Abstract

Understanding mulching influences on nitrogen (N) accumulation in soil is important for developing N management strategies for dryland wheat yield. A two year field experiment was carried out to investigate the effect of three mulching materials (film mulching, nylon mulching, and paper mulching) and different fertilizer (with or without fertilizer) on N accumulation in a winter wheat-fallow system. The results showed that the organic fertilizer application in fallow period could lead to a serial positive effect compared with the non-fertilization including increased N content of wheat at wintering stage, heading stage, and maturity stage, N accumulation at different growth stages, the ratio of N accumulation from emergency to jointing under the condition of film and nylon mulching, the ratio of N accumulation from anthesis to maturity under all mulching, pre-anthesis N translocation amount, post-anthesis N accumulation, and the contribution of post-anthesis N accumulation to N in grains under the condition of nylon mulching, paper mulching and no mulching. In addition, our results also showed that regardless of fertilization, N content of wheat at maturity, N accumulation in plant at anthesis and maturity, N accumulation and its ratio from jointing to anthesis under the film mulching treatment were all greater than those in the other treatments. Mulching increased post-anthesis N accumulation and the contribution of post-anthesis N accumulation to N in grains. In the context of organic fertilizer application, the contribution of post-anthesis N accumulation to N in grains under the treatment of nylon mulching was greater than that in the other treatments. However, without fertilizer, film mulching seemed to be better than other treatments. Therefore, organic fertilizer application and film mulching may be effective strategies for increasing N accumulation in grains, and the quality and yield of dryland wheat.

Key words: Fallow period, fertilizer, mulching, winter wheat, N accumulation.