摘要
黄土区土壤微量元素含量分布受母质、地形、水热条件、土壤类型等成土过程与成土条件的深刻影响,呈现出一定的规律性。与全国土壤平均含量比较,本区土壤锌、锰较低,钼很低,硼接近,铜略高。土壤有效态锌、硼、钼、锰属低水平,存在着大面积缺乏锌、硼、钼的土壤,近一半土壤面积缺锰。近年来,锌、硼、锰肥已在生产中大面积应用,获得了显著的经济效益。
Loessal soils are one of main soil types in the northern part of China. They are widely distributed over Shanxi, Shaanxi, Nei Monggol, Gansu, Ningxia, Qinghai and Henan provinces, with a calcareous reaction and pH of 7.5--8.5 and low content of organic matter. The yeild of crops in the soil regions is low because of drought and erosion.In comparison with the average contents of soils in the whole China, the contents of the total Zn and Mn of the soils in the loessal region are lower, Mo is very low, B is medium and Cu is slightly higher. The contents and distribution of trace elements in the soils have some regularities, which are affected by parent material, climate, topography and soil properties. The contents of Zn, Mn, Cu and Fe in soils increase with the increasing of soil clay particles from the nouthwest to the southeast. The content of B in the soils derived from river alluvium is higher than that in the soils derved from loess. And the content of Mo in the soils derived from loessal materials is the highest.The contents of available Zn, B and Mo in soils of the region are especially low. The samples which the values of available Mn, Zn, B and Mo are below. The critical levels account for about 50%, 56%, 62.7% and 74% respectively. It show that there exist large areas of Zn, B, Mo and Mn-deficient soils in the loessal region. The availability of trace elements in soils is affected by organic matter, pH and CaCO_3 The content of organic matter is positively correlated with the values of available Zn, Mn, B and Fe. The value of pH is negatively correlated with the contents of available Zn, Mn and Fe, but it is positively correlated with the content of available Mo. The amount of CaCO_3, is negatively correlated with the contents of Mn, Cu and Fe. The salinity of soils is the important factor affecting the valaes of available Mo and B.There enist processes of leaching, migration and accumlation of trace elements in the soil profile. Humus and argillic horizons are richer in Zn, Mn, Cu and Fe. Calcic horizon is rather low in the concentrations of these elements put is richer in total B.Several hundreds field experiments of trace element fertilizers in the soil region showed that an increase in crop yield of 8 15% could be obtained by adding Zn, B, Mn, and Mo fertilizers to maize, wheat, rape, cotton, millet, tobacco and beet. The area applied with these fertilizers has reached more than I0 million mu each year and excellent economical results have been obtained since 1984.
出处
《土壤学报》
CAS
CSCD
北大核心
1991年第3期317-326,共10页
Acta Pedologica Sinica
