Quantitative Study On Effective Accumulated Temperature,Growth And Development And Accumulation Of Nitrogen,Phosphorus And Potassium In Summer Maize

Prove the quantitative relationship between effective accumulated temperature and crop growth and nutrient accumulation under different nitrogen,phosphorus and potassium treatments,providing a theoretical basis for using effective accumulated temperature and other meteorological factors to establish a nutrient regulation mechanism of crop nutrition,and helping to achieve precise management of modern agricultural crops.In this paper,summer maize is used as the research object.On a fine time scale,the growth dynamic indexes（leaf age index,plant height,leaf area index and dry matter accumulation）and nutrient accumulation dynamics of summer maize under different nitrogen,phosphorus and potassium fertilization levels are studied.The difference of indicators（nitrogen accumulation,phosphorus accumulation,potassium accumulation）,and a dynamic model of summer maize growth indicators and nutrient accumulation based on effective accumulated temperature are simulated,and various characteristics of the equation under different fertilization levels are quantitatively analyzed The difference of the parameters,using the measured values to test the model,play a good role in predicting the growth and development of summer corn and the accumulation of nutrients.The main conclusions of the full text are as follows:1.When appropriate fertilization treatment is nitrogen fertilizer(N 180 kg·hm^-2),phosphate fertilizer(P₂O₅90 kg·hm^-2),potash fertilizer(K₂O 90 kg·hm^-2),with the increase of nitrogen,phosphorus,and potassium fertilization,the growth curve of summer maize plant height,leaf area,aerial dry matter accumulation and phosphorus and potassium accumulation showed a parabolic linear change,all based on appropriate fertilization treatment is the largest.The dry matter accumulation and nitrogen accumulation in ear of summer maize were still increased when excessive 50%nitrogen fertilizer compared with the appropriate amount of nitrogen fertilizer,but did not reach a significant difference.2.Under certain effective accumulated temperature conditions,the change trends of summer maize leaf age index,plant height and leaf area index are basically the same,showing a trend of slow increase in the early period,rapid growth in the middle period,and gradually stable in the later period.Using the Logistic model has better simulation results In terms of biological significance,the fit R²is above 0.98;the change trend of dry matter accumulation,nitrogen and phosphorus accumulation in ear and above ground is basically the same,showing a trend of slow increase in the early stage,rapid increase in the middle stage,and decelerated increase in the later stage.,The use of Gompertz model has better simulation effect and biological significance,and the fitting degree R²is above 0.97;the inter-annual potassium accumulation law is quite different compared with nitrogen and phosphorus,and the early stage still follows the S-shaped curve change,But the total accumulation in the later period has decreased.Generally speaking,the logistic model has a better simulation effect for the potassium accumulation of summer maize,and the fit R²is above 0.96.3.The growth rates of growth and nutrient accumulation indexes of summer maize under different nitrogen,phosphorus and potassium fertilization levels all showed a"single peak curve".The growth rate of summer maize growth and nutrient accumulation is closely related to the size and nutritional conditions.The performance between treatments is:under the condition of appropriate fertilization,the growth rate curve of each index shows the characteristics of rapid increase and decrease,excessive fertilization treatment And the growth rate curve of weight loss treatment shows the characteristics of slow rise and slow decline.4.The range of effective accumulated temperature during the rapid increase in nutrient accumulation period of summer corn after sowing is:nitrogen（482.31～1489.98°C·d）,phosphorus（531.28～1723.88°C·d）,potassium（597.41～971.45°C·d）,and nutrients after sowing The accumulated temperature required for the maximum rate of accumulation is:phosphorus（1127.58°C·d）>nitrogen（986.15°C·d）>potassium（784.43°C·d）.Compared with the appropriate treatment with no fertilization,the growth and development indicators and nutrient accumulation indicators of summer corn reach the required accumulated temperature during the critical period（accumulated temperature required to enter the rapid increase period,accumulated temperature required to enter the slow increase period,and accumulated temperature required for the maximum growth rate）Significant increase,the critical period growth rate（maximum growth rate,average growth rate during the rapid growth period）is significantly reduced.The effects of different nitrogen,phosphorus and potassium fertilization on crops can be quantitatively characterized by growth and development parameters and nutrient parameters.The effective accumulated temperature can be used to simulate the gradual increase period,rapid increase period and slow increase period of summer maize growth and nutrient accumulation under different nitrogen,phosphorus and potassium fertilization levels.It can be used to predict crop condition,the optimal fertilization period and has strong application value.