Predicting the Dissolution of Rock Phosphates in Flooded Acid Sulfate Soils
Predicting the Dissolution of Rock Phosphates in Flooded Acid Sulfate Soils
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预测淹没酸性硫酸盐土壤中磷酸盐的溶解
DOI：
10.2136/sssaj2003.0320
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
R. Yost
中科院分区：
文献类型：
--
作者：
S. Yampracha;T. Attanandana;A. Sidibe;R. Yost
泰国中部平原有76万公顷的硫酸盐土壤用于种植水稻（Oryza sativa L.）修为磷素营养不足严重限制了水稻的生长发育和产量。采用当地磷矿粉（RP）坎恰纳布里RP（KRP）、参比RP（突尼斯Gafsa）和含可溶性磷的KRP（KRPS），研究了淹水条件下6种酸性硫酸盐土壤中磷的溶出和有效性。对RP溶解和磷吸附有重大影响的土壤性质进行了研究，以开发一个模型和算法，估计RP的需求，水稻。高的KCl提取铝（Al_KCl）和低的土壤pH值促进了KRP，Gafsa和KRPS的溶解。大量的碳酸钙当量的RP增加土壤的pH值和限制RP溶解。用Bray 1和Bray 2浸提液测定了土壤对磷的吸附量。在某些添加硫酸盐的土壤中浸泡几天后，磷的吸附量明显大于RP的溶解量，从而降低了Bray 1水平。Bray 2可提取的磷随着KRP、Gafsa和KRPS的施用而增加。RP预测使用的算法的基础上预测的各种土壤中的溶解和吸附量是类似的RP需求的本地估计。
Seven hundred sixty thousand hectares of add sulfate soils in Central Plain of Thailand are used for rice (Oryza saliva L.) cultivation. Insufficient nutrient P seriously limits rice growth and yield. A local rock phosphate (RP) Kanchanaburi RP (KRP), a reference RP (Gafsa from Tunisia), and a KRP containing soluble P (KRPS) were used to investigate the dissolution and availability in six acid sulfate soils under flooded conditions. The soil properties that have a major influence on RP dissolution and P sorption were investigated for developing a model and algorithms for estimating the RP requirement for rice. High KCl-extractable aluminum (Al_KCl) and low soil pH enhanced the dissolution of KRP, Gafsa, and KRPS. The substantial calcium carbonate equivalent of the RP increased the pH of soils and limited RP dissolution. The P sorption of the soils was estimated using Bray 1 and 2 extractions. The P sorption was apparently greater than RP dissolution a few days after submergence in some add sulfate soils, decreasing the Bray 1 level. Phosphorus extractable by Bray 2 increased with incubation time where KRP, Gafsa, and KRPS were applied. Amounts of RP predicted using an algorithm based on predicted dissolution and sorption in the various soils were similar to a local estimate of RP requirement.