Impact of plastic film mulching and fertilizers on the distribution of straw-derived nitrogen in a soil-plant system based on 15N–labeling

Publication date: 1 May 2018
Source:Geoderma, Volume 317
Author(s): Lihong Zheng, Jiubo Pei, Xinxing Jin, Sean Schaeffer, Tingting An, Jingkuan Wang
Crop yield response to nitrogen (N) application has been well documented, but quantitatively tracing the distribution of exogenous straw derived N (straw-N) in a soil-plant system amended by plastic film mulching and fertilizers is poorly understood. Focus on this, we used a ¹⁵N tracer, applied as maize straw, into a monoculture maize field experiment in China to quantify the distribution of straw-N in a soil-maize system. The effects of straw-N utilization by maize were also assessed over the course of a six-month field experiment by adding ¹⁵N labeled maize straw into four fertilizer treatments (no fertilizer, N chemical fertilizer alone, manure fertilizer alone and manure combined with N chemical fertilizer) both with and without mulching. Mulching promoted straw-N transfer to stems, leaves and grains of maize. Fertilizers increased straw-N transfer to these plant parts both with and without mulching due to the increase of plant biomass, showing greater plant utilization rates of straw-N in the N fertilizer addition treatments, while residual rates of straw-N in soil decreased in these treatments. Nevertheless, fertilizer application relatively decreased the contribution of straw-N to N uptake of plant. The manure combined with N fertilizer treatment both with and without mulching had resulted in the highest straw-N accumulation in plant, but the lowest straw-N accumulation in soil. Meanwhile, mulching significantly increased straw-N distribution in plant but decreased in soil in the manure and manure combined N treatments. These results suggested that there were differences in straw-N turnover and uptake by maize in the soil-maize system due to the influences of plastic film mulching and different N sources of inorganic and organic fertilizers, especially showing that inorganic fertilizer positively primed straw-N distribution to plant compared to organic fertilizer.

Graphical abstract