The Studies On Salt-status Of Greenhouse Soil And Influent Factor Of Hebei Province

this research has studied the soil salt composition , salt accumulation and spatial distribution in different greenhouse of Hebei and the affection of organic fertilizer of different C/N to soil salt by investigation and simulated test, in order to provide scientific foundation to the peasant to use soil continued. The result showed :Contrast to the salt of crop plot, the soil salt of greenhouse of 0~20cm, 20~40cm ,40~60cm ,60~80cm layers have all increased . The content of soil salt of 0~20cm layer is the most and the EC of the four layers increased respectively 244%, 55%, 50%, 73%. The content of Ca2+, Mg2+, K+, SO42-, NO/ all increased except of HCCvOn the spatial distribution, the accumulation of soil salt is mainly occurred in 0~20cm layer. The percentage of soil salt of 20-40, 40-60, 60~80cm layers to 0~20cm layer are 50.0%, 43.5%, 41.9%. Except HCO3' increasing with soil layers, Ca2+, Mg2+, K+, Cr, SO42-, NO3' have all decreased.Simulated test showed that decomposed organic fertilizer has increased rape yield and alleviated the harm of secondary salinity. The decomposed organic fertilizer(75t/hm2) increased the production 13.9%~70.3% under chemical fertilizer. We can see that the effect of increasing production of decomposed organic fertilizer was more remarkable with the increase of chemical fertilizer.Stover decreased the content of soil salt and the soil EC, but it decreased rape yield under no chemical fertilizer. Under chemical fertilizer it increased rape yield, in the same time it decreased soil salt. Under chemical fertilizer (Fl, f2), low doses of stover (37.5t/hm2) increased rape yield 32.9% and 610% respectively; moderate doses of stover (75t/hm2) increased rape yield 46.8% and 1660% respectively; and high doses of stover (112.5t/hm2) increased rape yield 12.0% and 2290% respectively. From this we can see that stover is increasing with more chemical fertilizer.