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为探明控释氮肥对紫色土坡耕地氧化亚氮(N_2O)排放量的影响,以不施肥为对照(CK),研究了尿素(UR)、缓控释氮肥(CR)、缓控释氮肥+尿素(25%CR,尿素75%)各处理对玉米产量、玉米生育期的径流和氮素损失量以及N_2O排放量的影响。结果表明,对照处理玉米产量最低,径流损失量最大,壤中流氮素损失量和N_2O排放量要远低于施肥处理,说明施肥是造成氮素流失和氧化亚氮排放的主要原因。缓控释氮肥处理生育期的壤中流氮素损失量在4个处理中最大,为31.7 kg/hm~2,但N_2O排放量为0.35 kg/hm~2,比尿素处理降低了37%。控释氮肥+尿素处理壤中流氮素损失在施肥处理中最低,为20.9 kg/hm~2,N_2O排放量比尿素处理低15%。控释氮肥的氮素在生育期内缓慢释放,低的土壤无机氮使得控释氮肥能够降低坡耕地N_2O排放,但控释氮肥会导致壤中流氮素损失量增大。因此,控释氮肥和尿素配合使用在降低N_2O排放的同时,还能减少壤中流氮素损失。
In order to investigate the effect of controlled release nitrogen fertilizer on nitrous oxide (N 2 O) emissions on purple soil sloping farmland, urea (UR), slow release controlled release (CR) + Urea (25% CR, urea 75%) on corn yield, corn runoff and nitrogen loss and N 2 O emissions during maize growth. The results showed that the corn with the lowest yield and the largest amount of runoff loss, the nitrogen loss and N 2 O emission in the soil were much lower than those in the fertilization treatment, which indicated that fertilization was the main reason for nitrogen loss and nitrous oxide emission. The nitrogen loss in middle soil during slow-release nitrogen fertilizer treatment was 31.7 kg / hm ~ 2, but the N_2O emission was 0.35 kg / hm ~ 2, which was 37% lower than that of urea treatment. Controlled release nitrogen fertilizer + urea treatment Soil nitrogen loss in the fertilization treatment lowest, 20.9 kg / hm ~ 2, N2O emissions 15% lower than the urea treatment. Nitrogen released from controlled release nitrogen fertilizer slowly released during the growth period. Low soil inorganic nitrogen made it possible to reduce the N 2 O emission from sloping land with controlled release nitrogen fertilizer, but controlled release nitrogen fertilizer would lead to an increase of nitrogen loss in middle soil. Therefore, the combined use of controlled release nitrogen fertilizer and urea can reduce N2O emission and reduce nitrogen loss in soil middle stream.