| The Province of Henan,which as the “China granary” belongs to the serious water deficient area,however the main water requirement period of wheat and the period of rainfall in the area is dislocation,result that wheat production can't rely on days merely,and reasonable irrigation is the decisive factor of high and stable yield of wheat.In order to study the response of soil biological activities of winter wheat in well irrigation area of drip irrigation in Henan Province,look into the effects of different drip irrigation methods on soil biological activities in well irrigation area of Henan,then provide a biological basis for the best soil drip irrigation in the area.In this study,drip irrigation experiment of winter wheat was applied at Henan Agricultural University.Two levels drip irrigation quota(I:127.5 mm,90 mm)and interval(D:80 cm,60 cm)were conducted,respectively.In total,4 kinds of drip irrigation treatments(I127.5D60,I127.5D80,I90D60 and I90D80)were set up in the winter wheat field experiment.Soil samples of the treatments in winter wheat field were collected to measure soil water content in 0-100 cm profile before the start of drip irrigation and during the jointing stage,mature period,including harvest time of winter wheat,besides the topsoil samples of the treatments in winter wheat field were collected to analyze the quantities of soil bacteria,fungi and actinomycetes and the activities of soil enzymes during the periods of the flowering,filling and maturing of winter wheat,including invertase,urease,phosphatase,CAT,dehydrogenase,PPO.Determined and analyzed the soil microbial quantities,soil enzyme activities and wheat yield were determined when wheat harvest,respectively.The main results are as follows:Soil moisture content reached the highest at jointing stage and decreased to the lowest after harvest of the four treatments.On the whole,the soil water content of20-40 cm and 40-60 cm were higher than those of 0-20 cm,60-80 cm and 80-100 cmin all the periods,among which 80-100 cm was the lowest.Compared with I90D80 and I127.5D60,I127.5D80 and I90D60 treatment were more conducive to the improvement of soil water content,among these the I127.5D80 treatment was the most prominent.Soil bacteria and actinomycetes grew vigorously of I127.5D80,followed by I90D60,soil type tend to bacterial soil,especially in the period of mature.Compared with I127.5D60,the quantities of soil bacteria and actinomycetes were increased 5.48 times and 10.04 times of I127.5D80,respectively.Both irrigation quota and drip irrigation belt spacing can significantly affect the number of soil microorganisms,The response of different microorganisms to drip irrigation was not the same,among them,actinomycetes were the most sensitive,followed by bacteria,and fungi were the slowest;With the advance of the growth period of winter wheat,the variation trend of the quantity of three kinds of microorganisms is different,the number of soil bacteria and actinomycetes in I127.5D80 treatment showed a significant increasing trend,but there was no significant difference in the other treatments.The total number of soil microorganisms in filling stage were significantly higher than that of the flowering period,increased by 2.53,2.91,2.48 and 1.50 times in the four treatments,respectively.However,there were no significant differences in the total number of soil microbes from the filling stage to the maturity stage,except that the I127.5D80 treatment increased by 3.47 times.Both irrigation quota and drip irrigation spacing significantly affected soil CAT enzyme and dehydrogenase activities,but there was no significant changes in the activity of soil invertase,urease,phosphatase and PPO enzyme.I127.5D80 treatment was significantly higher than that of the other treatments in the grain filling stage and mature stage,and the CAT activity in soil was significantly lower during the flowering and filling stage.Among them,the maturity of dehydrogenase than I127.5D60,I127.5D60,I127.5D60 treatment were increased by 208.33%,50%,18.09%,CAT enzyme activity in the grain filling period decreased by 53.25%,10.88%,55.12% respectively.The correlation between soil water use efficiency,soil biological response coefficient and wheat yield of four kinds of drip irrigation was extremely significant positive correlation between each other.The order from high to low among these isI127.5D80 > I90D60 > I90D80 > I127.5D60.The treatment of I127.5D80 is the best choose of drip irrigation in winter wheat,whose water use efficiency,soil biological response coefficient and yield were the highest.There were significant differences in the number of soil microorganisms(bacteria,actinomycetes and fungi)and the activities of dehydrogenase and CAT of four treatments.Among them,the quantity of soil microorganism and soil dehydrogenase activity were the most sensitive in the mature stage,and the most sensitive period of soil CAT enzyme activity was in the flowering stage and filling stage.The treatment of I127.5D80 is more conducive to soil water storage,whose water conservation,soil biological response coefficient and yield of wheat were the highest,is the best irrigation method in the area. |
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