Agricultural Water Management (Sep 2023)
Strategy for matching fertilizer application with soil water before sowing can stabilize maize productivity under rainwater harvesting and mulching planting in dry areas: A six-year field experiment
Abstract
The application of rainwater harvesting and mulching planting (RHMP) methods has effectively improved the productivity in dryland farming. However, different RHMP methods lead to differences in soil water availability, which must be matched with appropriate amounts of fertilizer to obtain further improvements in farmland productivity. In this study, we conducted a long-term (2014–2019) in situ experiment by using a split-plot design with four planting methods (control treatment, NN, no film mulching and no ridge; RHMP, HS, half-film mulching and single ridge; HN, half-film mulching and no ridge; FD, full-film mulching and double ridge) as main treatments and four fertilizer application levels (N, no fertilizer; L, low fertilizer; M, medium fertilizer; and H, high fertilizer, with N:P2O5 rates of 0:0, 150:75, 300:150, and 450:225 kg ha–1, respectively) as sub-treatments. We studied the long-term soil water dynamics, crop growth responses, and economic benefits under the interactive effects of RHMP and fertilization. The results showed that RHMP changed the pattern of soil water consumption and recovery, thereby making it more compatible with the water demand of spring maize, and improving the water availability. Compared with NN, HS, HN, and FD increased the evapotranspiration by 8.7, 12.5, and 20.7 mm, respectively, the yield by 19.8%, 21.1%, and 69.4%, and the water use efficiency by 17.5%, 17.8%, and 61.8%. Under the same RHMP method, fertilization increased the consumption of soil water by crops but improved the water use efficiency. Compared with N, L, M, and H increased the evapotranspiration by 13.1 mm, 14.1 mm, and 15.4 mm, respectively, the yield by 198.7%, 228.5%, and 243.7%, and the water use efficiency increased significantly by 190.0%, 218.2%, and 231.9%. Due to the high variability of inter-annual rainfall (differences up to 419.1 mm during 2014–2019), the soil water availability varied significantly in different years, thereby affecting the yield and economic benefits. We also analyzed the responses in terms of the grain yield and net income to fertilizer application, as well as the soil water storage in the 0–200 cm soil layer before sowing under different RHMP methods. The amount of fertilizer that obtains the best yield and maximum economic benefit in the current year can be evaluated according to the soil water conditions before sowing in order to maximize the production of spring maize in the current season. The results obtained in this study provide a simple method for determining the amount of fertilizer based on water availability to improve and stabilize the crop production efficiency in arid regions.
