Effects Of Waterlogging Stress On Physicochemical Properties And Maize Nutrient Absorption And Distribution In Different Soil Types

In this paper,the lime concretion black soil and fluvo-aquic soil was conducted to study the changes of soil physicochemical properties and nutrient distribution under waterlogging stress,the influence of waterlogging stress on soil nitrate nitrogen leaching,nutrient uptake and distribution and nitrogen utilization efficiency of maize by a pool and soil column experiments.The main results were showed as follows:1.Waterlogging stress led to soil redox potential and oxygen diffusion rate decreased,the totalsoilreducing substances and active reducing substances content increased,waterlogging 1~5d soil redox potential and oxygen diffusion rate were reduced by 2.36%~56.30% and 5.37%~44.42%,the total reducing substances and activity was increased to 15.21%~329.79% and 3.57%~20.31%,two soiltypes with reducing substance accumulation and the redox potential decreased in lime concretion black soil was greater than fluvo-aquicsoil,but the oxygen diffusion rate decreased in fluvo-aquic soil was greater than lime concretion black soil.Waterlogging stress caused available N content decreasing significantly in two soil types,and more decreasing with longer waterlogging.The content of available P in two soil types showed an inverted parabolic variation with longer waterlogging.The available K content was a rising trend in two soil types with longer waterlogging in general.In two soiltypes,the decline of soil available nitrogen in fluvo-aquic soil was greater than that in lime concretion black soil,and the variation of available P and available K was greater than that in fluvo-aquic soil.2.Waterlogging stress caused the accumulation of N,P and K in maize decreasing,and more decreasing with the increase of waterlogging time,waterlogging 1~5d the accumulation of N,P and K was decreasing respectively by 24.97%~78.40%,22.00%~60.36% and 11.71%~57.17%.The nutrient accumulation of leaves and stems was reduced,the proportion of nutrients in leaves was reduced by 1.03%~22.26%,but the proportion of nutrients in stems was increased by 1.34%~64.42% under waterlogging stress.In two soil types,the decreasing in lime concretionblack soil was greater than that in fluvo-aquicsoil under waterlogging stress,and the N,P,K decreased respectively by 52.12%,40.88% and 37.32% in average.3.Initial waterlogging stress resulted in the increase of nitrogen leaching ability and nitrate leaching loss rise smartly in the two soiltypes,and waterlogging continued to decline,the treatment room was T1>T2>T3>CK.At maize seeding the nitrogen fertilizer use efficiency and nitrogen accumulation decreasedwiththe waterlogging time,waterlogging 1~5dboth of them decreased by 36.54%-70.23% and 29.79%-75.05% individually.In two soil types,nitrogen fertilizer leaching ability and nitrate nitrogen leaching loss in fluvo-aquic soil was significantly higher than that of lime concretion black soil,but the drop of nitrogen fertilizer use efficiency and nitrogen accumulation in lime concretion black soil is greater.Waterlogging changed the distribution proportion of different sources of nitrogen,nitrogen fertilizer supply increased,the proportion of soil nitrogen supply decreased,but soil nitrogen supply ratio is still above 73.73%.Under waterlogging stress,the proportion of nitrogen fertilizer in fluvo-aquic soil was greater than that in lime concretion black soil,,the nitrogen leaching loss and nitrogen fertilizer use efficiency of fluvo-aquic was higher intwo soil types.4.Waterlogging reducedmaize dry matter accumulation and yield significantly,and more decreasing with the increase of waterlogging time,waterlogging 1~5d the dry matter accumulation of maize seedling stage,silking stage,mature periodand yield were reduced by 11.45%~55.39%,15.36%~53.49%,14.45%~55.77% and 9.05%~30.15%.Waterlogging stress led to the barren ear tip of maize increased by 51.92%~207.54%,grain number and 100 grain weight were reduced by 2.07%~8.18% and 7.05%~20.41%.In different soil types,the drop of dry matter accumulation,corn yield,grain number and 100 grain weight in lime concretion black soil was greater than that in fluvo-aquic soil.