Comparison of physiological response to growth stage-based supplemental and conventional irrigation management of wheat

Evaluation of net return and grain quality characteristics of wheat for various irrigation strategies under the Mediterranean climatic conditions

This study evaluated crop water stress index (CWSI) and midday flag leaf water potential (ψi) on wheat (Triticum aestivum L. Adana 99) under the three different supplemental and conventional irrigation strategies using sprinkler line-source system during 2014 and 2015 in Adana, Turkey. The irrigation strategies were as follows: conventional irrigation (CI), supplemental irrigation (SI) during flowering (SIF), SI during grain filling (SIG), SI both during flowering and grain filling (SIFG). These strategies were tested under four irrigation levels 100, 75, 50, 25% and rain-fed. The CI100 treatment achieved the highest grain yield in both seasons, followed by CI75 and SIFG100. The CI75 had the greatest water use efficiency of 1.20 kg m− 3, and SIF25 resulted in the lowest WUE. Grain yield and available soil water correlated linearly to CWSI. These relations could be employed in predicting the yield response to water stress. A higher grain yield was obtained when irrigation was applied at CWSI values less than 0.26, suggestingCWSI as a good indicator to improve irrigation timing for wheat. Prolonged drought in early grain filling stage led to a decline in Ψi in the advanced growth stage which in turn reduced grain yield. Significant correlations between Ψi and grain yield and CWSI were obtained, which could be useful in improving wheat irrigation water management. CI100 is recommended when there is no water shortage; however, under water scarcity conditions CI75, SIFG100 and SIFG75, with higher WUE and relatively higher yields, are recommended.

Supplemental irrigation strategy for improving grain filling, economic return, and production in winter wheat under the ridge and furrow rainwater harvesting system

Water scarcity emerges as a prominent threat to the vegetative and reproductive phases of cotton plants. However, water deficit stress induces a reduction in stomatal conductance, altering the interplay between plant water and nutrients, and Irrigation water productivity (IWP). The relationship between IWP and cotton yield under deficit irrigation remains unclear in the irrigated area of Hyderabad, Sindh, Pakistan. The experiment was conducted at experimental stations of Agriculture Research Institute in Tandojam at two different sites during the cotton growing season 2022. The design of this study was based on a split-plot in RCBD including five deficit water stress levels (control treatment (existing irrigation practice 75 mm of water irrigation−1), 20% drought stress of existing irrigation, 20% drought stress of existing irrigation practice at alternate irrigation (even), 30% drought stress of existing irrigation practice and 20% drought stress of existing irrigation practice at alternate irrigation) and soil types. The findings revealed significant differences in soil moisture contents (SMCs) across all treatments, with a notable reduction in plant height and yield correlating with increased water stress. Despite variations in water stress and soil types affecting the number of opened bolls, the cotton yield and IWP demonstrated a decline, though not significantly under certain irrigation treatments. Across the deficit irrigation levels, 20% drought stress of existing irrigation practice at alternate irrigation (even) could significantly decrease yield by 6% and reduce IWP by 5% as compared to control treatment. However, the maximum IWP was recorded in the silt loam as compared to silt clay loam, respectively. The validation and calibration method of the CROPGROW-DSSAT model was designed to estimate cotton yield and IWP. The substantial R2 value indicates a strong concordance between the model-calibrated and observed data, signifying the CROPGROW-DSSAT model’s ability to simulate cotton yield and WUE under deficit irrigation strategies within the specific regional climate conditions of Hyderabad. Therefore, it is suggested that the specific deficit irrigation strategies may maintain cotton yield production while reducing water usage, with variations observed between different soil types.

