Abstract:

Nowadays, the plastic film mulching was applied in croplands all over the world, in order to study the effect of plastic film mulching on soil environmental factors and the nitrous oxide emission, the author made the typical purple soil in Chongqing as the research objective, and comparing with the traditional cropping system (no plastic film mulching), a field experiment was conducted in situ for half a year during the radish growing period by the method of static opaque chamber and gas chromatogram method. The result showed that the temperature of soil in 5 cm depth under the plastic film mulching was higher greatly and the total biomass of radish improved obviously than that of control (P=0.02 and P=0.005), the weight of leaves and stalk of radish under the plastic film mulching were also obviously higher than that of the control group (P=0.011 and P=0.013), but there was no significant differences in the soil moisture and nitrate nitrogen between two groups. During the radish growing periods, the average N2O flux was (58.59±10.76) μg/(m2?h) and total N2O emission amount was 1.58 kg/hm2 in the whole observing period, and the average N2O flux in the 4 stages of radish under plastic film mulching was (70.21±10.51) μg/(m2?h) in germinate stage, (65.43±5.66) μg/(m2?h) in leaves vigorous growing stage, (109.13±11.23) μg/(m2?h) in seedling stage and (62.81±15.10) μg/(m2?h) in stalk growing stage, respectively. The average N2O flux was (58.59±10.76) μg/(m2?h) and total N2O emission amount was 1.30 kg/hm2 under no film mulching in the whole observing period. The N2O emission amount increased 21.5% under plastic film mulching than no film mulching during the whole observing period. So planting the radish with film mulching method could improve the yield, but increased the N2O emission as well.