Agricultural Water Management最新文献

China’s agricultural production suffers significant constraints due to low water productivity (WP) and partial factor productivity for nitrogen (PFPN). The pivotal solution to enhance maize yield, WP, and PFPN is through optimizing field management practices. However, previous studies primarily focused on the effects of individual or coupled field management practices on maize yield, WP, or PFPN in an area or land mass, so it is necessary to conduct a comprehensive quantitative analysis of various field management practices on maize yield, WP, and PFPN at the national scale. In this study, we compiled 286 studies encompassing 6959 pairs of experimental data spanning from 1990 to 2023. Meta-analysis was conducted to observe the variations in maize yield, WP, and PFPN across diverse field management practices (straw returning, nitrogen fertilizer application, irrigation practice, and tillage practice) on a national scale. The results showed that nitrogen fertilizer application (215 kg N ha⁻¹) was the most effective in enhancing maize yield and WP by 68.1 % and 54.8 %, respectively. Additionally, irrigation had the most substantial impact on PFPN, enhancing 16.8 %. Straw mulching, application of slow and controlled release fertilizers, drip irrigation, and subsoiling were identified as the most effective practices in increasing maize yield, WP, and PFPN by Random forest model. Maize straw returning could reduce nitrogen fertilizer application by 20 kg ha⁻¹, while increasing WP and PFPN by 4.2 % and 11.6 %, respectively. Moreover, straw returning could reduce water consumption by 23–60 mm, while increasing WP and PFPN by 2.9 % and 6.8 %, respectively. These findings can provide a reference for the formulation of comprehensive management strategies for sustainable maize production in China and globally.

Olive trees are extremely drought-resistant species. This particularity could be used to reduce water needs in regulated deficit irrigation scheduling. However, the yield response to water deficit is linked to the moment and the level of water stress imposed. Pit hardening has been commonly used as the stage to decrease irrigation, but it is not measured under field conditions. The aim of this work is to describe the impact of water stress conditions on yield response for table olive trees, considering an accurate determination of the endocarp development. The experiment was performed from the 2020 to the 2023 seasons on a two-year-old super-high density table olive orchard (cv Manzanilla de Sevilla). The three irrigation treatments (six repetitions) were: Control, no water stress conditions throughout the season in 2020 and 2021, and mild water stress to reduce vigour in 2022 and 2023; Regulated deficit irrigation (RDI), based on a moderate to severe water stress during pit hardening, using midday stem water potential measurements; and Rainfed. Endocarp development was established using the pit-breaking pressure throughout the 2021, 2022 and 2023 seasons. Water relations, vegetative growth, number of inflorescence and fruits, yield and fruit quality were measured during the experiment. Crown volume limited yield in Rainfed treatments but not in RDI, compared to Control. The number of inflorescences and inflorescence set was not affected in RDI and Rainfed, only reduced in severe water stress in 2023. RDI presented a similar yield response to Control, with a reduction of 50 % on applied water and a significant more negative midday stem water potential. The Rainfed trees were unsuitable for table production because rehydration did not recover fruit size enough to be commercial. Endocarp maintained the capacity of growing until the end of the season.

Water resources are the premise of sustainable agricultural development in Northeast China (NEC), the country’s largest granary. Revealing the long-term evolution of water resources from multiple perspectives, such as surface water area (SWA) and groundwater storage (GWS), is crucial for understanding their current status and predicting future trends to formulate adaptive strategies to promote sustainable water management. Here, firstly, we annually mapped surface water in 1987–2023 using the Google Earth Engine (GEE) cloud service, all these historical 30-m Landsat records, and a mature surface water detection algorithm; then, we calculated annual GWS using Gravity Recovery and Climate Experiment (GRACE) satellite data and compared the trends of SWA and GWS to analyze the current status and evolution direction of water resources. We found continuous expansion of SWA (169.3 km²/yr) since 2002 after a 15-year consecutive decline, while GWS significantly declined (2.37 mm/yr). Quantitative attribution analyses identified the increasing artificial lakes and aquaculture ponds as the major drivers of surface water expansion, with a contribution of 85.0 %, suggesting that the expanding surface water bodies seen from space were just an illusion of increasingly abundant water resources. In addition, we revealed the increasing water evaporation (0.2 km³/yr) and the ratio (0.005–0.2 %/yr) of water evaporation to evapotranspiration (ET) with surface water expansion, indicating that the contribution of water evaporation to ET is more prominent and evaporative water loss has become a new threat to local water security and deserves much more attention. Our research can not only bring new insights into the current status of water security in China’s largest granary but also provide a typical case for reference in analyzing water resource changes in other similar regions.

