Got my soil report, not sure about the potassium

[petebert]

Got a soil report, they said I was deficient in nitrogen and potassium. They were really clear on how to apply the nitrogen but gave no instructions for the potassium. The field in question is actually pasture. It was just seeded for pasture last fall. It's been grazed once and I've put some nitrogen down. I plan to get one more grazing out of it.

If I'm reading this right, I need 200lbs/per acre of nitrogen. In the instructions they said to do it in split applications of 50lbs each, June, August, and September, although that only equals 150, not sure when I'm supposed to do the last 50.

They didn't give any instructions for putting the potassium down, it just says I need 155lbs/acre. How and when should I do potassium?

 

[powerscol]

I would add the potassium when I do the nitrogen, Do you have a local AGG store that can blend fertilizer? They could set you up at the correct rates in one mix. Or get the potassium separate and apply just like you will do the nitrogen in 3 or 4 applications. I assume you dont irrigate, but the best time to apply is just before expected rain. Do not apply to wet grass as it will burn. As for the last application I do a late fall one, just before expected snow and ground freeze.

 

[Oldtink]

You may find this from Penn State helpful. Crop and Soil Management — Penn State Agronomy Guide — Penn State Extension

Potassium and nitrogen fertilizer forms are highly soluble in water so as powerscol stated, apply just before a good soaking rain will result in the most benefit to the soil. You might also consider introducing some nitrogen fixing legumes in the future.

 

[joeu235]

They want you to split up the N application up because it's hard to get that much N at once. For example, 400 pounds and acre of 21-0-0 would only put out 84#s on nitrogen.

The other two nutrients are slowly used by the plants and can be put out at once.

 

[Bigfoot62]

They want you to split up the N application up because it's hard to get that much N at once. For example, 400 pounds and acre of 21-0-0 would only put out 84#s on nitrogen.

The other two nutrients are slowly used by the plants and can be put out at once.

Yeah, what Joe said.

I've included a link below that help explain the different types of Potassium fertilizer.

Realize now, that's 200# of Nitrogen and 155# of Potassium per acre. NOT just 355# of bagged fertilizer. (like 12-12-12) For example, my soil test a few years back recommended 120# per acre of potassium. That took 6 tons of muriate of potash for 52 acres.

Depending on the type of N applied, commercial fertilizer will only last for about 30-45 days. That's why you do it in stages. Plants take it up and it also evaporates. I use a lot of chicken manure here. It's a lot slower release rate than commercial. When I do apply commercial fertilizer, I'll usually get Ammonium Sulfate since my soil is deficient in Sulfur.

Potassium doesn't evaporate. You can put out as much as you need at one application. It will be there until it's used by the vegetation. Potassium

I hope all this helps, and doesn't just confuse you more.

 

[Soggy Bottom Outdoors]

Let me start by saying I know nothing about farming, fertilizer, or soil types in Michigan. I'm in KY and thats where I base my knowledge. Lets separate lbs and units. If we don't we can confuse lbs of nutrient and lbs of product. Lets also get our terms right, the product that potassium comes from is potash. sometimes they are used interchangeably. Nearly all soil tests I have done will recomend UNITS of nutrient per acre. In your case 155 uints of potassium per acre. Muriate of potash is the most common source of dry potash(in KY)and it is a 60% product. So 155 units divided by .60 will be 258.34 lbs of actual product per acre. Muriate of potash is a mined mineral, similiar to a soft rock. It is slow to break down and become available to the plant. Hence fall applications are very common which make it more available by the following spring. Again I'm from KY. Here it is common to make one fertilizer application in the spring on hay and pasture, usually March-April. Alfalfa can get a 2nd and 3rd shot. Some N application in late summer/early fall to stockpile grass for winter grazing. Hope this was helpful

 

[DaveOmak]

Depending on the organic matter in the soil, soil will only hold on to "so" much Nitrogen... after it has grabbed what it can hold, the rest is wasted... either volatility or rinsed out with rain or irrigation....

 

[petebert]

Any recommendations for something to apply the fertilizer with? So far I've been doing 50lbs at a time with a little tow behind, one acre at a time. Not terrible but not great either. I've been looking at the various 3 point or ATV types and none of the reviews are that great. I asked the local dairy farmer I work with and he says he rents something from the feed place but I think he said those are for doing a couple tons at a time.

 

[2addy]

Easiest way is anything like this: http://www.northerntool.com/shop/tools/product_200660636_200660636

There are bunches of these online so you should be able to find one fairly inexpensive. That one can handle 1100 pounds.

 

[powerscol]

Any recommendations for something to apply the fertilizer with? So far I've been doing 50lbs at a time with a little tow behind, one acre at a time. Not terrible but not great either. I've been looking at the various 3 point or ATV types and none of the reviews are that great. I asked the local dairy farmer I work with and he says he rents something from the feed place but I think he said those are for doing a couple tons at a time.

Check with you local fertilizer store. My coop offered their unit when I was only getting 1000lbs. I think they have several sizes too.