尿素与复合氮肥增效剂配施对水稻氮素利用的影响

采用^15N-尿素进行盆栽和田间试验，研究了复合氮肥增效剂用量、尿素与复合氮肥增效剂配施对水稻生长、籽粒产量和氮素吸收利用的影响。结果表明，适宜用量（施氮量的20％）的复合氮肥增效剂能显著促进水稻幼苗生长发育；尿素全量配施复合氮肥增效剂不影响水稻生长，能显著提高水稻植株Ndff％、氮吸收总量，氮素利用率和^15N的吸收量,尿素减量5％～15％（即减少施氮7．8～23．7kg／hm^2）配施复合氮肥增效剂基本上不影响水稻生长、籽粒产量和吸氮总量，能显著提高氮素的农学效率、生理效率和氮素利用率；植株吸氮总量、净吸收氮量和^15N总吸收量与不施增效剂的处理相当或有所提高。尿素减量达30％以上配施复合氮肥增效剂，对水稻植株生长和氮素吸收利用产生明显不利影响。尿素与施氮量20％的复合氮肥增效剂配施，不影响大田水稻植株生长和单季产量，能提高氮素利用率，节省氮肥投入达15％。

Effect of Urea Combined with Compound Nitrogen Fertilizer Synergists on Nitrogen Utilization of Rice

Pot and field experiments were conducted to study the dosage and the effect of compound nitrogen fertilizer synergists combined with different dosage of urea on the growth,yield,uptake and nitrogen use efficiency of rice with()~(15)N-labled.The results showed that the growth of rice seedling was obviously promoted with appropriate dosage of compound nitrogen fertilizer synergists(20% of N).Treated with urea and added with compound nitrogen fertilizer synergists,the growth of rice wasn't affected,the Ndff%,the total()~(15)N uptake and total nitrogen uptake of rice and the nitrogen use efficiency were increased.Treated with urea reduced by 5%~15%(7.8~23.7 kg/hm~2) and added with compound nitrogen fertilizer synergists,the growth,yield,and nitrogen content of rice were not affected,the total()~(15)N uptake and total nitrogen uptake of rice were the same as CK_2 or higher than it,and the nitrogen use efficiency,physiological rate and agronomic use efficiency of nitrogen were remarkably increased comparing to CK_2.Treatment with urea reduced by 30% and compound nitrogen fertilizer synergists,the growth and absorption and utilization of nitrogen of rice were apparently decreased.As a result,treated with appropriate dosage of compound nitrogen fertilizer synergists(20% of urea),the growth and yield of rice were not affected,the utilization of nitrogen was enhanced and the dosage of nitrogen fertilizer was decreased by 15%.