【摘要】 通过盆栽土培试验研究了尿素、控释氮肥对南方稻田冬油菜生长、产量、土壤肥效和氮肥利用效率的影响,为控释氮肥在油菜生产上的推广应用提供参考。试验选用油菜品种"湘油15",参考油菜大田种植施氮量,共设4个处理,以不施氮肥(CK)为对照,在施氮量均为200kg/hm~2的水平下,设置了3种氮肥处理:尿素(Urea)、控释氮肥1(CRNF1)和控释氮肥2(CRNF2)。对油菜生物量和产量、不同生育期下土壤无机氮、油菜氮素吸收、油菜生理特性、土壤微生物氮以及土壤酶活性等相关指标进行测定及分析。结果表明:较常规Urea处理相比,控释氮肥处理显著提高了油菜花期、收获期生物量,增产11.2%～20.1%;CRNF1处理显著提高了油菜花期、收获期土壤NO3--N含量,相比尿素处理分别提高43.2%和61.8%,CRNF2处理显著提高了油菜花期、收获期土壤NH4+-N含量,相比尿素处理分别提高18.7%和64.1%,保证了油菜生育后期土壤氮素供应;与Urea处理相比,控释氮肥显著提高了油菜薹期及生殖生长期油菜总氮吸收,最终氮肥利用率(NUE)提高23.1%～60.2%,氮肥农学利用率(NAE)提高19.1%～30.5%;CRNF1处理显著提高了油菜生长后期SPDA值和总叶绿素含量,相比尿素处理分别提高6.5%,10.1%;CRNF1处理极显著提高了油菜生长后期土壤微生物氮,较尿素处理提高142.5%;此外,控释氮肥显著提高了油菜生长后期土壤脲酶、FDA水解酶活性,相比尿素处理分别提高8.4%～12.9%,24.5%～32.4%。在总氮施用量不变的前提下,施用控释氮肥可提高油菜生殖生长期土壤有效氮含量,改善光合作用,增强土壤微生物量和微生物活性,促进氮素的吸收,提高氮肥的利用效率,进而增加油菜干物质累积,最终提高产量。更多还原

【Abstract】 Pot experiments were carried out to study the effects of urea and controlled-release nitrogen fertilizer(CRNF)application on soil fertility and nitrogen fertilizer use efficiency(NUE)and growth of rape in Southern China,and it could provide reference for the application and dissemination of CRNF in rape production.An experiment with a randomized complete block design was conducted to investigate the effects of urea and CRNF on rape biomass and yield,soil inorganic nitrogen at different growth stages,nitrogen uptake of rape,physiological characteristics of rape,soil microbial nitrogen and enzyme activity using high yielding variety"Xiangyou15".According to the standard amount of nitrogen application in rape field,four treatments were set up in this study,conventional urea(Urea),controlled-release nitrogen fertilizer 1(CRNF1),controlledrelease nitrogen fertilizer 2(CRNF2)and no nitrogen fertilizer(CK).The result showed that compared with the conventional urea treatment,CRNF significantly increased the biomass of rape by 11.2%～20.1%at flower-ing and harvest stage,the NO3-N concentration of rape at flowering and harvest stage in the CRNF1 treatment was significantly increased by 43.2%and 61.8%,respectively,and the NH4+-N concentration in soil in CRNF2 treatment was obviously increased by 18.7% and 64.1%,respectively,at flowering and harvest stage,which ensured the supply of soil nitrogen at the late growth stage of rape.Compared with the Urea treatment,total nitrogen uptake in rape was significantly increased by CRNF at the bolting and flowering stage.In eventually,the nitrogen use efficiency(NUE)was increased by 23.1%～60.2%and the agronomic nitrogen use efficiency(NAE)raised by 19.1% ～30.5%.CRNF1 treatment significantly increased the SPDA value and total chlorophyll content by 6.5% and 10.1%,respectively,at the late growth stage of rape.Compared with the Urea treatment,CRNF1 treatment significantly increased the soil microbial nitrogen by 142.5%at the late growth stage of rape.In addition,the activity of soil urease,FDA hydrolase in the CRNF application treatment were significantly increased by 8.4%～12.9% and 24.5%～32.4%,respectively,at the late growth stage of rape.These results demonstrate that under the condition of total nitrogen application rate unchanged,application of CRNF mainly increased soil available nitrogen content at later growth stages,improved photosynthesis,enhanced soil microbial biomass and enzyme activity,thereby increased nitrogen uptake of rape,increased NUE and dry matter accumulation of rape,and increased grain yield.更多还原