T. Tóth. 2007. Effect of some soil properties on the yield of winter wheat and maize in the salt-affected and chernozem soils
(in Hungarian). Földminősítés, földértékelés és földhasználati információ / Soil quality, land valuation and landuse information
(in Hungarian). Keszthely – Budapest. pp. 83-90. ISBN 978 96387616 3 7.

Abstract

Since soil is the basic factor of agronomy it is of overwhelming importance to quantify the relationship between soil and crop yield.
Despite several approaches there are still disputes on the definition and real meaning of „soil fertility”. Our basic question was whether
the extreme values of less fertile soils (salt-affected soils) do affect the crop yield more than in the case of more fertile soils (Chernozems)?
A new theoretical model was developed to describe the conceptual frame of crop yield, in which there are numerous closely related
physical/chemical/biological (sub)systems, such as soil water regime, acidity-alkalinity system, nutrient providing systems, etc.
In the theory a basic statement is, that in the less fertile soils the complexity of the network of systems, being responsible for crop
yield is less than in a more fertile soil. A consequence of this is, that if special soil properties related to some of the systems have
extreme values, these will affect the crop yield greatly. This means that not only the crop yield will be smaller in a less fertile soil,
but also the extremes have much greater effect on the crop yield. This effect must be present also in the statistical relationship
between the particular soil properties and crop yield as well. On the bell-shaped curve there will be differences in the height, width
and slope between a less and more fertile soils. In the case of maize and winter wheat the relationship between particular soil
properties and crop yield was analyzed on a less fertile (Solonetz) and more fertile (Chernozem) soil based on the Hungarian Crop
Data Set (AIIR). The statistical analysis of the data showed that the theory is promising for the description of the relationship between
soil properties and crop yield.