Irrigation and Drainage最新文献

The state of Rajasthan, with its arid and semiarid climate, has made significant advancements in irrigation after the green revolution. This research offers a comprehensive spatio-temporal analysis of irrigation development in Rajasthan, examining the dynamic shifts in irrigation patterns, sources and their compound annual exponential growth rates (CAEGRs), and assessing the impact of various sources of irrigation on the net sown area (NSA). Currently, almost three-fourths of irrigated areas use groundwater sources. Over the last decade, tubewell irrigation has expanded most rapidly (CAEGR: 2.5%), followed by canal irrigation (2.2%), whereas tank irrigation has sharply declined (−2.6%). Furthermore, tubewell irrigation utilization significantly impacts the NSA, especially during the Rabi season in western Rajasthan. However, this increase in groundwater irrigation has an environmental cost in terms of a significant decline in the groundwater level, particularly in districts with relatively high levels of tube-well irrigation. Business, as usual, is not sustainable, as depleting groundwater resources will adversely affect food security in the region. The Rajasthan experience emphasizes exploring the balance between short-term agricultural gains and the protection of critical ecosystems. It also offers vital lessons for dry and semiarid regions around the world that are facing similar challenges.

The coordinated management of water and fertilizer has become a necessary strategy to solve the global water crisis and improve crop productivity. This study undertook a field experiment to examine drip irrigation of maize utilizing lysimeters. The impacts of four distinct nitrogen fertilization treatments, with application rates of 105 (CK), 153 (T1), 204 (T2) and 255 kg ha⁻¹ (T3), on crop growth, development and the efficiency of water and fertilizer utilization were investigated separately. During the experimental period (2021–2022), the yield reached its maximum under the T2 treatment, which were 20% and 32% greater than that of the CK treatment. The water use efficiency (WUE) increased with increasing fertilizer application. Conversely, the partial factor productivity of nitrogen (PFPN) decreased with increasing fertilizer application. Using the calibrated HYDRUS-2D model, we analysed the impacts of irrigation volume and water–nitrogen interactions on water and fertilizer utilization. The simulations revealed an irrigation quota of 1855 m³ ha⁻¹; the maximum root nitrogen uptake was 196 kg ha⁻¹, whereas the nitrogen leaching loss from deep soil was only 12 kg ha⁻¹. These results provide a scientific basis for optimizing water–fertilizer management in water-scarce regions of North China.

This study investigates the impact of encroachment on farmers' satisfaction with irrigation water distribution in central Khyber Pakhtunkhwa, Pakistan. A sample of 466 farmers was selected through multistage stratified random sampling, and data were collected via an interview schedule. Chi-square and Kendall's Tau-c tests were used to analyse the relationships between watercourse encroachment and farmer satisfaction levels with the irrigation water distribution. The results revealed significant negative correlations between encroachments and farmer satisfaction, particularly for water channel obstructions (p < 0.05; T^c = −0.230), commercial building construction (p < 0.05; T^c = −0.056), rural habitation encroachments (p < 0.05; T^c = −0.238), buried watercourses (p < 0.05; T^c = −0.305), irrigation channel diversions (p < 0.05; T^c = −0.061), and restricted access for desilting and clearing (p < 0.05; T^c = −0.276). Interestingly, complaints about encroachment were positively associated with satisfaction (p < 0.05; T^c = 0.008). The study concludes that irrigation departments and government authorities have failed to address encroachment and act on farmers' complaints. It recommends mobilizing local communities, strengthening irrigation authorities, legally penalizing offenders, and improving irrigation water distribution to increase farmer satisfaction.

A field study was conducted (2021–2022) that evaluated the effects of deficit irrigation (DI) strategies [60% and 80% of crop evapotranspiration (ETc)] and plant growth regulators [PGRs; salicylic acid (SA) and naphthalene acetic acid (NAA)] on fruit yield, water use efficiency (WUE) and physiological responses of pomegranate grown in shallow basaltic soils. Irrigation at 80% ETc combined with SA and NAA significantly increased fruit yield by 32% and 40% and improved WUE by 65% and 75% under DI and partial root-zone drying (PRD), respectively. PRD outperformed DI, producing 8.56% higher yield and 6.25% higher WUE at the same irrigation level without PGRs. Physiological parameters such as the relative water content, membrane stability index (MSI), normalized difference vegetation index, photosystem II efficiency, chlorophyll content and photosynthetic rate were strongly correlated with fruit yield (r = 0.90–0.97). Under stress conditions, SA application increased the photosynthetic rate and MSI while reducing the leaf surface temperature by 6%, 8% and 2%, respectively, compared with those of untreated plants. Foliar application of SA (300 ppm) + NAA (45 ppm) under DI-80 or PRD-80 enhanced water productivity and fruit yield in pomegranates in challenging soil conditions in semiarid regions.

A field study was conducted (2021–2022) that evaluated the effects of deficit irrigation (DI) strategies [60% and 80% of crop evapotranspiration (ETc)] and plant growth regulators [PGRs; salicylic acid (SA) and naphthalene acetic acid (NAA)] on fruit yield, water use efficiency (WUE) and physiological responses of pomegranate grown in shallow basaltic soils. Irrigation at 80% ETc combined with SA and NAA significantly increased fruit yield by 32% and 40% and improved WUE by 65% and 75% under DI and partial root-zone drying (PRD), respectively. PRD outperformed DI, producing 8.56% higher yield and 6.25% higher WUE at the same irrigation level without PGRs. Physiological parameters such as the relative water content, membrane stability index (MSI), normalized difference vegetation index, photosystem II efficiency, chlorophyll content and photosynthetic rate were strongly correlated with fruit yield (r = 0.90–0.97). Under stress conditions, SA application increased the photosynthetic rate and MSI while reducing the leaf surface temperature by 6%, 8% and 2%, respectively, compared with those of untreated plants. Foliar application of SA (300 ppm) + NAA (45 ppm) under DI-80 or PRD-80 enhanced water productivity and fruit yield in pomegranates in challenging soil conditions in semiarid regions.

To address the complex many-to-many supply–demand relationship between channels and field plots in irrigation systems (where a single channel can irrigate multiple plots and a single plot can receive water from multiple channels), this study developed a novel optimized water distribution model for channel systems. The model innovatively incorporates channel water transmission time parameters to precisely control irrigation sequences and adopts a ‘rotation irrigation between groups—continuous irrigation within groups’ operational mode (based on an improved 0–1 model framework). Setting the optimization goal of synchronized water distribution completion among rotation groups enhances management efficiency. In the empirical study of the Bojili Irrigation District, the model optimized the lateral channel system by dividing it into two rotation groups, achieving the following: (i) The time difference in water distribution completion among channels within each group was significantly reduced (achieving synchronized completion); (ii) a substantial decrease in the flow adjustment frequency of branch channels. The results demonstrate that this model not only effectively resolves water distribution challenges in complex supply–demand networks but also provides scientifically sound and operational distribution schemes, offering decision-making support for precision management in irrigation districts.