Irrigation Water Productivity Research Articles

Integrated Effects of Water Stress and Plastic Film Mulch on Yield and Water Use Efficiency of Grain Maize Crop under Conventional and Alternate Furrow Irrigation Method

Water scarcity in arid regions increases the need for technologies to improve water productivity. The integrated effects of plastic film mulching and water stress on grain maize under conventional and alternate furrow irrigation methods are still poorly understood in Sindh’s climate. Therefore, field trials were conducted at Malir farm, Sindh Agriculture University Tandojam, Pakistan, during the cropping season 2020–2021 to investigate whether mulching is practicable for grain maize production under the different furrow irrigation methods. The experiments involved two types of furrow irrigation, two water stress levels (sufficient and severe water stress), and plastic film mulching. Treatments were laid out in a randomized block design and three replications. The conventional and alternate furrow irrigation method was assigned to the main plot, while the water stress and plastic film mulching were in sub-plots. The results showed that different furrow irrigation methods significantly affected plant growth, grain yield parameters, and crop harvest index. Significant highest plant growth and grain yield of maize crop were observed with the conventional furrow irrigation (CFI) compared with the alternate furrow irrigation (AFI) method. However, grain yield and irrigation water productivity (IWP) were increased significantly by the plastic film mulching. The results revealed that sufficient water stress was more effective in sustaining grain yield and IWP than crop irrigating at several water stresses. The interaction effect of furrow irrigation and water stress, furrow irrigation, and plastic film mulching significantly impacted the IWP of grain maize. The IWP of the maize crop was significantly higher under the AFI than the CFI method if it was mulched with plastic film and irrigated at sufficient water stress level.

Sustainable land-water-food nexus management: Integrated modelling approach

Land, water, and food resources are essential for human survival, economic development, and social stability. Water and land are the basic resources in irrigated agricultural systems. Sustainable agricultural development entails effective management of the land-water-food nexus. The complex relationship in land-water-food nexus, with large uncertainties encompassed therein. Approaches that interconnect Land-Water-Food have grown significantly in scope and intricacy. In evaluating solutions to accomplish Sustainable Development Goals (SDGs) under the contexts of rising demands, resource paucity, and climate change, nexus techniques are helpful. The nexus analysis includes the important interlinkages that could be addressed. In the water-food-land nexus system, optimization approach can increase irrigation water production and optimise the allocation of scarce resources. Model optimisation considers the uncertainties in the systems to help decision-makers devise effective strategies for allocating water and land resources effectively. Integrated modelling with efficient optimization methods aid in solving real-world nexus management issues and provides the results that could serve as the basis for effective management of land-water-food nexus and formulation of agricultural policies.

Alternate micro-sprinkler irrigation synergized with organic fertilizer: A sustainable water-fertilizer management technology of improving quality and increasing efficiency in Panax notoginseng production

The yield of Panax notoginseng (BurK.) F. H. Chen in Yunnan Province accounted for more than 90% of China's total yield, but extensive water and fertilizer management restricted improvement of yield, quality, and economic benefits of Panax notoginseng. Therefore, this study tried to propose an adaptive irrigation and fertilizer management strategy for Panax notoginseng production. A two-year (2017 and 2018) rain-shelter cultivation study in Yunnan Province of southwest China was conducted to analyze the influences of irrigation and organic fertilizer application on soil water distribution, root growth, water-fertilizer productivity, quality, and economic benefits of Panax notoginseng in four organic fertilizer application rates [500 (F1), 1000 (F2), 1500 (F3), and 2000 (F4) kg ha−1] combined with three micro-sprinkler irrigation schedules [I1: moderate deficit micro-sprinkler irrigation, (70–75%) θFC; I2: alternate micro-sprinkler irrigation, (70–75%) θFC / (80–85%) θFC; I3: slight deficit micro-sprinkler irrigation, (80–85%) θFC]. The results indicated that the increasing micro-sprinkler irrigation levels enhanced soil water content in 0–40 cm soil layer, but resulted in a reduction irrigation water productivity (IWP). Moreover, the increasing organic fertilizer application significantly led to reduced partial fertilizer productivity (PFP). Under the interaction of micro-sprinkler irrigation schedules and organic fertilizer application in 2017 and 2018, the I2F3 significantly obtained the highest soil water storage (SWS), root hydraulic conductivity, root morphological characteristics, root-shoot ratio, lowest root rot rate (4.68% in 2017 and 6.59% in 2018), largest yield (3614.5 kg ha−1 in 2017 and 3981.5 kg ha−1 in 2018), total saponin content (20.23% in 2017 and 23.28% in 2018), and economic benefits (25.28 × 104 $ ha−1 in 2017 and 32.6 × 104 $ ha−1 in 2018) of Panax notoginseng. Based on the above results, the comprehensive evaluation of five saponin contents and the comprehensive evaluation of the yield, IWP, PFP, economic benefits, and total saponin content of Panax notoginseng were analyzed by using a TOPSIS model in 2017 and 2018. We found that synergistic of alternate micro-sprinkler irrigation [I2, (70–75%) θFC / (80–85%) θFC] and organic fertilizer application (F3, 1500 kg ha−1) could decrease root rot, improve root growth, water-fertilizer productivity, quality, and economic benefits of Panax notoginseng.

