Water Footprint for Garlic under Irrigation Levels and Agrispon Application

Field experiment was conducted in Giza, Egypt, during two growing seasons of 2017-2018 and 2018-2019 on garlic crop, with the objective of investigating the effect of different irrigation levels (60, 80 and 100 % of water requirements and their combination with the foliar spraying applications of agrispon (with 0.5 and 1.0 ml/ liter) on growth and yield. The results indicated that increased irrigation level up to 100% led to increased vegetative characters of garlic and that the lowest growth and productivity was obtained by 60% irrigation level. When considering spray application of agrispon; with 1.0 ml/L increased growth and productivity followed by 0.5 ml/L; while control treatment gave the lowest productivity during the both seasons. Interaction effect between irrigation level and agrispon treatments indicated that 100% irrigation level combined with 1.0 ml/L spray application of agrispon gave the highest garlic productivity followed by 100% irrigation level combined with 0.5 ml/L spray application. The chemical analysis showed that the highest NPK was obtained by 100% irrigation level combined with 1.0 ml/L agrispon application during the both seasons. Regarding water footprint, the highest irrigation water footprint was obtained by 80% irrigation level followed by 60% irrigation level, while the lowest footprint was obtained by 100% irrigation level due to high garlic productivity under 100% irrigation level. The estimate water footprint for garlic was 525 m3/ton. The blue water footprint for garlic was 422 m3/ton about 80% form total water footprint, while gray water percentage about 20% with value of 103 m3/ton.

Growth and productivity assessments of peanut under different irrigation water management practices using CSM-CROPGRO-Peanut model in Eastern Mediterranean of Turkey

Irrigation water scheduling is crucial to make the most efficient use of ever-decreasing water. As excessive irrigation decreases yield, while imprecise application also causes various environmental issues. Therefore, efficient management of irrigation frequency and irrigation level is necessary to sustain productivity under limited water conditions. The objective of the current study is to assess the water productivity at various irrigation regimes during peanut crop growing seasons (2014 and 2015) in Eastern Mediterranean, Turkey. The field experiments were conducted with treatments consisting of three irrigation frequencies (IF) (IF1: 25 mm; IF2: 50 mm; and IF3: 75 mm of cumulative pan evaporation (CPE)), and four irrigation water levels (WL1 = 0.50, WL2 = 0.75, WL3 = 1.0, and WL4 = 1.25). WL1, WL2, WL3, and WL4 treatments received 50, 75, 100, and 125 of cumulative pan evaporation. The CSM-CROPGRO-Peanut model was calibrated with experimental data in 2014 and evaluated with second-year experimental data (2015). The model simulated seed yield and final biomass (dry matter) reasonably well with low normalized root mean square error (RMSEn) in various irrigation intervals. The model simulated reasonably well for days to anthesis (RMSE = 2.53, d-stat = 0.96, and r2 = 0.90), days to physiological maturity (RMSE = 2.55), seed yield (RMSE = 1504), and tops biomass dry weight at maturity (RMSE = 3716). Simulation results indicated good agreement between measured and simulated soil water content (SWC) with low RMSEn values (4.0 to 16.8% in 2014 and 4.3 to 18.2% in 2015). Further results showed that IF2I125 irrigation regime produced the highest seed yield. Generally, model evaluation performed reasonably well for all studied parameters with both years’ experimental data. Results also showed that the crop model would be a precision agriculture tool for the extrapolation of the allocation of irrigation water resources and decision management under current and future climate.

Interaction of cultivar and irrigation on mixtures of wheat (Triticum aestivum L.) with pea (Pisum sativum L.)

Intercropping is the simultaneous cultivation of two or more crops species in the same space for a considerable proportion of the growth period. Intercropping has several advantages and is used in both traditional and sustainable agriculture. The objective of the present study was to study the interactions among different pea and wheat cultivars and the effect of water availability on wheat-pea mixtures and the competition between the two species. The experiment was conducted for two successive growing seasons using two different irrigation regimes and two cultivars from each species. The different treatments were evaluated using morphological and agronomic characteristics. Intercropping treatment, cultivars, and irrigation level affected most of the characteristics that were studied and the competition between the two species. Biomass was higher by 47% and leaf area index by 34% under irrigation compared to the rainfed conditions. The different cultivars showed different response under the two water regimes. Based on the intercropping indices, the mixture ‘Yecora E’ - ‘Isard’ is favoured under irrigation while the combination ‘Elissavet’ - ‘Isard’ under low water availability. There was interaction between cultivars and irrigation and using different cultivars in intercropping can have higher yield advantage than monocropping by exploiting the environmental resources more efficiently. Therefore, the use of appropriate cultivars in mixtures can affect the growth, biomass yield and competition between the two species leading to higher yield and greater economic return.

