在农业生产上，化学肥料虽然可增产粮食３０％～４０％，但投资成本很大，而且长期使用可导致土壤酸化板结，有机质含量下降，并对人类赖以生存的生态环境造成污染。国外某些发达国家已限制使用化肥，我国的绿色食品热也在各地悄然兴起。专家断言，要改变这一状态，必须改... In agricultural production, though chemical fertilizers can increase the grain output by 30% ~ 40%, the investment cost is very big. Long-term use of chemical fertilizers can lead to the acidification of soil, the decrease of organic matter content, and the pollution of the ecological environment upon which human beings depend. Some developed countries in foreign countries have already restricted the use of chemical fertilizers, and the green food fever in our country has quietly risen everywhere. Experts assert that to change this state, we must change ...