三、讨论有些问题试验研究尚不能定论,但生产实践和理论研究都要求弄清它们。为此,提出商榷意见。 (一)耕层构造的概念应深化、扩展弄清土壤耕作的实质和在农业生产中的地位、作用,就要进一步查明其起作用的实体,即耕层构造。我们认为耕层构造是由地面覆盖,地表形态、内部结构和犁底形状4个部分组成的立体结构。其组成 III. DISCUSSION Some test research is still inconclusive, but both production practice and theoretical research require clarification. To this end, put forward opinions. (1) The concept of plow structure should be deepened, and the essence of soil plowing and its position and role in agricultural production should be expanded. It is necessary to further ascertain its role as the plowing structure. We believe that the topsoil structure is a three-dimensional structure composed of four parts: ground cover, surface morphology, internal structure and plowshare. Its composition