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A solid set sprinkler irrigation system with portable sprinklers was evaluated in a cluster of winter wheat fields in a semiarid area in the south of Iran. Irrigation performance indicators, including coefficient of uniformity (CU), distribution uniformity (DU), application efficiency (AE), potential application efficiency of the lower quarter (PELQ), application efficiency of the lower quarter (AELQ), deep percolation (DP), wind drift and evaporation losses (WDEL), and irrigation adequacy (ADirr) were analyzed in six irrigation events over three fields. Crop water productivity (WP) and final grain yield (GY) were also analyzed to assess the irrigation system efficiency. The results showed that in most irrigation events, the values of CU, DU, AE, PELQ, and AELQ were lower than 81%, 70%, 75%, 65%, and 65%, respectively, as the minimum recommended values in the literature. Furthermore, the ADirr values were between 0% and 80% in the irrigation events. The performance of different irrigation scheduling methods, including NETWAT software (known as the national reference method for irrigation scheduling), Penman–Monteith and Kc, Penman–Monteith and measured Kc, and calibrated Penman–Monteith and Kc were investigated based on monitoring the soil moisture deficit (SMD). Analysis showed that NETWAT estimated the lowest evapotranspiration for all of the wheat growth stages, which indicates an improper choice of irrigation scheduling method. This means that NETWAT highly underestimated the crop water requirement and resulted in a high soil water deficit, whereas the Penman–Monteith and measured Kc had the best match with the SMD. Moreover, in different fields, GY and WP varied between 2.7 and 3.55 Mg ha−1 , and 0.36 and 0.48 kg m−3 , respectively. Our detailed analysis revealed that the main reasons for the inefficient performance of the irrigation system were primarily related to the irrigation system design, scheduling, and setup. Therefore, accountability for the outdated design and subsequent system failure can be attributed to the irrigation system designer(s), the public agricultural agency responsible for approving the system design, and the scientific representative(s) responsible for the irrigation system. This study underscores the detrimental impact of inadequate management and design on the modern irrigation systems, highlighting their potential to reduce crop yields and water productivity significantly. [ABSTRACT FROM AUTHOR]

Excessive water and nitrogen inputs in agricultural production can result in resource wastage and environmental pollution. This makes it imperative to identify effective farmland management strategies to ensure sustainable agriculture development, and it remains to be explored whether biochar can be an effective solution. In this study, a 2-year (2021 and 2022) field experiment was conducted with two irrigation levels, W100 (ET) and W80 (0.8 ET), and three nitrogen fertilizer levels, NH (270 kg ha−1), NM (180 kg ha−1), and NL (90 kg ha−1), in full combination with biochar (30 t ha−1). The NM and N0 treatments without biochar at both irrigation levels were set as controls. The results of the study showed that there was no significant difference in maize yield between the high and medium N treatments. Further, maximum water productivity (WP), nitrogen agronomic efficiency (NAE), and nitrogen recovery efficiency (NRE) were obtained in NM treatments when water and nitrogen were kept consistent. Deficit irrigation was effective in reducing water consumption and increased WP by 15.54% and 11.06% in 2021 and 2022, respectively. Biochar application increased WP, nitrogen use efficiencies, and significantly increased the yield by 7.02% and 6.46% in 2021 and 2022, respectively. Therefore, the application of biochar can be an effective measure to promote crop growth and resource use. Based on the results of this experiment, an irrigation level of 0.8 ET in combination with NM and biochar application is recommended to ensure the sustainability of agricultural production.

