Since middle period of the 1990s , food supply of our country has transformed from long - term shortage to supply and demand balanced and the harvest year that have enough and to spare . the restrained factor of agricultural development has changed from restraint of resource to double restraint of resource and demand 20世纪90年代中期以来,我国食物供应实现了由长期短缺向供求平衡、丰年有余的转变,农业发展由受资源约束转变为资源与需求的双重约束。