Effects Of Soil Amendments On Oat Growth And Soil Properties In Arid Area

In view of the poverty of the soil,drought,low yield and so on,a field experiment studied the effect of different soil amendments and the mixture of these amendments on oat growth and the affecting mechanism of the soil amendments for soil physics and chemical properties in order to provide academic basis for improving soil physical,chemical and microbial properties,and increasing oat yield and water use efficiency in arid area,saving water and increasing production.The results showed that:1.Different soil amendments all could increase the content of soil organic matter,available N,available P and available K.Compared with control, each index increased by8.24%-30.22%,7.60%-19.29%,5.15%-29.45%and27.86%-68.86%.Organic matter.available P, N was PAA-K+HA-K>PAM+HA-K>PAA-K>PAM>HA-K. The content of available K was PAA-K+HA-K>PAA-K>PAM+HA-K>HA-K>PAM.2. PAA-K+HA-K.PAM+HA-K.PAA-K, PAM and HA-K all could improve soil water content of0-60cm soil layer and the five kinds of soil amendments increased by respectively12.95%,7.96%,7.89%,5.11%and2.78%compared with control.But they had no effect on60-100cm soil layers.These soil amendments could reduce the soil bulk density of0-10cm,10-20cm,20-40c, and40-60cm soil layers, and compared with contrast,the soil bulk density in0-10cm,10-20cm,20-40cm,and40-60cm soil layers reduced by1.38%-4.2%,1.34%-5.37%,1.32%-5.26%and0.65%-1.99%. They produced no obvious effect on60-100cm soil layers.Among them,PAA-K+HA-K was the greatest to decrease the bulk density of soil,and there was no significant difference between them.All the soil amendments could reduce soil compaction.Compared with control, soil compaction respectively reduced by81.22-437.54kPa,318.86-828.19kPa and169.89-696.53kPa.PAA-K+HA-K>PAM+HA-K>PAA-K>PAM>HA-K>CK.meanwhile,10-20cm soil layer was the most obvious.All of them can significantly increased>0.25mm soil aggregate content of0-10cm,10-20cm and20-40cm soil layers.The＞2mm and2-1mm aggregate content increased much greater. PAA-K+HA-K.PAM+HA-K were significantly higher than the other single soil amendments.However.thc difference between them was not significant.3.Soil amendment significnatly increased soil microbial biomuss C.N and P of0-10cm,10-20cm and20-40cm soil layer in the growing stages of oat:the effect of the mixed use was more significant than the single use; with the increase of soil depth.soil microbial biomass decreased.and soil microbial biomass C.N and P had the same trend:the value increased first and then decreased from seeding stage to maturity.and it reached the highest value at the heading stage.The change of soil enzyme activity was the same as soil microbial biomass;different soil amendments all increased soil catalase and sucrase activity,however.different treatments in different stages and soil layers had different differences,and the activity and the difference value among treatments decreased with the increase of soil depth; it reached the highest value at the heading stage; soil urase activity of PAA-K+HA-K, PAM+HA-K and HA-K treatments were lower than contrast at the seeding stage while higher than contrast at the heading and maturity.4.Soil amendments increased plant height of oat significantly. Compared with control, plant height of PAA-K,PAA-K+HA-K,PAM,PAM+HA-K and HA-K increased by0.71%-7.09%,1.48%-5.65%,1.51%-6.38%,2.72%-5.60%and3.29%-5.60%; among the five soil amendments,the mixed use had much higher plant than the others.They had the same effect on dry matter accumulation, and all the using of the soil amendments for increasing dry matter accumulation was much greater than contrast:among them.the accumulation of PAA-K+HA-K was the greatest, which was15.06%compared the contrast and the second was PAM＋HA-K,which was12.08%. PAA-K and PAM were after them.The using of HA-K had the lowest dry matter accumulation.5.AII soil amendments had significant effect on oat yield and its components;grain yield of all the treatments was significantly higher than that of contrast;the yield of the mixed use was higher than that of the single use;the yield of PAA-K+HA-K and PAM-HA-K was3010.7kg/hm2and2915.6kg/hm2,and increased by25.92%and21.94%respectively;the biological yield had a same result of grain yield.The water use efficiency of each treatment in2010and2011was significantly higher than that of contrastand the change trend was the same as yield: ompared with control. the water use efficiency of PAA-K+HA-K. PAM+HA-K. PAA-K. PAM and HA-K treatments increased by40.17%,30.83%,26.22%.16.56%and9.94%respectively, and soil water storage increased by11.47mm,5.81mm,3.96mm,2.87mm and0.53mm.WUE and soil water storage of PAA-K+HA-K was significantly higher than that of other treatments.6.The yield was positive with all soil indexes except available K and soil urase activity. The order of correlation coefficient from high to low was soil organic matter(0.996)＞soil sucrase activity(0.994)＞soil catalase activity(0.993)＞soil microbial biomass C(0.992)＞soil microbial biomass P(0.990)＞soil water content(0.980)＞available P(0.964)＞available N(0.962)＞soil microbial biomass N(0.913)＞soil urase activity(0.746)＞available K(0.720). Soil organic matter, soil sucrase activity, soil catalase activity, soil microbial biomass C, soil microbial biomass P, soil water content, available P and available N all were significantly positive with yield(P＜O.O1). Soil microbial biomass N was significantly positive with yield(P<0.05).So soil organic matter, soil sucrase activity, soil catalase activity, soil microbial biomass C, soil microbial biomass P, soil water content, available P, available N and soil microbial biomass N could be an effective index to judge oat yield in Wuchan.7. As a whole,from oat yield and WUE,the mixed use of two kinds of soil amendments was much better on oat production and planting. PAA-K+HA-K had a better effect between PAA-K+HA-K and PAM+HA-K.