Effects of soil temperature, flooding, and organic matter addition on N2O emissions from a soil of Hongze Lake wetland, China.

Yan Lu,Hongwen Xu

doi:10.1155/2014/272684

Abstract

The objectives of this study were to test the effects of soil temperature, flooding, and raw organic matter input on N2O emissions in a soil sampled at Hongze Lake wetland, Jiangsu Province, China. The treatments studied were—peat soil (I), peat soil under flooding (II), peat soil plus raw organic matter (III), and peat soil under flooding plus organic matter. These four treatments were incubated at 20°C and 35°C. The result showed that temperature increase could enhance N2O emissions rate and cumulative emissions significantly; moreover, the flooded soil with external organic matter inputs showed the lowest cumulative rise in N2O emissions due to temperature increment. Flooding might inhibit soil N2O emissions, and the inhibition was more pronounced after organic matter addition to the original soil. Conversely, organic matter input explained lower cumulative N2O emissions under flooding. Our results suggest that complex interactions between flooding and other environmental factors might appear in soil N2O emissions. Further studies are needed to understand potential synergies or antagonisms between environmental factors that control N2O emissions in wetland soils.

Highlights

Climate change has been a major issue within the twenty-first century
Higher cumulative N2O emissions were observed under high temperature as well (Figure 2, BIV)
Significant differences were found between AI and AII, AIII and AIV, BI and BII, and BIII and BIV (n = 3, P < 0.05). These results show that irrespective of incubation temperature, flooding inhibits soil N2O emissions; the decline of N2O emissions under flooding was more obvious in soils plus organic matter

Summary

Introduction

Climate change has been a major issue within the twenty-first century. Concentrations of N2O in the atmosphere are lower than those of either CH4 or CO2; on a per mole basis, N2O has demonstrated a higher ability to disrupt the radiation balance than the other two gases aforementioned. N2O has attracted much attention because it is a potent greenhouse gas with long atmospheric lifetimes, and it is involved in ozone depletion as well [1, 2]. Measurements of N2O emissions have been increasing steadily. The vast majority of studies have focused on N2O emissions from agroecosystem, as affected by temperature, soil type, crop growth, and management practices [3,4,5]. There is much uncertainty surrounding the effect of flooding or the joint effects of several factors, for example, flooding and temperature changes

Objectives

Methods

Results

Discussion

Conclusion