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

Abstract

Straw mulching has been widely used to conserve soil water and enhance soil fertility in dryland cropping systems. However, the lack of soil nutrient availability due to the immobilization with straw mulch decomposition would result in a decrease in crop yield and harvest index. Based on a 9-yr straw mulching field experiment, we evaluated the effect of late topdressing in 2 yr on crop yield under a winter wheat (Triticum aestivum L.) monoculture system in the Loess Plateau of China. Three treatments were included as straw mulching at rates of 9,000 (HSM) and 4,500 kg ha -1 (LSM) during growing season and control without mulching (CK) from 2008 to 2019. Topdressing as urea was added to each plot at wheat tillering from 2017 to 2019. Across 2 yr, straw mulching significantly increased soil water storage at most growing stages.Compared with CK, straw mulching promoted wheat growth (tiller density and plant density) but decreased grain yield and harvest index significantly. Soil mineral N contents in later wheat-growing stages and net photosynthetic rate, transpiration rate of wheat flag leaf and leaf water use efficiency during filling stage decreased with HSM and LSM when compared with CK. However, late topdressing significantly increased wheat grain yield in both years. Generally, additional application of N fertilizer in the late growing stage could alleviate the yield decrease by straw mulching and should be considered for sustainable crop production in the Loess Plateau of China.

Allelopathic Effects of Corn Straw and Its Water Extracts on Four Weed Species and Foxtail Millet

“…Straw covering can effectively reduce soil moisture evaporation and regulate soil temperature [18][19][20]. Microbial decomposition and rainwater leaching covered with straw can improve soil fertility [21] and physicochemical properties [22][23][24], can promote soil water fertilizer interaction, and are widely used in conservation tillage [25,26]. Cai et al [27] revealed that the soil water storage capacity of corn straw covered within a soil depth of 200 cm increased.…”

Coupled one-off alternate furrow irrigation with nitrogen topdressing at jointing optimizes soil nitrate-N distribution and wheat nitrogen productivity in dryland

“…Topdressing nitrogen (TN), a strategic intervention for crop yield improvement, furnishes N nutrition vital for subsequent growth stages, particularly when soil N content is suboptimal (Li et al, 2020;Ji et al, 2021;Fu et al, 2022). Zain et al (2021) discovered that TN applied at the jointing stage syncs with wheat's N demands, optimizing NUE in China North Plain.…”

“…Yet, combining AFI with other approaches, such as N management and planting modes, has been demonstrated to enhance NUE in wheat crops ( Ghasemi-Aghbolaghi and Sepaskhah, 2018 ). Topdressing nitrogen (TN), a strategic intervention for crop yield improvement, furnishes N nutrition vital for subsequent growth stages, particularly when soil N content is suboptimal ( Li et al., 2020 ; Ji et al., 2021 ; Fu et al, 2022 ). Zain et al.…”