摘要
为了了解石灰性土壤主要根系深度内不同土层土壤磷形态分布,了解土壤供磷能力和施磷后磷的存在状态,采取河南省十县市石灰性潮土、褐土的73个0～20、20～40cm土样进行土壤磷形态的分级测定。结果表明,Ca-P平均共占无机磷总量的76.41%,表明在这十个地区中无机磷以钙磷为主。0～20cm土层有效磷和全磷总量比20～40cm土层多。不论是长期施磷肥的土壤还是不施磷肥的土壤,土壤有效磷和全磷均呈表层(0～20cm)含量较高,20～40cm以下含量骤减的空间分布特征。随着土层深度的增加,有效的成分比例降低,无效的成分比例提高。0～20cm土层有机磷总量比20～40cm土层高,有机磷在两个土层的差异主要是因为中度活性有机磷含量的不同。随着土层加深,活性OP和中活性OP在有机磷中的比重呈减小趋势,而无效的中稳性OP和高稳性OP则呈增加趋势。在0～20cm和20～40cm土层中,随着有机质和有机磷的减少,中性和碱性磷酸酶都有规律地随之减少。不同土层的磷素活化系数对比分析表明,石灰性土壤表层全磷向有效磷的转化较难,亚表层供磷能力更差,磷的有效化程度更低。研究表明石灰性土壤有效磷的供应主要集中在表层0～20cm,随深度增加明显降低。
73 samples of Calcareous Chao-soil and Cinnamon-soil were sampled in 10 countys of Henan province, the samples of 0-20cm, 20-40em were compared to investigate the phosphorus form difference between two layers by soil phosphorus-classified method. The results show that calcareous-P was the main form in calcareous soil. The available-P in 0--20cm are more than 20-40cm whether phosphorus fertilizer was applified or not. The unavailable-P increased with the depth increased. The organic-P in 0-20cm layer are more than 20-40cm, mainly because of the difference of the middle active organic-P between the two layers. With the depth increase, active organic-P and middle active organic-P decreased, on the contrary, the unavailable organic-P ie. middle stable organic-P and high stable organic-P increased. The activity of neutral and alkaline phosphatase decreased with the depth down in soil. All these studies demonstrated that the availability of phosphorus reduced with the depth deepen.
出处
《中国农学通报》
CSCD
2008年第9期277-282,共6页
Chinese Agricultural Science Bulletin
基金
河南省自然科学基金项目(960203011)资助
关键词
石灰性土壤
土层
磷形态
分级
有效性
calcareous soil, phosphorus form, soil layers, classification, availability
