Understanding dry matter and nitrogen accumulation for high-yielding film-mulched maize.

摘要

Film mulching is a very common technique in agriculture worldwide, but few studies have focused on the dry matter (DM) and N accumulation of mulched crops. Understanding the grain yield (GY) associated with DM and N accumulation is essential for improving crop production. We conducted a 3-yr field experiment with six N fertilizer rates (0, 100, 200, 250, 300, and 400 kg ha-1) in the semiarid climate of northwest China to determine the GY and DM and N accumulation of film-mulched maize (Zea mays L.). The results showed that relatively high GYs (13.1-15.1 Mg ha-1) were obtained using N fertilizer rates of 200 to 400 kg ha-1 in the 3 yr despite large year-to-year differences in rainfall. When the N rate was below 250 kg ha-1, the GY, DM, and N accumulation increased significantly as the N fertilizer rate increased. A linear-plateau model best described the relationship between the GY and the DM and N accumulation during the pre-silking stage and a linear model the relationship during the post-silking stage. We conclude that optimizing N management to improve DM and N accumulation (especially post-silking) is the key to ensuring a high yield of film-mulched maize.