Adaptation Strategy Can Ensure Seed and Food Production With Improving Water and Nitrogen Use Efficiency Under Climate Change

AbstractAdaptation strategies can reduce the negative impacts of climate change on food security. As an important part of food security, more attention should be paid to seed security, as it determines the crop planting area and ultimately affects food production, especially in major seed production locations, such as the Hexi Corridor in China. This region is an important production base of grain (including field maize and wheat) and maize seed, but the shortage of water resources and low use efficiency of water and nitrogen (N) seriously constrain the sustainable development of agriculture. Formulating an adaptation strategy to balance the seed and food production and resource use efficiency is an important way to maintain regional as well as national food production. We established an optimization‐simulation framework, which consists of a novel crop production function and a grid‐based crop model, APSIM. This framework was used to optimize agricultural management and evaluate its performance considering the spatio‐temporal variability of climate and soil properties, actual crop water consumption and N uptake during each growth stage, and interactive sensitivity coefficients of water and N at different growth stages under climate change. We show that the proposed adaptation strategy could save 0.31 km³ of irrigation water and 22 thousand tonnes of N fertilizer, and increase seed and food production by 33 thousand tonnes, compared with traditional practices. Significant increases in irrigation water productivity and N use efficiency can be expected by using the adaptation supporting the sustainable development of agriculture.

Spatio-Temporal Distribution Characteristics and Driving Factors of Main Grain Crop Water Productivity in the Yellow River Basin.

To reveal the relationship between agricultural water resource consumption and grain production in the Yellow River Basin, the irrigation water productivity (WPI), crop water productivity (WPC), total inflow water productivity (WPT), and eleven influencing factors were selected. The spatial and temporal distribution characteristics and driving factors of water productivity of the main crops in the Yellow River Basin were analyzed with the spatial autocorrelation analysis, grey correlation analysis, sensitivity analysis, and relative contribution rate. The results showed that the minimum mean values of WPI, WPC, and WPT were 0.22, 0.35, and 0.18 kg/m3 in Qinghai, respectively, the maximum mean value of WPI was 2.11 kg/m3 in Henan, and the maximum mean values of WPC and WPT were 0.71 and 0.61 kg/m3 in Shandong, respectively. The changing trends in WPI and WPT in Qinghai and in WPC in Shandong were insignificant, whereas the WPI, WPC, and WPT in other provinces showed a significant increasing trend. Water productivity displayed a certain spatial clustering feature in the Yellow River Basin in different years, such as a high-high (H-H) aggregation in Henan in 2005, and an H-H aggregation in Shanxi in 2015 for WPI. The water productivity had a significant positive correlation with the consumption of chemical fertilizer with a 100% effective component (CFCEC), effective irrigated area (EIA), plastic film used for agriculture (PFUA), and total power of agricultural machinery (AMTP), while it had a significant negative correlation with the persons engaged in rural areas (PERA). There was a large grey correlation degree between the water productivity and the average annual precipitation (AAP), CFCEC, PFUA, consumption of chemical pesticides (CFC), and AMTP in the Yellow River Basin, but their sensitivity was relatively small. The main driving factors were EIA (8.98%), agricultural water (AW, 15.55%), AMTP (12.64%), CFCEC (12.06%), and CPC (9.77%) for WPI; AMTP (16.46%), CFCEC (13.25%), average annual evaporation (AAE, 12.94%), EIA (10.49%), and PERA (10.19%) for WPC; and EIA (14.26%), AMTP (13.38%), AAP (12.30%), CFCEC (10.49%), and PFUA (9.69%) for WPT in the Yellow River Basin. The results can provide support for improving the utilization efficiency of agricultural water resources, optimizing the allocation of water resources, and implementing high-quality agricultural developments in the Yellow River Basin.

