UBC Theses and Dissertations
A method for developing soil management units Zweck von Zweckenburg, Elizabeth Maria Erna
The purpose of the present study was to develop a quantitative methodology to define optimum land use systems. Soil survey data were assessed for capability, suitability and feasibility uses to establish interpretative soil units for which planning and management recommendations could be made. The study was agriculturally oriented due to the availability of agricultural productivity data for suitability assessments from four sources: farmer survey, direct estimate by expert consensus, research station data and plot trials-Soils were grouped using cluster analysis on the basis of permanent inherent soil properties. The technique did not group the soils satisfactorily for management purposes due to statistical limitations of the procedure in assessing overlapping and interdependent variables, such as soil characteristics, and restrictions imposed by the soils data set which was neither adequately large nor diverse to form multimember soil groups. Stepwise discriminant analysis was more successful in assessing the interpretative soils data and in identifying discriminant soil parameters. The Canada Land Inventory derived capability classes were separated by drainage, the quantitatively defined suitability classes were separated by parent material and the socioeconomically defined feasibility groups were separated by pH and coarse fraction. Comparison of the interpretative soils classifications revealed that the capability ratings overestimated actual measured yield and that current land use did not realize the full agricultural potential of the land. Feasibility, unlike capability and suitability, stressed parameters other than soil properties in land evaluation. The suitability assessment based upon actual observed productivity data measured under real market conditions was recommended as the most quantitative land evaluation approach. Other soils can be added to the open ended system and optimal use can be made of all soils using guidelines developed by key farmers under real market conditions for soils suitability groups.
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