1964年于朝阳县西大营子公社饮马池大队西北沟生产队搞了一个山地“四种”的增产样板。全生产队耕地290亩,其中山地(坡耕地)占62%,粮食作物250亩,分布在山地上的粮食作物为180亩。为了推广山地零种、混种、套种、补种的增产经验,曾设置了上述“四种”的示范样板,起到了显著的增产作用。 In 1964 in Chaoyang County West Camp sub-communes Yinmachi brigade northwestern ditch team came up with a mountainous “four” model of stimulation. The entire production team of 290 acres of arable land, of which mountain (slope farmland) accounted for 62%, 250 acres of food crops, distributed in the mountains of 180 acres of food crops. In order to promote the experience of increasing yield of zero, mixed, intercropping and replanting in mountainous areas, the above-mentioned “four kinds” demonstration models have been set up and played a significant role in increasing yield.