Beijing Key Laboratory of Farmyard Soil Pollution Prevention-Control and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.
Teagasc, Department of Crops, Environment and Land Use, Environmental Resources Centre, Johnstown Castle, Wexford, Ireland.
J Sci Food Agric. 2022 Jan 30;102(2):740-749. doi: 10.1002/jsfa.11405. Epub 2021 Jul 8.
The pH adjustment of acidic red soils with lime materials is beneficial for the reduction of phosphorus (P) fixation. However, the reasons for varying levels of P activation after adding different lime materials have not been fully investigated. Therefore, this study examined changes in soil labile P and P forms after phosphate application to calcium carbonate (CaCO ) and dolomite amended red soil during a 120-day incubation period. Also change of P sorption properties in the amended soil samples from day 120 were examined through a sorption-desorption experiment.
The increase of soil H O-P and NaHCO -P in the CaCO and dolomite amended soil treatments was mainly ascribed to the decline of the NaOH-P. However, when compared with the control treatment after 120 days, soil Olsen-P significantly increased by 34% and 66% in the CaCO and dolomite treatments. The Hedley P fractionation results demonstrated that the CaCO application caused a notable increase of HCl-P (stable Ca-P), which was 88.4% higher than that in the dolomite treatment. However, the formation of stable P was strongly suppressed in the dolomite treatment due to the presence of magnesium (Mg), which was identified by the negative relationship between M3-Mg and HCl-P. In line with these findings, P sorption-desorption work showed weaker P binding energy in the dolomite treatment relative to the CaCO treatment.
In terms of increasing P availability in red soil, this study suggests that dolomite should be used to substitute CaCO in order to reduce the soil P fixation. © 2021 Society of Chemical Industry.
用石灰材料调节酸性红壤的 pH 值有利于降低磷（P）的固定。然而，添加不同石灰材料后 P 活性程度不同的原因尚未得到充分研究。因此，本研究在 120 天的培养期内，考察了向碳酸钙（CaCO）和白云石改良的红壤中添加磷酸盐后土壤有效磷和磷形态的变化，以及 120 天后土壤磷吸附特性的变化。
CaCO 和白云石改良土壤处理中土壤 H2O-P 和 NaHCO3-P 的增加主要归因于 NaOH-P 的减少。然而，与对照处理相比，120 天后 CaCO 和白云石处理中土壤Olsen-P 分别显著增加了 34%和 66%。Hedley P 分级结果表明，CaCO 的应用导致 HCl-P（稳定 Ca-P）显著增加，比白云石处理高 88.4%。然而，由于镁（Mg）的存在，白云石处理中稳定磷的形成受到强烈抑制，这可以通过 M3-Mg 与 HCl-P 之间的负相关关系来证明。与这些发现一致，磷吸附-解吸研究表明，与 CaCO 处理相比，白云石处理中磷的结合能较弱。
就提高红壤中 P 的有效性而言，本研究建议用白云石代替 CaCO，以减少土壤 P 的固定。 © 2021 英国化学学会。
