酸性土壤可持续利用

The Sustainable Use of Acid Soils

酸性土壤主要分布于水热资源丰富的热带和亚热带地区,植物生产潜力巨大。由于酸性土壤中存在酸害、铝毒和养分缺乏等多种胁迫因子,酸性土壤的植物生产潜力难以充分发挥。全球酸性土壤约占陆地总面积的30%,约50%耕地和潜在可耕地属于酸性土壤,中国酸性土壤约占国土总面积的22.7%。发挥酸性土壤的作物生产潜力,将为保障粮食安全做出巨大贡献。酸性土壤不仅限制了农业生产力,而且对生物多样性和生态环境造成了负面影响。酸性土壤可持续利用对于农业生产和生态环境保护均具有重要意义。酸性土壤的可持续利用可以通过土壤酸性改良和肥力并重提高、化肥和有机肥施用相结合、充分利用植物遗传潜力、发挥酸性土壤生态功能等一系列对策加以实现。自然条件下的土壤酸化本身是一个缓慢过程,但是人类活动如氮肥过量施用和大量酸沉降,极大地加速了土壤酸化。将来的研究应从降低氮肥的施用量和酸沉降的排放量来减缓土壤酸化速率,前者主要依赖于氮肥利用率的提高,后者主要依赖于工业化技术的提高和国家政策制度。

Acid soils are mainly distributed in the tropical and subtropical regions with abundant heat and water resource and have a huge potential for agricultural production. However, some co-existing soil stresses such as soil acidity, aluminum toxicity, and nutrient deficiency greatly limit the agricultural production potential in acid soils. In the world, acid soils cover approximately 30% of the global land and up to 50% of cultivable and potentially arable land. In China, acid soils account for about 22.7% of the total land area.Improving the capability of plants to adapt to the stressful factors in acid soils can contribute to food security.Acid soils not only limit agricultural productivity but also have negative effects on ecological environments, the sustainable use of acid soils can play an important role in agricultural productivity and ecological environments. We can realize the sustainable use of acid soils through increasing soil pH value and fertility,applying chemical fertilizers with organic fertilizers, using plant genetic potentiality, and developing soil ecological functions. Natural soil acidification is a very slow process, but various anthropogenic activities,especially the overuse of nitrogen fertilizer and acid depositions, greatly accelerate soil acidification. Soil acidification can be decelerated through decreasing the application rate of nitrogen fertilizers and the deposition of acids, and the former depends on the improvement of nitrogen fertilizer use efficiency while the latter depends on the improvement of industrial technology and national policies.