The Change in Aggregate Following Cultivation

Studies on the aggregate of soil (III)

Abstract

In regard to the rational use of fields, it is important to understand seasonal changes in soil aggregates under cultivation conditions.
In this paper, both qualitative and quantitative changes in soil aggregates following the cultivation of soybean or rice, are studied seasonally and distributionally.
The results obtained are as follows:
(1) In autumn, aggregates are formed with the cultivation of soybean. Though whole aggregates are not always stable quantitatively, enlarged stable aggregates remain until the following spring.
(2) The degree of aggregate formation following cultivation of rice depends mainly on the management of soil water. Large stable aggregates are formed under relatively humid conditions involving little change in moisture.
(3) Change in aggregates is better expressed by taking into consideration the rate of solid phase and organic matter in the soil.
(4) Many physical properties of soil except aggregates do not change remarkably with crop cultivation.
Based on the above, crop cultivation does not harm the physical properties of soil, but actually, makes the soil somewhat better.