, Ferdowsi University of Mashhad. Four different irrigation intervals (one, two, three and four weeks with four plant densities (20, 30, 40 and 50 plants/m2 were compared in a spilt plot arrangement based on randomized complete block design with four replications. Irrigation intervals and plant densities allocated in main plots and subplots, respectively. Different characteristics such as plant height, distance of first capsule from soil surface, number of branches per plant, number of grains per capsule, number of capsules per plant, grain yield, 1000-seed weight, harvest index and oil yield were recorded. The results showed that there were no significant difference between different irrigation intervals in terms of distance of first capsule from soil surface, number of grains per capsule, 1000-seed weight and harvest index. Different irrigation intervals had significant effects on plant height, number of branches per plant, number of capsules per plant, grain yield and oil yield. There were significant differences between different plant densities in terms of distance of first capsule from soil surface, number of branches per plant, number of graines per capsule, number of capsules per plant, grain yield, harvest index and oil yield. The highest grain yield (798/7 kg/ha and oil yield (412/8 kg/ha were obtained at one week and four weeks irrigation intervals, respectively. Between all treatments, 50 plants/m2 and one week irrigation interval produced the highest grain yield (914/7 kg/ha and oil yield (478/6 kg/ha. Because of shortage of water in Mashhad condition, the results recommended that, 50 plants/m2 and two weeks irrigation interval produced rather acceptable grain yield, with less water consumption.

Evaluation of the Increased Rates of Water Super Absorbent and Humic Acid Application under Deficit Irrigation Condition on Some Agroecological Characteristics of Zea Mays Using Response Surface Methodology

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M Jahan

2017-03-01

Full Text Available Introduction Water super absorbents are water absorbing natural or synthetic polymers (they may contain over 99% water. They have been defined as polymeric materials which exhibit the ability of swelling in water and retaining a significant fraction (> 20% of water within their structure, without dissolving in water content. The applications of hydrogels are grown extensively. These materials do not have any harm to the environment. Development of using super absorbent hydrogels to reduce crises such as soil erosion, frequent droughts or providing food security requires knowledge of their behaviors and performances in the soil. Humic substances are a mixture of different organic compounds that extract from various sources such as soil, humus, peat, oxidized lignite and coal. They are different in molecular size and chemical structure. A little amount of humic acid increase soil fertility by improving the physical, chemical and biological characteristics of soil. Increase in agricultural production and productivity depends, to a large extent, on the availability of water. Hence, the importance of irrigation is however, the availability of irrigation facilities which is highly inadequate in Iran. Determining the optimal amount of irrigation water has always been a main goal of researchers. Among the problems of excessive irrigation can be pointed to leach the nutrients especially nitrogen from the soil, the pollution of groundwater and environment and reduce fertilizer use efficiency, especially water-soluble fertilizers. To determine the optimal irrigation water and fertilizer, the use of mathematical models is inevitable. One of the most common methods used to optimize these factors is the central composite design. A central composite design is an experimental design, useful in response surface methodology, for building a second order (quadratic model for the response variable without needing to use a complete three-level factorial experiment

Irrigation management strategies to improve Water Use Efficiency of potatoes crop in Central Tunisia

Science.gov (United States)

Ghazouani, Hiba; Provenzano, Giuseppe; Rallo, Giovanni; Mguidiche, Amel; Douh, Boutheina; Boujelben, Abdelhamid

2015-04-01

In Tunisia, the expansion of irrigated area and the semiarid climate make it compulsory to adopt strategies of water management to increase water use efficiency. Subsurface drip irrigation (SDI), providing the application of high frequency small irrigation volumes below the soil surface have been increasingly used to enhance irrigation efficiency. At the same time, deficit irrigation (DI) has shown successful results with a large number of crop in various countries. However, for some crops like potatoes, DI is difficult to manage due to the rapid effect of water stress on tuber yield. Irrigation frequency is a key factor to schedule subsurface drip irrigation because, even maintaining the total seasonal volume, soil wetting patterns can result different during the growth period, with consequence on crop yield. Despite the need to enhance water use efficiency, only a few studies related to deficit irrigation of horticultural crops have been made in Tunisia. Objective of the paper was to assess the effects of different on-farm irrigation strategies on water use efficiency of potatoes crop irrigated with subsurface drip irrigation in a semiarid area of central Tunisia. After validation, Hydrus-2D model was used to simulate soil water status in the root zone, to evaluate actual crop evapotranspiration and then to estimate indirectly water use efficiency (IWUE), defined as the ratio between crop yield and total amount of water supplied with irrigation. Field experiments, were carried out in Central Tunisia (10° 33' 47.0" E, 35° 58' 8.1° N, 19 m a.s.l) on a potatoes crop planted in a sandy loam soil, during the growing season 2014, from January 15 (plantation of tubers) to May 6 (harvesting). Soil water status was monitored in two plots (T1 and T2) maintained under the same management, but different irrigation volumes, provided by a SDI system. In particular, irrigation was scheduled according to the average water content measured in the root zone, with a total of 8