Residual effect of maize (Zea mays) + blackgram (Vigna mungo) intercropping on growth, factor productivity and resource-use efficiency of succeeding wheat (Triticum aestivum) under integrated crop management

A 2-year field experiment was conducted during the winter (rabi) season of 2019–20 and 2020–21 at the ICAR– Indian Agricultural Research Institute, New Delhi to study residual effect of the preceding blackgram (Vigna mungo (L.) Hepper) intercropped maize (Zea mays L.) on succeeding wheat (Triticum aestivum L.) growth, factory productivity, resource-use efficiency, and yields. The treatments consisting of 9 integrated crop management (ICM) variants allotted to mainplots and 2 cropping systems (maize–wheat; maize+blackgram–wheat) in subplots, were replicated thrice in a split-plot design. Different combinations of tillage, crop-establishment patterns, integrated nutrient, weed, pest, and disease management were used to create the integrated crop management (ICM) treatments. The conservation agriculture (CA) embedded ICM, viz. ICM7 , Zero-till + Permanent raised beds + maize crop-residue retention at 3 t/ha + 100% RDF + Glypho-PP fb Sulf+Met at PoE + 4 irrigations of 45 mm each + Need-based IDM/ IPM recorded significantly higher growth (99.9 cm), dry-matter accumulation (1127 g/m2), growth indices (crop growth rate 18.1 g/m2 /day), production (37.5 kg/ha/day)-, monetary (627.8 INR/ha/day)-efficiencies, irrigation water productivity (2.57 kg/m3) and wheat grain yield (5.57 t/ha). While conventional tillage (CT)-based treatments recorded significantly higher partial factor productivity (57.2, 265.8, 206.6 kg grain/kg of applied N, P and K respectively). The succeeding wheat crop benefited significantly from the residual effect of preceding blackgram intercropping in terms of growth, resource-use efficiency (irrigation water productivity, 2.07 kg/m3) and productivity (5.16 t/ha). The factor productivity, resource-use efficiency, grain yield of wheat under CA-based ICM can be enhanced by preceding blackgram + maize intercropping.

Grain Yield and Water Productivity of Irrigated Rice Affected by Transplanting Dates in Bangladesh

Selection of suitable transplanting window is essential for getting desired crop yield and optimizing irrigation water. This study was conducted in four different locations of Bangladesh (Gazipur, Mymensingh, Cumilla and Bogura districts) to investigate the effect of transplanting period on irrigation water productivity during irrigated rice (Boro) cultivation. Ceres-rice model incorporated in DSSAT was used to estimate rice grain yield and agronomic parameters for Boro 2016-17. Daily weather data and soil data were collected from Bangladesh Meteorological Department (BMD) and Soil Resource Development Institute (SRDI). The estimated irrigation scheduling using CROPWAT- 8.0 model was used as input to the DSSAT model. Rainfall distribution showed only about 22% (2% in winter and 20% in pre-monsoon) of annual rainfall occurred in irrigated rice growing period. Delay transplanting after 15 December, the cultivar BRRI dhan28 faced higher mean daily temperature resulted shorter life span. The increased seasonal mean temperature by 2.8ºC in Gazipur and Bogura and 2.6ºC in Mymensingh and Cumilla from 15 December to 01 March reduced growth duration by 24 days in Gazipur, Mymensingh and Bogura and by 26 days in Cumilla district. Cumilla received the maximum rainfall, however Gazipur experienced the lowest among the four study locations. The received rainfall amount increased with the advancement of transplanting date from 15 December. The increased rainfall reduced the irrigation demand of the cultivar. On the contrary, reduced growth duration due to delay transplanting decreased the grain yield. Transplanting up to 1 February produced almost similar grain yield, while irrigation demand decreased from 15 December transplanting. Water productivity showed increasing trend for late transplanting. Considering grain yield and irrigation water productivity, 15 January to 1 February transplanting were found suitable transplanting period for the study locations. Rice crop establishment within the recommended period could be optimized the grain yield and irrigation water productivity in the selected study locations. Thus, maximum coverage of rainfall can be reduced the irrigation demand. Consequently, it may help to optimize groundwater use and to arrest the groundwater mining. Bangladesh Rice J. 25 (2) : 21-30, 2021