Supplemental irrigation and modified plant density improved photosynthesis, grain yield and water productivity of winter wheat under ridge-furrow mulching

Adopting different irrigation and nitrogen management based on precipitation year types balances winter wheat yields and greenhouse gas emissions

به منظور بررسی اثر میزان آب آبیاری و روش اعمال کم آبیاری بر عملکرد و پارامترهای فیزیولوژیکی و فتوسنتزی ذرت علوفه ای رقم سینگل کراس 704، آزمایشی در سال زراعی 1393، در مزرعه پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی خراسان رضوی انجام شد. آزمایش به صورت فاکتوریل در قالب بلوک های کامل تصادفی در 4 تکرار اجرا گردید. تیمارهای مورد بررسی عبارت بودند از تیمار آبیاری کامل، کم آبیاری تنظیم شده با تأمین 80 و 60 درصد نیاز آبی، آبیاری ناقص ریشه به طور متغیر (PRD) و تأمین 100، 80 و 60 درصد نیاز آبی و آبیاری ناقص ریشه به طور ثابت (FPRD) و تأمین 100، 80 و 60 درصد نیاز آبی. نتایج آزمایش نشان داد که همزمان با کاهش میزان آب مصرفی عملکرد تر و خشک علوفه ذرت در تیمار کم آبیاری تنظیم شده کاهش یافت اما در تیمار آبیاری ناقص ریشه به طور متغیر تفاوت معنی داری بین میزان عملکرد در تیمارهای تامین 100 و 80 درصد نیاز آبی مشاهده نشد. بیشترین عملکرد علوفه تر با میانگین 72099 کیلوگرم در هکتار مربوط به تیمار آبیاری کامل بود. بررسی صفات فیزیولوژیک طی چهار مرحله نمونه برداری در طول فصل رشد، نشان داد که شاخص سطح برگ تحت اثر متقابل تیمارهای آبیاری قرار گرفت. تفاوت معنی داری بین شاخص سطح برگ گیاهان در تیمار آبیاری کامل و سطوح 100 و 80 درصد تامین آبی در تیمار PRD وجود نداشت. همبستگی مثبت و معنی داری بین شاخص سطح برگ و عملکرد علوفه تر (r2= 0.98, p

Yield response and N-fertiliser recovery of tomato grown under deficit irrigation

Raised beds modulate physiological responses, yield and water use efficiency of wheat (Triticum aestivum L) under deficit irrigation

To sustain agricultural productivity and safeguard global food security, and confront the escalating challenges posed by climate change and water scarcity, it is essential to enhance the growth and productivity of rice under water stress. This study investigated the effects of lanthanum chloride on the chlorophyll fluorescence characteristics and grain yield of rice under different irrigation modes. The rice cultivar H You 518 was selected and sprayed 20, 100, or 200 mg·L−1 lanthanum chloride at the booting and heading stages under deficit irrigation (where no rewatering was applied after the initiation of stress, allowing the water layer to evaporate naturally under high temperatures) or conventional irrigation (with daily rewatering to maintain a consistent water level). The results showed that the application of low concentrations lanthanum chloride promoted the chlorophyll content, whereas high concentrations decreased the chlorophyll content, under deficit irrigation, the effect of lanthanum chloride on the green fluorescence parameters of rice leaves at the booting stage was greater than that at the heading stage, and the booting stage was more sensitive to water deficit. The application of 100 mg·L−1 lanthanum chloride reduced the initial fluorescence (F0) and the non-photochemical quenching coefficient (qN); promoted the activity of leaf photosynthetic system II (PSII); and maximized the photochemical quantum yield (Fv/Fm), photochemical quenching coefficient (qP), and PSII relative electron transfer efficiency (ETR). Under deficit irrigation, this treatment significantly enhanced grain yield by increasing the thousand-grain weight, spikelet filling rate, and number of grains per panicle. These results suggest that spraying 100 mg·L−1 lanthanum chloride at the booting stage under deficit irrigation can effectively increase the chlorophyll content, thereby increasing the light energy conversion efficiency of the PS II reaction center, ultimately resulting in increased spikelet filling rate and grain yields.

