EVALUATION ON THE SOIL QUALITY AND SUITABILITY OF GREEN FOOD PRODUCING AREA IN NEHE CITY OF HEILONGJIANG PROVINCE

Based on the 1∶250 000 land quality geochemical survey data of black land in Northeast China, the soil nutrients, soil environmental quality, comprehensive soil quality and suitability of green food producing area in Nehe City are evaluated according to the Soil Quality Geochemical Evaluation Standard and Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (Trial). The results show that there is fertile land and clean environment in Nehe City, which is suitable for the development of green agriculture. Among the 16 indexes, including N, P, K, organic matter, CaO, MgO, Fe₂O₃, S, B, Zn, Mn, Cu, Mo, Co, Ge and V, except Cu and Zn are relatively deficient, Ge and B deficient, the others are rich or relatively rich. The comprehensive soil nutrient grades are mainly rich and medium, with distribution areas of 3 666.74 km² and 2 574.11 km², accounting for 56.94% and 39.97% of the total area respectively. The soil environmental quality is dominated by Grade Ⅰ(risk free), covering an area of 6 435.78 km², accounting for 99.94% of the total; while the Grade Ⅱ(risk controllable)area is only 4 km², occupying 0.06%. The comprehensive soil quality is largely fine-grade soil, covering 3 806.06 km² and accounting for 59.11% of the total area, with the good-grade of 2 574.11 km²(39.97%)and medium-grade of 59.61 km²(0.92%), no poor- and inferior-grades soil. The soil area conforming to Grade-AA green food production area is 6 461.5 km², accounting for 97.5% of the total area, that conforming to Grade-A 38.1 km²(0.58%), and that does not meet the requirements is 65.6 km²(0.99%).