Study Of The Available Nutrient Use Efficiency Of Phosphorus And Potassium In Red Soil, Fluvo-aquic Soil And Black Soil

In this experiment, three common soil types were selected for study. We studiedthe growth of maize by means of laboratory analysis of soil phosphorus and potassiumfixation situation, together with pot experiment of maize under different phosphorusand potassium application levels. Then, we calculated the available nutrient useefficiency under different fertilizer application and soil types according to thenumber of soil available phosphorus and available potassium, as well as theaccumulation of phosphorus and potassium of maize. Equations of soil availablenutrient use efficiency under different fertilizer application and soil types weresimulated. And the results are as follows:1. Fixation abilities to soil phosphorus and potassium are different as fordifferent soils. Red soil has the highest fixation ability to phosphorus whilefluvo-aquic soil has the lowest. Black soil has the highest fixation ability topotassium while red soil has the lowest. Black soil fixes more cooper than red soiland fluvo-aquic soil does. Fluvo-aquic soil and black soil have more fixation abilityto manganese than red soil does. Three soils have the similar fixation ability tozinc.2. Phosphorus affects the growth of maize. The biomass of maize increases with theincrease of fertilizer phosphorus under the lower phosphorus condition. Morephosphorus application does not always increase the biomass of maize. There are nosignificant differences for biomass of maize under the same phosphorus applicationlevels for three soils in the first harvest. But the biomass of maize planted in redsoil is significantly lower than that is planted in Fluvo-aquic soil, and the biomassof maize planted in black soil is in the middle in the second harvest. Total biomassesof maize planted in three soils have no significant differences. We find out thatPotassium has significant effect on maize biomass. With the increase of fertilizerpotassium application, the biomass of maize planted in three soils all increase.However, total biomasses for maize planted in three soils have no significantdifference.3. Accumulation of phosphorus for maize in the first harvest is similar to thesituation of yield change. Accumulation of phosphorus for maize in the second harvestincreases to the highest at the very beginning, and then decreases. Total phosphorusaccumulation has no difference under all treatments except that no fertilizerphosphorus is provided for maize planted in red soil. Also, there are no significantdifferences of phosphorus accumulation for maize planted in Fluvo-aquic soil underall treatments. Application of phosphorus to black soil has the tendency to increasethe accumulation of phosphorus to maize, but the difference is not significant. Totalphosphorus accumulations for maize planted in these three soils have no significantdifferences. With the increase of fertilizer potassium, the yield of maize planted in three soils also increases. And total potassium accumulations for three soils haveno significant difference.4. Three soils have higher phosphorus use efficiency when no fertilizer phosphorusis used. With the increase of fertilizer phosphorus application, the nutrient useefficiency of all soils all decreases. The nutrient use efficiency of phosphorus for Fluvo-aquic soilis higher than that of black soil while the latter is higher than that of red soil. In condition of lowerfertilizer potassium application, the nutrient use efficiency of potassium increases with the increaseof fertilizer potassium application for maize in the first harvest. With the increase of fertilizerpotassium application, the nutrient use efficiency decreases. We observe that nutrient use efficiencyof potassium after two harvests decreases with more potassium application to three soils. Nutrientuse efficiency of potassium for black soil is higher than red soil while Fluvo-aquic soil has thelowest efficiency.Soil available nutrient use efficiency of phosphorus has index relations with the levels of fertilizerphosphorus application, and the two things have significant correlations with each other. Soilavailable nutrient use efficiency of potassium has polynomial relations with the levels of fertilizerpotassium application, and the correlation between Fluvo-aquic soil and its formula is alsosignificant.