The AquaCrop model is used to predict rice yield in response to different irrigation management in the Yanyun irrigation area in Yangzhou, China, and the constraints to rice production were identified to maximize water productivity based on model simulations. The model was calibrated by comparing measured and predicted canopy cover (CC), yield, and soil water content during the growing season in 2018. The results showed that, for CC simulations, R2 was 0.99, RMSE was 3.6%, and NRMSE was 5.3%; for Biomass simulation, RMSE was 0.50 t/ha, and NRMSE was 5.3%. Different irrigation strategies were analyzed for a long-term simulation period from 1955 to 2014. The simulated rice yield increased rapidly as irrigation demand increased initially, and then gradually stabilized. The simulated rice yield fluctuated in the different years. The Pearson type-III model method was used to identify different hydrological years of wet, normal, and dry years. The analysis identified the wet year as 1991, normal year as 1981, and dry year as 1966. In the different rainfall years (1991, 1981, and 1966) water use efficiency (WUE), water productivity (WPet), and irrigation water productivity (IWP) were utilized to determine the irrigation strategy. The predicted highest WPet in the wet year was 1.77kg m−3, while the lowest WPet in the dry year was 1.13 kg m−3. The highest IWP was 19.78 kg m−3 in the wet year, and 9.32 kg m−3 in the normal year; while the lowest IWP in the dry year was 1.90 kg m−3. IWP was significantly higher in the rainy year, while WUE was significantly lower. On the other hand, WPet was more extensive in the wet year because the yield was higher, and the Evapotranspiration (ET) was smaller in comparison to the dry year.

The AquaCrop model is used to predict rice yield in response to different irrigation management in the Yanyun irrigation area in Yangzhou, China, and the constraints to rice production were identified to maximize water productivity based on model simulations. The model was calibrated by comparing measured and predicted canopy cover (CC), yield, and soil water content during the growing season in 2018. The results showed that, for CC simulations, R2 was 0.99, RMSE was 3.6%, and NRMSE was 5.3%; for Biomass simulation, RMSE was 0.50 t/ha, and NRMSE was 5.3%. Different irrigation strategies were analyzed for a long-term simulation period from 1955 to 2014. The simulated rice yield increased rapidly as irrigation demand increased initially, and then gradually stabilized. The simulated rice yield fluctuated in the different years. The Pearson type-III model method was used to identify different hydrological years of wet, normal, and dry years. The analysis identified the wet year as 1991, normal year as 1981, and dry year as 1966. In the different rainfall years (1991, 1981, and 1966) water use efficiency (WUE), water productivity (WPet), and irrigation water productivity (IWP) were utilized to determine the irrigation strategy. The predicted highest WPet in the wet year was 1.77kg m−3, while the lowest WPet in the dry year was 1.13 kg m−3. The highest IWP was 19.78 kg m−3 in the wet year, and 9.32 kg m−3 in the normal year; while the lowest IWP in the dry year was 1.90 kg m−3. IWP was significantly higher in the rainy year, while WUE was significantly lower. On the other hand, WPet was more extensive in the wet year because the yield was higher, and the Evapotranspiration (ET) was smaller in comparison to the dry year. [ABSTRACT FROM AUTHOR]

The Potential Climatic Water Productivity (PCWP) is an important indicator to quantify the effect of intrinsic factors on physical water productivity. The crop calendar is one of the important factors affecting this index. Considering the importance of maize farming and the necessity of improving water productivity, PCWP index has been investigated for eight agronomic calendars and five maize farms between 2015 and 2016. Crop calendars were extracted from available official sources and expert meetings. The PCWP components are determined from the FAO Growth Model (yield) and the standard FAO Penman-Monteith method (evapotranspiration). The mean PCWP for maize forage in the second crop cultivation has increased by 23%, compared to the first cultivation; therefore, the use of second cultivation calendars is recommended in regard to the promoting water productivity. In spite of a 13.7% increase in PCWP in the second maize-grain cultivation, the use of the first cultivation calendars is recommended. Due to changes in water productivity (WP) and its components, water allocation and irrigation scheduling based on ETc appropriate to the crop calendar is essential. However, WP based ETc and actual yield are not appropriate for correct comparison, analysis, and crop calendar selection, so it is necessary to use PCWP values based on climatic potential production (CPP) under water conditions (IPP) and ETc. [ABSTRACT FROM AUTHOR]

