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Influence of soil pH on cotton morphology, lint yield and lint quality

Sharry, Raedan Lane
The influence of commodity prices has led to an increase in cotton production in Oklahoma over the past decade. With this increase in production there has been growing interest in growing cotton in fields that have been traditionally managed for winter wheat production. The soils are sometimes found to be acidic, largely due to previous production practices, specifically, over application of nitrogen fertilizers. This study was conducted to evaluate the influence of soil acidity on cotton physiological growth and yield. The study took place at Perkins, OK and Stillwater, OK (EFAW Farm). Yield was evaluated using relative yield across a soil pH range of 4.0-8.0. Soil pH was altered utilizing aluminum sulfate and hydrated lime. Two cultivars, Nexgen 3930 and Deltapine 1612 were used at all locations. Soil acidity negatively affected cotton growth and yield. Relative yield was estimated to reach critical threshold at a soil pH of 5.4 while morphological measurements produced similar results. KCl extractable Al was also measured and relative yield was observed to be negatively correlated with Al. This study also conducted an evaluation of net present value of lime application as a function of soil pH, cost of lime application, lint value, lint yield goal, and location. Amelioration of soil acidity may be required to maximize profitability of cotton production in some conditions.