Effects of Corn Stalks and Urea on N2O Production from Corn Field Soil

Kaikuo Wu,Yuchao Song,Chen Feng,Ping Gong,Yue Meng,Wei Bai,Liangshan Feng,Lili Zhang,Zhe Zhang

doi:10.3390/agronomy11102009

Abstract

Returning corn stalks to the field is an important and widely used soil management practice which is conducive to the sustainable development of agriculture. In this study, the effects of corn stalks and urea on N2O production in corn field soil were investigated through a 21-day incubation experiment. This study showed that increasing amounts of urea added to soil with a history of corn cultivation leads to increasing overall N2O emissions, by increasing both the intensity and the duration of emissions. Although N2O production was affected primarily by urea-derived NH4+-N and NO3−-N, its main source was native soil nitrogen, which accounted for 78.5 to 94.5% of N2O. Returning corn stalk residue to the field reduced the production of N2O, and the more urea was applied, the stronger the effect of corn residue on reducing N2O emissions. Combining the application of corn stalks and urea could reduce the concentration of NH4+-N and NO3−-N derived from urea, and then reduce the substrate required for N2O production in nitrification and denitrification processes. In addition, the combined application of corn stalks and urea could effectively inhibit the abundance of key N2O-producing genes AOA amoA, nirS and nirK.

Highlights

Mitigating negative global climate change caused by greenhouse gas (GHG) emissions is one of the major challenges in sustainable development [1,2]
At the N ha−1 (N1) and N2 levels, N2O flux decreased to a lower level one week after fertilization, while at the N3 level, it decreased to a lower level two weeks after fertilization
It may be that NH4+-N and NO3−-N derived from urea are easier to be used by microorganisms compared to native soil N, promoting an increase in the number of microorganisms, accelerating the mineralization of soil nitrogen [20,27] and making soil N the main source of N2O

Summary

Introduction

Mitigating negative global climate change caused by greenhouse gas (GHG) emissions is one of the major challenges in sustainable development [1,2]. Liaoning Province is one of China’s 13 main grain-producing areas, and the semi-arid area of northwestern Liaoning accounts for more than 2/3 of corn cultivation in this province [12]. This extensive area of cultivation is an extensive area of N2O production. Exploring the processes associated with N2O production in corn fields in semi-arid northwestern Liaoning has important practical significance for farmland greenhouse gas emission reduction. The determination of these genes helps us to better understand the pathway of N2O production

Methods

Results

Discussion

Conclusion