Improvement's energy used in sprinkler irrigation systems

The effects of the climatic change in the agricultural sector are more perceptible each day, this is reflected basically through the periods of drought that are increased in frequency and intensity. This reality forces us to carry out an efficient use of the available water; the inadequate water use pumped for the irrigation implies the low efficiency of the electric power for this activity. With the objective of valuing the effectiveness of the energy used in this activity in practice, a pilot study was conducted in Victoria II belonging to the Camagüey Agrarian enterprise. The electric power consumption in the irrigation was controlled in all the irrigation systems of the productive unit during the campaign of the cultivation of the bean in the year 2017, the productivity of the energy used in the irrigation in all irrigation systems of the technologies of pivot machines and sprinkler irrigation systems was determined, the obtained values were compared taking like reference the most favorable result. The evaluations demonstrated that during the cycle of the cultivation, losses take place in the use of the water due to the imperfect irrigation programming and low uniformity of distribution of the water, which is reflected in the low productivity of irrigation water and energy together with the concern about planting. This shows that the efficiency index of pivot machine is only 76%, and the efficiency index of sprinkler system is 63%.

Climate-smart technologies for reducing water footprints in different cropland ecosystems: a meso analysis

Water footprints (WFs) in crop production are an ecological measurement of water utilization that represents the cumulative groundwater quantum consumed within a region (district/state or country) to produce the crops. WFs in crop production have great significance for ecosystem’s sustainability, as high WFs are posing a serious challenge for the scientists and presents researchable issues for reducing WFs for increased crop water productivity. Crop need based approaches and improved climate smart technologies (CSTs) instead of conventional approaches help in reducing the irrigation water use without compromising crop yields. In view of global warming, need to reduce the water intake in agricultural production has been thought as an urgently sustainable issue. Amongst various crops of South Asia, rice–wheat cropping system extensively cultivated on ~ 12.5 million ha (Mha), has large WFs. A large scale field experimentation suggested several permissible techniques having overwhelming significance for reducing WFs in crop production. Amongst the several CSTs, laser levelers for precision leveling, cultivars with short duration rice varieties, delayed transplanting of rice seedlings, soil matric potential (or tensiometer) based irrigation scheduling, direct drilling of rice seeds, crop establishment on permanent beds, mechanical rice seedling transplanting, and crop diversification through oilseed/pulses has considerable significance in water saving and decreased WFs. Nonetheless, all technologies are not universally efficient in reducing WFs, and depend up on several factors of which soil texture and climatic conditions are the major determinants. For feeding the burgeoning population and to sustain and/or increased food production, technological focus should be on widespread adoption of technologies which aims at reduced WFs either by decreasing water loss from the leaf and/or soil. The present review deals with WFs in crop production, and the technologies to enhance irrigation water productivity and ecosystems’ sustainability of predominant cropping system of South Asia, particularly in water-harassed regions.

Cool- and Warm-Season Turfgrass Irrigation with Subsurface Drip and Sprinkler Methods Using Different Water Management Strategies and Tools

This study compared the performances of subsurface drip irrigation (SDI) to sprinkler irrigation (SI) of cool-season turf mix (CS) and warm-season (WS) turfgrass species while investigating their response to different irrigation scheduling strategies. Moreover, the suitability of crop water stress index (CWSI) for monitoring water stress and scheduling irrigation was tested. Irrigation was applied up to the field capacity when 30%, 50% and 70% of total available water was consumed. All parameters, including color, quality, fresh yield, dry matter yield, irrigation water productivity, water productivity, vegetation height and mowing, differed significantly for different irrigation methods and water supply strategies for both species. The best visual turf was maintained under non-limiting soil moisture conditions (30%) in all main and sub-treatments. At this irrigation threshold, maximum and minimum amounts of irrigation water were applied in SI CS treatment (523.5 mm) and SDI WS treatment (298.6 mm), respectively. Warm-season turf required up to 40% less water than cool-season turf mix. In the water-scarce regions, 50% treatment for cool-season and 70% treatment for warm-season can be suggested for acceptable visual quality, lower water consumption and less frequent clipping. The mean CWSI before irrigation, representing irrigation threshold, ranged between 0.22–0.70.

