P & K Application Following Cover Crops in Mississippi Soybeans
Applied Research
Bill Burdine
Agronomy Specialist
Mississippi State University
Verona
Abstract
Mississippi producers spend over $280 million annually on fertilizer and costs continue to rise. Cost of inorganic fertilizers makes improving nutrient efficiency a top priority in row crop production. Using cover crops to improve nutrient availability to subsequent cash crops has been suggested by numerous researchers (Calegari et al., 2013; Borkert et al., 2003) however data specific to Mississippi is lacking. The effects of cover crops on P2O5 and K2O availability in Mississippi soybean systems is lacking. A study conducted across Mississippi determined soybean yields could be increased up to 8 bushels/acre with the addition of P2O5 or K2O when nutrient values were insufficient per soil analysis. This factorial arranged, randomized block designed study was to determine if A) cover crop systems would improve nutrient availability and soybean yield and B) if fall applied P2O5 and K2O would increase yield. A significant interaction was seen between years. In 2021, soybean yield increased when cover crops were used but in 2022, cover crops decreased yield (2022 suffered from extreme drought). In 2021 and 2022, fall-applied P fertilizer increased soybean yield in no-cover and radish treatments while yields decreased in cereal rye. In 2021, fall-applied K increased yield in crimson clover only, whereas in 2022, fall-applied K increased soybean yields in all cover crop treatments. Cereal grains are believed to be beneficial to soybean production, however, it may take multiple years before benefits begin to be realized. Further study is needed to quantify years of cover cropping before yields increase. Additional study is also needed to determine how soil moisture affects nutrient availability in cover crop situations.
Poster has NOT been presented at any previous NACAA AM/PIC
This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.
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Authors: Bill Burdine
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Burdine, B. Agronomy Specialist, Mississippi State University, Mississippi, 38879