缓控释氮肥对寒地水稻产量、氮肥利用率及氮在黑土中分布的影响

Effects of slow and controlled release nitrogen fertilizer on rice yield,nitrogen use efficiency and nitrogen distribution in black soil in cold region

缓控释氮肥在寒地黑土水稻上的应用效果和施用技术尚不十分明确,采用定位试验方法进行为期3年的试验研究,明确不施氮肥(CK)、全部普通氮肥一次性基施(BU100%B)、全部缓控释氮肥一次性基施(CRU100%B)、农民习惯施肥(FP)、60%缓控释氮肥和40%普通氮肥混合一次性基施(MBC)条件下,水稻产量、效益、氮素吸收利用和无机氮在土壤剖面中累积与分布的差异。结果表明,与CK比较,各施氮处理产量、效益、氮素利用率和无机氮在土壤剖面中的累积显著提高。MBC处理在产量、效益、氮肥利用率和减少土壤无机氮积累方面效果最好。与FP处理相比,MBC处理3年水稻平均增产6.2%,经济效益增加17.7%,氮肥利用率增加16.9%,氮肥农学效率增加16.4%,差异显著(P<0.05)。施用缓控释氮肥减少了无机氮在剖面(0~90 cm)中的累积,MBC处理较FP土壤无机氮累积量平均降低7.9%,CRU100%B较BU100%B处理平均降低10.7%,且差异显著(P<0.05)。无机氮在土壤剖面中的分布由上到下逐渐减少,0~30、30~60和60~90 cm土层分别占无机氮累积总量的38.3%~54.6%、28.8%~35.7%和14.0%~26.1%。施用缓控释氮肥增加了无机氮在土壤上层剖面(0~30 cm)的累积,减少了无机氮在土壤深层剖面(60~90 cm)的累积量。在0~30 cm剖面中,MBC较FP处理无机氮平均增加12.4%,在60~90 cm剖面中,无机氮平均降低19.7%。可见,施用缓控释尿素提高了氮肥利用率、增加了水稻产量和效益、降低了土壤无机氮在深层剖面的残留,进而降低了氮素淋失的环境风险。

The effects and application techniques of slow and controlled release nitrogen fertilizer on rice in cold black soil are not very clear.A 3-year experimental study was conducted by using the method of location test.Five treatments were set up,including no nitrogen application(CK),all common nitrogen one-time base application(BU100%B),all slow and controlled release nitrogen one-time base application(CRU100%B),farmers’practice(FP)and 60%slow and controlled release nitrogen fertilizer and 40%common nitrogen fertilizer mixed one-time base application(MBC).The differences in rice yield,benefit,nitrogen uptake and utilization,and soil inorganic nitrogen accumulation and distribution in soil profiles were determined.The results showed that compared with CK,the yield,benefit,nitrogen use efficiency and soil inorganic nitrogen accumulation in soil profile were significantly increased by introgen application.MBC treatment had the best effect on yield,benefit,nitrogen use efficiency and reducing soil inorganic nitrogen accumulation.Compared with FP treatment,MBC treatment increased rice yield by 6.2%,economic benefit by 17.7%,nitrogen use efficiency by 16.9%and nitrogen agronomic efficiency by 16.4%,with significant differences(P<0.05).Application of slow and controlled release nitrogen reduced the accumulation of soil inorganic nitrogen in the 0-90 cm profile.Compared with FP treatment,the accumulation of soil inorganic nitrogen in MBC was reduced by 7.9%,and CRU100%B was 10.7%lower than that of BU100%B,on average(P<0.05).The distribution of soil inorganic nitrogen in soil profile decreased gradually from top to bottom,and the soil layers of 0-30,30-60 and 60-90 cm accounted for 38.3%-54.6%,28.8%-35.7%and 14.0%-26.1%of the total soil inorganic nitrogen accumulation,respectively.Application of slow and controlled release nitrogen fertilizer increased the accumulation of soil inorganic nitrogen in the upper soil profile(0-30 cm)and decreased the accumulation of soil inorganic nitrogen in the deep soil profile(60-90 cm).Compared with FP treatment,soil inorganic nitrogen of MBC treatment increased by 12.4%in 0-30 cm profile,and decreased by 19.7%in 60-90 cm profile,on average.In conclusion,application of slow and controlled release urea can improve nitrogen use efficiency,increase rice yield and benefit,reduce soil inorganic nitrogen residue in deep soil profile,and reduce the environmental risk of nitrogen leaching.