This study hypothesized that different base fertilizer application has different effects on improving the efficiency of maize water utilization and promoting maize growth. Utilizing field positioning sloping farmland micro-zone experiments, six distinct types of base fertilizers were designed: a control group without fertilization (CK), chemical fertilizer alone (T1), a mixture of local farmyard manure (40% pine needles and 60% livestock manure, T2), a 50% reduction in chemical fertilizer combined with farmyard manure (T3), the incorporation of crushed straw through deep plowing (T4), and the fermentation of crushed straw mixed with urea before field application (T5). The results indicate that, compared to the CK treatment, the T3 and T5 treatments significantly enhanced soil moisture content, with increases ranging from 4.06% to 18.67% during the normal year (2023) and the drought year (2024), respectively. Additionally, the water utilization efficiency of maize was improved significantly, with values of 35.38% and 41.54%, and the yield increased by 12.30% to 25.92%. The maize yields under T3 and T5 treatments reached 12.19 and 13.31t/ha, respectively. Therefore, we propose that crushing straw and incorporating urea and water for fermentation as a base fertilizer in maize fields can ensure efficient water use in this region, leading to higher yields.

This study was conducted to reveal the response relationship between soil preferential flow characteristics and soil pore structure of sloping cropland under contour antislope step measures in the alpine canyon area of Southwest China. In the sub-watershed of Nantangjing, Yunlong County, the upper and lower slopes of primary sloping cultivated land (PSC) and contour reverse-slope terraced rectified land (CR) were used for the study, and a field staining tracer test was used to compare the differences in preferential flow morphology between different slopes with and without measures. The maximum infiltration depth of preferential flow under the contour reverse-slope terrace land preparation reached 21 cm. The stained area ratio tended to decrease with increasing soil depth. Compared to the original slope farmland, the stable infiltration rate under land preparation increased from 0.017 to 0.244 cm³·s⁻¹, and the maximum macroporosity increased by up to 17.00%. Furthermore, land preparation measures significantly enhanced the correlation between macropore quantity and preferential flow characteristics, with the highest correlation coefficient reaching 0.98. And the soil factors in total porosity, total nitrogen and organic matter were particularly influential on preferential flow. Contour antislope terracing promotes the formation and development of preferential soil flow by remodeling soil structure and optimizing pore network distribution.

Nitrogen deposition can significantly impact soil biogeochemical cycling; however, its effects on the decomposition processes and nutrient release from leaf and twig litter in subtropical plantations remain inadequately understood. In this study, we focused on the Pinus yunnanensis Franch. forest in the central Yunnan Plateau, southwestern China, and explored how nitrogen addition influences litter decomposition nutrient release over two years, under four levels: control (CK, 0 g·m⁻²·a⁻¹), low nitrogen (LN, 10 g·m⁻²·a⁻¹), medium nitrogen (MN, 20 g·m⁻²·a⁻¹), and high nitrogen (HN, 25 g·m⁻²·a⁻¹). The results indicate that after 24 nitrogen application treatments, the rates of remaining mass in both leaf and twig litters followed the pattern: LN < CK = MN < HN. Under all nitrogen application treatments, the rate of remaining mass in leaf litters was significantly lower than that of twig litters (p < 0.05). Under LN, the mass retention in leaf and twig litters decreased by 3.96% and 8.41%, respectively, compared to CK. In contrast, under HN treatments, the rates of remaining mass in leaf and twig litters increased by 8.57% and 5.35%, respectively. This demonstrates that low nitrogen accelerates decomposition, whereas high nitrogen inhibits it. Significant differences in the remaining amounts of lignin and cellulose in both leaf and twig litters were observed when compared to CK (p < 0.05). Additionally, decomposition time and nitrogen deposition had significant effects on the remaining rates of nutrients (C, N, P) and their C/N, C/P, and N/P in litters (p < 0.05). Following nitrogen application, the C/N of the litters significantly reduced, while the N/P increased. The results suggest that nitrogen addition alleviates the nitrogen limitation on the litters while intensifying the phosphorus limitation.