Journal Article

Methane uptake in semiarid farmland subjected to different mulching and nitrogen fertilization regimes

Li, Shiqing, Chen, Huai, Jiang, Haibo, Huang, Xinya, Chen, Xinping, Luo, Shasha, Zhan, Ai, Liu, Jianliang

2016

Overview

Methane (CH 4 ) uptake by dryland soils is an important part in the global CH 4 budget and is sensitive to the management practice. This research measured the annual CH 4 flux over 2 years at the rain-fed maize fields in semiarid northwestern China using the static chamber technique. Methane uptake was measured under three mulching practices with the same nitrogen (N) application: no mulching (NM), gravel mulching (GM), and plastic film mulching (FM). In addition, methane uptake was also measured under film mulching management and three different N fertilizer rates: 0 (N0), 250 (N250), and 380 (N380) kg N ha −1 . The results showed that the rain-fed maize fields acted as a sink for CH 4 , with the annual mean uptake rate of 21.3–40.8 μg CH 4 -C m −2  h −1 . The soil CH 4 uptake was positively correlated with soil temperature, but negatively correlated with soil moisture; these two factors together explained 35.5–50.9 % of the variance in CH 4 uptake. Compared to the NM treatment, the mulching treatments markedly increased the topsoil temperature, but the annual CH 4 uptake was significantly reduced by 5.2–6.7 % in the GM treatment and by 26.3 % in the FM treatment, most likely because the increased soil moisture restricted CH 4 oxidation and diffusion. The CH 4 uptake showed an increasing tendency with the N rate, probably because N fertilization decreased soil moisture and increased soil NO 3 − content. These results help in understanding the effects of agricultural managements on CH 4 uptake and to properly assess the role of dryland soils in the global CH 4 budget.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Agricultural land / Agricultural management / Agriculture / arid lands / Arid zones / Biomedical and Life Sciences / China / Composting / Corn / fertilizer analysis / fertilizer rates / Fertilizers / Gravel / Life Sciences / Methane / Mulching / nitrates / Nitrogen / nitrogen fertilizers / Original Paper / oxidation / plastic film / Rain / Soil fertility / Soil moisture / Soil Science & Conservation / Soil temperature / soil water / Topsoil / variance / Zea mays