Effects Of Water And Fertilizer On Morphological Characteristics,Physiological Process And Yield Components Of Winter Wheat

Cultivation and fertilization are important factors affecting the increase of crop yield.Because of the unreasonable tillage method and fertilizer application,the problems of soil compaction,shallow tillage layer and low utilization rate of soil water and fertilizer are caused.To solve the above problems,two factors(tillage depth and fertilizer type),three levels(tillage depth:20 cm(D20),25 cm(D25),30 cm(D30),fertilizer types: application of slow-release fertilizer(W1),application of slow-release fertilizer and water-retaining agent and calcium ammonium sulfate(W2),application of water-retaining agent and calcium sulfate(W3))were set up through field experiments.The effects of tillage depth and fertilizer species on soil physical and chemical properties,soil water-salt migration and distribution,maize growth,water consumption and yield were studied in order to find out reasonable tillage depth and fertilization methods,and to provide theoretical basis for water and fertilizer conditioning,improving physical and chemical properties and increasing maize yield.The main conclusions of this study are as follows:(1)The depth of the tilling layer and the type of fertilizer have an effect on soil water content and soil water storage consumption.the variation trend of soil water content in different treatments on the profile is basically consistent.The influence of tillage depth on the water content of 0-100 cm soil layer is large in the early stage of growth,and there is no obvious law in the later stage.The water content of 0-100 cm soil layer treated by D25 and D30 is larger than that of D20 treatment,breaking the plough bottom layer and expanding the soil reservoir capacity.The water consumption of different treatments increased first and then decreased with the growth period.The consumption of soil water storage during the whole growth period of D25 treatment is larger than that of other treatment;the consumption of soil water storage in W2 treatment is larger than that of other treatment,and the ability of soil water storage and soil moisture conservation is enhanced by breaking part of plough bottom layer and three kinds of fertilizer mixed application.(2)The depth of the tilling layer and the type of fertilizer have effects on the soil bulk density,field water holding capacity and saturated water content.The bulk density of each treated soil increased first and then decreased as the soil layer deepened.The deeper the tillage depth,the more can affect the soil bulk density,the soil bulk density treated D30 the whole growth period is smaller than other treatments;the influence of fertilizer types on the soil bulk density of 0-30 cm is larger in the early stage of growth period,the soil bulk density treated W2 the whole growth period is smaller than other treatments,and the effect of mixed application of three fertilizers on loose soil is better.The water-holding capacity and saturated water content of each treatment decreased first and then increased.Under the same fertilizer type,D25 treatment increased the field water holding capacity and saturated water content;under the same tillage layer depth,W2 treatment increased the field water holding capacity and saturated water content,and the tillage layer depth 25 cm and 3 kinds of fertilizer mixed application improved the soil pore condition,thus effectively increased the field water holding capacity and saturated water content.(3)The depth of the tilling layer and the type of fertilizer have effects on total nitrogen,total potassium,total phosphorus content and nitrate nitrogen accumulation.The contents of total nitrogen,total potassium and total phosphorus in each treated soil are basically consistent in the section,and the whole content decreases with the increase of soil depth.the depth of tillage layer is different,and the nutrient is different with water migration,but the total nitrogen,total potassium and total phosphorus content of the whole D25 treatment is higher than that of other treatment cm.at the same tillage layer depth,the total nitrogen,total potassium and total phosphorus content of the W2 treated soil layer is larger than that of other treatments,and the mixed application of three fertilizers reduces nutrient leaching and loss.The distribution trend of nitrate nitrogen accumulation in each treated soil was consistent.the nitrate accumulation was different between different treatments,D25 the nitrate accumulation was less than other treatments,D25 treatment made nitrate nitrogen more easily to the deep soil leaching,and the root system ligation was deeper,which was beneficial to root absorption,but D30 treatment caused nitrate leaching to below 80 cm,and the root system was difficult to absorb and utilize;the nitrate accumulation of W2 treatment was less than other treatment,and the mixed application of three fertilizers improved the condition of nitrate absorption and utilization.(4)The depth of the tilling layer and the type of fertilizer have significant effects on both physiological and biological indicators of maize.The change trend of net photosynthetic rate,transpiration rate and stomatal conductance of each treatment was the same in growth period.the net photosynthetic rate,transpiration rate and stomatal conductance were significantly increased by D25 treatment under the same fertilizer species,and the net photosynthetic rate,transpiration rate and stomatal conductance were significantly increased by W2 treatment during the whole growth period at the same tillage layer depth.The plant height and stem thickness of D25 treatment were higher than those of other treatment,and the W2 treatment had higher plant height and stem thickness than those of other treatment.(5)The depth of the tilling layer and the type of fertilizer have a significant effect on the yield and water use efficiency of maize.Under the same fertilizer species,the yield of D25 treatment increased by 14.1% and 12.8% compared with that of D20 and D30 treatment,respectively,and the water use efficiency of D25 treatment was higher than that of other treatments and the difference was significant.At the same tillage layer depth,the yield of W2 treatment was significantly larger than that of other treatments,with an increase of 7.0% to 9.0%;the water use efficiency of W2 treatment was significantly larger than that of other treatments.