Climate-smart irrigation strategy can mitigate agricultural water consumption while ensuring food security under a changing climate

Effect of water saving management practices and nitrogen fertilizer rate on crop yield and water use efficiency in a winter wheat–summer maize cropping system

Effects of deficit irrigation on yield, water productivity, and economic returns of wheat

While paddy fields produce a high yield, they also require a large amount of water and produce a significant amount of methane. Therefore, the adoption of water-saving irrigation techniques for rice cultivation is critical. Furrowed rice farming may be a viable alternative to paddy rice cultivation. The objective of the present study was to evaluate the impact of alternate partial root-zone drying irrigation on rice yield, milled rice quality, and cooking quality under furrow rice cultivation. A two-year field trial was conducted on a local rice cultivar, Tarom Hashemi, in 2015 and 2016. Seven water regimes, including three levels of regulated deficit irrigation (RDI), three levels of alternate partial root-zone drying irrigation (APRDI), and conventional flooding irrigation (CFI), were used in this study. In RDI and APRDI treatments, plots were irrigated when soil matric potential had reached −0.1 (RDI1 and APRDI1), −0.3 (RDI3 and APRDI3), and −0.6 bar (RDI6 and APRDI6). RDI1 and APRDI1 treatments produced milled rice yield similar to the CFI, while irrigation water productivity (IWP) was significantly higher by 22.9% and 45.7%, respectively. Regardless of the soil water potential, the IWP in APRDI treatments was 16% higher than that of RDI treatments. Severe water stress (RDI6 and APRDI6) caused a marked increase in amylose content and alkali spreading value of milled rice resulting in improved cooking quality. Nitrogen uptake in APRDI treatments was 2% higher than that of RDI treatments. On average, methane emission per milled grain yield declined by 77.9% and 78.7% in RDI and APRDI treatments, respectively. Our data indicate that the expensive and laborious practice of puddling can be avoided to increase water productivity and improve rice quality without sacrificing yield. The results also show that furrow rice cultivation could significantly reduce the methane emission contribution of rice production.

A field experiment was conducted on a sandy farmland in Northwest China to estimate on the response of maize evapotranspiration and yield to deficit irrigation. The five irrigation treatments consisted of specific combinations of full irrigation and limited irrigation in different crop growing phases (I, from elongation phase to heading; II, from heading phase to milk; III, from milk phase to physiological maturity) were designed. And for estimation of maize evapotranspiration, reference crop evapotranspiration (ET0), basal crop coefficient (Kcb), soil evaporation coefficient (Ke), and water stress coefficient (Ks) in different treatments were calculated. Results showed that; 1) the crop actual evapotranspiration (ETc) for treatments SII (deficit irrigation in phase I), ISI (deficit irrigation in phase II), IIS (deficit irrigation in phase III), SIS (deficit irrigation both in phase I and III), and III (full irrigation) were 570, 604, 579, 542, and 607 mm, respectively. (2) The phase II was the most sensitive phase to water deficit, with reductions in leaf area index (LAI), biomass, yield, irrigation water productivity (IWP), and harvest index (HI). In this phase, the effect of water stress on Ke and Ks was slight, and the evapotranspiration has no obvious difference between full irrigation and limited irrigation. (3) Deficit irrigation in phase I can slow down the crop development in early phase, and can also reduce maize biomass and yield. In this phase, water stress obviously reduced Ke and Ks, and the evapotranspiration in limited irrigation treatments were obviously lower than full irrigation treatment in this phase. (4) However, deficit irrigation in phase III has no significant effect on height and leaf area of maize, and did not also significantly reduce maize biomass and yield. In this phase, the evapotranspiration in limited irrigation treatments were also obviously lower than full irrigation treatment. It can be concluded that it was possible to reduce water consumption and maintain the maize yield by adopting deficit irrigations from milk to physiological maturity, then from elongation to heading, but not from heading to milk in this sandy farmland regions. Key words: Evapotranspiration, deficit irrigation, sandy farmland, maize.