长期不同施肥对水稻土交换性钙、镁和有效硫、硅含量的影响

Effects of Long-term Various Fertilization on exchangeable Ca and Mg,and available S and Si Contents in Paddy soils

为探明合理施肥和土壤培肥的理论依据,研究了4种长期定位施肥(CK、NPK、OM30、OM60)对湖南主要水稻土交换性钙、交换性镁、有效硫、有效硅含量的影响。结果表明,长期不同施肥改变了供试水稻土中上述养分的含量。在含钙较低的黄泥田、河沙泥、红黄泥中,施肥使土壤交换性钙含量显著升高,在相同土壤中其含量高低依序为OM30,OM60,NPK;在含钙较多的青灰泥、白鳝泥、紫潮泥中,施肥使土壤交换性钙含量降低,降低幅度与施入的有机肥量呈负相关。在黄泥田、河沙泥、青灰泥、白鳝泥、紫潮泥中,施肥使交换性镁含量降低,而在红黄泥中施肥则使交换性镁含量升高。NPK处理使含硫较高的黄泥田、青灰泥、白鳝泥、紫潮泥有效硫含量升高,使含硫较低的红黄泥有效硫含量降低;有机、无机肥配施处理(OM30、OM60)使所有试验水稻土有效硫含量升高。施用钙镁磷肥和有机肥能够提高土壤有效硅含量。

The regularities of secondary elements＇ change caused by different fertilization in paddy soils in Hunan province were studied. The levels of exchangeable Ca and Mg, available S and Si in paddy soils were measured based on experiments for twenty years with 4 treatments including CK, NPK, OM30, and OM60. The results showed that long-term fertilization altered the contents of those elements nutrition in different paddy soils surely. The contents of exchangeable calcium were increased significantly under fertilization treatments, in which the order for increasing exchangeable Ca value in the same soil was： OM30〉 OM60〉 NPK〉 CK, in Yellow clayey earth, Alluvial sandy earth, and Reddish yellow clayey earth, in which content of calcium was less; contrarily, the contents under CK in Blue gray clayey earth, whitish clayey earth, and Purple tidal clayey earth, in which contents of calcium was more, were much higher than that under NPK, OM30, and OM60, in which the exchangeable Ca value negatively correlated to the amount of organic manure applied. The contents of exchangeable magnesium under fertilization treatments decreased in Purple tidal clayey earth, Blue gray clayey earth, Alluvial sandy earth, Yellow clayey earth, and Whitish clayey earth, but increased significantly in Reddish yellow clayey earth. The contents of available sulfur under NPK treatment were more than that under CK in Purple tidal clayey earth, Blue gray clayey earth, Yellow clayey earth, and Whitish clayey earth, which have a high sulfur concentration, and less in Alluvial sandy earth and Reddish yellow clayey earth which have a low sulfur concentration; however, the contents of available sulfur under OM30 and OM60 were increased in all the experimental soils. The contents of available silicon also rose under fertilization treatments in all experimental soils.