Optimizing Sowing Patterns and Nitrogen Management Strategies Used to Balance Maize Crop Productivity, N2O Emissions, and Economic Benefits in the Loess Plateau Region of China

Understanding the combined effects of sowing patterns and nitrogen (N) management strategies on crop productivity, environmental costs, and economic benefits is important to ensuring the sustainable development of dryland agriculture. Thus, we conducted a three-year field experiment to explore two spring maize sowing patterns (FS, flat sowing; RFPM, ridge and furrow plastic film mulching) and four N management strategies (N0, no N fertilizer; N1, normal urea as base fertilizer; N2, split application of normal urea at sowing and a large flare period at a ratio of 3:2; N3, all controlled-release urea as base fertilizer) on growth, the grain yield, the N uptake and utilization efficiency, N2O emissions, and economic benefits in the Loess Plateau region of China. Our results showed that compared to FS, RFPM promoted growth of the spring maize canopy and increased the grain yield, cumulative N uptake, and N use efficiency. RFPM promoted N2O emissions by improving the soil's hydrothermal environment, but it reduced the environmental cost (yield-scaled N2O emission). RFPM increased the production cost, but it increased the net income by improving the total output. Compared to traditional N management strategies (N1), N2 and N3 treatments improved the spring maize productivity and net income, and they reduced the environmental costs by improving the synchronization of the nitrogen supply. However, due to the decreasing rural labor force available in China, N3 is more beneficial in terms of reducing labor inputs. Therefore, we suggest that RFPM and N3 can be combined to form an efficient management strategy for spring maize production in the Loess Plateau that balances crop productivity, N2O emissions, and economic benefits.