N2O emission in relation to plant and soil properties and yield of rice varieties

K.K. Baruah , B. Gogoi , P. Gogoi , P.K. Gupta

Nitrous oxide (N2O) is a major greenhouse gas contributing to global warming. Rainfed rice fields are considered to be a notable source of atmospheric N2O emission. To investigate the dynamics of N2O emission and the relationship of plant and soil properties with emission of N2O in rice, a field experiment was conducted. The five popularly grown rice varieties Luit, Disang, Kapilli, Siana and Phorma were grown in the fall season under rainfed conditions. N2O emission was measured at seven-day intervals starting from the day of transplanting for the whole crop growing season. We also measured soil parameters, e.g. soil pH, soil temperature, soil organic carbon, soil NO$_{3}^-$-N, and field water level; and plant growth parameters: root-shoot dry weight, root length and leaf area. Our results show that N2O emission from the plant varieties ranged from 1.24 μg to 379.40 μg N2O-N m−2h−1. Seasonal N2O emission from the rice varieties ranged from 77 to 150 mg N2O-N m−2. Root dry weight, shoot dry weight, soil NO$_{3}^-$-N, root length, leaf area and field water showed relationships with N2O emission. Root and shoot weight, soil NO$_{3}^-$-N and field water were found to be the main factors influencing N2O emission. The varieties Phorma and Siana, with lower grain productivity but profuse vegetative growth, showed higher seasonal N2O emission.

Mots clés: leaf area; nitrous oxide; rice ecosystem; grain yield

Domaines: Sciences agricoles; Ecologie, Environnement

K.K. Baruah, B. Gogoi, P. Gogoi, P.K. Gupta. N2O emission in relation to plant and soil properties and yield of rice varieties. Agronomy for Sustainable Development, 2010, 30 (4), ⟨10.1051/agro/2010021⟩. ⟨hal-00886534⟩