5种旱地土壤的供氮特点及其与土壤性质的关系

用盆载黑麦草和土壤间隔淋洗好气培养的方法，研究了湖北省５种主要旱地土壤的供氮特点。结果表明，供试土壤基础供氮量以江陵潮土和武汉黄棕壤最大，新洲潮土（酸性）和枣阳黄褐土次之，咸宁棕红壤最小。潮土和黄褐土前期供氮多而后期供氮少；棕红壤供氮最平稳，前后期都保证了一定的供氮量，但其供氮强度最弱、供氮数量最少；酸性潮土和黄棕壤处于上述２类土壤之间。土壤氮素矿化一级动力学模型可以较好地描述供土壤的供氮特征。土壤供氮快慢与土壤粘粒含量、有机碳／有机氮比率及有机质氧化稳定系数有关。

THE CHARACTERISTICS OF NITROGEN SUPPLY IN FIVE UPLAND SOILS IN HUBEI PROVINCE AND ITS RELATIONS WITH THE SOIL PROPERTIES

The basic amounts of soil nitrogen supply were the largest in the chao soil from Jiangling and the Yellow-brown soil from Wuhan among five upland soils in Hubei Province, while the acid soil from Xingzhou and Yellow-cinnamon soil from Zaoyang were less and the Brown-red soil from Xianning was the least.The nitrogen supply amounts and intensities were large in the early days and then became very small in latter periods in the chao soil and Yellow-cinnamon soil.But they were stable in the Brown-red soil, large in the early days and also keeping a certain level in the later stages. And those of the acid chao soil and the Yellow-brown soil were between the above two types.The nitrogen supply characteristics of the five soils were well described by first-order mineralization kinetic model.The speed of nitrogen supply was related to the soil clay contents, the ratio of organic C/organic N and the soil organic matter stability.