用三种浸提方法研究长期定位试验中土壤磷素有效性  

Application of Three Extraction Procedures to Study Phosphorus Availability in Long-Term Experiment

作　　者：雷明江[1] 杜昌文[1] 杨玉华[2] 周健民[1] 王火焰[1] 陈小琴[1] 

机构地区：[1]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,江苏南京210008 [2]长江大学农学院,湖北荆州434025

出　　处：《水土保持学报》2007年第2期85-88,146,共5页Journal of Soil and Water Conservation

基　　金：国家重点基础研究发展规划"973"项目资助(2005CB121102)

摘　　要：基于15年石灰性潮土长期定位施肥试验,用水浸提法、Olsen法、Mehlich3法研究土壤磷素有效性。结果表明:长期不施磷的处理,土壤磷素有效性常年维持在本底的极低水平;施磷均能增加水溶性磷、Olsen-P、Mehlich3-P的含量,但磷钾配施及大量施用有机肥的效果最明显,其次是有机肥与NPK配施,只施无机肥(NPK,NP)增加的幅度相对较小;然而,在当前的施磷水平下,土壤“不缺磷”,但不能建立较大的有效磷库,并且以Olsen-P、Mehlich3-P的临界点为标准,土壤磷素流失的风险不大;水溶性磷、Olsen-P、Mehlich3-P的比值约为1¨10¨25,用幂函数、指数方程、对数方程能较好地模拟3种浸提磷之间的转化关系;水溶性磷、Olsen-P、Mehlich3-P与作物地上部吸磷量均达到极显著正相关,相关系数分别为0.563,0.854和0.930,表明用水浸提法、Olsen法、Mehlich3法研究长期定位试验中土壤磷素的有效性均可行。Based on the 15-year long-term fertilization experiment in calcareous fluvo-aquic soil, three extraction procedures （water, Olsen and Mehlich3） were used to study soil phosphorus availability. The results showed that ：①Soil phosphorus availability maintained at the wondrously low level as background soil without phosphorus fertilization; ②The contents of water soluble phosphorus （WSP）, Olsen-P and Mehlich3-P increased signifi- cantly with the application of PK and organic manure, followed by combined application of organic manure with inorganic fertilizer, but application of inorganic fertilizer alone （NPK, NK） showed a relatively lower effect; ③ However, inputting phosphorus fertilizer with current amount could result in soil phosphorus to the level as ＂nondeficiency＂ but far from setting up a large available phosphorus pool, while soil phosphorus loss risk was low with the criterion values of Olsen-P and Mehlich3-P; ④The ratio of WSP, Olsen-P and Mehlich3-P was 1：10： 25; Power function, exponential function and logarithmic equation were optimum indications to simulate their converted relationships, respectively; ⑤WSP, Olsen-P and Mehlich3-P were positively correlated to phosphorus accumulation in the shoot of crops, correlation coefficients were 0. 563, 0. 854 and 0. 930, respectively; Which indicated that these three extraction procedures were feasible approaches to study soil phosphorus availability under the long-term experiment.

关 键 词：长期定位试验 潮土 水溶性磷 Olsen—P Mehlich3-P 磷素有效性 

分 类 号：S151.9[农业科学—土壤学] S143.2[农业科学—农业基础科学]