Effect of Soil Moisture Deficit on Aerobic Rice in Temperate Australia

Declining water availability is pressing rice growers to adopt water-saving irrigation practices such as aerobic rice to maintain profitability per megalitre (ML) of water input. Irrigators require well-defined irrigation thresholds to initiate irrigation to maximise water productivity. Such thresholds do not exist for temperate rice regions. Adopting a strategy that has been reported to succeed in non-temperate environments may fail in temperate climates, and therefore, needs investigation. This study aimed to investigate, in a temperate Australian environment, the effect of increasing soil moisture deficit during the rice vegetative period on crop physiological development, grain yield and water productivity. The study was conducted in a commercial farm using a randomised complete block design in the 2020/21 and 2021/22 growing seasons. Automated gravity surface irrigation technologies were adopted to enable high-frequency irrigation. Extending soil moisture deficit beyond 15 kPa was found to significantly delay panicle initiation by at least 13–14 days, exposing rice to cold temperatures in Year 1 during the cold-sensitive early pollen microspore period. This reduced yield by up to 55% (4.5 t/ha) compared to the 15 kPa treatment that was not impacted by cold sterility. In the absence of cold sterility, irrigated water productivity and total water productivity ranged between 1.02 and 1.61 t/ML, and 0.84 and 0.93 t/ML, respectively. The highest yields (8.1 and 7.5 t/ha) were achieved irrigating at a soil tension of 15 kPa in growing seasons 2020/21 and 2021/22. This research demonstrates that sound water productivity can be achieved with aerobic rice cultivation in temperate climates, providing cold temperatures during early pollen microspore are avoided. The quantification of the delay in crop development caused by increasing soil moisture deficit provides rice farmers greater confidence in determining the irrigation strategy and timing of pre-emergent irrigation in regions at risk of cold sterility. However, due to the high labour demand associated with aerobic rice, the adoption of aerobic rice at a commercial scale in this Australian environment is unlikely without adopting automated irrigation technology.

Simulating Long-Term Effects of Sowing Date on the Yield of Dryland and Irrigated Winter Wheat

Highlights This study employed AquaCrop model to simulate winter wheat growth in Oklahoma. Different sowing dates and water availability at the time of sowing were investigated. 5 October was found to be the most optimum sowing date by producing overall greater wheat yields. 25% decrease in dryland crop yield was noted when soil water content at sowing was decreased from 100% to 40% of total available water. Abstract. Dryland winter wheat is the most widely grown crop in Oklahoma, where water availability and temperature variations are the major factors affecting the yield of this crop. These effects were assessed using the AquaCrop model. Model calibration and validation were performed using field measurements collected from 11 site-years. The validated model satisfactorily simulated soil water content, maturity biomass, and yield, with overall normalized root mean square errors of 11%, 5%, and 9%, respectively. The model was then used in long-term (1994-2019) simulations of winter wheat at three locations in Oklahoma’s wheat belt under five sowing dates (15 Sept., 25 Sept., 5 Oct., 15 Oct., and 25 Oct.) and three soil water contents (SWC) of 40%, 70%, and 100% of the total available water at sowing. The highest simulated average dryland yields (6.4 to 6.6 Mg ha-1) were obtained for early to mid-October sowing dates under the largest SWC at sowing. The lowest average yields (2.67 to 4.15 Mg ha-1) belonged to earlier sowing (mid-September) under the smallest SWC at sowing. Irrigation had a positive impact on the yield of winter wheat and this impact increased for later sowing. The yield of winter wheat sowed in mid-September increased by 0.28 Mg ha-1 under irrigation when averaged for all years and sites, while late-October average yield was 0.96 Mg ha-1 higher than dryland average yield. Irrigation water productivities also increased with later sowing dates. Keywords: AquaCrop, Irrigation water productivity, Oklahoma, Soil water content.

Effects of Irrigation Methods and Scheduling on Water and Onion Productivity in Semi-Arid Areas of Ethiopia

