Wheat Straw Incorporation Coupled With Direct Seeding Method Influence Nitrogen Uptake and Translocation in Rice

Abstract

On-farm trials were performed to investigate the nitrogen (N) uptake, N translocation, and grain yield of rice planted via different direct seeding methods into a field after wheat straw incorporation. The study conducted using two direct seeding methods, dry direct seeding of rice (DDSR) and wet direct seeding of rice (WDSR), in a field without or with straw incorporation demonstrated that straw incorporation negatively influenced both grain yield and N uptake in direct-seeded rice. Compared with WDSR, DDSR suffered significant negative effects, with a 7.2% decrease in grain yield and an 8.0% decrease in N uptake. Additionally, N uptake in direct-seeded rice with straw addition decreased by 6.5% at the middle stage and 9.5% at the late stage compared with that without straw incorporation. Straw incorporation prolonged the initial phase of growth and thus shortened the N uptake days in the last two phases. Moreover, the total N uptake of rice was positively associated with the uptake rate and the uptake days during the latter stages. Specifically, WDSR exhibited a higher N uptake rate, N uptake days, and N translocation ability than DDSR, which increased the N uptake in stem and panicle, total N uptake, and grain yield at maturity. These results indicated that straw incorporation decreased grain yield and N uptake, which was related to the fewer N uptake days in the latter stages caused by the prolonged early growth stage for direct-seeded rice. Nevertheless, using WSDR in a field incorporated with straw alleviated the losses in N uptake and grain yield.