%0 Journal Article
%T ON ESTABLISHING A OPEN SYSTEM TO DEVELOPE AGRICULTURE IN THE NORTHWEST SEMI-ARID REGION IN CHINA<br>建立开放系统,发展西北半干旱地区农业
%A Liu Xunhao
%A <br>刘巽浩
%J 自然资源学报
%D 1989
%I 
%X The northwest semi-arid negion is one of the most undeveloped zones in China. It is characterized by the closed or simi-closed traditional organic farming with very low input, inefficient function and low output.In this paper several controvcrtille models of agriculture are discussed and some priciples for establishing a open system and concrete suggestions for developing production are presented.
%K closed system
%K open system semi-arid region
%K organic farming
%K model of rolling a snow ball<br>封闭系统
%K 开放系统
%K 半干旱地区
%K 有机农业滚雪球模式
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=3FF3ABA7486768130C3FF830376F43B398E0C97F0FF2DD53&cid=A7CA601309F5FED03C078BCE383971DC&jid=4DCB9A3AF3395AF0101DE5302EF3C300&aid=998B8F2B16114374FE5D81C957814280&yid=1833A6AA51F779C1&vid=E158A972A605785F&iid=CA4FD0336C81A37A&sid=59906B3B2830C2C5&eid=13553B2D12F347E8&journal_id=1000-3037&journal_name=自然资源学报&referenced_num=0&reference_num=2