A global meta-analysis of yield and water productivity responses of vegetables to deficit irrigation

Strategies promoting efficient water use and conserving irrigation water are needed to attain water security to meet growing food demands. This meta-analysis study evaluated the effect of deficit irrigation (DI) strategy on eight vegetables to provide a quantitative estimate of yield and water productivity (WP) responses under variable soil textures, climates, and production systems (open-field and greenhouse). This study analyzed 425 yield and 388 WP comparisons of different DI levels to full irrigation (FI), extracted from 185 published studies representing 30 countries. Moving from the highest (> 80%FI) to the lowest (< 35%FI) irrigation level, the overall yield decline was 6.9 to 51.1% compared to FI, respectively. The WP gains ranged from 8.1 to 30.1%, with 35–50%FI recording the highest benefits. Soil texture affected the yield significantly only under the least irrigation class (< 35%FI), wherein sandy clay and loam recorded the highest (82.1%) and the lowest (26.9%) yield decline, respectively. Among the climates, temperate climate was overall the most advantageous with the least yield penalty (21.9%) and the highest WP gain (21.78%) across various DI levels. The DI application under the greenhouse caused lesser yield reduction compared to the open-field. The WP gains due to DI were also higher for greenhouse (18.4%) than open-field (13.6%). Consideration of yield penalties and the cost of saved irrigation water is crucial while devising the reduced irrigation amounts to the crops. The yield reductions under low to moderate water deficits (> 65%FI) accompanied by gains in WP may be justifiable in the light of anticipated water restriction.

Yield Performance and Physiological Response of a Maize Early Hybrid Grown in Tunnel and Open Air under Different Water Regimes

Climate change is one of the most important and studied phenomena of our age and it can have a deep impact on agriculture. Mediterranean countries are and will continue to be strongly affected by changing environmental factors, including lack of precipitation and prolonged heatwaves. The current study aimed to assess the adaptability of an early maize hybrid grown in two temperature conditions and subjected to different irrigation water regimes. The experimental design was a randomized complete-block design with two different temperature conditions: (i) ordinary temperature in open field (OF) and (ii) high temperature (about 3 °C higher than the current condition) under a poly-ethylene tunnel (PE). In both environments, five irrigation level treatments were applied: 100% (DI100), 75% (DI75), 50% (DI50), 25% (DI25), and 0% restoration of water lost by evapotranspiration (DI0). The responses of maize plants were assessed in terms of yield, nitrogen content determination, nitrogen use efficiency, leaf gas exchanges, and leaf water potential measurements. In both conditions, yield and its components linearly decreased as the irrigation water amount reduced, and even the DI0 plants did not produce. Notably, the PE-DI100 treatment had a significantly higher yield than the corresponding treatment in the open air (9.9 vs. 8.5 t ha−1), due mainly to the increased number of ears per square meter (13 vs. 11 m2, respectively). Though, as far as it concerns physiological parameters, a significant effect of environmental conditions was found, with values significantly lower under the protected environment, compared to the plants in the open field. Considering our results, it can be assumed that correct management of amount and time intervals of irrigation could adapt the maize to future climate change.

Pigeonpea (Cajanus cajan L.) Growth, Yield and Monetary Influence by Drip Irrigation and Mulch in Vertisols of Madhya Pradesh

Background: Farmers are facing many constraints related with pigeonpea cultivation therefore proper resources management and scientific practices can increase the production and productivity of pigeonpea. Drip and mulching can be a way to achieve the goal of more crop per drop. Methods: The field experiments were conducted during kharif season of year 2016-17 and 2017-18. The study area is located (23°16'48'' N-latitude, 77°21'36'' E-longitude) in Madhya Pradesh. The experiment was laid out in vertisols with twenty seven treatment combinations consisting of three mulching, three discharge rate (2 lph-D1, 4 lph-D2 and 8 lph-D3) and three irrigation levels viz. 60% CPE (I1), 80% CPE (I2) and 100% CPE (I3). Well treated bold seeds of pigeonpea (TJT-501) were dibbed in soil on ridge-furrow land configuration. Result: The plant height was maximum in 2 lph (175.78 cm), I2 (176.10 cm) and number of branches, number of pods per plant, seeds per pod also followed the same trend. Maximum yield was registered with D1 (16.48 q/ha) followed by D2 (14.91 q/ha) and D3 (14.46 q/ha). Irrigation level I2 (16.01 q/ha) registered 13.77% higher seed yield than I1 (14.07 q/ha). In case of discharge rate, B:C decreased as rate increased. Among irrigation level treatments, lowest value (1.26) of B:C recorded with 60% CPE whereas highest B:C (1.56) was registered with 80% CPE, which is at par with 100% CPE (1.52). It can be concluded that pigeonpea cultivation is not economical with mulch and 100% supply of irrigation during kharif. It is viable to supply irrigation as per CPE only at branching, flowering and pod development stages.

