白浆土生态平衡施肥参数的研究

试验主要研究了生态平衡施肥模型的4个参数:①P-作物从肥料中吸收氮量(kg.hm-2);②Lfsp-肥料和土壤氮损失量与作物从耕层土壤有效氮中吸收氮总量(kg.hm-2);③Wn+1-肥料残留氮量与季后耕层土壤有效氮剩余总量(kg.hm-2);④Wn-播种前耕层土壤有效氮总量(kg.hm-2),并根据黑龙江省气候特点,将生态平衡施肥模型的参数进行了修正,在用空白田土壤测定结果计算Lfsp值时,原公式用同一年作物播种前与收获后土壤测定结果之差,而试验采用后一年与前一年春季土壤测定结果之差,修正后大豆Lfsp值为12kg.hm-2,首次在黑龙江省运用修正后的生态平衡施肥参数预测出大豆白浆土生态平衡施氮量,大豆达到2160kg·hm-2产量需施纯氮42.5kg.hm-2。

Ecological balanced fertilization parameters in albic soil

Four parameters of an ecological balanced fertilization model were studied: ① P(kg·hm-2),nitrogen absorbed from fertilizer;② Lfsp(kg·hm-2),sum of lost nitrogen from fertilizer,soil nitrogen and nitrogen absorbed by crop;③ Wn+1(kg·hm-2),sum of residual chemical fertilizer nitrogen and nitrogen in the plowed horizon after harvesting;④ Wn(kg·hm-2),total nitrogen in the plowed horizon before seeding.According to the climatic characteristics in Heilongjiang Province,the model's parameters were adjusted.When calculated Lfsp,the results of check plots(CK) were used.In the original model,difference of available soil nitrogen in autumn and that in spring in the same year was used.In this experiment,the difference of available soil nitrogen in spring of experimentation and that in spring of the year before were used.The adjusted Lfsp of soybean was 12 kg·hm-2.The adjusted parameters were applied to predict the rate of fertilizer of soybean in albic soil in Heilongjiang Province for the first time,the predicted rate of nitrogen was 42.5 kg·hm-2 for a yield of 2 160 kg·hm-2.