With the consolidation and development of the people’s commune in our country.the agricultural production is more and more increasing on a large scale. For the further development of agriculture,there is a gr eat needof detailedsoil maps with which the commune membere can know the soil conditions of their commune more clearly and make the farm plan more perfectly.
In the present paper,based on 10 soil mapping points represented different soil conditions of the communes in various parts of this country, an attempt is made to deal with the following problems:
1.The type and scale of the base map According to the authors’ experience,it is necessary to make two kinds of base maps,namely the common topographic map and the field block map.The scale of the topographic map varies from 1: 2, 000 to 1: 10, 000 for various soil regions.For example,in the red earth region where the land is highly dissected into rolling hills with paddy soils filled in gullies,the larger acale is required;on t he other hand, in the region of alluvial plain with gentle flat topography,the smaller scale is usually sufficient. The field block map is useful especially forthe old agricultur al region where the form and pattern of land.being highly reformed during the past time, cannot be exactly denoted in the common topographic map.Moreover, such field block map is easily understood by the commune members and cadres.
In this paper,the soil mapping by means of aerophotograph is alsodiscussed.
2.The soil map
The authors are of the opinion that one set of maps including soil condition map and land utilization map is better than a single sheet of soil map,
Different kinds of maps compiled according to the requirement of different regions are as follows:
(1)See of soil maps-including general soil map and separate maps of the depth of the plowed layer,the tex tural variation,the pH and the nutrient status of soils
(2)Set of maps of land utilization,evaluation and soil reclamation.
(3)Maps of special requirement, such as the maps showing the degree of erosion of hilly and mountain soils,soil salinization,and the degree of mineralization,chemical composition,water-table of ground-wate r in saline soil region.