有机无机配施对水稻产量及氮肥残效的影响

为揭示有机无机配施条件下;N尿素在稻田土壤中的残效状况,在我国北方棕壤性水稻土上进行盆栽试验,结合土壤氮素供应及水稻对肥料氮的吸收利用,探寻最佳的施肥方式。设置空白(CK)、尿素(N)、秸秆+尿素(NS)、猪粪+尿素(NM)、稳定性尿素(NI)、秸秆+稳定性尿素(NIS)、猪粪+稳定性尿素(NIM)7个处理。结果表明,稳定性尿素、秸秆、猪粪的添加均能影响;N标记的尿素在土壤中的残留、转化及水稻吸收利用。相比于N,NI显著延缓了尿素水解(P<0.05),增加水稻返青期和分蘖期铵态氮的供应,增加各生育期生物量及产量,提高了水稻的收获指数和氮素回收利用率。秸秆和猪粪的添加均显著提高了土壤微生物量碳氮,增强了氮素供应能力。NS或NIS增加了水稻穗及地上部分对肥料氮的吸收利用,其具有最高的收获指数(0.39~0.47)。相比于N,NIM提高水稻产量约137%,增加水稻分蘖期和成熟期生物量分别约1.98%和53%,提高了氮素回收利用率,约是N的1.82倍。秸秆配施氮肥的微生物量碳氮具有较好的耦合性,猪粪添加的增产效果更为明显。总之,在我国北方稻田土壤中,从产量及生物量的角度,NI、NIM为推荐施用模式,从肥料氮固持及培肥土壤的角度,NS、NIS是值得长期探索的施用方式。

Effect of organic and inorganic fertilizer on rice yield and nitrogen residual effect

In order to explore the residual effect of;N-labeled urea in paddy soil under the conditions of organic and inorganic application,a pot experiment was conducted on brown paddy soil in the northeast of China and the proper fertilization methods were selected by combining the supply of soil nitrogen and the uptake of fertilizer nitrogen by rice.Seven treatments were setup:control(CK),urea(N),straw+urea(NS),pig manure+urea(NM),stabilized urea(NI),straw+stabilized urea(NIS)and pig manure+stabilized urea(NIM).The results showed that the addition of stabilized urea,straw and pig manure changed the soil conversion and rice uptake of;N labeled urea.Compared with N,NI significantly delayed the urea hydrolysis(P<0.05),and increased the supply of NH;-N at rice seedling and tillering stages,thus improving rice biomass and yield at whole growth stage,so was the rice yield and nitrogen recovery efficiency.The addition of straw and organic fertilizer significantly increased the soil microbial biomass carbon or nitrogen,enhanced the ability of nitrogen supply.NS or NIS increased the uptake and utilization of fertilizer nitrogen in panicle and above-ground biomass,which represent the highest harvest index(0.39~0.47).NIM increased rice yield by 137%compared with N,which also improved the rice biomass at tillering and maturation stage by 1.98%and 53%,respectively and improved nitrogen recovery rate,which was about 1.82 times that of N.The microbial biomass carbon and nitrogen of straw combined with nitrogen fertilizer had better coupling and the increase effect of pig manure was more obvious.In conclusion,in the paddy field soil in northern my country,from the perspective of yield and biomass in season,NI and NIM are recommended as fertilization patterns,NS and NIS are worthy of long-term exploration from the perspective of fertilizer nitrogen fixation and soil cultivation.