Mengyang Wang

Developing efficient water-saving irrigation technologies that utilize high sand-laden water is an important approach to alleviating agricultural water scarcity in the Yellow River Basin. This study aims to investigate sedimentation patterns and fluid movement characteristics in drip irrigation emitters under such challenging water conditions. The dynamic changes in Dra and Cu were determined through short-period intermittent clogging tests to evaluate the anti-clogging performance of four different emitter types. The distribution and particle size composition of the deposited sediments inside the emitters were analyzed using a high-resolution electron microscope and a laser particle size analyzer. Additionally, the RNG k-ε turbulence model was used to simulate the fluid movement inside the emitters. The results showed that the B drip irrigation belt had better sediment tolerance and operational stability. The anti-clogging capacity of drip irrigation can be improved by optimizing the combination of emitter channel structure and sediment content. The fluid in the channel was divided into mainstream zone and vortex zone. Sediment particles increased in the backing-water zone and vortex center, where particles of 0.05–0.1 mm were more prone to settling due to reduced transport capacity. Energy dissipation primarily took place at the curvature of the emitter channel, and within each channel unit, gradually decreasing along the vortex flow direction, with the lowest dissipation aligning with sediment deposition zones. These findings provide a theoretical basis for mitigating clogging in high sand-laden water drip irrigation systems, offering valuable insights for improving the effective utilization of water resources in the Yellow River Basin.

Brassica chinensis L. is often grown using ‘excessive water and fertilizer’, which has a negative impact on the inter-root soil environment and the yield and quality of the plant. As the concept of green and sustainable development takes root in people’s minds, it is important to determine the right amount of water and fertilizer. Based on this, the effects of different irrigation rates and microbial fertilizers on the inter-root soil environment and yield and quality of B. chinensis were investigated. A pot experiment was carried out with two irrigation levels (W1: 80–90% of field water capacity; W2: 70–80% of field water capacity) and three fertilizer treatments (F0: no fertilizer; F1: CPS Powder Drill microbial fertilizers; F2: Maya 85 microbial fertilizers). The results showed that microbial fertilizer and irrigation amount, as well as their interaction, all had significant effects on yield, polyphenol content, soluble protein content, nitrate content, and the activities of soil enzymes, such as urease, sucrase, and catalase (p < 0.05). Increases in irrigation amount and the application of microbial fertilizer can increase the yield of B. chinensis, effectively improve the activities of sucrase, urease, and catalase in soil, increase the contents of vitamin C, chlorophyll, soluble protein, and total phenol in leaves, and reduce the content of nitrate. In addition, the findings of the principal component analysis indicated that the F2W2 treatment was the optimal treatment. The results of this study demonstrate that an 80–90% field water capacity, in conjunction with Maya 85 microbial fertilizers, yields an optimal outcome, with a score of 1.86. This outcome suggests that this combination of water and fertilizer can be used as a recommended protocol for the cultivation of Brassica chinensis L.