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在大田设立小区进行了两个试验,以研究稻草和肥料处理策略对小麦吸收土壤氮和标记氮的影响.第一个试验以~(15)N标记硫酸铵,施用量折合氮素113公斤/公顷,稻草按以下4种方式处理:①焚烧,免耕;②小麦播前6周,稻草混入土壤;③小麦播种时,稻草混入土壤;④稻草置于地面,免耕.结果是:处理①使小麦吸收氮量增加47%,吸收水稻茬地残留氮(~(15)N示踪)的量从1.2增加到2.1公斤/公顷.处理④使水稻茬地残留氮吸收量增加到2.5公斤/公顷.第二个试验设120个小区,其中60个施氮100公斤/公顷;另外60个不施氮.施氮小区的稻草产量为21吨/公顷,不施氮小区为11.5吨/公顷.这两种稻草产量水平与5种处理方式(上述四种处理方式加上焚烧后翻耕处理)组成联合因子试验.~(15)NH_4~(15)NO_3在播种期或分蘖期一次全量施用,或两期各半施用.不论是否焚烧稻草,翻耕比免耕减产0.7吨/公顷,土壤氮吸收量减少了12公斤/公顷,化肥氮吸收量减少了10公斤/公顷.小麦播种时,将稻草混入土壤的处理,对小麦长势明显不利,但却增大了吸收化肥氮素的比例.延迟施肥亦可增大吸收化肥氮素的比例.在稻麦轮作制度下,不论是否焚烧稻草,免耕都可促进小麦吸收土壤氮和化肥氮的活性,增加小麦产量.
Two experiments were carried out to set up a plot in Daejeon to study the effects of straw and fertilizer treatment strategies on nitrogen uptake and soil nitrogen uptake by wheat plants. The first experiment was conducted with ~ (15) N-labeled ammonium sulfate at an applied nitrogen yield of 113 kg / Hectare, straw in the following four ways: ① incineration, no tillage; ② 6 weeks before sowing, straw mixed with soil; ③ wheat sowing, straw mixed with soil; ④ straw placed on the ground, no tillage. The results are: The amount of nitrogen absorbed by wheat increased by 47% and the amount of retained nitrogen (~ (15) N traced) on rice stubble increased from 1.2 to 2.1 kg / ha.④ The residual nitrogen uptake of rice stubble was increased to 2.5 kg / Hectare.The second experiment set 120 plots, of which 60 nitrogen application of 100 kg / ha; the other 60 no nitrogen application.Nitrogen yield of straw area of 21 tons / hectare, non-nitrogen area of 11.5 tons / hectare. The combination of these two straw production levels and five treatments (the above four treatments combined with post-incineration plowing) formed a combined factor test.A total amount of (15) NH_ (4) ~ (15) NO_3 was applied at the time of sowing or tillering stage, Or two halves of the application.Whether or not burning straw, tillage than tillage reduction of 0.7 tons / ha, soil nitrogen uptake A decrease of 12 kg / ha, fertilizer nitrogen absorption decreased by 10 kg / ha.When sowing wheat, the straw mixed into the soil treatment significantly adverse to wheat growth, but increased the proportion of nitrogen absorbed by the fertilizer. Delayed fertilization also Can increase the proportion of nitrogen absorbed by chemical fertilizers.Under the system of rice and wheat rotation, no-till or no-tillage can promote the activity of wheat absorbing nitrogen and nitrogen and increasing the yield of wheat.