Influence of no-tillage and precipitation pulse on continuous soil respiration of summer maize affected by soil water in the North China Plain

Abstract

Soil respiration (RS) from cropland in response to tillage practices contribute to global climate change. We quantified the effect of no-tillage (NT) and conventional tillage (CT) on RS and precipitation in the North China Plain (NCP). An in-situ automatic sampling and measurement method was applied during the maize (Zea mays L.) growth stages in 2018 and 2019. The continuous daily RS, soil water content and temperature were monitored during all the maize growth stages, whereas maize grain yield, aboveground biomass, and soil microbial biomass were measured after harvest. The mean RS across tillage practices on bright days was higher in 2018 (16.69 g CO2 m−2 d−1) than that in 2019 (12.99 g CO2 m−2 d−1). Compared with CT, NT increased RS on bright days by 31.44% in 2018 and 15.60% in 2019. However, mean RS on rain-affected days across tillage practices was lower in 2018 than that in 2019. NT increased mean RS after precipitation in 2018 (p < 0.05). The contribution of RS after precipitation to cumulative RS (across tillage practices) was higher in 2019 (51.90%) than that in 2018 (41.18%). Mean soil water content and temperature were higher in 2018 than that in 2019 (p < 0.05). NT increased soil water content on bright days in 2019. Furthermore, soil water content was more important in regulating RS in 2018, while soil temperature was more critical after precipitation in 2019. Crop productivity was lower in 2019 than in 2018 (p < 0.05). However, neither crop productivity nor soil microbial biomass varied with tillage practices (p > 0.05). Overall, influence of tillage practices and precipitation on RS were different according to soil water content. Therefore, it is necessary to decrease excessive irrigation to reduce RS in dry years and to conduct continuous observations on RS after precipitation in the NCP.