Studies On Effect Of Soil Amendments On Activation Of Soil Nutrientsand Rice Yield In Cold Waterlogged Paddy Soils

The experiments were carried out in the experiment station of Institute of AgriculturalResources and Environment, Guangdong Academy of Agricultural Sciences during2011～2012.Experiment with fixed site on continuous was conducted to study the effects of open ditchdrainage, The combination different soil amendments (self-developed desulphurization ashamendment, biochar, lime, silicon-calcium fertilizer, humic acid) and open ditch drainage on thesoil physical and chemical properties, microbiologic properties, root activity, rice nutrientuptake, rice growth characteristics, yield and component of rice in south typical coldwaterlogged paddy filed. Discusses the mechanism of action of soil amendment，meanwhileReveals the change rule of various performance indicators and their mutual relation of soilcharacteristics and rice plants under different soil amendments. The main results were asfollows：1Treatments with amendments significantly improved soil microbial activity, delayed senescenceof rice population, increased accumulated amount of rice dry matter, enhanced effective panicles numbers andseed setting rate. The treatments with desulphurization ash amendment and biomass charcoal weremost obviously, panicle number increased by12.1%and10.7%, accumulated amount of rice drymatter improved68.8%and50.5%compared to CK, respectively. While the Eh in treatments withdesulphurization ash increased by20.8%. soil respiration intensity and the amounts of actinomycetes intreatments with biomass charcoal increased by67.6%and127.6%.Different soil amendments treatmentsshowed beneficial effect on soil fertility and rice population quality，with application ofdesulphurization ash amendment and biomass charcoal having the largest effect．2Treatments with amendments not only increased rice yield, but also increased N, P and Kthe nutrient content of rice to some extent. Treatments with desulphurization ash and biochar andsilicon-calcium fertilizer increased N, P and K uptake in grain and straw. K uptake in straw oftreatments with desulphurization ash and biochar increased by32.2%and29.8%compared toCK, respectively. Meanwhile, different soil amendments can improve pH and available nutrientof soil, the available N, available P, available K of treatments with desulphurization ash andbiochar increased by20.8%and21.8%,50.5%and48.1%,62.2%and57.3%compared to CK,respectively.3Treatments with amendments, except for lime, significantly increased the intensity of bleeding sap,root shoot ratio, biomass and enhanced the flux of N, P, K in bleeding sap. Treatments with desulphurizationamendment and biomass charcoal increased the intensity of bleeding sap most. Compared with CK, the flux of P in bleeding sap increased by29.60%and19.70%, respectively during filling stage. The root/top ratio oftreatment with desulphurization ash increased31.6%, compared to CK in mid-tillering stage. Different soilamendments can improve rice yield of cold waterlogged paddy field. Besides, the effect of yield increase willincrease with the appication of amendments. To sum up, amendments of desulphurization ash amendment andbiomass charcoal could be the optimal choice for cold waterlogged paddy field...