Nurseries and greenhouses face challenges of limited water supply and increased demand for irrigation efficiency to minimize runoff and mitigate water loss to the environment. Overhead irrigation systems are among the most widely used methods for container plants, particularly in small container sizes. However, there is a lack of research examining the distribution uniformity (DU) of the most used sprinklers in nursery settings. Our study investigated the DU of different overhead sprinkler types and models commonly used in outdoor nurseries in the United States to guide greater adoption of higher irrigation efficiency technology. Catch-can experiments compared ten different sprinkler models in small (4.6 m × 4.6 m) and large (9.1 m × 9.1 m) square experimental plots in Irvine, California. We measured water volume, wind speed, and operating pressure, and calculated the application rate for 189 test runs conducted between Mar 2020 and May 2023. Our results show that of the models tested, the greatest DU was achieved by the Hunter MP2000 at 276 kPa (DU = 0.78 ± 0.05) in the small spacing, and the Senninger Xcel Wobbler with a 3.97 mm nozzle at 172 kPa (DU = 0.76 ± 0.06) in the large spacing. Wind speed and operating conditions affected the DU and spatial uniformity of irrigation among the ten models, highlighting the importance of maintaining operating pressures at the manufacturer's recommendations to ensure optimal application rates and DU. Together these results offer a quantitative comparison of sprinkler performance at different operating pressure and in a wide range of wind speeds, allowing users to select sprinkler models that best fit their operation and maximize water conservation.

Sugarcane cultivation covers a large area of agricultural land in southwestern Iran. Considering the high water demand of sugarcane and Iran's limited water resources, optimizing efficient Subsurface Drip Irrigation (SDI) systems is key. To support the design of SDI systems, we conducted an on-farm split-plot experiment in southwestern Iran, investigating the effect of dripper installation depths and mulch on crop and soil properties (medium soil texture). The main factor was mulch management comprising M1: the incineration of crop residues, and M2: leaving sugarcane residues on the soil surface after harvest. The sub-factor was SDI at three installation depth (ID) of the laterals: ID1: 15 cm, ID2: 25 cm, and ID3: 35 cm. The main and interaction effects of treatments were investigated on the vertical and horizontal distribution of soil moisture, salinity, and nitrate, and on the quantity and quality of sugarcane yield. The results illustrated that with increasing the dripper installation depth from 25 to 35 cm in average, soil moisture increased (4.4 %) and soil salinity and nitrate decreased by 17.5 and 11 % respectively, which also resulted in 11.2 % non-significant decrease in yield. Using mulch saved moisture by 18.4, 5.7 and 5.3 %, but decreased salinity by 27.2, 22.9 and 21.9 %, and nitrate by 25.6, 18.2 and 14.1 %, at depths of 0–30, 30–60 and 60–90 cm, respectively. While ID3 showed higher moisture levels, ID2 provided moisture at FC over growing season. We identified ID2 under M1 with a higher yield (132.6 t ha^–1), total biomass (231.1 t ha^–1), and irrigation water productivity (6.4 kg m^–3) compared to the other IDs as a promising on-farm dripper ID to promote moisture conservation and salinity avoidance. This research also requires studying sugarcane growth under ID2 treatments in different soil textures and irrigation water qualities.

Concerns about the over-extraction of groundwater and the environmental effects of that have increased the need to change mental patterns about water consumption. This study is aimed on the psychological analysis of the blockage of unauthorized water wells in the agricultural sector of Iran through the integration of PMT and TPB models. The research model was tested with 384 farmers. A questionnaire was used for data collection, the validity and reliability of which were obtained to be at an optimal level. For testing the research hypotheses Smart-PLS4 software was used. The research findings showed that the effects of six variables being attitude, subjective norm, perceived severity, response cost, response efficacy, and self-efficacy on intention were significant; however, the effect of perceived vulnerability on intention was not significant. Based on structural equation modeling results, the intention variable mediates significantly the relationship between dependent and independent variables. The independent and mediating variables were able to explain 49 % of the variance of farmers' behavior toward blockage of unauthorized water wells. Other than providing a new theoretical perspective toward understanding the blocking behavior of unauthorized water wells, the present study findings provide valuable insights for enhancing conservation behavior. To encourage people to participate in conservation behaviors, practical suggestions are provided for relevant policy-makers and planners as well as water conservation advocates.

