我国耕地总量的动力预测及其建议

近年来,我国耕地资源总量正在以较大的幅度逐年减少,其原因主要有:建设用地、生态退耕、农业结构调整、灾害损毁等占用,这将危及国家的粮食安全。为解决耕地面积大幅下降的情况,根据我国国情,建立了若干耕地总量动力方程。依据《中国的粮食问题》白皮书提出的实现粮食95%的自给目标,2010年耕地保有量应达到1.2166×10⁸hm2的要求,在数值模拟的基础上提出了若干保护耕地的方案,并对2004～2010年我国的耕地总量进行数值预测。预测表明:①以目前的耕地减损速度仅依靠每年从耕地后备资源中开发补充耕地很难保障国家粮食安全;②在我国耕地减少总量中,生态退耕占了很大的比重,如何协调好二者的关系是保证国家粮食安全的重要方面。因此,建议我国应在降低逐年上升的建设用地对耕地的占用,制订合理的退耕计划下,提倡精准农业、提高粮食单产、降低肉类消费。

Dynamic Prediction and Suggestion of Total Farmland in China

The total farmland resource is decreasing at a rather greater speed in recent years in China.The major reasons include:construction land use,ecologic defarming,agricultural struc- ture adjustment,catastrophic failure and so on,which will badly affect the safety of food supplies in our country.To solve the problem of national food security caused by cropland reduction,we advance several dynamic equations on arable land change according to current situation.By the 95% self-sufficiency goal of foodstuff brought forward by the white book Food Issue in China,the insurance quantity of cultivated land should be 1.216 6×10⁸hm2.In our model,we present several recommendations and projects for protecting farmland correspondingly based on numerical simulation,and make a cultivated land output prediction from 2004 to 2010.The result of the study shows:(1) only depending on supplement from reserved cultivated land is not enough to ensure food safety by the yearly decrease rate of farmland at present; and (2) returning arable land to forest and grass plays an important role in the general decrease of cultivated land and their mutual coordination is the key problem to ensure national food security.So we should try our best to reduce farmland occupation for construction purpose,make reasonable ecologic defarming planning,encourage precision farming to increase per unit area productivity and adjust people's dietary structure to reduce meat consumption.