A multiparametric model for predicting the draught of two model plough bodies in four different soils

Investigations were carried out in order to determine relationships between soil parameters and draught of model plough bodies. Four kinds of soils were used: two natural soils and two mixtures of natural components. Using the power model of multiple regression, based on dimensionless variables, for each soil the predictive equation was obtained, containing the coefficients of horizontal and vertical soil compaction by a plunger, soil bulk density, soil moisture content and scale coefficient of the implement. For each equation a determination coefficient > 50% was obtained. On this basis the generalized predictive equation for four soils was obtained, introducing additionally both organic matter content and silt content (< 0.02 mm) as parameters differentiating particular kinds of soil. In this equation the coefficient of horizontal compaction was introduced as the only soil parameter measured by penetrometer, while all other parameters were soil physical properties, measured by standard methods. For field conditions and full scale plough bodies a hypothetical nomogram was constructed. To prove its validity additional investigations should be conducted.