The Effects of pH Change through Liming on Soil N2O Emissions

Muhammad Shaaban,Yupeng Wu,Lei Wu,Shan Lin,Peng Xu,Ronggui Hu,Aneela Younas,Yanbin Jiang,Xiangyu Xu,Avelino Nunez-Delgado,Zheng Sun

doi:10.3390/pr8060702

Abstract

Nitrous oxide (N2O) is an overwhelming greenhouse gas and agricultural soils, particularly acidic soils, are the main source of its release to the atmosphere. To ameliorate acidic soil condition, liming materials are added as an amendment. However, the impact of liming materials has not been well addressed in terms of exploring the effect of soil pH change on N2O emissions. In the present study, a soil with pH 5.35 was amended with liming materials (CaMg(CO3)2, CaCO3, Ca(OH)2 and CaO) to investigate their effects on N2O emissions. The results indicate that application of liming materials reduced the magnitudes of N2O emissions. The maximum reduction of soil N2O emissions took place for Ca(OH)2 treatment when compared to the other liming materials, and was related to increasing soil pH. Mineral N, dissolved organic C, and microbial biomass C were also influenced by liming materials, but the trend was inconsistent to the soil pH change. The results suggest that N2O emission mitigation is more dependent on soil pH than C and N dynamics when comparing the different liming materials. Moreover, ameliorating soil acidity is a promising option to mitigate N2O emissions from acidic soils.

Highlights

Soil acidity is a master variable that hinders plant growth by limiting nutrient availability and impacts both the quantity and quality of crops
The most rapid changes of mineral N dynamics were observed in the CaCO3 treatment, whereas the highest reduction of nitrous oxide (N2 O) emissions occurred in the Ca(OH)2 treatment
The present research showed that the application of liming materials reduced magnitudes of N2 O

Summary

Introduction

Soil acidity is a master variable that hinders plant growth by limiting nutrient availability and impacts both the quantity and quality of crops. Soil acidification occurs very slowly naturally as soil is weathered, but this process is accelerated by intensive agriculture [1,2]. Soil acidity is expressed in terms of pH, and its extent and degree impact a wide range of soil biogeochemical properties. Soil acidification is a natural and very slow process that takes over hundreds of years to develop. It may reach its greatest expression within a few years under intensive agricultural practices and in humid regions where rainfall is sufficient to leach down the nutrients [3]. Most processes developing soil acidification are natural, anthropogenic activities have a major impact on some of them. Several reasons may contribute to soil acidification and excessive use of nitrogen (N) is one of them [3]

Methods

Results

Discussion

Conclusion