Purpose

Subsurface soil acidity in conjunction with aluminium (Al³⁺) toxicity is a major limitation to agricultural production globally. The conventional use of surface-applied lime is often insufficient at correcting subsurface acidity; therefore, new practices and ameliorants are required.

Methods

This 3-month leaching experiment investigated whether animal wastes and other novel ameliorants in combination with lime could improve alkalinity movement, leading to greater amelioration of acid subsurface soil layers compared with lime alone. Five ameliorants (mature dairy compost, vegetable garden compost, poultry litter, potassium humate and gypsum) were added at a rate of 18 mg dry matter g⁻¹ to the topsoil layer either without or with lime (target pH 5.5).

Results

All ameliorants with lime improved alkalinity movement below the amended layer (0–10 cm), with pH increases of 0.03–0.10 units at 1 month and 0.02–0.20 units at 3 months. In comparison, the Al³⁺ concentrations in 10–12-cm and 12–15-cm layers were significantly decreased by 2–5.5 μg g⁻¹. With lime, the improvements in alkalinity movement with ameliorants were in the order of gypsum > vegetable garden compost > potassium humate > poultry litter > mature dairy compost. Without lime, each amendment increased soil pH in the subsoil, with their effectiveness decreasing in the order of poultry litter > vegetable garden compost > mature dairy compost > gypsum > potassium humate.

Conclusion

Some organic amendments are effective in addressing subsoil acidity. When combined with lime, their additive effects are limited.

中文翻译：

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与石灰混合后，新型材料对碱度沿酸性土壤剖面向下运动的影响

目的

地下土壤酸度和铝（Al ³⁺）毒性是全球农业生产的主要限制。表面施用石灰的常规使用通常不足以校正地下酸度；因此，需要新的做法和改善措施。

方法

这个为期3个月的浸出实验研究了动物粪便和其他新型改良剂与石灰的组合是否可以改善碱度运动，与单独使用石灰相比，可以改善酸性地下土壤层的状况。在无或有石灰（目标pH 5.5）的情况下，以18 mg干物质g ^-1的速率将五种改良剂（成熟的乳品堆肥，菜园堆肥，家禽垃圾，腐殖酸钾和石膏）添加到表土层。

结果

所有含石灰的改良剂均改善了经改良层（0–10 cm）下的碱度运动，第1个月的pH值增加了0.03–0.10单位，第3个月的pH值增加了0.02–0.20单位。相比之下，在10–12-cm和12–15-cm层中的Al ³⁺浓度显着降低了2–5.5μgg ^-1。使用石灰，改善剂对碱度的改善作用依次为石膏>菜园堆肥>腐殖酸钾>家禽垫料>成熟的乳品堆肥。在没有石灰的情况下，每种改良剂都会增加土壤中的pH值，其有效性以家禽垃圾>菜园堆肥>成熟的乳品堆肥>石膏>腐殖酸钾的顺序降低。

结论

一些有机改性剂可有效解决土壤的酸性问题。当与石灰结合时，它们的累加作用受到限制。