贵州高原黄壤的供氮能力研究

The nitrogen supply ability of yellow soil in Guizhou plateau

利用稳定性同位素1 5N标记氮肥在不同作物上进行数年的盆栽试验、田间微区及小区试验 ,结果显示 ,“A”值与土壤碱解氮含量存在显著相关 ,特别是与植株吸收土壤氮量占碱解氮及全氮含量的百分率具极显著相关 ,植物地上部吸收土壤氮量与其占土壤碱解氮、全氮含量的百分比例亦呈极显著相关关系。据此可以利用田间试验的无肥区植物地上部吸收土壤氮量占碱解氮含量的比率 ,确定一个换算系数。研究中提出贵州中部海拔 10 0 0～ 12 0 0m地带黄壤对玉米、水稻供氮换算系数为碱解氮含量的 0 3 ,13 0 0～ 14 0 0m地带换算系数为 0 2。

Nitrogen fertilizer labeled with stable isotope 15 N were applied to different crop to study the ability of supply nitrogen of yellow soil By means of pot cultivation trials,field trials and plot trials for several years,it was found that the “A” value was related to the contents of soil hydrolysable nitrogen The quantity of N absorption by the aerial part was significantly related to the ratio of hydrolysable nitrogen to the total nitrogen of the soil So we could use the ratio of the quantity of N absorption by the aerial part of crops from the unfertilized soil in field trial to the quantity of hydrolysable nitrogen to define a conversion coefficient It was concluded that the yellow soil′s conversion coefficient of nitrogen supply was 0 3 of hydrolysable nitrogen content for maize and rice at an elevation of 1000～1200 meter and 0 2 at an elevation of 1300～1400 meter region