Risk assessment and source analysis of soil heavy metal pollution from lower reaches of Yellow River irrigation in China.

Science.gov (United States)

Zhang, Pengyan; Qin, Chengzhe; Hong, Xin; Kang, Guohua; Qin, Mingzhou; Yang, Dan; Pang, Bo; Li, Yanyan; He, Jianjian; Dick, Richard P

2018-08-15

The level of concentration of heavy metal in soil is detrimental to soil quality. The Heigangkou-Liuyuankou irrigation area in the lower-reach of Yellow River irrigation, as home to a large population and a major site to agricultural production, is vulnerable to heavy metal pollution. This study examined soil quality in Heigangkou-Liuyuankou irrigation areas of Kaifeng, China. Pollution in soil and potential risks introduced by heavy metal accumulation were assessed using Nemerow, Geoaccumulation, and Hakanson's ecological risk indices. Statistics and Geographic Information Systems (GIS) were used to model and present the spatiotemporal changes of the pollution sources and factors affecting the levels of pollution. The heavy metals found in the sampled soil are Cr, Ni, Cu, Zn, Cd, Pb, As, and Hg. Among them, Cd is more concentrated than the others. The southwestern region of the studied area confronts the most serious heavy metal pollution. There exist spatial disparities of low concentrations of different heavy metals in the study area. Hg and Cd are found to pose the highest potential ecological risks. However, their risk levels are not the same across the study area. Levels concentration of Ni, Cu, Zn, Cd, Pb, As, and Hg in soil are highly correlated. In combination, they post an additional threat to the ecological environment. Transportation, rural settlements, and water bodies are found to be the major sources of Cr, Ni, Cu, Zn, Cd, Pb, and Hg pollution in the soil; among the major sources, transportation is the most significant factor. Copyright © 2018 Elsevier B.V. All rights reserved.

Wastewater retreatment and reuse system for agricultural irrigation in rural villages.

Science.gov (United States)

Kim, Minyoung; Lee, Hyejin; Kim, Minkyeong; Kang, Donghyeon; Kim, Dongeok; Kim, YoungJin; Lee, Sangbong

2014-01-01

Climate changes and continuous population growth increase water demands that will not be met by traditional water resources, like surface and ground water. To handle increased water demand, treated municipal wastewater is offered to farmers for agricultural irrigation. This study aimed to enhance the effluent quality from worn-out sewage treatment facilities in rural villages, retreat effluent to meet water quality criteria for irrigation, and assess any health-related and environmental impacts from using retreated wastewater irrigation on crops and in soil. We developed the compact wastewater retreatment and reuse system (WRRS), equipped with filters, ultraviolet light, and bubble elements. A pilot greenhouse experiment was conducted to evaluate lettuce growth patterns and quantify the heavy metal concentration and pathogenic microorganisms on lettuce and in soil after irrigating with tap water, treated wastewater, and WRRS retreated wastewater. The purification performance of each WRRS component was also assessed. The study findings revealed that existing worn-out sewage treatment facilities in rural villages could meet the water quality criteria for treated effluent and also reuse retreated wastewater for crop growth and other miscellaneous agricultural purposes.

Irrigation scheduling with the neutron probe

International Nuclear Information System (INIS)

Travers, P.

1987-01-01

The operational theory of the neutron probe is briefly outlined and its application and uses discussed in relation to determination of soil compaction and irrigation scheduling. Graphic examples are given of alluvial soil moisture profiles and how this information can be used to improve trickle irrigation in vineyards. 3 refs., 7 figs

The use of treated wastewater for chemlali olive tree irrigation: effects on soil properties, growth and oil quality

Energy Technology Data Exchange (ETDEWEB)

Ben Rouina, B.; Bedbabis, S.; Ben Ahmed, C.; Boukhris, M.

