THE ADSORPTION CHARACTERISTIC AND BIOLOGICAL AVAILABILITY OF SOIL NUTRIENTS

Chemical analysis, adsorptive reaction and biological diagnosis were systematically employed to study the status of nutrients in six soils and determine the demanding order for fertilizers. The results showed that N deficiency was widely existed in the soils, followed by P, K, S, Fe,Cu deficiency, and Zn and B in some soils. The deficient degree and order of soil nutrients varied among the test soils. A strong adsorption for Mn was found in the low Mn concentration solution. Cu, Zn and B adsorption rates were not influenced by their concentrations in corresponding adsorption solutions. Phosphorus adsorption differed among the six soils. The basic soil productivity (plant dry weight) varied from 2.73 to 5.55 g/ pot and was significantly increased by fertilization with small differences among three soil types.