UACES Facebook Potassium Fertilization Trends in Soybean - January 12, 2010

Potassium Fertilization Trends in Soybean - January 12, 2010

You Tube - Link to watch video on You Tube.Link to transcript

Audio/Video    Script:

[Title Slide – Potassium Fertilization Trends in Soybean with Dr. Nathan Slaton, Professor of Crop, Soil, and Environmental Science]

[Dr. Nathan Slaton] One other study on potassium that’s noteworthy, this has been going on at our Pine Tree Branch Station since two-thousand, it’s rotated with rice. Generally, we no-till it to keep from moving our treatments around and we annually apply rates of zero to a hundred sixty pounds of K20 per acre per year. And regardless of whether its rice or soybeans, every year we put out optimal rates of all the other nutrients. So the only that that differs in this test area is potassium, everything else is managed uniform.

[Slide with table – Soybean Yields – Long Term Fertilization Trends]







Lb K2O/A








0 42 32 41 45 43
40 46 34 47 62 50
80 46 35 52 64 54
120 46 39 53 67 58
160 48 35 56 67 60
LSD0.1 3 NS 2 4 6
Increase b/a 6 0 15 22 17

This slide here shows the first year, two-thousand all the way to the current year. The crop grown that particular year is shown below it. The potassium fertilizer rate applied each year is shown in the left-hand side. And down here at the bottom this summarizes here the maximum yield difference where we see statistically significant differences between the unfertilized check and the K rate that maximized yield.

One thing to note, the first four years of this study, there was only one positive, significant response to K and it was in soybean the first year. The second year we were in beans I think if we had a higher yield I think we would have probably seen a significant difference there. And what I want you to focus on is the fact that after four years of cropping, four years of depleting this treatment right here the soil of potassium, look at what we are seeing, with soybean 15, 22, 17 bushel differences and even if we move up to this lowest rate, our yields improve quite a bit. That’s why, you know, usually when you call and say I’m looking to cut out my fertilizer cause I can’t afford it, maybe you can do that for a couple of years, but guys if you do it too long its gonna come back to haunt you, so even using a sub-optimal rate is better than doing nothing.

[Narrator] Your Arkansas Soybean Podcast is a production of the University of Arkansas Division of Agriculture and was funded in part by the Arkansas Soybean Promotion Board. For more information on soybean farming in Arkansas contact your local county Extension Office. [Title slide - For more information contact your local county Extension office. Your Arkansas Soybean Podcast, University of Arkansas Division of Agriculture, Arkansas Soybean Promotion Board]


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