Tuber yield and water efficiency of early potato varieties (Solanum tuberosum L.) cultivated under various irrigation levels

This study aims to determine the effects of differences in variety and irrigations levels on potato yield (appropriate humidity, temperature, shading the plants from the sun if necessary) on potato yield in greenhouse conditions. Functions of potato production with respect to water use were developed for five dates of measurements of plant growth, in relation to the various vegetation phases. On the basis of potato vegetation phases, the potato water demand was determined. An experiment was conducted using the randomized sub-block method. The first order factor were the two varieties of potato that were grown under drip irrigation with three water regimes as a second factor experiment: level 1 (pF 2.7), level 2 (pF 2.5) and level 3 (pF 2.2). The variety had a significant effect on the weight of potato tubers. The irrigation level had only a significant effect on the total potato biomass. The potato harvest date had a significant effect on both of the examined treatments. The growth dynamics of the aboveground part and potato tubers were the highest in conditions of constant level 1. Regardless of the variety studied, on level 3 caused a reduction in potato biomass production.The highest water consumption was observed during the tuber potato growth period to flowering. The values were varied from 0.39 l/pot day level 1 (in both investigated cultivars) to 0.99 l/ pot/day (humidity level 3 for Julinka cultivar) in July. The most intensive increase in water consumption was observed at the level 3. The average W index of the average daily water dose calculated for Denar cultivar amounted 0.40 l day−1 in the first period (O1) to 0.79 l day−1 in the fifth period (O5) and for Julinka cultivar 0.49 l day−1 (O1) to 0.92 l day−1 (O5). Stress due to water shortage and/or excessive levels of water in the soil negatively influenced the yield of potato tuber. Potato varieties reacted differently to soil water content.

Photosynthetic Physiological Characteristics of Water and Nitrogen Coupling for Enhanced High-Density Tolerance and Increased Yield of Maize in Arid Irrigation Regions

To some extent, the photosynthetic traits of developing leaves of maize are regulated systemically by water and nitrogen. However, it remains unclear whether photosynthesis is systematically regulated via water and nitrogen when maize crops are grown under close (high density) planting conditions. To address this, a field experiment that had a split-split plot arrangement of treatments was designed. Two irrigation levels on local traditional irrigation level (high, I2, 4,050 m3 ha−1) and reduced by 20% (low, I1, 3,240 m3 ha−1) formed the main plots; two levels of nitrogen fertilizer at a local traditional nitrogen level (high, N2, 360 kg ha−1) and reduced by 25% (low, N1, 270 kg ha−1) formed the split plots; three planting densities of low (D1, 7.5 plants m−2), medium (D2, 9.75 plants m−2), and high (D3, 12 plants m−2) formed the split-split plots. The grain yield, gas exchange, and chlorophyll a fluorescence of the closely planted maize crops were assessed. The results showed that water–nitrogen coupling regulated their net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), quantum yield of non-regulated non-photochemical energy loss [Y(NO)], actual photochemical efficiency of PSII [Y(II)], and quantum yield of regulated non-photochemical energy loss [Y(NPQ)]. When maize plants were grown at low irrigation with traditional nitrogen and at a medium density (i.e., I1N2D2), they had Pn, Gs, and Tr higher than those of grown under traditional treatment conditions (i.e., I2N2D1). Moreover, the increased photosynthesis in the leaves of maize in the I1N2D2 treatment was mainly caused by decreased Y(NO), and increased Y(II) and Y(NPQ). The coupling of 20%-reduced irrigation with the traditional nitrogen application boosted the grain yield of medium density-planted maize, whose Pn, Gs, Tr, Y(II), and Y(NPQ) were enhanced, and its Y(NO) was reduced. Redundancy analysis revealed that both Y(II) and SPAD were the most important physiological factors affecting maize yield performance, followed by Y(NPQ) and NPQ. Using the 20% reduction in irrigation and traditional nitrogen application at a medium density of planting (I1N2D2) could thus be considered as feasible management practices, which could provide technical guidance for further exploring high yields of closely planted maize plants in arid irrigation regions.