How Tillage and Fertilization Influence Soil N2O Emissions after Forestland Conversion to Cropland
Open Access
- 25 September 2020
- journal article
- research article
- Published by MDPI AG in Sustainability
- Vol. 12 (19), 7947
- https://doi.org/10.3390/su12197947
Abstract
Soil nitrous oxide (N2O) emissions are influenced by land use adjustment and management practices. To meet the increasing socioeconomic development and sustainable demands for food supply, forestland conversion to cropland occurs around the world. However, the effects of forestland conversion to cropland as well as of tillage and fertilization practices on soil N2O emissions are still not well understood, especially in subtropical regions. Therefore, field experiments were carried out to continuously monitor soil N2O emissions after the conversion of forestland to cropland in a subtropical region in Southwest China. One forestland site and four cropland sites were selected: forestland (CK), short-term croplands (tillage with and without fertilization, NC-TF and NC-T), and long-term croplands (tillage with and without fertilization, LC-TF and LC-T). The annual cumulative N2O flux was 0.21 kg N ha−1 yr−1 in forestland. After forestland conversion to cropland, the annual cumulative N2O flux significantly increased by 76‒491%. In the short-term and long-term croplands, tillage with fertilization induced cumulative soil N2O emissions that were 94% and 235% higher than those from tillage without fertilization. Fertilization contributed 63% and 84% to increased N2O emissions in the short-term and long-term croplands, respectively. A stepwise regression analysis showed that soil N2O emissions from croplands were mainly influenced by soil NO3− and NH4+ availability and WFPS (water-filled pore space). Fertilization led to higher soil NH4+ and NO3− concentrations, which thus resulted in larger N2O fluxes. Thus, to reduce soil N2O emissions and promote the sustainable development of the eco-environment, we recommend limiting the conversion of forestland to cropland, and meanwhile intensifying the shift from grain to green or applying advanced agricultural management practices as much as possible.Keywords
Funding Information
- National Key Research and Development Program of China (2017YFD0200105)
This publication has 43 references indexed in Scilit:
- Soil aggregation and organic carbon as affected by topography and land use change in western IranSoil and Tillage Research, 2012
- High-yield maize with large net energy yield and small global warming intensityProceedings of the National Academy of Sciences of the United States of America, 2012
- Towards an agronomic assessment of N2O emissions: a case study for arable cropsEuropean Journal of Soil Science, 2010
- Nitrous oxide and methane emissions from long-term tillage under a continuous corn cropping system in OhioSoil and Tillage Research, 2009
- Measurements of Nitrate Leaching from a Hillslope Cropland in the Central Sichuan Basin, ChinaSoil Science Society of America Journal, 2009
- Initial cultivation of a temperate‐region soil immediately accelerates aggregate turnover and CO2and N2O fluxesGlobal Change Biology, 2006
- Compost Applications Increase Water‐Stable Aggregates in Conventional and No‐Tillage SystemsSoil Science Society of America Journal, 2003
- Modeling global annual N2O and NO emissions from fertilized fieldsGlobal Biogeochemical Cycles, 2002
- Emissions of N2O and NO from fertilized fields: Summary of available measurement dataGlobal Biogeochemical Cycles, 2002
- Soil Structure and Organic Matter I. Distribution of Aggregate‐Size Classes and Aggregate‐Associated CarbonSoil Science Society of America Journal, 2000