Prediction accuracy evaluation of five soil test methods

Author

William D. Bishop

Date of Award

6-1954

Degree Type

Thesis

Degree Name

Master of Science

Major

Agronomy

Major Professor

Eric Winters

Committee Members

L. N. Skold

Abstract

How much fertilizer should farmers use to produce economical crop yields? Crop response to fertilization is one of the important factors to be considered in arriving at the answer. Farmers look to agricultural scientists to supply this information. The expense and the time of running field experiments make it desirable to employ other less expensive and less time-consuming methods for predicting crop response to fertilizer applications. To supplement field fertilizer experiments, scientists have developed rapid chemical tests for the purpose of supplying farmers needed information about the fertility levels of their soils. The chemical tests are used to predict crop responses on soil not studied.

Many different laboratory tests have been developed in this and other countries. Every state in the United States and many foreign countries are using one or more of these methods in a soil testing program. The University of Tennessee Agricultural Extension Service initiated a state-wide soil testing service in 1944. The central laboratory was located in Nashville, Tennessee. Farmers are using the service at an increasing rate each year. During March 1954, 24,005 soil samples were analyzed for pH, available phosphate, and available potash as compared to 5,251 during March of 1953. Specific lime and fertilizer recommendations are made for crops to be grown on the field from which each soil sample was taken.

The information supplied by these rapid laboratory tests is no better than the correlation between results from field experiments and the soil testing methods used. When one considers the number of farmers using this service and the amount spent for lime and fertilizer by these farmers, it is apparent that the soil testing methods used should be as reliable as possible. The purpose of this investigation is to determine the extent to which crop response to fertilization correlates with different levels of soil phosphorus and potassium as determined by the various soil test methods and to select the most reliable method for Tennessee conditions.

Recommended Citation

Bishop, William D., "Prediction accuracy evaluation of five soil test methods. " Master's Thesis, University of Tennessee, 1954.
https://trace.tennessee.edu/utk_gradthes/8994