Pro Ag Supply

Building soil P is expensive. The math and the field don’t agree. Just jumped in the combine helping the family farm . Bean yields around here have been pretty good. Can’t speak for everybody, but overall solid. Quality’s a little off. I was listening to a video saying phosphorus needs to be 50 ppm, preferably 100. We just finished a field that made over 60. Around here most APHs are 43 to 45. Mother Nature gets the credit. She did the work. That field tested 3 to 10 ppm phosphorus. Do you really believe another 10, 12, 15 bushel was sitting there just because the soil test number was higher? I ran the math with Grok on building this ground to 50. 11-52-0 at $1,152 a ton is $1.11 a pound of P₂O₅. University data (Iowa State, Minnesota, SDSU, Tri-State) says it takes about 16 to 20 pounds of P₂O₅ to move a Mehlich-3 test 1 ppm. From 5 ppm to 50, that’s roughly $900 an acre on paper. At pH 7.2, calcium ties a lot of that up. Figure 40 percent fixation and you’re closer to $1,500 an acre before you even count crop removal working against you every year. Then ask how many bushels that takes to break even. Chasing that ppm, I’d go broke — or I’d be better off buying more land. We foliar fed this field several times. No check strip, so I can’t prove it paid. I believe it did. Exudation drives phosphorus uptake, stimulation and plant health drives exudation. The more you stimulate the crop, the more phosphorus gets in the plant. - both are important soil P and Uptake. Can’t spend it all just to get it applied to the soil. I’m not anti-phosphorus. I want P in the field. I’m anti-losing money chasing a magical ppm. South Dakota cash beans are about $12.40 tonight. At that price, $1,200 an acre is 97 bushels. $2,000 is 161 bushels. Spread over five years, you need an extra 19 to 32 bushel every single year just to get your money back. Not once. Every year.