| In order to response to the crisis of water resources and develop the water-saving planting pattern in North China Plain better, study of the effect of a new water-saving irrigation method(the pipe-evenly-moving irrigation) on the variation of soil moisture and water use efficiency of summer maize. By adjusting the moving speed of the pipe in the field and the irrigation time, controlling the irrigation flow, to improve the irrigation precision. The experiment was conducted at the agronomy experimental station of Shandong agricultural university during the summer maize growing season in2013. There are four irrigation treatments:no irrigation (W0), traditional furrow irrigation (W1), the pipe irrigation (W2) and the pipe-evenly-moving irrigation (W3). Objectived to investigate the soil water dynamic change, farmland evapotranspiration, physiological characteristics, grain yield and the WUE (Water Use Efficiency) of summer maize under these four irrigation treatments especially the treatments W3. The result shows that:1. The soil water dynamic change and farmland evapotranspiration. The soil water storage and the irrigation uniformity of summer maize is the highest under the treatment W3. Because the irrigation precision of pipe-evenly-moving irrigation is high, it can ensure all levels of soil water storage stability than the other two irrigation methods. The pipe-evenly-moving irrigation fully guaranteed the0-60cm soil layer pondage and moisture content on the space of homogeneous, avoided the phenomenon of local water shortage in summer maize roots and thus affected their growth and development because of the uneven irrigation and the deep excessive leakage caused by localized irrigation. It can not only conducive to the deep root growth of summer maize in the late growth stage, but also can reduce the surface runoff andevaporation and groundwater seepage, improve water use efficiency, and to meet the water requirements of crop root. Therefore, the soil moisture uniformity of pipe-evenly-moving irrigation is the highest. It has more obvious advantages, and the preserving soil moisture effect is good. Due to the reduction of the invalid evaporation, the evapotranspiration of pipe-evenly-moving irrigation is lower in the same irrigation quota than the pipe irrigation.2. Growth, yield and formation mechanisms on summer maize With the development of growth period, the LAI of summer maize on different treatments increased at first but later decreased, that is the LAI increased rapidly after jointing, reached the maximum in blossom period and then decreased. The LAI of W3is the largest of the4different irrigate treatments. The largest LAI is higher than that of WO35.5%, W113.5%, W210.5%.The height of summer maize in Maturity of W3is higher than that of WO5%, W11.8%, W21.3%. It can be seen that the photosynthetic rate of W3is a little higher than that of W2under the same irrigation quota, and it is especially more obvious in the11:00-12:00at noon, and the transpiration rate of W3is lower than that of W2. The transpiration rate of summer maize decreased with the decrease of moisture. When the lower limit appropriate moisture, the pipe-evenly-moving irrigation can reduce the transpiration rate, reduce the leaf transpiration, and finally improve the water use efficiency of leaf, thus lays a foundation for crop high yield. The pipe-evenly-moving irrigation fully guarantees the summer maize’s demand for water, and ensure the smooth progress of the photosynthesis, increased the dry matter accumulation. The dry matter accumulation in filling stage of W3is higher than that of WO23.07%, W13.23%, W23.90%and is higher than that of W013.33%, W13.03%, W24.29%in maturity. An increased the dry matter accumulation in grain of summer maize in filling, conducive to increase the total output of summer maize. The result shows that:The maize yield is9758.70kg/hm2, and is higher than that of W022.1%, W111.4%, W26%.3. Water use efficiencyThe pipe-evenly-moving irrigation has increased the water use efficiency of leaf level, population level and final yield level in varying degrees. The WUE of leaf level reached12.3of the pipe-evenly-moving irrigation, and is higher than that of W036.52%, W19.33%, W211.08%; The WUE of population level of pipe-evenly-moving irrigation is higher than that of W02.13%, W18.42%, W25.89%; The WUE of final yield level of pipe-evenly-moving irrigation is higher than that of W010.5%,W116.8%, W27.5%, and the trend is consistent with the trend of production. The irrigation water use efficiency of W3is the highest and is higher than that of W139.2%, W26.0%. From this point of view, pipe-evenly-moving irrigation can improve the water use efficiency and irrigation water use efficiency of summer maize effectively than traditional furrow irrigation and the pipe irrigation.In summary, the results indicated that the pipe-evenly-moving irrigation is one of the effective means of summer maize yield and water saving, and it can improve the WUE. It is a water-saving irrigation method which is worthy of promotion in North China Plain which area lack of water resource. |
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