Soybeans absorb approximately 40 to 45% of their total N, P & K at the beginning of bean formation, when the vegetative plant parts have reached their maximum content. All of these nutrients go into the seed because the grain contains approximately 70% N, 75% P, and 55% K of all the nutrients absorbed.

During the first month of planting, daily nutrient uptakes are small – much less than 1 lb./acre/day. In the second and third month, the daily nutrient requirement can reach 8 lbs. Nitrogen, 0.40 lbs. Phosphorous, and 4 lbs. of Potash.

At soybean yields of 30 to 70 bushels/acre, 1/3 to1/2 (yields above this are proportionately higher) of the Nitrogen absorbed by the plant is in the form of nitrates and ammonium ions. Pre-plant Nitrogen is recommended depending upon soil analysis results. Phosphate and Potassium should be included with nitrogen soil applications. Since peak Nitrogen uptake corresponds with pod set and seed filling, supplemental Nitrogen is recommended during these stages of growth.

High levels of available Phosphorous are associated with high soybean yields. The greatest demand for Phosphorous is at mid-bloom and mid-pod set. Phosphorous is required for normal Nitrogen fixation. Average mineral recovery from fertilization under good conditions ranges from 10 to 20%. TPSL® has successful in increasing this percentage, especially in drip and pivot irrigation, by using adjuvants such as humic acid, sugars, beneficial soil bacteria and other things.

The SOIL TEST - Depending upon your soil’s chemistry, most nutrients can be rapidly “tied-up” into plant-unavailable (insoluble) compounds! It is only the plant-available nutrient compounds – available when the plants need them - that count! Most all other soil tests report at least some amount of those “tied-up / plant-unavailable” compounds, giving you a false sense of adequacy – even as your plants show obvious signs of distress and decline! This hopefully explains why your plants clearly show certain nutrient deficiencies, even though your soil test reports come back showing those nutrients as being adequate or high! All of this can be avoided!