Evaluation of water use efficiency and optimal irrigation quantity of spring maize in Hetao Irrigation District using the Noah-MP Land Surface Model

Evaluation on the responses of maize (Zea mays L.) growth, yield and water use efficiency to drip irrigation water under mulch condition in the Hetao irrigation District of China

مهمترین هدف برنامه‌ریزی و مدیریت آبیاری افزایش بهره‌وری و راندمان مصرف آب و در عین حال دارا بودن یک سامانه پایدار تولید است. به منظور بررسی تاثیر انواع خاک‌پوش بر کارایی مصرف آب، شاخص‌های رشدو عملکرد ذرت، پژوهشی به صورت طرح بلوک‌های کامل تصادفی با 6 تیمار و 3 تکرار در سال زراعی 93-94 در مزرعه پژوهشی دانشگاه شهرکرد انجام شد. تیمارها شامل شاهد (بدون پوشش)، پوشش پلاستیک شفاف، پلاستیک سیاه، گونی نخی کناف، گونی سفید و آبی بود. در طول فصل کشت، رطوبت خاک تا عمق توسعه موثر ریشه اندازه‌گیری و آبیاری‌ها بر اساس کمبود رطوبت خاک با تأمین نیاز آبی کامل تعیین و اعمال گردید. در طول فصل رشد نمونه‌برداری برای تعیین میزان ماده خشک برگ، ساقه و میزان آماس نسبی برگ انجام گرفت و در پایان فصل رشد نیز میزان حجم آب مصرفی، میزان دانه تولیدی، اندازه‏گیری و ثبت گردید. نتایج نشان دادکه خاک-پوش‌ها در تمام مراحل اندازه‏گیری تأثیر افزاینده بر محتوای نسبی آب برگ داشته‌اند که این می‌تواند ناشی از تأثیر آن‌ها بر حفظ رطوبت خاک باشد. خاک‌پوش پلاستیک شفاف بیشترین تأثیر را بر شاخص برداشت با مقدار 97/53 درصد داشت که این مقدار متناظر افزایش 32 درصد نسبت به تیمار شاهد بود. بیشترین و کمترین میزان کارایی مصرف آب به ترتیب مربوط به تیمار گونی‌سفید و شاهد با مقادیر 7/2 و 4/1 کیلوگرم وزن خشک دانه بر مترمکعب بدست آمدکه این معادل افزایش 93 درصد میزان کارایی مصرف آب می‌باشد. بنابراین خاک‌پوش گونی‌های سفید وآبی بیشترین تأثیر را بر حفظ رطوبت خاک و عملکرد محصول دارا بودند.

This paper modifies and uses an advanced computable general equilibrium model coupled with biophysical data on land and water resources by Agro-Ecological Zone (AEZ) at the river basin level to examine the economy-wide consequences of im-provements in water use efficiency (WUE) in irrigation in South Asia. This is the first time the benefits of such improvements have been evaluated in an economy-wide context. It shows that such improvements increase production of food items, enhance food exports, and significantly improve food security in South Asia. Improvement in water use efficiency also leads to lower food prices, provides the opportunity to extend irrigated areas, decreases demand for cropland, and enhances reforestation. Im-provement in water use efficiency in irrigation also generates important net GDP gains across the South Asia region. Investments in improved WUE of up to 40% can be economically justified in Bangladesh, India, and Sri Lanka. However, in Nepal, for an improvement of more than 20% in WUE, the economic gains are smaller than costs from the associated investments. In Pakistan and rest of South Asia, an improvement in WUE of up to 30% appears to be economically profitable.

Comparison of sprinkler, trickle and furrow irrigation efficiencies for onion production

Effect of irrigation amount and water salinity on water consumption and water productivity of spring wheat in Northwest China

Effects of biochar and inorganic fertiliser applications on growth, yield and water use efficiency of maize under deficit irrigation

In areas of finite groundwater resources, the groundwater used for irrigation must be used as efficiently as possible. Yields and water use characteristics of longer-maturity corn (Zea mays L.; 118-d relative maturity), shorter-maturity corn (97-d relative maturity), and grain sorghum [Sorghum bicolor (L.) Moench] under full and limited irrigation were evaluated from 1993 to 1996. Mean yield of longer-maturity corn was 15 bu/acre greater than that of shorter-maturity corn and 50 bu/acre greater than that of grain sorghum. Longer-maturity corn used the greatest amount of water, 3.4 in, greater than shorter-maturity corn or grain sorghum. Average water use rates were similar among the three crops. Mean water use efficiency for longer-maturity corn was not different from that of shorter-maturity corn; mean water use efficiency of grain sorghum was 1.4 bu/acre per in, less. Mean yield of fully irrigated crops was 15 bu/acre greater than that for crops under limited irrigation (replacing 70% of crop evapotranspiration [ET]). Water use efficiency of crops under limited irrigation was 0.7 bu/acre per in, greater than under full irrigation, but full irrigation of corn was more profitable than limited irrigation. These yields, average water use rates, and water use efficiencies indicate no justification for choosing shorter- over longer-maturity corn.

