为了配合当前生产大跃进,本所同志试制出一批土化肥.现将其中几种比较好的介绍出来,以供各地参考.一、土法制过磷酸钙制过磷酸钙最重要的原料是硫酸.我国硫酸制造工业在解放后是有很大发展,但距农业上广泛制造过磷酸钙要求尚远.为了解决不用硫酸而能制出过磷酸钙的问题,我们特研究出本方法. In order to tie in with the current production of the Great Leap Forward, our comrades try out a group of soil fertilizers. Now several of them are better introduced for reference. First, the indigenous system of the most important raw material of SSP superphosphate is sulfuric acid The sulfuric acid manufacturing industry in our country developed greatly after the liberation, but it is still far from the requirement of extensive manufacture of superphosphate in agriculture.In order to solve the problem of producing superphosphate without sulfuric acid, we specially developed this method.