Study On Phosphorus Efficient Mechanism In Different Intercropping System

As lack of resources, to protect food security we must take the resource-efficientand intensive way to improve crop yield. At present, China’s phosphate fertilizerproduction and application were ranked first in the world. However, on the one hand,China’s phosphate rock resource is a serious shortage and as the increasing ofphosphate fertilizer prices increased the agricultural cost; the other hand, phosphorusis easily fixed in the soil and poor mobility, so the crop phosphate seasonal utilizationis only10-15%. In the past20years, as the continued application phosphate fertilizerthe soil available P level significantly was increased, but most of the phosphorus havebeen fixed in the soil, converted to cumulative phosphorus, leading to massiveaccumulation of phosphorus in the soil. Therefore, to explore to improve the cropseason fertilizer phosphorus and soil cumulative activation of phosphorus in the use ofnew ways to become the Country’s significant demand. Previous studies have shownthat reasonable collocation could improve crop phosphorus utilization efficiency inintercropping system，due to the different of crops root characteristic, the rhizospheresoil microorganism quantity and enzyme biological characteristics are different, whichprovided a new idea for improving the phosphorus efficiency. A field experiment wasconduct to study on p uptake, yield, the rhizosphere acidic phosphatase, pH and toexplore the mechanism of phosphorus efficient and the response to phosphate ofdifferent intercropping systems: chickpea‖corn, beans‖maize, rape‖maize andsoybeans‖maize, which provided the theory basis for mining intercroppingadvantages, realizing intercropping stable and high yield and increasing phosphorusefficiency. The main conclusions were as follows:1. The land equivalent ratio of four intercropping systems were larger than1, all havethe obvious yield intercropping advantage， Which were1.13to1.28of chickpea‖maize1.11to1.15of soybean‖maize，1.24to1.31of faba bean‖maize, and1.20to1.24of rape‖maize. The intercropping maize yields were greater than those of monoculture maize.2. Intercropping system’s ability to use phosphorus. Rape, beans aboveground Puptake significantly increased with the increasing in phosphate levels; Chickpeas,soybeans and maize aboveground P uptake were not changed significantly with theincreasing of phosphate levels. Intercropping maize aboveground P uptake wassignificantly higher than that of monoculture maize.3. The rhizosphere soil pH of five kinds of crops were lower compared to bulk soil pH,and significantly decreased with the growth process. The extent of pH decrease in therhizosphere of various crops, the decreased range of rhizosphere pH of chickpeas, fababean, rapeseed, and soybean was more than that of maize.4. Five kinds of crop root all could secrete acidic phosphatase but the amount ofsecretion is different，roots acidic phosphatase of faba bean, rape, soybean and chickpeawere more than those of maize.