The scarcity of fresh water resources has severely limited agricultural production in arid areas. Although brackish water irrigation or fresh water deficit irrigation can alleviate the water resources crisis, both may cause water and salt stress to crop. Therefore, this study is based on the functional advantages of Bacillus subtilis in soil improvement and crop growth promotion to alleviate water and salt stress and build safe and efficient water-saving irrigation patterns. In this study, cotton (No. 50 Chuangmian) was selected as the research crop, and five application rates of Bacillus subtilis (0, 22.5, 45, 67.5 and 90 kg·ha⁻¹) were combined with three irrigation patterns (brackish water, fresh water and fresh water deficit irrigations) to study the effects of Bacillus subtilis on soil moisture and salinity, soil microbial community, cotton physiology and growth under water and salt stress. The results showed that Bacillus subtilis could enhance soil water retention capacity, promote soil desalination, improve cotton growth indices (plant height, stem diameter, leaf area index, dry matter accumulation), and then increase yield and water use efficiency (WUE). Compared with the control treatment, the yield and WUE of Bacillus subtilis application treatments increased by 3.32–54.67 % and 1.68–41.07 %, respectively. In the cotton physiology characteristics, Bacillus subtilis increased proline content and the activity of superoxide dismutase, peroxidase and catalase while decreased malondialdehyde content in cotton leaves. Bacillus subtilis could enhance the relative abundance of bacteria with the functions of nitrogen fixation, stress resistance and biocontrol. A structural equation model proved that Bacillus subtilis could improve yield and WUE indirectly by directly improving soil microbial diversity, alleviating water and salt stress, and then improving cotton physiology and growth. According to a comprehensive evaluation of cotton physiology and growth, it was determined that the optimal improvement effect was achieved when the application rate of Bacillus subtilis was 45 kg ha⁻¹; the synergistic effect of brackish water irrigation and Bacillus subtilis (45 kg·ha⁻¹) was superior to that of fresh water deficit irrigation combining with Bacillus subtilis (45 kg·ha⁻¹), which could be considered a priority strategy for alleviating the fresh water crisis in arid areas and promoting the efficient increase in cotton yield.

Irrigated agriculture is the dominant user of water globally, but most water withdrawals are not monitored or reported. As a result, it is largely unknown when, where, and how much water is used for irrigation. Here, we evaluated the ability of remotely sensed evapotranspiration (ET) data, integrated with other datasets, to calculate irrigation water withdrawals and applications in an intensively irrigated portion of the United States. We compared irrigation calculations based on an ensemble of satellite-driven ET models from OpenET with reported groundwater withdrawals from hundreds of farmer irrigation application records and a statewide flowmeter database at three spatial scales (field, water right group, and management area). At the field scale, we found that ET-based calculations of irrigation agreed best with reported irrigation when the OpenET ensemble mean was aggregated to the growing season timescale (bias = 1.6–4.9 %, R² = 0.53–0.74), and agreement between calculated and reported irrigation was better for multi-year averages than for individual years. At the water right group scale, linking pumping wells to specific irrigated fields was the primary source of uncertainty. At the management area scale, calculated irrigation exhibited similar temporal patterns as flowmeter data but tended to be positively biased with more interannual variability. Disagreement between calculated and reported irrigation was strongly correlated with annual precipitation, and calculated and reported irrigation agreed more closely after statistically adjusting for annual precipitation. The selection of an ET model was also an important consideration, as variability across ET models was larger than the potential impacts of conservation measures employed in the region. From these results, we suggest key practices for working with ET-based irrigation data that include accurately accounting for changes in soil moisture, deep percolation, and runoff; careful verification of irrigated area and well-field linkages; and conducting application-specific evaluations of uncertainty.

Groundwater banking has been used for demand-oriented management of groundwater resources in semi-arid and arid regions. This paper aims to propose a new framework for seasonal groundwater banking. In this framework, crop production functions are used to estimate users' bid packages representing the price of each unit volume of water in each auction period. The bid packages, along with users' water rights, are considered inputs of an optimization model, which maximizes the profit of users participating in the groundwater bank. The main outputs of the optimization model are the volumes of exchange and storage of water, as well as the water price in the auction periods. The efficiency of the proposed framework has been evaluated by applying it to the Nough region in the Rafsanjan Plain, central Iran. An existing plan for inter-basin water transfer to this region is also considered in the water banking framework. The results illustrate that the total annual profit of all users after the establishment of the bank compared to the status quo has increased up to 43.8 %. The profit of the water-recipient basin has also increased more than 4 times compared to the existing condition. In addition, water banking with a water transfer system increases the economic productivity of water and crop production by 37.32 % and 22.41 %, respectively.