ABSTRACT

The long-term application of chemical fertilisers in calcareous soil causes the stable P in soil to accumulate and not be effectively utilised. In this study, whether acidic compost tea (CT) could increase the available P in calcareous soil was evaluated through a pot experiment. The P forms of the samples were analysed using Hedley sequential P fractionation. CT had significant effects on different soil P fractions and P uptake (p < 0.05). Compared with organic fertiliser (OF), acidic CT increased the availability of H₂O-P and NaHCO₃-P by 15.9% and 12.6%, respectively, it mainly comes from the dissolution of HCl-P and residue-P. CT also promoted the growth and yield of cotton and significantly increased P use efficiency by 13.8% and 31.6% (p < 0.05), respectively, compared with OF, because the H⁺ in CT reduced the pH of the calcareous soil, promoted the dissolution of stable P in soil, and reduced the fixation of P from the fertiliser. However, the organic matter in CT did not contribute much to the desorption of P. These findings provide a new idea for the activation and utilisation of P in calcareous soil.

摘要

石灰质土壤长期施用化肥，导致土壤中稳定的磷积累，得不到有效利用。在这项研究中，通过盆栽试验评估了酸性堆肥茶（CT）是否可以增加钙质土壤中的有效磷。使用 Hedley 顺序 P 分馏分析样品的 P 形式。CT对不同土壤磷含量和磷吸收有显着影响（p  < 0.05）。与有机肥（OF）相比，酸性CT使H ₂ O-P和NaHCO ₃ -P的有效性分别提高了15.9%和12.6%，主要来自于HCl-P和残渣-P的溶解。CT还促进了棉花的生长和产量，使磷的利用效率显着提高了13.8%和31.6%（p < 0.05)，分别与OF相比，因为CT中的H ⁺降低了钙质土壤的pH值，促进了土壤中稳定P的溶解，减少了肥料中P的固定。然而，CT中的有机质对磷的解吸贡献不大。这些发现为钙质土壤中磷的活化和利用提供了新的思路。