土壤保肥-供肥机理及其调节 Ⅰ.棕壤型菜园土的P素保持与供应

Mechanism of nutrient preservation and supply by soil and its regulation I. P preservation and supply by brown earth type vegetable garden soil.

对辽宁省北部、中部及南部的棕壤型菜园土１５对肥、瘦地的保Ｐ供Ｐ性能的测定表明，在绝大多数供试土样中，肥地及其各粒级微团聚体的全Ｐ量、Ｐ解吸量及Ｐ解吸率均大于瘦地及其各相应粒级微团聚体的，Ｐ吸附量则相反．不论肥地或瘦地，＜１０μｍ微团聚体均比＞１０μｍ微团聚体具有更大的Ｐ吸附能力．供试菜园土的＜１０μｍ微团聚体亦具有较大的供Ｐ潜势，其Ｐ解吸率比其他农用土壤相同粒级微团聚体的大１个数量级．

etermination of P preservation and supply performances of 15 pairs of fertile and infertile brown earth type vegetable garden soils sampled from northern, central and southern Liaoning Province show that in most soil samples tested, fertile soils and their various particle sizes of microaggregates had a larger amount of total and desorbed P and a higher rate of P desorption, but a smaller amount of adsorbed P than infertile soils and their corresponding particle sized of microaggregates. The microaggregates of <10μm had a more stronger ability of P adsorption than those of >10μm in both fertile and infertile soils. The microaggregates of <10μm in test vegetable garden soils had a large potential of P supply, and their P desorption rate was one order of magnitude higher than that of other agricultural soils.