Phosphorus recommendations, with pricing and soil testing considerations
University of Minnesota Extension nutrient management specialist Dan Kaiser talks with the Linder Farm Network about recommendations for phosphorus applications, considering prices and soil testing.
TRANSCRIPT
Linder Farm Network: It’s time for the AFREC Spotlight, the Agricultural Fertilizer Research and Education Council with University of Minnesota nutrient management specialist Dan Kaiser. Dan, what are your recommendations for phosphorus applications, with price considerations and soil testing?
Dan Kaiser: One of the things certainly, I mean, soil testing, we preach that quite a bit that it does tend to be a good option at least to determine where you need phosphorus. And I’ve got a lot of data now, I mean, close to twenty years of data here in Minnesota looking at phosphorus response. If you’re above a certain level, particularly if you’ve been maintaining high levels over time with cheaper phosphorus, it may be a good time now to really look at what other options you might have.
Certainly starter is an option because in many cases it doesn’t take a whole lot if you’re going to get a response, if you’re kind of up near those high levels, if there is a chance you’re going to get it, that first 10 to 20 units P2O5 is probably all you’re going to need. So I think that’s the thing right now, you know, going into this fall, with prices, I’ll be kind of curious to see what growers attitudes are going to be towards some of this because if nitrogen prices stay high, I mean, really phosphorus to me is the easiest one since the soil test does a good job of predicting where you’re going to see a response that it’s one of the easier ones to at least trim back on more versus some of the other nutrients just because of of the soil test being so good at predicting the the responses in in given areas of fields.
If it’s been a few years, I think it’s a good good time to do it. I mean, you know, certainly, the prices in soil testing does tend to increase over time, but it isn’t like the fluctuations we see with fertilizer prices. So it might just be a good time to see if you’ve been at least applying maintenance year after year, whether or not it’s just taking a sample, a random sample from a field just to see where it’s at. Because if you are well above critical levels, say twenty, thirty part per million, there’s certainly a few years there where you could go with, you know, either with no phosphorus or reduced rates and still get maximum yield.
So, I mean, it’s, you know, we view sometimes phosphorus to being banked in the soil. It’s a good time to withdraw right now, especially where things are at until we see fertilizer prices come down.
Linder Farm Network: Dan Kaiser, University of Minnesota nutrient management specialist. For more information visit MNSoilFertility.com