Theses and Dissertations

Issuing Body

Mississippi State University


Xiaofei Li

Committee Member

Ardian Harri

Committee Member

Brian Mills

Committee Member

William Maples

Date of Degree


Original embargo terms

Complete embargo for 2 years

Document Type

Graduate Thesis - Open Access


Agricultural Economics

Degree Name

Master of Science (M.S.)


College of Agriculture and Life Sciences


Department of Agricultural Economics


This study estimated soybean yield responses to K fertilizer using trials data from 18 sites in Mississippi from 2011-2016. Eight response functions were fitted, including linear, linear plateau, quadratic, quadratic-plateau, square root quadratic, spherical plateau, exponential, and exponential-plateau functions. The ratio of high responsive, low responsive, and no responsive sites to K rates is 3:3:12 respectively. The response functions led to different predicted optimal K rates, and the best response function for each site was determined by the Vuong closeness test and economic loss analysis. The predicted economically optimal K rates are 157, 73, and 0 lb/acre for high, low, and no response sites respectively, and the average optimal K rate is 55 lb/acre. Compared to the currently used regional uniform K fertilizer rate of 80 lb/acre, the response-based K rates are expected to generate soybean production gain of about $14 per acre for Mississippi soybean producers.

Available for download on Tuesday, August 15, 2023