N2O Emission and Mineral N Release in a Tropical Acrisol Incorporated with Mixed Cowpea and Maize Residues

Agronomy

Kwame A. Frimpong²  David O. Yawson²  Kofi Agyarko¹ 

[1] Department of Agricultural Education, University of Education, Winneba, Mampong Campus, Ghana;Department of Soil Science, University of Cape Coast, Cape Coast, Ghana;

关键词: cowpea-maize residue;    nitrous oxide emission;    N mineralization;    tropical acrisol;   

DOI  :  10.3390/agronomy2030167

来源: mdpi

【 摘 要 】

A laboratory microcosm incubation was conducted to study the influence of mixed cowpea-maize residues on N₂O emission and N mineralization in a tropical acrisol. The soils were incorporated with different ratios of cowpea:maize mixtures on weight basis: 100:0, 75:25, 50:50, 25:75 and 0:100, and a control treatment in which there was no residue incorporation. The results show that N₂O and CO₂ emissions were higher in the sole cowpea treatment (100:0) than the sole maize treatment (0:100) and the control. However, cowpea-maize residue mixtures increased the proportion of N lost as N₂O compared to the sole treatments. This interactive effect was highest in the 75:25 treatment. The 50:50 treatment showed moderate N₂O emission compared to the 100:0, 75:25 and 25:75 treatments but with corresponding steady N mineralization and appreciable mineral N concentration. It is concluded that mixing cowpea-maize residues might increase the proportion of N lost as N₂O in a tropical acrisol. However, compared to the other residue mixture treatments, mixing cowpea-maize residues in equal proportions on weight basis might offer a path to reducing N₂O emissions while maintaining a steady N mineralization without risking good N supply in acrisols. The study therefore offers potential for mitigating greenhouse gas emissions while maintaining soil fertility in tropical acrisols. However, further studies under both laboratory and field conditions will be required to verify and validate this claim.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.