CONTRAST EXPERIMENTAL STUDY ON THE METHODS OF CALCAREOUS SOIL AMELIORATION IN KARST MOUNTAINOUS AREA——A CASE STUDY OF LONGHE HAMLET,PINGGUO COUNTY,GUANGXI
LUO Wei-qun, JIANG Zhong-cheng, QIN Xiao-qun(Institute of Karst Geology, CAGS,Guilin 541004,China)
In this paper, taking Longhe hamlet in Guohua Town of Pingguo County , Guangxi Province as an example, based on systematic analysis of the characteristics and barrier factors of calcareous soil, the principles and methods of calcareous soil amelioration were discussed. The theory of karst dynamic system was taken as the instruction, the contrast experimental study about calcareous soil amelioration by returning straw to soil and balance manure have been conducted. The results showed that not only corn yield and economic efficiency are increased, moreover straw and remnant stubble output that provide material bases for further improvement of calcareous soil are increased, by balance manure. The good output increase and improvement soil effects of calcareous soil amelioration that are restricted in karstification intensity by returning straw to soil can be obtained. The matching type and applying way of straw influence karstification intensity, and cause significant differences in the improvement effect of different amelioration schemes. The improvement soil effects of various schemes were positively correlated with the karstification intensity.With regard to the matching type of straw, the improvement effect is corn straw+manure corn straw+soybean strawcorn straw+nitrogenous fertilizercorn straw. With regard to the way of manure straw, the improvement effect is turning and pressingcovering.