Highlights Irrigation experiments on onion productivity were conducted at two sites for two consecutive years in Ethiopia. Factors from irrigation interval and irrigation method analyzed independently and factorially. Basin irrigation and fixed irrigation produced higher bulb yields and water productivity. Farmers’ income can be enhanced using improved irrigation practices for increased onion productivity. Abstract. How to meet the crop water demand and improve crop productivity is a particular concern for small-scale farmers, where the availability of water resources is limited. This study evaluated three different irrigation methods (furrow, basin and border) and two types of irrigation scheduling (CROPWAT schedule and farmers’ practices) with three replications for two consecutive years (2016-2017) at two sites using onion crops. The results showed that the CROPWAT schedule, basin irrigation method, and their interactions showed better performances and produced higher yield and water productivity. An average of 26 and 27 metric tons/hectare of onion were obtained under the basin irrigation method and basin irrigation with CROPWAT schedule combined, respectively. The water productivity (WP) and irrigation water productivity (IWP) also showed higher results under the basin irrigation method compared to other treatment combinations. The basin irrigation method produced higher marketable onion bulbs with firm medium bulb sizes that are essential for onion producers to earn maximum profit. The findings of this study also indicate that focusing on enhanced irrigation scheduling techniques and irrigation methods is paramount for better onion productivity in irrigation water-limited areas. Keywords: Irrigation interval, Irrigation methods, Irrigation practices, Onion productivity, Water management.

Advances in Bioremediation of Agricultural Soil Contamination

With the rapid advancement of industrialization and agricultural intensification, the issue of farmland pollution has garnered significant attention. This paper introduces the sources and hazards of farmland pollution, along with the types, principles, and technical advantages of bioremediation. Additionally, it makes a brief prediction of future farmland restoration efforts. Research indicates that the primary sources of farmland pollution currently include four factors: the natural environment, atmospheric deposition, irrigation water, and agricultural production activities. There are two primary methods of remediation for farmland contamination: phytoremediation and microbial remediation. Phytoremediation is mainly used in heavy metal pollution treatment and can be divided into hyper-accumulation plants and low-accumulation crops based on the remediation method. Microbial remediation, meanwhile, is primarily utilized to remediate organic pollution and assist phytoremediation.

Agronomic and physio-biochemical responses of lettuce to exogenous sodium nitroprusside (SNP) applied under different irrigation regimes

Drought adversely affects crop production in areas with water shortages. In such areas, various methods need to be implemented to alleviate the effect of water stress on plants. Nitric oxide (NO) is an important plant growth regulator that affects various physiological processes. In this study, we determined ways to increase water-stress tolerance of lettuce by applying exogenous sodium nitroprusside (SNP, a donor of NO). In total, 12 treatments were administered, including three SNP doses (0, 50, and 100 µM) and four levels of irrigation (I100, I80, I60, and I40). An increase in the doses of NO partially increased the water consumption of lettuce under full and deficit irrigation conditions. The highest water consumption (125.1 mm) and the highest yield (39.1 t/ha) were recorded for lettuce plants that were administered the I100 treatment with 100 µM SNP. SNP significantly increased the lettuce yield and irrigation water productivity (IWP) under deficit irrigation and full irrigation. SNP promoted chlorophyll synthesis by increasing photosynthesis. The application of 100 µM SNP increased catalase (CAT) activity approximately three times compared to CAT activity in the control group, and it also significantly increased peroxidase (POD) activity. Additionally, high doses of SNP reduced membrane damage in lettuce leaves. These results indicated that under water stress, exogenous NO improves photosynthesis by increasing chlorophyll synthesis, activates antioxidant enzymes, such as CAT and POD, protects lettuce against oxidative damage, and increases irrigation water productivity, thus increasing the yield.

Row spacing and irrigation management affect soybean yield, water use efficiency and economics

Declining water levels in the Mississippi River Valley Alluvial Aquifer necessitates research on the management practices that can reduce irrigation water use and improve irrigation water use efficiency. A three-year field study from 2019 to 2021 evaluated the effects of row spacing and irrigation management on soybean seed yield and quality, irrigation water use efficiency (IWUE), water productivity (WP), and profitability. Soybean was planted in two row spacings [single- (SR) and twin-row (TR)] and irrigated with three different methods [every row irrigated (ERI), alternate row irrigated (ARI), non-irrigated (NI)]. Soybean yields were increased with application of irrigation either as ERI or ARI as compared to NI in all three years ranging from 20% to 79%. The ERI had 20% increase in yield over ARI in 2021, whereas no significant differences were found between ERI and ARI in 2019 and 2020. Averaged over row spacing, IWUE was 66–91% greater with ARI compared to ERI. Only 2021 showed an increase (34%) in WP with irrigation applied as ARI than NI. Differences in rainfall amount among years and amount of irrigation applied under different treatments affected the soybean yields. Soybean yield showed reduction by 0.37–1.2 kg ha−1 with each unit increase in cumulative stress (kPa-days) for soil moisture potential drier than the −40 kPa on very fine sandy loam soils. Twin-row soybean had higher expected returns in all cases except for the NI and ERI in 2021. The TR soybean produced the greatest average risk-return than other treatments. The ARI with TR had the second highest overall risk-return trade-off. The ARI resulted in an equivalent risk-return production system as ERI for SR soybeans. Alterations in furrow irrigation methods could be more beneficial than row spacing to improve soybean productivity and IWUE.

