Emission of N2O on pulse–rice crop rotation in upland

The Seasonally Integrated Flux (SIF) of N2O emission during pulse cultivation in Rabi season (Season-I: December to April) in rain-fed uplands of Orissa, was found to be 17.7 ± 0.07, 18.7 ± 0.16 and 43.3 ± 0.14 gha−1 for horse gram (HG), black gram (BG) and green gram (GG) respectively. During the subsequent Rabi season (Season-II), the SIF of N2O for BG and GG cultivated in the same fields were 20.9 ± 0.24 and 38.0 ± 0.42 gha−1 respectively. Similarly SIF values during rice cultivation with different cultivars have also been calculated to be in the range −20.05 ± 0.33 to 21.98 ± 0.29. Statistical analysis showed good correlation of N2O emission with climatic and soil parameters like temperature, nutrient N and organic matter in soil during pulse cultivation. Multivariate analysis was carried out to factorize the results obtained. Using student ‘t’ test, the N2O emission was observed to be similar for two consecutive Rabi seasons for pulses like BG and GG.