Effects Of Water And Nitrogen Coupling On Physiological Characteristics And Yield Of Oats

Oat is affected by many factors in the growth process,of which water and nitrogen fertilizer play a vital role.In this test,two oat varieties of Baiyan 2 and Baiyan 7 were selected according to the sensitivity of water and fertilizer of different oat varieties and their barren tolerance.The effects of different water and nitrogen conditions on oat growth,physiological,photosynthetic and yield were studied.The result is as follows:1.With the increase of nitrogen application and irrigation,the growth indexes of plant height,leaf area,stem thickness,main root length and root weight of oats all showed a gradually increasing trend;The root-shoot ratio is the opposite,showing a gradual decline.The indicators of the two varieties are based on high water and nitrogen(W1N3)as the maximum value.With the growth and development process,the oat growth index reached the maximum at the heading stage,and the growth index of each treatment of Baiyan 2 was greater than that of Baiyan 7 in the three periods.2.Under the same irrigation conditions,as the amount of nitrogen application increased,the physiological indexes of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),malondialdehyde(MDA),soluble sugar and soluble protein in oat leaves are gradually showing Declining trend.When the amount of nitrogen was the same,the physiological indicators of oats were: W2> W1.3.Under normal water treatment(W1),net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),and intercellular carbon dioxide concentration(Ci)and other photosynthetic indicators are higher than that of drought treatment(W2),under the condition of W2,different nitrogen treatments showed that W2N3> W2N2> W2N1.It can be known that nitrogen application under drought conditions can effectively promote photosynthesis of plants to produce organic matter and increase yield.Pn,Tr,Gs,and Ci all reached their maximum at high water and nitrogen(W1N3).With the growth period advancing,chlorophyll content and relativewater content of leaves showed a trend of increasing first and then decreasing.The water use efficiency(WUE)reached the lowest value during the jointing stage,and the water use efficiency under drought conditions was higher than the normal water conditions.4.With the increase of nitrogen application and irrigation,the spike length,spikelet number,spikelet weight,spikelet number and thousand-grain weight of oats showed an upward trend.Oat yield peaked under W1N3 treatment.5.The correlation analysis results of oat physiological indicators and yield showed that SOD,POD and soluble protein were significantly negatively correlated with yield,and CAT and soluble sugar were significantly negatively correlated with yield;The correlation analysis results of oat growth index and yield showed that leaf area and stem thick ears were significantly correlated with yield,and root-shoot ratio was extremely significant correlated.In summary,this study concluded that W1N3 was the optimal treatment,and the yield of oats reached the highest under W1N3 treatment conditions.For two oat varieties,Baiyan 2 had better barren tolerance than Baiyan 7 and had higher yield.