Taking 7-year-old apple trees (Hanfu) as the test material, an experiment with three irrigation levels including high water (W1, 85%-100%θf, θf was the field water holding capacity), medium water (W2, 70%-85%θf) and low water (W3, 55%-70%θf), and three nitrogen application levels, high (N1, 600 kg·hm-2), medium (N2, 400 kg·hm-2) and low (N3, 200 kg·hm-2), was conducted to investigate the effects of water and nitrogen coupling on photosynthetic characteristics, yield and water and nitrogen utilization of apple trees in mountainous areas under surge-root irrigation (SRI). The results showed that the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (gs), intercellular CO2 concentration (Ci), leaf instantaneous water use efficiency (WUEi) of apple trees leaves decreased with decreasing nitrogen application rates under the same irrigation amount, but Ci increased. Under the same nitrogen application rate, foliar Pn, Tr, gs and WUEi decreased with decreasing irrigation amount, but Ci increased. The daily average values of Pn and Tr under W1N1 treatment were the largest, while W2N2 treatment had the largest WUEi. Apple yield, irrigation water use efficiency (IWUE) and nitrogen partial productivity (NPFP) were significantly affected by irrigation and nitrogen application. The W2N2 treatment had the highest yield (26761 kg·hm-2). IWUE increased significantly with the decreasing irrigation and the increasing nitrogen application, while NPFP increased significantly with the increases of irrigation and the decreases of nitrogen application. Results of the regression analysis showed that the combination of irrigation and nitrogen application was closest to W2N2 treatment when yield and IWUE got the optimal solution. Therefore, W2N2 treatment was the best combination mode of water and nitrogen application for apple under SRI in Northern Shaanxi mountain area.

Irrigation scheduling and water use efficiency of cucumber grown as a spring-summer cycle crop in solar greenhouse

In view of the growing scarcity for irrigation water global necessity is felt to improve water use efficiency in irrigation as it consumes a largest chunk of total available water. Innovative technologies are evolved for efficient water management to improve crop productivities. In this paper, findings of studies concerned to increasing water use efficiency are discussed. A field experiment on effect of drip irrigation in cotton indicated that by applying same quantity and 50 per cent of water as of surface irrigation (control), yield increased by 28 per cent and 10 per cent, respectively. When water applied through drip irrigation was 25 per cent of the control, yield reduced by 2.5 per cent, but in this case highest water use efficiency was observed. Demonstrations on water use efficiency in the surface irrigation revealed that adoption of alternatively alternate furrow irrigation (AAFI) saved irrigation water by 13 per cent and increased water use efficiency by 15.91 per cent over farmers' method of Furrow Irrigation (FI). While in case of border strip irrigation with 80 per cent cutoff length increased wheat yield by 9.25 per cent over farmers' practice with water saving of 9 per cent and increased water use efficiency by 20 per cent. Independent economic analyses of adoption of drip and advanced irrigation techniques convinced the financial feasibility of adopting new technologies, which can be promoted through the state supported measures like irrigation subsidies.

The experiment was conducted using automatic rain shelter to study the effect of precisely controlled water quota of alternate subsurface drip irrigation (ASDI) on spring maize yield and water use efficiency (WUE). The results showed that jointing to heading stage and heading to hilling stage were the key stages of water requirement for spring maize under ASDI. In particular, both the water consumption percentage and diurnal water consumption in these two stages were higher than in other stages and were more sensitive to water deficit stress. The water demand in these two stages should be prioritized if irrigation was limited. Maize yield generally increased with the increasing irrigation quota. When the irrigation quota below 2764.5 m3·hm-2, the yield increased rapidly with the increasing irrigation quota. The yield increase then slowed down after the irrigation quota reached 2764.5 m3·hm-2. The maximum of maize yield of 12109.0 kg·hm-2 was obtained at the irrigation quota of 3357.1 m3·hm-2. Compared to fixed subsurface drip irrigation (FSDI), under the same irrigation quota, the yield, WUE and irrigation water use efficiency (IWUE) of spring maize in ASDI treatment were improved by 5.4%, 1.4% and 5.6%, respectively. Compared to FSDI, the maize yield in ASDI decreased by 1.8%, but its WUE and IWUE increased by 11.0% and 22.7% when the irrigation quota decreased by 20%. The optimal irrigation quota of ASDI for spring maize in the study area was1600.4-3357.1 m3·hm-2 by taking into account of yield and WUE.

