不同控氮比掺混肥对土壤无机氮与脲酶及冬小麦产量的影响

开展田间小区试验,研究了控释氮肥与尿素掺混施用对土壤无机氮与脲酶及冬小麦产量的影响,旨在寻求控释氮肥与尿素最佳掺混比例,提出缓解氮肥损失、降低面源污染、节约成本、易于推广的施肥方式。结果表明:较常规尿素处理,控释氮肥与尿素掺混对土壤铵态氮含量影响总体差异不显著;在小麦分蘖期,常规尿素处理土壤硝态氮含量和土壤脲酶活性较高,而小麦拔节期至成熟期,则以掺混40%比例以上控释氮肥处理的土壤硝态氮含量和脲酶活性较高;各施氮处理对小麦穗粒数和千粒重影响差异不显著,产量以掺混40%控释氮肥处理最高,较常规尿素处理增产14%,因产值最高,投入成本适中,净收入水平和产投比均为最高,分别为5 875.72元·hm~(-2)和2.24,较常规尿素处理提高了23.24%和9.27%。综上,40%控释氮肥与60%尿素掺混处理在提高土壤无机氮含量,激活小麦生长中、后期脲酶活性,增加冬小麦产量方面效果显著。

Effects of bulk blend fertilizers with different controlled nitrogen ratios on the soil inorganic nitrogen, urease and winter wheat yield

To reveal the effect of different application of controlled release nitrogen fertilizer combined with urea on the soil inorganic nitrogen ,urease and winter wheat yield ,we carried out the field experiment aimed at studying the opti-mum combination of controlled release nitrogen fertilizer and conventional urea and thereby putting forward proposal for reducing nitrogen fertilizer loss and non-point source pollution ,and saving cost as well .The results showed that compared with urea ,combination application of controlled release nitrogen fertilizer and urea treatment had less influence on soil NH4+ -N contents .At wheat tillering stage ,urea treated soil NO3- -N contents and urease were more active .By con-trast ,soil NO3- -N contents and urease activity were higher by combination of urea and 40% controlled release nitrogen fertilizer at the later growth stage .Nitrogen fertilizer treatments had a little influence on the grain number per panicle and the 1000-weight of wheat . While 60% urea blended with 40% controlled release nitrogen fertilizer (40% CRU ) in-creased grain yield significantly ,as high as 14% compared with urea treatment .As the output value was the highest ,in-put cost was moderate ,the net income level and output/input ratio were the highest ,respectively ,5 875 .72 yuan·hm-2 and 2 .24 ,compared with the urea treatment increased by 23 .24% and 9 .27% .In conclusion ,the combined applica-tion of 40% controlled release nitrogen fertilizer with 60% conventional urea was the optimum ratio with the beneficial ef-fect of improving soil inorganic nitrogen contents ,activating the urease activity during the later growth stage of wheat ,and increasing the yield of winter wheat .