长期不同施肥红壤性稻田水稻产量和氨挥发的变化

采用密闭室法测定长期不同施肥制度下双季稻田氨挥发速率及其影响因素,并分析双季稻田氨挥发与产量的关系。结果表明:节肥型有机无机结合农业施肥处理(JF处理)的水稻产量与全肥型有机无机结合农业施肥处理(OM处理)和单施无机肥(NPK处理)的差异不显著,显著高于单施化学氮钾肥(NK处理)的产量;双季稻氮素农学利用率(NUEA)以JF处理的最高,早稻和晚稻分别为17.4和8.9 kg.kg-1,显著高于NK处理;双季稻氨挥发累积量以OM处理最高(86.2 kg.hm-2),NK处理次之(78.2 kg.hm-2),显著高于JF处理(60.7 kg.hm-2);氨挥发速率主要受田面水NH4+-N质量浓度的影响。由于气温和降雨的影响,施早稻分蘖肥后氨挥发速率显著高于施基肥后的,而施晚稻基肥和分蘖肥后的没有差异。因此,JF处理在稳定产量的基础上,能够减少氨挥发量,并且提高了土壤中有机质和全氮含量。

Dynamic change of ammonia volatilization and rice yield during double-rice growing seasons in red paddy soil under different long-term fertilizing systerms

Ammonia volatilization under different long-term fertilizer systems of double rice field was monitored with a continuous airflow enclosure method,and its main affecting factors were investigated,meanwhile,the relationship between ammonia volatilization and rice yield was analyzed.The results showed that there were no significant differences in rice yield between combined inorganic/organic fertilizers at reduced rate(JF)and full rate(OM),and chemical fertilizer(NPK)treatments,all higher in rice yield than phosphorus deficient(NK)treatment.The agronomic nitrogen use efficiency(NUEA)of JF treatment was the highest in both early-and late-rice growing seasons.NUEA in JF treatment were 17.4 and 8.9 kg·kg-1,respectively,which were significantly higher than in NK treatment.The cumulative amounts of ammonia volatilization in OM treatment during the double rice seasons(86.2 kg·hm-2) was the highest,and NK treatment(78.2 kg·hm-2) was the second,which was higher than JF treatment(60.7 kg·hm-2).Ammonia volatilization rate was mainly dependent on NH4+-N concentration in surface water.Because of lower air temperature and rainfull after basal fertilizer application,the rate of ammonia volatilization in early rice after tiller fertilizer application was higher than after basal fertilizer application,while they were no difference in late rice.In conclusion,JF system could maintain a constant higher rice yield,not only with low ammonia volatilization,but also for a high soil organic and N content.