Assessment of influence of fertilization quality on crop yield

Abstract

To study the dependence of crop yields on the quality of fertilizer application, the authors theoretically investigated the responsiveness of plants to increasing fertilizer doses and the distribution of the fertilizer dose over the field. We obtained a mathematical model of the dependence of yields on the dose and the quality of fertilizer application. It was revealed that the average dose and the unevenness of their distribution, which is characterized by the coefficient of variation, affect the yield of agricultural crops, and consequently the effectiveness of fertilizers. As unevenness increases, the responsiveness function transforms: the maximum possible yield decreases significantly, the maximums of the graphs shift towards smaller doses. The decrease in yield also depends significantly on the nature of the responsiveness functions. The greatest fall of this indicator should be expected with its parabolic change depending on the increasing doses of fertilizers applied. It has been proved that when applying 40 kg of active ingredient (ai) per 1 hectare and increasing the coefficient of dose variation from 0 to 60 percent, the yield reduction does not exceed 1 percent, at higher doses (120 kg ai per ha) it reaches 7 percent. It is established that the yield depends on the degree of uneven distribution of fertilizers, the fertilizer dose and the type of yield curves.