2009-07-01

Olive tree (Olea european L.) cultivation, the major tree crops in Mediterranean countries is being extended to irrigated lands. However, the limited water availability, the severe climatic conditions and the increased need for good water quality for urban and industrial sector uses are leading to the urgent use of less water qualities (brackish water and recycled wastewater) for olive tree irrigation. The aim of this work was to asses the effects of long term irrigation with treated waste water (TWW) on the soil chemical properties, on olive tree growth and on oil quality characteristics. (Author)

The use of treated wastewater for chemlali olive tree irrigation: effects on soil properties, growth and oil quality

International Nuclear Information System (INIS)

Ben Rouina, B.; Bedbabis, S.; Ben Ahmed, C.; Boukhris, M.

2009-01-01

Olive tree (Olea european L.) cultivation, the major tree crops in Mediterranean countries is being extended to irrigated lands. However, the limited water availability, the severe climatic conditions and the increased need for good water quality for urban and industrial sector uses are leading to the urgent use of less water qualities (brackish water and recycled wastewater) for olive tree irrigation. The aim of this work was to asses the effects of long term irrigation with treated waste water (TWW) on the soil chemical properties, on olive tree growth and on oil quality characteristics. (Author)

Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

NARCIS (Netherlands)

Paudel, K.

2010-01-01

Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since

Estimating Leaching Requirements for Barley Growth under Saline Irrigation

Directory of Open Access Journals (Sweden)

Ahmed Al-Busaidi

2012-01-01

Full Text Available The utilization of marginal water resources for agriculture is receiving considerable attention. The lands irrigated with saline water are required to reduce salt accumulations through leaching and/or drainage practices. A field experiment was carried out to investigate the effect of saline irrigation and leaching fraction on barley (Hordeum vulgare L. growth. For this purpose highly saline water was diluted to the salinity levels of 3, 6 and 9 dS m-1 and applied by drip irrigation at 0.0, 0.15, 0.20 and 0.25 leaching fractions (LF. The results of the experiment showed that both quantity and quality of water regulated salts distribution within the soil in the following manner: a the salts were found higher near or immediate below the soil surface; b an enhanced LF carried more salts down the soil horizon but there was no significant difference in plant yield between different treatments of leaching fractions. Salinity of water significantly impaired barley growth. The good drainage of sandy soil enhanced the leaching process and minimized the differences between leaching fractions. The increment in saline treatments (3, 6 and 9 dS m-1 added more salts and stressed plant growth. However, the conjunctive use of marginal water at proportional LF could be effective in enhancing the yield potential of crops in water-scarce areas.

Soil salinization processes in rice irrigation schemes in the Senegal River Delta

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Ceuppens, J.; Wopereis, M.C.S.; Miezan, K.M.

1997-01-01

Soil salinization constitutes a major threat to irrigated agriculture (mainly rice, Oryza sativa L.) in the Senegal River Delta. It is generally hypothesized that salinization is caused by (i) capillary rise from a saline water table and (ii) concentration of salts in the field due to lack of adequate drainage facilities. The impact of field water management and rice cropping intensity on salinization in the Delta was determined using an electromagnetic conductivity meter (Geonics EM38). More than 4000 measurements were made in 40 rice fields on a typical heavy clay soil (Vertic Xerofluvent). Thirty EM38 measurements per field (0.25 ha) estimated average field soil salinity with a relative error of 20%. A multiple linear regression model based on EM38 readings explained 60 to 75% of the variability in conductivity of 1:5 saturation extracts at 0- to 5-, 10- to 15-, and 30- to 35-cm depths. Higher cropping intensity limited upward salt transport from the water table. Average horizontal and vertical EM38 measurements increased in the following order two rice crops per year with drainage: 0.73 and 0.98 dS m -1 ; one rice crop per year with drainage: 1.26 and 1.76 dS m -1 ; one rice crop per year without drainage: 2.23 and 2.98 dS m -1 ; and abandoned fields: 4.77 and 4.29 dS m -1 . Results indicate a beneficial effect of flooded rice on salinity for this type of heavy clay soil. Irrigation development in the area needs to be accompanied by monitoring of water table depth. (author)

Root Zone Sensors for Irrigation Management in Intensive Agriculture

Directory of Open Access Journals (Sweden)

Jochen Hemming

2009-04-01

Full Text Available Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method. An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS, such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.