Impact of maize growth on N2O emission from farmland soil

Abstract

Crop growth is a key factor that effects nitrous oxide (N2O) emission in farmland soil. Clarification and quantification of the impact of maize growth on N2O emission are important to guide maize planting and patterns, which is also useful for building model to simulate N2O emission in an agroecosystem. In this study, we carried out a three-year (2013-2015) field experiment to evaluate the contribution of maize growth on N2O emission using a split-plot design. The factors included planting versus not planting maize, and four rates of nitrogen (N) application (0, 150, 300, 450 kg N/ha). Our results showed the impacts of maize growth on N2O emission decreased linearly with the growth of maize from the 43rd day after sowing (y = -1.07x + 26.85, R2 = 0.95). Nitrogen fertilizer application can reduce the impacts of maize growth on N2O emission. The impact of maize growth on soil NH4+-N and NO3--N are similar to N2O emission, and they have a strong correlation. We concluded that maize growth reduces soil N2O emission but N application can exert an antagonistic effect, and the impact of maize growth on soil NH4+-N and NO3--N largely determines the impacts of maize growth on N2O emission.

Keywords

• global warming
• zea mays l.
• nitrification
• fertilization
• greenhouse gas
• nitrogen uptake
• growth dynamic