| Leaching of base cations, application of large amount of N-fertilizers and acid participation has resulted in widespread soil acidification. Deficiency of nutrient elements, and the toxicities of aluminum, manganese as well as the activation of heavy metals are common limiting factors for the growth of plants in most acid soils. The fast increasing population in the world and the limited arable land sources pose an urgent need for the rehabilitation of acidic soils. There exist 0.137 billion hectares arable soil in China. About one third of them are acid soil with low productivity. It is significant to develop and deploy new methods to enhance the productivity of acid soils. The balanced supply of nutrients is the base of achieving high crop yield and quality. In plant nutrition, nutrient balance involves not only macro-elements, but also between medium and microelements. Deficiency of zinc and boron in some acidic soils has been found to be the causes for the decrease in yield of maize, cotton, rice and rapeseed, and in quality of apple and orange. Application of zinc and boron is a common amendment. It is also a popular agricultural practice to apply lime for the amelioration of acidic soils. Lime may play multiple roles in acidic soils such as neutralizing soil acidity, replenishing exchangeable Ca>, and changing the form and reducing the concentration of aluminum, manganese and other toxic elements. Ionic activities of elements in the soil are affected by the change of soil pH caused by application of lime. The availability and transformation of many elements are influenced by the acidity and chemical performance of Ca> in soil solution. The conclusion can be drawn that the dual impacts of pH and Ca> will change the solubility, activity, fraction and interaction of the elements. Present studies were initially focused on combination status, transformation and the effect on plant and soil itself of calcium, zinc and boron in acid soil, so as to reveal the mechanism of their availability and activity, and develop regulating measurements. Comprehensive research methods including pot experiment, incubation experiment, kinetic and dynamic studies were adopted for the purpose. The testing soil was acidic purple soil, taken from Beibei, Chongqing. lettuce (Lactuca saliva var.augustana Irish) was chosen as the testing plant. Pot culture experiment involved 12 treatments, 5 replications each, including Ca, Zn, B, and combinations of Ca-Zn, Ca-B, Zn-B, Ca-Zn-B. Biomass, concentration and ratio of elements were designed as parameters to reflect the effects of different treatments on plant. Incubation experiment with same treatments but without plant was carried out synchronously under constant temperature (23 1 C) and 20% soil moisture, in order to study the processes of transformation and variation of availability of Ca, Zn, B as influenced by their interactions and soil properties. The incubated soil samples were taken out in certain interval for the analyses of availability and fractionation of Ca, Zn, B in a duration of 256 days. The adsorption and desorption of soils to Ca, Zn, B, and the dynamic study of Ca+Zn, Ca+B, Zn+B, and Ca+Zn+B were designed to reveal the rate of chemical reaction and the effect of interaction of these elements on adsorption-desorption. The main results are summarized as follows: 1 The application of Ca, Zn, B and their combinations increased the biomass of lettuce by 1 09%-248% comparing with control, and the contribut...
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