Excessive water and nitrogen inputs in agricultural production can result in resource wastage and environmental pollution. This makes it imperative to identify effective farmland management strategies to ensure sustainable agriculture development, and it remains to be explored whether biochar can be an effective solution. In this study, a 2-year (2021 and 2022) field experiment was conducted with two irrigation levels, W 100 (ET) and W 80 (0.8 ET), and three nitrogen fertilizer levels, N H (270 kg ha−1), N M (180 kg ha−1), and N L (90 kg ha−1), in full combination with biochar (30 t ha−1). The N M and N 0 treatments without biochar at both irrigation levels were set as controls. The results of the study showed that there was no significant difference in maize yield between the high and medium N treatments. Further, maximum water productivity (WP), nitrogen agronomic efficiency (NAE), and nitrogen recovery efficiency (NRE) were obtained in N M treatments when water and nitrogen were kept consistent. Deficit irrigation was effective in reducing water consumption and increased WP by 15.54% and 11.06% in 2021 and 2022, respectively. Biochar application increased WP, nitrogen use efficiencies, and significantly increased the yield by 7.02% and 6.46% in 2021 and 2022, respectively. Therefore, the application of biochar can be an effective measure to promote crop growth and resource use. Based on the results of this experiment, an irrigation level of 0.8 ET in combination with N M and biochar application is recommended to ensure the sustainability of agricultural production. • Deficit irrigation reduced water consumption and increased water productivity (WP). • Biochar promoted crop growth and resource utilization combined with suited W/N programs. • Medium N increased water productivity and did not significantly reduce yield than high N. • Biochar, medium N, and deficit irrigation produced high yields, WP & N utilization. [ABSTRACT FROM AUTHOR]

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Bioenergy crops are well known for their ability to reduce greenhouse gas emissions and increase the soil carbon stock. Although such crops are often held to be in competition with food crops and thus raise the question of current and future food security, at the same time mitigation measures are required to tackle climate change and sustain local farming communities and crop production. However, in some cases the actions envisaged for specific pedo-climatic conditions are not always economically sustainable by farmers. In this frame, energy crops with high environmental adaptability and yields, such as giant reed ( Arundo donax L.), may represent an opportunity to improve farm incomes, making marginal areas not suitable for food production once again productive. In so doing, three of the 17 Sustainable Development Goals (SDGs) of the United Nations would be met, namely SDG 2 on food security and sustainable agriculture, SDG 7 on reliable, sustainable and modern energy, and SDG 13 on action to combat climate change and its impacts. In this work, the response of giant reed in the marginal areas of an agricultural district of southern Italy ( Destra Sele ) and expected farm incomes under climate change (2021–2050) are evaluated. The normalized water productivity index of giant reed was determined (WP; 30.1 g m − 2 ) by means of a SWAP agro-hydrological model, calibrated and validated on two years of a long-term field experiment. The model was used to estimate giant reed response (biomass yield) in marginal areas under climate change, and economic evaluation was performed to determine expected farm incomes (woodchips and chopped forage). The results show that woodchip production represents the most profitable option for farmers, yielding a gross margin 50% lower than ordinary high-input maize cultivation across the study area. [ABSTRACT FROM AUTHOR]

Dry direct-seeded rice is an alternative cropping technique that should require less water and labor than classical transplanted-flooded rice. Here, we studied growth, yield and resource use efficiency of rice cultivation in Central China, in 2012 and 2013. We compared dry direct-seeded rice and transplanted-flooded rice. For dry direct-seeded rice, we maintained aerobic conditions up to five-leaf stage followed by anaerobic conditions until maturity. We grew three rice cultivars: Lvhan1, Huanghuazhan, and Yangliangyou6. We measured grain yield, yield components, water consumed, water productivity and nitrogen use efficiency for grain production (NUEg). Our results show that grain yield of dry direct-seeded rice, of 9.01 Mg/ha, is identical to grain yield of transplanted-flooded rice, across cultivars and for both years. The grain yield of dry direct-seeded rice is mainly controlled by the panicle number. Moreover, dry direct-seeded rice uses 15.3 % less water than transplanted-flooded rice. Dry direct-seeded rice increased the grain nitrogen use efficiency by 20.3 % in 2012 and 11.2 % in 2013. [ABSTRACT FROM AUTHOR]