从土壤肥力变化预测中国未来磷肥需求

近年来,我国磷肥用量持续增长,土壤有效磷含量也增加很快,这些变化对磷肥生产和施用将产生什么影响？这是一个关乎我国粮食安全和环境安全的重要问题,值得进行深入地探讨。本研究通过对我国8种典型农业土壤上磷收支平衡和有效磷消长关系的分析,获得预测我国主要农田土壤中有效磷变化模型的参数,即每100kg hm^-2磷盈余平均可使我国土壤有效磷水平提高约3.1mg kg^-1。结果表明,从1980年到2003年我国除经济作物外的主要农田土壤上累积磷盈余约为392kg hm^-2,由此推出目前我国农田土壤有效磷水平约为19mg kg^-1左右。从农业需求和环境保护角度确定的土壤有效磷最适范围应在30～50mg kg^-1之间。而要在未来的30a内使我国土壤有效磷水平提高并维持在40mg kg^-1左右,磷肥的消费将在30a间经历一个先升后降的过程,磷肥需求将在2020年左右达到最高峰1250万t,到2035年降至1050万t,此后应一直维持这一水平。

PREDICTION OF PHOSPHATE FERTILIZER DEMAND IN CHINA BASED ON CHANGE IN SOIL PHOSPHATE FERTILITY

The consumption of P fertilizer has been increasing dramatically in China and so has the content of available P in the soil since the 1980's. However, how the change will affect production and application of P fertilizer in China remains to be unclear and a concern related to food safety and environment safety. Relationship between P balance and change in soil Olsen-P in eight different types of arable soils were evaluated. Results show that on average, about 3.1% of the annual P surplus in the arable land in China was considered as Olsen-P. In the period from 1980 to 2003, the cumulative P surplus reached about 392 kg hm-2, from which it can be inferred that currently the content of Olsen-P in the arable land of China is about 19 mg kg-1. If soil available phosphorus is to be increased to and maintained around 40 mg kg-1 in the future thirty years, the demand for phosphorus fertilizer will rise to 12.5 million tons in 2020 and then drop to 10.5 million tons in 2035.