Improvement of water and crop productivity of silage maize by irrigation with different levels of recycled wastewater under conventional and zero tillage conditions

Although wastewater irrigation has a long history involving different stages of development, the future expectation to improve crop yield and water productivity in wastewater irrigation practices is still relevant. Therefore, the aim of this study is to evaluate water productivity, yield and crop quality of silage maize irrigated with different application levels (100%, 67%, and 33% of irrigation need) of recycled wastewater with three replicates in conventional tillage and zero tillage practices and comparing them with full fresh water irrigation. The results of two-year field studies showed that zero tillage resulted in saving 10.1% of irrigation water on average compared to conventional tillage and actual evapotranspiration in silage maize with zero tillage was 7.4% less. Biomass yield was the highest in full irrigation with wastewater under zero tillage. Zero tillage practice provided 12.0% and 13.2% higher water productivity(WP) and irrigation water productivity(WPirrig), respectively compared to conventional tillage. The WP was higher in treatments with wastewater with 100% and 67% irrigation levels, while the WPirrig was higher in treatment with wastewater with 67% irrigation level. While the crop total soluble solids, nutrients, crude protein, chlorophyll(SPAD), leaf area index and leaf relative water content (LRWC) values were higher in full irrigation with wastewater, acid and neutral detergent fibers and membrane damage was lower. Crude protein in zero tillage was lower than in conventional tillage, while SPAD and LRWC were higher. It could be concluded that wastewater can increase silage maize biomass yield and crop quality. This result may be more valuable in terms of both protecting scarce fresh water resources and contributing to the environment with waste disposal. Moreover, 67% irrigation treatment with wastewater can be preferred for the higher WP and WPirrig values, and zero tillage can be used as a practical treatment that contributes to the yield and water saving.

Yield, water productivity and nutrient balances under different water management technologies of irrigated wheat in Ethiopia

Development of irrigation technologies and agricultural water management systems holds significant potential to improve productivity and reduce vulnerability to climate change. Our study dealt with the behavior of irrigation water productivity, partial nutrient balance and grain yield of wheat under the application of different irrigation water management technologies in the Koga irrigation scheme in Ethiopia. For our analysis, we considered three nutrient fluxes entering and leaving farmers’ fields. Our experimental design had three irrigation blocks with three different irrigation water management practices (wetting front detector, Chameleon soil moisture sensor and farmers’ practice as control) on three farm plots replicated in each block. To calculate irrigation water productivity and grain yield of wheat, the amount of irrigation water applied and the agronomic attributes of wheat yield were recorded during the irrigation period. Further, three input and output variables were considered to determine the partial nutrient balances of nitrogen (N), phosphorus (P) and potassium (K). The results showed that the amount of irrigation water used was 33% and 22% less with a wetting front detector and Chameleon sensors, respectively, compared to the farmers’ practice. The wetting front detector (WFD) and Chameleon sensor (CHS) treatments gave a 20% and 15.8% grain yield increment, respectively, compared to the farmers’ practice plot. The partial nutrient balances of N and K were negative for the wetting front detector and chameleon sensor practices while it was positive for P in the control (farmers’ practice) treatment. We conclude that irrigation water management with appropriate technologies can improve yield, water productivity and the nutrient utilization. However, further research needs to be conducted on the suitability of irrigation management technologies to achieve full nutrient balance.

