Ability of Mitscherlich-Spillman Model to Estimate Critical Soil Phosphate Levels

Abstract

Abstract:More than 150 years research groups from different countries have been studying the effect of various factors on the productivity of the plants described by so-called productivity functions (PF). Interest to PF stems from the needs of economists, agronomists, agricultural chemists and environmentalists who use the PF modeling as a basis for solving their problems. The article describes development of models of productivity for agricultural chemistry and approaches to its calibration. The phenomenon of quasi-linearity (R 2 > 0.998) of Mitscherlich-Von Boguslawski functions within the range of 30 to 90% efficiency after logarithmic transformation of the argument and practical applications of the method were considered. The limitations were considered in the use of recommendations in relation to the properties of the scale of the studied factors. The approach proposed is applicable to only the values belonging to an absolute scale (ratio scale). The analysis of the possibility and feasibility to assess the so called critical levels of mobile phosphates was made using modeling with recently published Rothamsted long-term experimental data.