Experiment Studies About The Water Saving Effect Of Wide-ridge And Furrow Irrigation Mode

Highly efficient agricultural production needs the highly efficient water resources utilization. The combination of water saving technological measures' and agronomic measures is an effective method of dealing with them. Wide ridge and furrow irrigation is a mode of combination of the ridge cultivation mode and furrow irrigation method. It increases the ridge width when cultivating to make the multiple row cultivation easy and use the furrow between wide ridges to irrigate. As far as ridge cultivation concerned, it has so more surface area, lighted area and soil-atmosphere touched area than plane cultivation. So its difference in temperature of day and night is obvious, which redounds to draining and reducing the moisture in field. So it's used widely. In recent years there have been break throughs in furrow irrigation mode. Especially the appearance of controlled alternative irrigation promoted the rapid development of new theories. Meanwhile the new theory of regulated deficit irrigation provides a new considerations for water saving, yield increasing and improving the quality of product. The conception of wide ridge and furrow irrigation is to discuss and study on application based on the two advanced water saving theories. It hopes to be a breakthrough in traditional irrigation and relative water saving theory. Therefore, an experimental study has been conducted on spring maize planted in greenhouse and field.There are mainly three parts in this thesis: firstly, in order to make sure of the various relations between time and spatial variability of soil water content, the writer studied the rules of soil water movement between ridge and furrow when irrigating in greenhouse; secondly, compare wide ridge and furrow irrigation to regulated deficit irrigation and controlled alternative irrigation and study the water-saving effect in plant hight, leaf grow, root/shoot ratio, distribution of above-ground dry material, yield and water use efficiency etc.; finally, the writer evaluates the benefit of water-saving of wide ridge and furrow irrigation in operation management, water saving and increasing production and benefit/investment ratio. Then studies out the irrigation schedule initially.According to the researches of the thesis, the main results are as follows:(1) The water content gradient results in lateral infiltration and increases the water content gradient between surface layer and deep layer of ridge and the soil water content of surface layer of ridge increases gradually after irrigating. The results show that, under the condition of film-mulching, the water content gradient in lateral and ridge's vertical results that obvious lateral infiltration and water supply to ridge is much more obvious than bare land. 17 days after irrigating, as fas as film mulched concerned, the water content of surface layer of ridge reaches to 75%～80% of field capacity. It's 15% higher than the bare land.(2) If using wide ridge and furrow irrigation mode, it's plan I especially the film-mulched treatment that refer to the controlled alternative irrigation obtained better effect of water saving and yield increasing. As to the irrigation plan II which refers to regulated deficit irrigation, the wide ridge and furrow irrigation treatment couldn't reach to anticipatory effect of water saving and yield increasing.As to the irrigation plan I, the irrigation times of film-mulched wide ridge and furrow irrigation treatment is two times less than CAI and the bare land treatment. And among the developing indexes, it has the same even better effect of water saving and yield increasing than CAI. Although the irrigation amounts is 11.76% and 0.41% more than CAI and the bare land treatment, the yield is 19.71% and 16.14% more than them, WUEa is 24.43% and 128.12% higher than them and the benefit ratio is 3.43% and 7.11% higher than them. The 1000-grain Weight is bigger than them also. The effect of yield increasing is obvious. It shows that, if suitably control the lower water limits of different growing periods, the film mulched wide ridge and furrow irrigation treatment performed well in consuming water, regulating, improving grain quality, increasing yield of per unit area, accelerating the form of economical yield, so that can reach to relatively anticipatory effect of water saving and yield increasing.(3) The comparison and analysis on effects of operation management, water saving and production increasing and benefit ratio show that wide ridge and furrow irrigation mode has the same even better effect of water saving and yield increasing than CAI but not RDI. It shows that the influence of water regulated deficit in space is obvious than in time if take wide ridge and furrow irrigation as a new water wane irrigation mode, a"time and space"irrigation mode.Wide ridge and furrow irrigation technique has been put forward initially. As to field crops, it can be the mode of"time and space"regulated deficit irrigation if considered the develop period and water supply of root layer system. But it's lack of deep experimental study in fully exploring the potential of high efficiency water using and"time and space"regulated deficit new theory. It needs to study further.