Rating of Soil Texture for Maize in Bulgarian Land Evaluation System - Shortcomings and Improving Methods

Abstract

Land Evaluation System accepted in Bulgaria works with requirements of 22 major crops and maize is one of them. This system is not updated at the state level from 1988 onwards. With the advancement of scientific knowledge аnd change in terms of practical use require this to be done. Especially in the assessment of soil texture methods adopted have the following shortcomings: only evaluate fallow land (surface 30-36 ст); previously used to develop scales on which ratings are assigned at intervals and their limits are allowed unrealistic results (increases or reductions); natural water regimes, which is important for the situation the behavior of soil texture in determining the productivity of land are not recorded in connection.
In this study provides аn approach to overcome thе shortcomings listed - recalculation of soil texture for whole root space (an existing method, but little known in Bulgaria); developed regression equations for adequate assessments and their orientation at different conditions of natural water regimes. Everything stated concerns corn grown without irrigation.