The evaluation of soil particle composition and salt dynamics is essential for promoting the sustainable development of oasis agriculture in arid regions under long-term mulched drip irrigation (MDI). In this study, we employed the space-for-time substitution method to investigate the long-term effects of MDI on soil particle composition and salinity. Additionally, seven fields, with MDI durations ranging from 0 to 16 years, were selected to represent the primary successional sequence though time in Northwest China. Soil samples were collected from three soil depths (0–30 cm, 30–60 cm, and 60–100 cm) and then analyzed in the laboratory for soil particle composition and salt content. Our findings demonstrated that influenced by the depth of mechanical cultivation and the maximum wetting front depth, the long-term application of MDI significantly altered both the structure of soil layers and the composition of soil particles after 8 years. Soil sand content and soil salinity gradually decreased, whereas the content of soil silt and clay increased with increasing MDI duration throughout 0–100 cm soil depth. Furthermore, the rates of soil desalination stabilized after 10 years of MDI application, with desalination levels exceeding 90% in the 0–100 cm soil layer. Additionally, the soil mass fractal dimension (Dm) exhibited an upward trend across 0–100 cm soil depth. The changes in soil particle composition indirectly influenced the variations in Dm and salt content. Our study demonstrated that long-term application of MDI effectively mitigated soil salinity, changed soil structure, and ultimately enhanced soil quality and cotton yield.

Increasing the planting density of summer maize to improve the utilization efficiency of limited soil and water resources is an effective approach; however, how the leaf water-use efficiency (WUE_L), yield, and RUE respond to planting density and genotypes remains unclear. A 2-year field experiment was performed in the North China Plain (NCP) to investigate the effects of planting density (high, 100,000 plants ha⁻¹; medium, 78,000 plants ha⁻¹; and low, 56,000 plants ha⁻¹) and genotypes (Zhengdan 958 and Denghai 605) on the leaf area index (LAI), photosynthetic characteristics, dry-matter accumulation, WUE_L, and RUE of maize. The objective was to explore the effect of density and genotype on the WUE_L and RUE of maize. Increasing planting density boosted LAI, light interception, dry-matter accumulation, and spike number but reduced the chlorophyll content, net photosynthetic rate, transpiration rate, and 1000-kernel weight. Both high and low planting densities were averse to RUE and yield. Zhengdan 958 increased the WUE_L by 19.45% compared with Denghai 605, but the RUE of Denghai 605 was 18.19% higher than Zhengdan 958, suggesting that Denghai 605 had a greater production potential as the planting density increased. Our findings recommend using 78,000 plants ha⁻¹ as the planting density with Denghai 605 to maintain summer maize yields in the NCP.

Soil moisture is the most crucial factor influencing crop growth. However, the shortage of soil water storage causes the reduction of yield, referred to as crop water stress (Omondi et al. 2021). Rainwater is the primary source of soil moisture, especially under rainfed agricultures (Jaramillo et al. 2020), but the frequency and intensity of extreme weather events, such as prolonged droughts and heavy rainfall, are expected to increase (Chen et al. 2020, Tang et al. 2021), which increase water loss through evaporation and runoff. Insufficient precipitation during critical growth stages is not adequate for crop water demands and biomass production (Huang et al. 2021); conversely, too much rainwater during the rainy season intensifies the problems of crop lodging and soil erosion (Routschek et al. 2014) and further jeopardised agricultural output (Malhi et al. 2021). Therefore, effective field crop management for cli

Brackish water drip fertigation has emerged as a promising approach for improving water use efficiency in saline agricultural regions where freshwater resources are limited. However, emitter clogging remains a critical challenge that compromises the long-term reliability and sustainability of these systems. Potassium fertilizers are widely applied through fertigation, yet the effects of different potassium sources on emitter clogging under brackish water conditions remain poorly understood. This study evaluated the impacts of five commonly used potassium fertilizers, including potassium dihydrogen phosphate (K1), potassium nitrate (K2), potassium chloride (K3), potassium sulfate (K4), and potassium tripolyphosphate (K5), on emitter hydraulic performance and clogging characteristics in a brackish water drip irrigation system. A 500 h fertigation experiment was conducted using six identical experimental platforms, one for each treatment, with three different types of non-pressure-compensating drip tape monitored within each platform. Changes in emitter performance were assessed using relative average discharge (Dra), Christiansen uniformity coefficient (CU), statistical uniformity coefficient (Us), and clogging randomness index. In addition, X-ray diffraction (XRD) analysis was employed to identify the mineral composition of accumulated clogging materials under different fertilizer treatments. Emitter performance differed among the potassium fertilizer formulations under the tested brackish-water conditions. Among the tested fertilizers, potassium sulfate (K4) maintained the most stable hydraulic performance, with a final Dra value of 83.62 ± 1.06%, whereas potassium chloride (K3) caused the greatest decline in emitter discharge, reducing Dra to 76.62 ± 1.05%. XRD analysis revealed that quartz and carbonate minerals were the dominant components of clogging deposits, although their relative proportions varied among fertilizer treatments. The differences in clogging development were closely associated with variations in mineral deposition patterns and hydraulic performance deterioration. Overall, potassium fertilizer selection plays an important role in maintaining the operational stability of brackish water drip fertigation systems. Under the tested brackish-water conditions, potassium sulfate showed the most stable hydraulic performance among the fertilizer treatments.