津郊潮土磷素组成及其演变规律的定位研究

１９７９～１９９３年研究了长期定位施肥对天津郊区潮土磷素组成及其演变规律的影响。结果表明，潮土磷素组成以无机磷为主，其中又以磷酸钙盐最多，其次是闭蓄态磷酸盐，而磷酸铝盐和铁盐所占比例很少。长期定位施肥对潮土速效磷影响显著，变幅也最大，其中化肥的影响高于有机肥，平均每施入２８ｋｇ／ｈｍ２或亏缺磷素４５ｋｇ／ｈｍ２，土壤速效磷约升或降１ｍｇ／ｋｇ。潮土速效磷的累积与下降呈现阶段性，开始１～２年变幅大，其后６～８年时间保持稳定变化，当速效磷升降到某一定值时，变幅显著降低。小麦、夏玉米连作年产在１１１９８ｋｇ／ｈｍ２水平下，平均每生产１００ｋｇ籽实，施磷１．２ｋｇ，在１４年中可保持土壤磷素平衡

Long term Posting Study on Components and Change of Phosphorus in Chao Soil of Tianjin Suburbs

Effect of long term posting fertilization on components and regular changes of phosphorus in chao soil was studied in Tianjin during 1979-1993.Results showed that inorganic phosphorus was predominant,in which Ca P occupied the largest percentage,O P was second and only small part was the Al P and Fe P.Long term posting fertilization could significantly influence both the content of soil available P and the range of its changes.The effects of chemical phosphorus were more obvious than those of organic sources.The increasing and decreasing of soil available P depended heavily on whether chemical phosphorus was applied or not ,soil available P increased or decreased at the rate of 1 mg/kg when P 45kg/ha was removed or P 28kg/ha was added.In addition,study also suggested that the changes of soil available P differed with the periods of experiment at time.Soil available P changed largely in the first two years,and the changes became smaller in the later 6-8 years,finally it remained in a normal value with quite small changes.Soil phosphorus could be balanced in 14 years when 18kg/ha year P 2O 5 was applied per 100 kg of grain yield under the wheat corn cropping system with the grain yield of 11198kg/ha in total.