| Straw mulching plays a significant role in soil temperature regulation,improving farmland underlying surface properties and soil water storage ability.Water consumption of crop can be divided into normal plants transpiration and soil evaporation,evaporation is considered invalid water.To minimize the water consumption of crops without changing the crop yield,people have focused on the soil evaporation.This paper mainly studies the effect of straw mulching on soil evaporation and growth of summer coin under drip irrigation.Tests are done in China Water Conservancy and Hydropower Research test base at Daxing District of Beijing(116 ° 15?E,39 ° 39? N)during June to October in 2013.The main conclusions are as follows:(1)Straw mulching has obvious inhibitory effect on evaporation;the average daily evaporation of straw mulching group and the control group is seedling stage?jointing stage>jointing?tasseling stage>tasseling?filling stage>grouting?mature stage;Contrast to the control group,covering treatment has inhibited evaporation by an average of 43.6%,and the daily evaporation is 0.75 mm less than those in control group,and the most significant stage is jointing stage to mature stage after grouting,the inhibition rate was 44%.During the reproductive period,straw mulching reduced evaporation of 50.99 mm,and provided more moisture for summer maize transpiration effectively,the biggest gap of the monthly evaporation between the control group and straw mulching group appears in August,and basically the same in July and September.(2)Under the condition of straw mulching,the plant height,leaf area index,dry matter content,and chlorophyll value of summer corn is bigger than that in the control group;it had the greatest influence on leaf area index;And leaf area index under straw mulching keeps bigger than the control group,it also found that the yield per hectare under the condition of straw mulching is about 150-160 kg higher than the control group.The WUE of summer corn is also a litter bigger than the control group.(3)The effect of straw mulching on temperature of each soil layer changed with the crop growth.Before jointing stage,the effect of straw mulching on surface soil temperature was bigger than the control group,and cooling effect of straw mulching was weakened with the deepening of the depth.After jointing stage,the effect was greater on the soil below 10cm,the surface soil temperature(Ocm)fluctuated great;and straw mulching also influenced the moisture and temperature of different heights between summer corn,the effect was greater on the soil above 10cm while there were almost no influence on the soil above 60cm.110cm.(4)Effects of straw mulching on the moisture content of the soil is also obvious.0-20 soil moisture content in the first three stages are higher than the control group,covering treatment group were higher than the control group 2.41%,0.3%,3.37%,stage 4 2.1%lower than the control group.In the forth stage covering treatment were lower than the control group 2.1%.Under straw mulching condition,the relative moisture on the soil above 10cm was lower than the control group at the seedling?jointing stage while it was higher than the control group at the other three stages:jointing-tasseling stage,tasseling?filling stage,grouting?mature stage.The difference of relative moisture on the soil above 60cm and 110cm between covering treatmeat and the control group wan not big. |
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