Study On Effects Of Regulated Deficit Irrigation On Physiological, Ecological Characteristics, Yield And Quality Of Soybean

As a new irrigation theory, regulated deficit irrigation (RDI) was different from traditional irrigation ones. According to genetic and ecological characteristic of crops, deficit water supply at a certain extent could be imposed on them in a proper stage, and they would increase the Water Use Efficiency (WUE) through improving themselves. It also could regulate the ratio between nutrient organs and procreation organs, and increased their economic values.Heilongjiang province had been authorized by agricultural ministry to become a example for the plan to improve soybean production, and pushed large-scale territorial planting for single variety. But the yield and quality of soybean in Heilongjiang province were affected by odds of precipitation in time and space and frequent drought in spring or summer, and difficult to cope with others in drastic market competition. This experiment had studied on the effect of stage, intensity and measure of RDI on soybean by controlling irrigation, and occurrence, effect rules of compensative effects to offer academic arguments for making use of water reasonably and improving quality of soybean. The experiment drawed conclusions as follows:1 Effect of Regulated Deficit Irrigation on growing indexes of soybean. (1)On plant height: Moderate water stress treatments declined the plant height of soybean significantly in seedling stage and blooming stage. The plant height of soybean grew quickly after resuming water supply. When moderate and high water stress treatments restarted water supply, day increasement of theirs are more than that of light water stress treatments. (2)On root/shoot ratios: Water stress treatments in seedlings and blooming stage increased the root/shoot ratio of soybean, but change of root/shoot ratio of soybean in pod-filling stage increased firstly, and then decreased. (3)On dry matter: Water stress treatments declined the dry matter of soybean significantly. Day increasement of the dry matter and pod weight were more than that of check treatment after resuming normal irrigation, which showed compensative effects. Water stress treatments in pod-filling stage deferred the growing period of dry matter.2 Effect of Regulated Deficit Irrigation on physiological indexes of soybean. (1)On root vitality: The treatments of Regulated Deficit Irrigation had strong effect on root vitality of soybean. The root vitality of soybean increased with augment of intensity of water stress treatments. The declining rate of root vitality for check treatment was higher than that of water stress treatments. (2)On chlorophyll: Prolonging time and augment of intensity for water stress increased chlorophyll content of soybean. Chlorophyll content of soybean tended to decline after resuming water supply, but it showed no difference significantly comparison with check treatment.3 Effect of Regulated Deficit Irrigation on yield of soybean: The water stress treatments in seedling stage and flowering stage had no obvious effect on yield of soybean. The yields of light treatment of Dongnong42 in pod-filling stage and of Dongnong163 in flowering stage were higher than that of check treatment.4 Effect of Regulated Deficit Irrigation on quality of soybean: The treatments of Regulated Deficit Irrigation increased the fat content of Dongnong42 and protein content of Dongnong163 significantly, but had no significant effect on protein content of Dongnong42 and fat content of Dongnong163. ...