The Economics of Fertilization with Nathan Slaton - January 2012
[Video shows various pictures of soybean fields with specialists or agents in fields. Music plays in the background]
[Title Slide – Ag Day Presentations: Nathan Slaton at Lonoke County, January 4, 2012. Your Arkansas Soybean Podcast. Presented by University of Arkansas Division of Agriculture Research and Extension U of A System, Arkansas Soybean Promotion Board.]
[Slides - Fertilization Costs, Nathan Slaton, Professor and Director of Soil Testing, firstname.lastname@example.org. Fertilization economics and Productivity, Drawing of puzzle pieces. 2011 U A C E S Budget for Flood/Furrow Irrigation Soybeans. 18% production budget - $51.40 per acre for 0-40-60; $0.61 per pound P205;$0.45 per pound K20. Recommendation for soil with medium soil test P & K levels.]. It doesn’t really matter how you slice it. Guys, if we’re talking about soybean. The big thing with soybean is the old adage that we’ve said for years, if you’ve only got “X” amount of dollars to buy fertilizer, you probably need to be spending that money on potash if you’re growing beans. And that hasn’t changed because our research with phosphorus shows that the yield responses to phosphorus are really rare and when we do see them they tend to be much smaller than what type of responses we get from potash.
Probably the most common recommendation that we have out of silt-loam soils in Arkansas is going to be for about 60 units of phosphates and about 120 units of potash. And that’s over $110 per acre.
[Slide with table]
P & K Fertilizer Costs for Soybeans
U of A Recommendations
Soil Test Level and Potassium Recommendations (lb. K20/acre)
|Above optimum||Optimum||Medium||Low||Very Low|
|lb P205/acre||0 lb. K20||50 lb. K20||60 lb. K20||120 lb. K20||160 lb. K20|
|Level||Rate||$ Sum P & K costs/acre|
[Most common recommendation $108.60. Retail fertilizer prices from November/December 2011 tracked by D T N $0.71 per pound P205 and $0.55 per pounds K20].
Based on the long-term study that we have going at the Pine Tree Station, [the] eliminating fertilization is really not a good answer if you’ve got decent yield potential. Just cutting back will go a long way. You may not be producing your maximum yield but you can certainly maintain some yields. [Chart showing Yield Response to Annual K Rate for soybean yield bushels per acre from 2000-2010 for potassium rates K20 per acre per year for 0, 40, 80, and 160 pounds].
I’m showing four potassium rates and these apply to the same plots every year. They range from zero, 40, 80, and 160 units of potash per acre per year. And the main thing I want to look at, is there’s 40 pounds of K-20, which is the square here.
It’s not the lowest, it’s not the highest, but if you look, some years, like this particular year, I mean here’s your rate, zero, 40, 80 and 160. So it’s always substantially higher than the zero.
Here’s another year here where it’s almost the same yield as 80. My point is, don’t just cut fertility out of your program, OK, you can cut back and it will take you a long ways, because when you start looking at where we’re at, twelve years after we started this particular study, we are routinely seeing 20-bushel yield differences between the check and our highest yielding treatment.
From applying nothing to applying fertilizer at a relatively high rate every year. The other point I’d make here, you know that high rate is almost always the top yielding treatment, but it doesn’t mean it’s the most economical.
[Narrator with music playing in the background] Your Arkansas Soybean Podcast is a production of the University of Arkansas Division of Agriculture, and was funded impart by the Arkansas Soybean Promotion Board. For more information on soybean farming in Arkansas contact your local county extension office.
[Title slide – Your Arkansas Soybean Podcast. Video shows various pictures of soybean fields with specialists or agents in fields. U of A Division of Agriculture Research and Extension University of Arkansas System, Arkansas Soybean Promotion Board. For more information on soybean farming in Arkansas contact your county extension office or go to www.uaex.edu. Your Arkansas Soybean Podcast.]