Relation Between Nitrous Oxide Emission Flux and Fertilization andIrrigation of the Late Rice Paddy-Fields in Guangzhou Area

Nitrous oxide emission flux had direct relation with the kinds of fertilization and the methodsof irrigation applied to the rice field during the late rice growing season. There were four kinds of fertiliz-ers applied. The mean amounts of N2O emission flux, the ratio of which for the four treatments, i. e.,chemical fertilizer only, chemical fertilizer plus pig muck, chemical fertilizer plus mushroom fertilizer andpig muck only was 10: 2: 1:0. Nitrous oxide continuously flowed from the field applied with only chemicalfertilizer during the whole growing period. Because flooding the rice field would lower down the nitrousoxide emission, while drying the field would result in increase of the emission, flooding the rice fieldwould be an efficient methed to reduce the N2O emission flux atter application of fertilization.