【摘要】 <正> 太湖地区是我国水稻高产地区之一。在长期耕种利用下,土壤肥力发生了很大变化。为了不断提高土壤肥力,水稻土的培肥研究十分重要。近年来,我国开展了太湖地区水稻土的研究,取得了一定的成果。熊毅等在总结群众经验的基础上提出,爽水性是肥沃水稻土的标志,而耕层出现鳝血斑和青泥条,可分辨水稻土的肥瘦。陈家坊和姚贤良等则很强调土壤通气孔隙对水稻高产的重要。此外,也有研究水稻土的质地和氮素营养等。但以往的研究很少联系复合胶体特性与水稻土肥力的关系。本文着重探讨有机质的复合与团聚作用,及其对水稻土肥力特性的影响,为土壤培肥提供依据。更多还原

【Abstract】 Three representative types of paddy soil (well permeable, side bleached and gleyed) and three kinds of plant material (azolla, rice straw and milk vetch) were used in the experiment. The results obtained are summarized as follows:The content of 1.0—0.25 mm water-stable aggregates in the paddy soil of high-fertility ranged from 2—14% greater than that in the paddy soil of low-fertility. The destruction perecentage of structure and the degree of dispersion were higher for the infertile paddy soils.Soil organo-mineral complex is an important factor in determining soil fertility and it is closely related to the structure of paddy soils. It was found that about 80—90% of organic matter in paddy soils were associated with clay fraction, forming organo-mineral complexes. The quantity of complexed organic carbon was significantly correlated with the total content of organic carbon of the soil and aggregates (Fig. 3). the quantity and degree of additional complexing of organic matter (QAC and DAC) incresed with the raising of fertility of the soil (Table 6). If the amount of organic material added to the soil less than 1% of the dry soil weight, the largest coefficient of complexing (CC) might be obtained (Fig. 7). According to the preliminary investigation of ’QAC’, ’DAC’ and ’CC’, the effect of the organic materials on the soil structure improvement is in the following order: Azolla>Rice straw>Milk vetch (Fig.4—6).The higher relative viscosity and lower apparent negative charge of the colloidal complex were found in the fertile paddy soils with a better aggregation (Table 9, 11).更多还原