摘要:
近年来,国内外意识到常年单纯使用化肥会导致地力衰退,作物产量下降,但缺乏微观长期定位的数据资料。为此,我们作了7个稻作季有机、无机肥料结合的定位试验初探表明:尿素表施的,产量保持率降为81.6—89.0%,尿素加红萍的为100.5—102.6%;尿素加稻草的为101.1—101.7%;而长期单独使用尿素,有导致水稻产量下降的趋势,若与有机肥料配用,就有促进水稻增产的趋势。同时表明,以投入每公斤纯氮计,能提高经济效益分别为1.10—1.28倍和0.80—0.96倍。并且能提高氮素的产投比,一般为8.0—9.0%,高者可达22.6%。经测试表明,无机氮配加有机肥红萍、稻草的结构,对土壤全氮和有机质的增加幅度较为明显,全氮增0.019—0.049%,有机质增0.08—0.66%。同时对土壤容重、比重和分散系数有下降趋势,分别容重降为0.045—0.120g/cm3,比重为0.015—0.030g/cm3,分散系数为0.68—4.53%;但对物理性粘粒0.01mm含量,一般增加1.73—5.79%。结果表明,改善了土壤生态环境,促进了土壤生态良性循环的作用。
Abstract:
Although the common understanding that applying only chemical fertilizer in long duration will cause the deterioration of soil fertility and decrease crop yield has been reached, few data on long-term observation in fixed location were reported.Our studies in continuously seven cropping seasons showed that, the yield-maintaining rates of urea-broadcasting, urea+azolla, urea+ricestraw treatments are 81.6-89.0%, 100.5-102.6%and 101.1 - 101.7% respectively.Combining application of inorganic fertilizer with organic manure tends to enhance rice grain yield.When calculating on the input of each kg pure nitrogen, the economical benefits of applying azolla and ricestraw were increased 1.10-1.28 and 0.80 - 0.96 folds respectively.Furthermore, the input/output ratio of nitrogen application was increased 8.0 - 9.0%,maximal-ly, 22.6%.Applying inorganic N with azolla and ricestraw caused the increase of soil total N (0.019 -0.049%), O.M.(0.08-0.66% ), decrease of soil B.D (0.0450 - 0.120g/cm3), specific gravity (0.015 - 0.030g/cm3), dispersive coefficient (0.68 - 4.53%), also the increase of physical clay content ( 0.01mm, 1.77-5.79%) .The soil microecological environment was improved.
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