| The experiments have studied on rape's activation and utilization of different forms inorganic P of acid soil and its physiological change by field experiment, sand culture experiment and root mat experiment. The results showed as follows:1. The field experiment shows:â‘ Rape and being green dressing could activate phosphorus and alleviate chemical fixation of P fertilizer and evidently increased the content of rapidly available phosphorus in soil. Rape could use Ca-P, decreased the transformation of P into O-P, which could enhance the validity of P in acid soil.â‘¡Apply the fertilizer or not, planting rape can improve phosphorus application efficiency of succeeding peanut crop, observably promote the growth of peanut fruit, enhance its economic yield, thus, it plays an important role in cultivation system of rape and peanut.2. The sand culture experiment shows:â‘ Rape can utilize FePO4 and AlPO4 to keep its growth.â‘¡Under P-stress, rape can adapt p-starvation by enhancing root top ration, increasing APase(acid phosphatase) activity in root, enhancing the synthesis of organic acid in plants and excretion of organic acid from root and so on.â‘¢ Rape's ability of utilizing AlPO4 is higher than that of FePO4 and it still can obtain much higher biomass in lower phosphorus concentrations conditions.â‘£ Rape adaptability to P-stress was related to the levels and the forms of P in the environment, the response of rape was most obviously when the concentration of available P in environment rises to certain degree, and rape is much sensitive to AlPO4.3. Root mat experiment shows:CD Rape affected inorganic P most in the range of 03mm from root surface, and got a certain influence on the inorganic P within 38mm, while it has no effect beyond 8mm.(2) According to the effect of rape roots on the affected distance and decreased degree of inorganic P, the validity of four kinds of inorganic phosphorus was: Ca-P>Al-P>Fe-P>O-P.
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