soil test values | Ag Data Commons

Improved Tropical Forage Fertilizer-P Calibration: In support of FRST to conduct state-level soil-fertility correlation and calibration trials for P and/or K

There is a need to validate current soil test critical levels as well as carry out calibration studies (crop response to fertilizer P at varying soil test levels). We report on a calibration experiment using an improved tropical forage, Brachiaria decumbens in a soil with soil test P in the Low category.

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Legacy Phosphorus and Potassium Correlation Experiments: Qulin, Missouri

Correlation experiments for P and K were conducted from 1968-1973 at a research farm in Qulin, Missouri to better define the relationships between soil tests, crop yields, and fertilizer treatments. Three crop rotations each were conducted for P and K trials (ranges C, D, E, F, G, and H), and included corn, soybean, wheat, cotton, and sorghum.

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Alfalfa Response to Potassium Rate and Timing of Application

Alfalfa production is a key component of livestock production in Tennessee. Alfalfa has the ability to take up luxury amounts of potassium, which can lead to high plant tissue K concentrations and lower concentrations of other nutrients. The objectives of this research were to determine 1) whether Tennessee K recommendations for alfalfa were sufficient and accurate, and 2) if splitting K applications impacted alfalfa yield.

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