Winter wheat nitrogen utilization under different mulching practices on the Loess Plateau

Abstract

Winter wheat (Triticum aestivum L.) is one of the most important cereal crops in the world, and mulching is mostly practiced in the semi-arid region of Northwest China. We examined the effect of different mulching practices on soil N, plant N uptake, N use efficiency and yield of wheat with similar fertilizer rate. The experiment was conducted for 5 yr with four replicates. The five practices included: Control (CK), nitrogen fertilizer and no mulching (NM), nitrogen fertilizer plus plastic film mulching (PM), nitrogen fertilizer plus ridge mulching and furrow seeding (RM+FS), and nitrogen fertilizer plus straw mulching (SM). We found that yield and biomass of winter wheat were significantly affected by different mulching practices during the five growing seasons. Compared to the NM treatment, the PM, SM, and RM+FS treatments increased grain yield by 13, 9, and 4%, respectively, and biomass by 19, 13, and 10%, respectively. Compared to the NM, the RM+FS and PM treatments tended to decrease average grain, straw, and chaff N concentration, while straw mulching tended to increase average grain, straw, and chaff N concentration. Compared to the NM treatment, all mulching treatments consistently increased NUE, and straw mulching had the most significant effect. Nitrate-N in the NM was most likely to leach into deep layers, followed by the SM and the lowest nitrate-N leaching risk was in the two plastic film mulching treatments. The PM could increase winter wheat yield and decrease the risk of nitrate-N leaching. Thus, PM performed better among the mulching practices.

Late topdressing can sustain wheat grain yield under straw mulching in the Loess Plateau of China

“…X. Chen et al. (2020) reported that straw surface return did not show the tendency for declines in soil nitrate‐N concentration, while the grain yield of straw mulch was the highest of all treatments. This was disagreed with our study because of the higher rate of N fertilization and soil N concentration.…”

“…Straw mulching, as a kind of conservation agricultural practice, has been widely adopted in the last few decades especially in the dryland areas of India (Chakraborty et al., 2010; Sharma et al., 2011), Spain (Jordán et al., 2010), United States (Baumhardt et al., 2013), and China (Chen et al., 2020; S. X. Li, Wang, et al., 2013; J. Wang et al., 2018). Numerous studies have reported the effect of straw mulching on soil water conservation (Chakraborty et al., 2010; J. Wang et al., 2018) and soil temperature regulation (Awe et al., 2015; Scott et al., 2010) as well as crop production and water use (S. Li et al., 2021; R. Li, Hou, et al., 2013; P. Zhang et al., 2015).…”

“…In this case, the significant decreases in grain yield as well as harvest index with straw mulching highlights the possible deficits in both soil moisture and nutrient availability in the late stage (J. Wang et al., 2018). Application of crop residue with high C/N ratio, such as wheat straw, can increase soil N immobilization and reduce N availability to crops (X. Chen et al., 2020; Lu et al., 2015; Scott et al., 2010), which may have a negative effect on crop yield formation (Rusinamhodzi et al., 2011). The nutrient deficit during late growing stages have led to the decrease of wheat grain yield, but this speculation has not been reported clearly.…”

“…Straw mulching, as a kind of conservation agricultural practice, has been widely adopted in the last few decades especially in the dryland areas of India (Chakraborty et al, 2010;Sharma et al, 2011), Spain (Jordán et al, 2010), United States (Baumhardt et al, 2013), and China (Chen et al, 2020;S. X. Li, Wang, et al, 2013;.…”

“…Application of crop residue with high C/N ratio, such as wheat straw, can increase soil N immobilization and reduce N availability to crops (X. Chen et al, 2020;Lu et al, 2015;Scott et al, 2010), which may have a negative effect on crop yield formation (Rusinamhodzi et al, 2011). The nutrient deficit during late growing stages have led to the decrease of wheat grain yield, but this speculation has not been reported clearly.…”