Bayesian multi-model projection of irrigation requirement and water use efficiency in three typical rice plantation region of China based on CMIP5

Dry matter accumulation after silking and kernel weight are the key factors for increasing maize yield and water use efficiency

The article presents the results of experimental research on the effect of drip irrigation system designs on the formation of irrigation regimes, productivity, and efficiency of water use by sunflower hybrids. In addition, the main components of evapotranspiration were taken into account, and coefficients of water consumption (WCC), irrigation efficiency (IE), and irrigation water use efficiency (WUE) were chosen as criteria for the efficiency of drip irrigation. Short-term field research was carried out during 2020-2022 on the lands of the Brylivske experimental field of the Institute of Water Problems and Reclamation of the National Academy of Agricultural Sciences (Kherson region, subzone of the Dry Steppe). Analytical and mathematical as well as statistical methods were used to process experimental data. The scheme of the three-factor field experiment provided various options for laying irrigation pipelines of drip irrigation systems (in the horizontal and vertical planes), as well as the implementation of a pulsed water supply mode (standard). The version with a natural moisture supply (without irrigation) was the control. The results of experimental research proved that the method of laying drip irrigation pipelines had a direct effect on the parameters of the formation of drip irrigation regimes and the productivity of sunflower hybrids in the conditions of the Dry Steppe. The mechanism of evapotranspiration formation of sunflower crops in irrigated and non-irrigated conditions has been determined. It was statistically proven that the application of subsoil drip irrigation with the laying of irrigation pipelines at a depth of 0.3 m and a distance between them of 1.0 m is the most appropriate for growing sunflower hybrids. This is explained by biological features, namely drought resistance of this crop. Thus, in field experiments, the variant with in-soil laying of drip irrigation pipelines provided almost identical yield (4.01-4.09 t/ha) when having lower crop water consumption coefficients (1088.7-1125.7 m3/t) and higher efficiency of irrigation water use – 2.27-2.41 kg of grain per 1 m3 of irrigation water.

Water scarcity and the excessive application of nitrogen fertilizer are key factors limiting the sustainable development of the hybrid seed maize industry in the oasis agricultural areas of the Hexi Corridor in China. To determine the optimal water–nitrogen management regime of hybrid seed maize, we established a field experiment in 2020–2021 with three irrigation quotas (W1, W2, and W3 were 60, 80, and 100% of the local conventional irrigation quota, respectively) and four nitrogen application levels (N0, N1, N2, and N3 were 0, 190, 285, 380 kg·hm−2). We analysed the influence of different water–nitrogen combinations on indices of seed vigour, yield, water use efficiency (WUE), irrigation water use efficiency (IUE), the partial productivity of nitrogen fertilizer (NFP), and the nitrogen fertilizer agronomic use efficiency (NFA) of hybrid seed maize. A comprehensive growth evaluation system for hybrid seed maize was established based on the AHP, entropy weight, and TOPSIS methods, and a coupled water–nitrogen response model for hybrid seed maize was established with the objectives of obtaining high-yield, efficient, and high-seed vigour. The results showed that the yield of hybrid seed maize, NFP, and NFA gradually increased with the increase in the irrigation amount, while IUE continuously decreased; the yield of hybrid seed maize, WUE, and NFA increased and then decreased, while NFP continuously decreased with an increase in the amount of nitrogen application. Further, treatment N2W3 had higher water and nitrogen use efficiency and the highest yield and seed viability with a yield of 9209.11 kg·hm−2 and germination percentage, germination index, and vigour index of 97.22, 58.91, and 1.55%, respectively. The model of the integrated growth response of hybrid seed maize to water–nitrogen showed that the combined benefits of the hybrid seed maize yield, WUE, and seed viability could be maximised in conjunction with the irrigation rate ranging from 3558.90 to 3971.64 m3·hm−2 and the fertiliser application rate of 262.20 to 320.53 kg·hm−2. This study can provide scientific guidance and act as a decision-making reference for the productive, efficient, and sustainable development of hybrid seed maize in the oasis agricultural area of the Hexi Corridor.