Crop production on acidic soils: overcoming aluminium toxicity and phosphorus deficiency

作者：Shao Jian Zheng · 发表于：Annals of Botany · 年份：2010 · DOI：10.1093/aob/mcq134 · 被引用次数：206 · 研究领域：Aluminum toxicity and tolerance in plants and animals、Plant Micronutrient Interactions and Effects、Clay minerals and soil interactions

Approximately 30 % of the world's total land area consists of acid soils, and it has been estimated that over 50 % of the world's potential arable lands are acidic (von Uexküll and Mutert, 1995). Aluminium (Al) in these soils will be solubilized into ionic forms, especially when the soil pH falls to lower than 5. These ionic forms of Al have been shown to be very toxic to plants, initially causing inhibition of root elongation by destroying the cell structure of the root apex and thus affecting water and nutrient uptake by the roots; as a consequence, plant growth and development is seriously hindered. On the other hand, phosphorous (P) is easily fixed by clay minerals that are rich in acids soils, including various iron oxides and kaolinite, and hence rendering it unavailable for root uptake. Thus, Al toxicity and P deficiency are considered to be two main constraints for crop production in acid soils. In order to produce a better crop yield on acid soils, farmers are recommended to apply alkaline materials such as lime (primarily calcium carbonate) to increase the soil pH and thus eliminate Al toxicity, and to apply P fertilizer to increase the bioavailable P in soil. However, soil has a huge buffering capacity that is able to diminish the effects of all kinds of amendments, and the soil acidification process is accelerated by factors such as acid rain and excess application of ammonium-based inorganic nitrogen fertilizers. Hence the effects of practices such as applying li...