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通过室内研究和盆栽试验研究施用石灰的机理,并在湖南省代表性稻田土壤上试验、示范和推广。结果表明:稻田施用石灰引起pH升高,Eh降低,还原物质增多,三者之间符合电化学反应原理。施石灰使土壤有机质矿化率比对照高2～3倍,胡敏酸和富里酸降幅较胡敏素要大;增加了水稻从土壤中的吸氮量,同时也加剧了化肥氮的挥发损失,降低了氮的残留率;使磷肥向Al-p转化并增加了O-P,增加了土壤对磷的最大吸附量,而吸附强度(K)和吸持度(S)却随之降低;使水溶态钾和交换态钾降低,固定量增加,但被固定的钾离子仍能被1NHNO_3提取,对水稻仍然有效。亩施90～100公斤石灰,明显抑制水稻前期生长,在pH 5.5以下的稻田中,亩施石灰30～50公斤可明显增产,pH>5.6的稻田则无明显效益。
The mechanism of applying lime was studied through indoor research and pot experiment, and the experiment, demonstration and popularization were carried out on representative paddy soils in Hunan Province. The results showed that the application of lime caused the increase of pH, the decrease of Eh and the increase of reducing substances in paddy field, and the electrochemical reaction was in accordance with the three. The lime mineralization rate of soil organic matter was 2 ~ 3 times higher than that of the control, and the decrease of humic acid and fulvic acid was larger than that of humin. The nitrogen uptake of rice from the soil was also increased, which also exacerbated the volatilization loss of fertilizer nitrogen and decreased The residual rate of nitrogen; the conversion of phosphate fertilizer to Al-p and the increase of OP, increased the maximum adsorption of phosphorus to soil, while the adsorption strength (K) and retention (S) decreased; And the exchangeable potassium decreased, the fixed amount increased, but the fixed potassium ions can still be 1NHNO_3 extraction, the rice is still valid. Mushu 90 ~ 100 kg of lime, significantly inhibited the early rice growth in paddy fields below pH 5.5, 30 to 50 kg of lime can be significantly increased, pH> 5.6 of the rice is no significant benefit.