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荒地黑土通常均具有良好的结构性状,用湿筛法可测定得其表层土壤中>0.25毫米粒径的水稳性团聚体含量达70％以上。黑土经开垦耕种后,团聚体的水稳性常常明显下降,从而影响及黑土的其他物理性质和耕作特性。 影响黑土团聚体水稳性的因素颇多,本文着重探讨土壤养分状况与这一性状变化的关系。 一、黑土开垦后土壤团聚体水稳性变化的一般规律 黑土经开垦耕种后,水稳性团聚体的含量常常明显减少,同时,水稳性团聚体的粒径组成也迅速变为小粒径的团聚体占绝对优势。这一变化在开垦后的最初若干年内即可明显发生,尤其是团聚体粒径组成的变化更是如此(表1)。
The black soil in the wasteland usually has good structural characteristics. The content of water-stable aggregates> 0.25 mm in surface soil can be determined by the wet sieving method to reach more than 70%. After reclamation and cultivation of black soil, the water stability of the aggregates often drops significantly, which affects other physical properties and cultivation characteristics of the black soil. There are many factors affecting the water stability of black soil aggregates. This paper focuses on the relationship between soil nutrient status and the change of this trait. First, after the reclamation of black soil aggregates water stability of the general rule of black soil reclamation cultivation, the content of water-stable aggregates often significantly reduced at the same time, the water-stable aggregates of particle size composition also quickly become small particle size Agglomerate absolute advantage. This change was evident in the first few years after the reclamation, especially as the composition of aggregate size changed even more (Table 1).