Rational biochar application rate for cotton nutrient content, growth, yields, productivity, and economic benefits under film-mulched trickle irrigation

Biochar application to soils has been proven to be an efficient way for yield enhancement in agricultural systems. However, what is the most economical biochar application rate (BCAR) for cotton in saline-alkali soils in arid and semi-arid zones remains unclear. To narrow the gap, this study aims to investigate how biochar application affected the nutrient content, growth, yield, quality, and productivity of cotton, and to find the rational BCAR. The three-year field experiments of biochar application combined with plastic film mulched drip irrigation were conducted for cotton in Xinjiang, China. The biochar was continuously applied to the farmland at 0 (in 2018)+ 0 (in 2019)+ 0 (in 2020), 10 + 10 + 10, NT (no test)+ 25 + 25, 50 + 50 + 30, and 100 + 100 +NT t ha−1 during cotton growth period of 2018–2020. The cotton growth, yield, and quality indicators were observed and used for computing water-fertilizer productivity. The cost-benefit analysis was referred to recommend a rational BCAR. All four biochar application treatments increased the leaf/stem/root nutrient (N, P, and K) content than control during different cotton growth stages. The daily relative content of chlorophyll increased with the increasing BCAR and were larger at biochar treatments of 50 and 100 t ha−1 than 0, 10, and 25 t ha−1. The growth and yield-related indicators (plant height, stem diameter, leaf area index and seed yield), irrigation water productivity, and partial fertilizer (N, P, and K) productivity consistently increased than control under biochar application conditions, and the BCAR of 10 t ha−1 showed the greatest advantages in enhancing germination rates, cotton yields, water-fertilizer productivities, and financial income than biochar treatments of 0, 25, 50 and 100 t ha−1. However, neither cotton fiber quality indices (length, Micronaire, strength or uniformity index) were significantly affected by biochar applications. Based on the economic analysis, the rational BCAR was 10 t ha−1 each year (continued for three years) for cotton planting, which was a best dose that could be applied to arid zones and have not been reported before.

Enhancing resource use efficiency of alfalfa with appropriate irrigation and fertilization strategy mitigate greenhouse gases emissions in the arid region of Northwest China

With the increasing global warming concerns, appropriate agronomic practices for improving crop yields while reducing greenhouse gases (GHGs) emissions are essential for sustainable agricultural production. However, little information is available if these benefits can be achieved simultaneously in arid pastoral agriculture systems with irrigation and nitrogen (N) management. We assumed that the local practiced irrigation (600 mm) and N (300 kg ha −1 ) applications for spring wheat in the arid regions of Northwest China are excessive, and optimizing irrigation-N rates would improve the resource use efficiency of alfalfa and reduce GHGs emissions. A two-year field study (2015–2016) was conducted to investigate the effects of irrigation regimes (I L , 300 mm; I M , 450 mm; and I H , 600 mm) and N application rates (F 0 , 0; F L , 150; F M , 225; and F H , 300 kg ha −1 ) on forage yield, resource use efficiency, and GHGs emissions from alfalfa fields. The GHGs emissions during alfalfa growing seasons were assessed by analyzing gas samples using the static chamber-gas chromatography method. High irrigation and N application (I H F H ) was associated with elevated GHGs emissions, global warming potential, and greenhouse gas intensity, but lower irrigation water productivity (IWP) and partial factor productivity of N (PFP N ). Reducing the irrigation and N rates decreased the GHGs emissions but differently affected alfalfa yield and resource use efficiencies. Among all the treatments, I M F L and I H F L resulted in the highest alfalfa yields, IWP, and PFP N . However, I M F L showed a good trade-off between yield benefits and environmental performance manifested by lower GHGs emissions, GWP, and GHGI. The I M F L reduced the cumulative emissions of nitrous oxide by 67.83% and 67.16%, carbon dioxide by 31.05% and 34.60%, GWP by 61.72% and 70.40%, and GHGI by 74.37% and 79.78%, while increased alfalfa yield by 49.24% and 46.45%, IWP by 99.05% and 94.97%, and PFP N by 198.44% and 192.90% compared to I H F H . Regardless of all the treatments, the alfalfa field acted as a CH 4 sink during both crop-growing seasons. Our results suggest that the application of 450 mm irrigation and 150 kg N ha −1 could be used as an appropriate management strategy for enhancing resource use efficiencies and mitigating GHGs emissions, GHGI, and GWP from alfalfa fields. The findings can provide an opportunity for greenhouse gas mitigation without alfalfa forage yield reduction following the proper irrigation and fertilization regimes in the arid region of northwest China and areas with similar agro-climatic conditions. • Intensive irrigation and fertilization increase GHGs emissions and global warming potential. • Enhancing resource use efficiency with suitable irrigation and N rates mitigate GHGs emissions. • Soil moistures and inorganic N contents are the major factors regulating GHGs emissions. • 450 mm irrigation and 150 kg N ha –1 maintain high alfalfa yields and minimize environmental impacts.