土壤保肥-供肥机理及其调节Ⅱ.棕壤型菜园土的腐殖质结合形态及其肥力学意义

采自辽宁省不同地区的１５对棕壤型菜园土肥、瘦地及其各粒级微团聚体的有机质储量和腐殖质结合形态的研究表明，肥地及其各粒级微团聚体的有机质和各结合形态腐殖质的含量与松结态腐殖质占有机质总量的比例均比瘦地及其各相应粒级微团聚体的高，稳结态腐殖质的比例较小，紧结态腐殖质的比例肥瘦地大体相当．无论肥地或瘦地，小粒级微团聚体的有机质和各结合形态腐殖质的含量及松、稳结态腐殖质占有机质总量的比例均较大粒级的高，而紧结态腐殖质则相反，表明大、小粒级微团聚体具有不同的肥力学意义

Mechanism of nutrient preservation and supply by soil and its regulation

Studies on the storage of organic matter and the binding status of humus in 15 pairs of fertile and infertile brown earth type vegetable garden soils and their various fractions of microaggregates sampled from different regions of Liaoning province show that fertile soils and their various fractions of microaggregates had a larger amount of organic matter and various binding status of humus and a higher ratio of loosely bound humus vs. total organic matter, but a lower ratio of steady bound humus than infertile soil and their corresponding particle sized microaggregates. The ratio of tightly bound humus vs. total organic matter had a little difference. In both fertile and infertile soils, the smaller size of microaggregates had a larger amount of organic matter and various binding status of humus and a higher ratios of loosely and steady bound humus than the larger sizes of microaggregates, but the ratios of tightly bound humus reversed, indicating that the smaller and the larger sizes of microaggregates played different roles in soil fertility.