Effects Of Water Management And Soil Acidification On Potassium In Paddy Soil In Cold Region

This experiment take the white pulp soil、the black soil、 the meadow soil and the dark brownsoil to study the effects of drying and wetting cycle on the availability of K by simulationexperiment. Set the two treatments: drying and wetting cycle and drying treatment and wettingcycle after adjust soil pH treatment. Determination the soil leached pH, soil available potassium、effective potassium and slow-release potassium content in the soil after alternating drying andwetting and the soil available potassium、effective potassium and slow-release potassium contentin different soil layer. Studying the effects of drying and wetting cycle and soil acidification on theavailability of K by simulation experiment. The results showed:1. Under the condition of fertilizer applied, and leached K amount in four paddy soil increaseswith an increase the times of drying and wetting cycle or flooded time. Under the condition ofalternation drying and wetting, the white pulp soil leached K amount is about2.5times that underthe condition of continuous flooding, differences reached extremely significant level (p <0.01),theblack soil leached K amount of alternation drying and wetting is significantly higher than that theleached K amount of continuous flooding treatment (p <0.05), the meadow soil leached K amountof alternation drying and wetting is significantly lower than that continuous flooding treatment (p <0.05), only difference of the dark brown soil leached K amount in two types of water managementis not significant.2. Compared with continuous flooding, available K and effective K content of0to5cm in fourtypes soil was increased by alternation drying and wetting, under the alternation drying and wettingtreatment, white pulp soil available K supply increased by66.8%, black soil increased by5.1%, andthere is no effect on the meadow soil and dark brown soil. But to5-20cm soil layer in each typeof paddy soil,compared with alternation drying and wetting, continuous flooding treatmentincreases available supply by9.5%-23.0%, fertilization for soil slow-release K content of differenttypes of paddy soil in different layer has little effect, but compared with the soil slow-release Kcontent before training, different water management treatments are resulting in a reduce of soilslow-release K content, and alternation drying and wetting promoted the release of slow-release Kin different type soils compared with continuous flooding treatment.3.Compared with continuous flooding, after alternation drying and wetting, soil available Kcontent in white pulp soil、black soil and dark brown were higher than soil available K content after12times continuous flooding, available K content increased by12.82%、12.82%and12.82% respectively. Soil available K content under continuous flooding treatment in dark brown soil washigher than that under alternation drying and wetting treatment, up to4.53%. Effective K content inwhite pulp soil and meadow soil increased by5.93%and5.93%respectively. But effective Kcontent in black and dark brown soil under continuous flooding treatment was higher than thatunder alternation drying and wetting treatment, increased by2.42%and3.02%respectively. Onlyslow-release K content in dark brown soil is higher than that after12times continuous flooding,growth rate of1.05%, and slow-release K content in white pulp soil、black soil and meadow soil,continuous flooding was higher than that alternation drying and wetting12times, and the black soilhas the highest growth rate, at8.32%, followed by white pulp soil, is7.16%.4. The effect of alternation drying and wetting on soil leached K amount under four pH treatmentperformances as pH3.5and pH4.5soil is higher than pH5.5and pH6.5soil, and this trend was moresignificant after fertilization, in addition to black, the other three types of soil leached K amountshowed a trend of downward after rising.5. The effect of alternation drying and wetting on soil leached pH under four pH treatmentperformances was not significant, the influence of alternation drying and wetting processing after theprocessing of eluent soil pH value and the processing of soil pH value had no significant difference, theoverall performance for pH3.5and pH4.5soil presented the same trend, pH5.5and pH6.5soil presentedthe same trend.6. With the increase of soil pH, soil available K amount showed a trend of increase in the0to10cm soil layer and in10to20cm soil layer distribution of the amount showed a trend of decrease.After alternation drying and wetting, with the rise of soil pH, white pulp soil total available Kcontent increases, but the dark brown soil appears the opposite trend, available K content had nosignificant change in the black soil and meadow soil. The soil effective K and available K showed asame trend. Slow-release K content in0~20cm soil layer of four types is relatively close, and thedifferences of slow-release K content in four types of soil under different pH treatment was notsignificant. But compared with the original soil, total slow-release K content in four types soilunder different pH treatment, dark brown soil increased the most, white pulp soil increased theleast.