Effects Of Water And Nitrogen Coupling Study On Physiological Characteristics And Yield Of Winter Wheat And Summer Maize

Field experiment was conducted during 2008-2009, the effects of water and nitrogen coupling on physiological characteristics and yield of winter wheat and summer maize were studied in order to provide the framework for reasonable irrigation and fertilization, based on 2-3 years location study.1.The chlorophyll content of maize leaves showed an increasing trend with nitrogen amount when it was irrigated one time. Under the three times irrigation condingtions, the highest chlorophyll content appeared in nitrogen amount of 480kg/ha. The irrigation treatments for the chlorophyll content of maize leaves showed no significant difference under the same nitrogen amount and it showed no significant difference when it was more than 240kg/ha. The chlorophyll content of wheat leaves indicated an increasing trend with nitrogen amount under the one time irrigation condition. The highest clorophyll content of wheat leaves appeared in nitrogen amount of 480kg/ha under three times irrigation. The chlorophyll content of wheat leaves was remakably improved by the anthesis irrigation under the same nitrogen amount. The anthesis irrigation can extent the function of wheat leaves. Water and nitrogen coupling was the best under the three times irrigation and nitrogen amont of 480kg/ha.2. Under the same nitrogen amount SOD activity and POD activity of maize leaves were remarkably decreased by the anthesis irrigation of maize. Under one time irrigation the highest SOD activity and POD activity appeared in nitrogen amount of 480kg/ha. Under three times irrigation the highest SOD activity and POD activity of maize leaves appeared in nitrogen amount of 240kg/ha. SOD activity and POD activity of maize leaves decreased when the nitrogen was too much and the soil with high water content. SOD activity and POD activity of wheat leaves were remarkably improved by the anthesis irrigation of wheat under the same nitrogen amount. Under two irrigation treatments condition SOD activity and POD activity of wheat leaves increased between nitrogen amount 0-240kg/ha and there were no significent diffirence between nitrogen amount 240-600kg/ha. Water and nitrogen coupling was the best under three times irrigation and nitrogen amount of 240kg/ha.3.There were no significant difference on Fv/Fm andФPSII of maize leaves under two irrigation treatments. The highest Fv/Fm andФPSII of maize leaves appeared in nitrogen amount of 480kg/ha and it showd significant difference than no nitrogen control. Pn of wheat leaves showed no significant difference with nitrogen amount under one irrigation time. Under three irrigation times conditions there was significant difference in Pn between control and different nitrogen treatment. There were no significant difference exist between treatments when the nitrogen amount more than 240kg/ha. Pn of the wheat leaves was remakebly improved by the anthesis irrigation under the same nitrogen amount.Water and nitrogen coupling was the best when it was irrigated three times and fertilized 480kg/ha.4.Total phosphorus content in stalk and grain of maize was decreased with nitrogen treatments while it was increased under no fertilized control when anthesis irrigation was applied. The highest total phosphorus content in stalk and grain of maize appeared at three times irrigation and no fertilizer control. There were no significant difference in total phosphorus content of grain between the nitrogen treatments, while in stalk it was lower in control than other nitrogen treatments under irrigation one time. Total phosphorus content in stalk and grain of wheat showed a decreasing trend with nitrogen amount in both one time and three times with nitrogen amount between 0-480 kg/ha. Total phosphorus content was decreased in stalk of wheat while in grain there was no significant difference when it was irrigated under the same nitrogen treatments.5. Total nitrogen content was increased in stalk of maize while it was decreased in grain by the anthesis irrigation under the same nitrogen amount. Total nitrogen content in stalk of maize showed an increasing trend with nitrogen amount under the two irrigation treatments. Total nitrogen content in grain peaked at nitrogen amount of 600kg/ha under one time irrigation, while it peaked at nitrogen amount of 240kg/ha under three times irrigation .Total nitrogen content in stalk of wheat showded an increasing trend with nitrogen amount when it was irrigated one time in winter wheat. Total nitrogen content in stalk of wheat peaked at 480kg/ha under three times irrigation condition. Total nitrogen content in grain of wheat showed an increasing trend between nitrogen amount of 0-240kg/ha and there was no significant difference when nitrogen amount more than 240kg/ha under one time irrigation condition.Total nitrogen content in grain of wheat showed an increasing trend with nitrogen aount under three times irrigation.Total nitrogen content in grain of wheat was decreased by the anthesis irrigtion under the same nitrogen amount.6. Total nitrogen absorption of maize and wheat were decreased by the anthesis irrigation under the same nitrogen amount. They showed an inceased trend with nitrogen amount under the same irrigation condition, but there were no significant difference when the nitrogen amount more than 240kg/ha.7. The NRA, content of soluble protein of the flag leaves and grain yield were remakably improved by the anthesis irrigation under the same nitrogen amount. The NRA and the content of soluble protein showed an increasing trend with nitrogen amount, when it was irrigated one time in winter wheat. Under the two times irrigatation conditions with appropriate moisture content, NRA and the content of soluble protein were all showed a parabola type with the highest NRA and the content of soluble protein appeared in nitrogen amount of 240kg/ha and 480kg/ha, respectively, and decreased when too much nitrogen applied. It had the highest yield when it was irrigated two times and fertilized 480kg/ha in the whole year. The result indicated that increasing irrigation showed a good effect on nitrogen effectiveness in high-yielding wheat production.8.The kernel filling process could be described with Logistic equations. Maize grain weight was showed a parabola type with nitrogen amount, the anthesis irrigation of summer maize decreased grain weight under high nitrogen amount. Winter wheat grain weight decreased as nitrogen amount increased, the anthesis irrigation of winter wheat improved grain weight remarkly. The mean grain fillling rate and the grain filling time were positive correlation for grain weight, but was negative correlation remarkly between the mean grain fillling rate and the grain filling time(R=-0.9667). Summer maize had the highest yield when it irrigated one time and fertilized 480kg/ha. Winter wheat had the highest yield when it irrigated three times and fertilized 480kg/ha.