Experiment Study About The Effect Of Surge Irrigation On Moisture Vertical Infiltration In Sandy Soil

Surge irrigation is a new kind of surface irrigation technique which provides intermittent water supply with intermittent valve. It can reduce the penetration and speed up the water advance. In order to solve the problem of increasingly serious water shortage, surge irrigation has become which has wide attention and positive development in agricultural water saving activities all over the world today. As a large nation of agricultural irrigation, it is more necessary for China to do research into our own surge irrigation technique and program.In this article, I simulated the vertical moisture permeability of surge irrigation in sandy soil in the loess plateau region by 1-d vertical soil column laboratory experiment and orthogonal design. The unit weight and moisture content of experimental soil is 1.6g/cm3 and 5%.The soil should be filled into glass tube well-bedded. I use a Markov bottle to control water flow rate, use temperature and humidity sensors to obtain corresponding data and use a ruler to measure Wetting front downward distance. The study had an orthogonal experiment design concentrated on the influence of different water supply time, circulation rate and cycle numbers on moisture permeability. By making comparison with continuous irrigation, I used EXCEL and SAS software to do statistical analysis of the result. The conclusion is as follows.1) Surge irrigation has a significant influence on soil temperature in depths from 0 to 5 cm.Circulation rate of 1/2,1/3 and 1/4 are bigger than continuous irrigation. And their influence on temperature change increases in an order.2) Wetting front descending advance rate of surge flow irrigation in the first cycle has little difference with continuous irrigation, but it begins to decrease obviously in the second cycle. It proves that surge flow irrigation can form a dense layer on soil surface and slow down moisture infiltration effectively.3) In the third cycle and later period of surge flow irrigation, the changing of infiltration is not significant. So we can shorten irrigation time and improve the efficiency of using water when the two cycles of surge irrigation is adopted.4) When circulation rate is 1/3, water pause time is enough to assure dense layer formed on soil surface. This period is also not too long to form cracks. Therefore, it’s an optimal cyclic rate.