Pasture problem

[shaz]

I have one pasture with some strange soil test results.
PH 7.7!
Potash = optimum (whatever that is)

Phosphate = 454lbs/acre :???:
I know there is not a solid number on how much phosphate is too much but it seems like 300lb/acre is the number I see the most.
I've been using litter on this pasture but think I may need to stop for a while.
The pasture grows legumes very well but the fescue is a laggard. Rye grass does ok.

It would seem that I need to consume this excess phosphate somehow. Given that I should have a massive clover crop this spring what would you guys plant as a companion forage to the clover? I'm ok with just adding a little commercial potash every year until the pasture gets back to normal.

 

[bigbull338]

heres what id plant to use that,id plant clover rye grass vetch an singletary peas.an if it all comes up,youll have grazing out your ears.planting all of that is very costly but it would be worth it.

 

[Douglas]

Around here land that was in tobacco in the past, is often very high in P and it never comes down much.

 

[James T]

I have one pasture with some strange soil test results.
PH 7.7!
Potash = optimum (whatever that is)

Phosphate = 454lbs/acre :???:
I know there is not a solid number on how much phosphate is too much but it seems like 300lb/acre is the number I see the most.
I've been using litter on this pasture but think I may need to stop for a while.
The pasture grows legumes very well but the fescue is a laggard. Rye grass does ok.

It would seem that I need to consume this excess phosphate somehow. Given that I should have a massive clover crop this spring what would you guys plant as a companion forage to the clover? I'm ok with just adding a little commercial potash every year until the pasture gets back to normal.

Shaz, do you know if that 454 lbs was STP (Soil Test Phosphorous)?
Check out the following article and see if it helps to understand: http://www.sera17.ext.vt.edu/Documents/ ... ations.pdf

Excerpt: "An STP of 300 lbs/A is a good indicator that P build-up in the soil is a valid environmental concern for that particular field. Growers with management alternatives for manure or litter should reduce or totally avoid animal manure or P applications from any source on high P fields. Current scientific evidence is limited on how much P can be tolerated for all fields in all situations. However, it is known that high P fields can require as much as 15 to 20 years of continuous crop harvesting, with no added P during that time, to reduce high STP levels. Therefore, it is to the landowner’s advantage not to let STP build to high levels if he has alternatives for management.
• A STP of 300 lbs/A should not be considered an absolute maximum number for P applications at this time except in specific watersheds that have been determined to have excess P loads harmful to water quality and the environment.
• Growers should be encouraged to make commercial fertilizer applications formulated with N and K2O to meet the forage needs of fields where animal manure is no longer applied. It must be recognized that decreased fertility will result in a loss of forage cover and increased erosion, which could create a greater P problem in runoff than continued manure applications.
Research has shown that when erosion is kept to a minimum, dissolved P is predominant in runoff water, but as erosion increases the percentage of particulate P in the runoff increases."

 

[shaz]

Around here land that was in tobacco in the past, is often very high in P and it never comes down much.

Funny you should mention it. It used to be a tobacco field as late as 2003.

 

[shaz]

I have one pasture with some strange soil test results.
PH 7.7!
Potash = optimum (whatever that is)

Phosphate = 454lbs/acre :???:
I know there is not a solid number on how much phosphate is too much but it seems like 300lb/acre is the number I see the most.
I've been using litter on this pasture but think I may need to stop for a while.
The pasture grows legumes very well but the fescue is a laggard. Rye grass does ok.

It would seem that I need to consume this excess phosphate somehow. Given that I should have a massive clover crop this spring what would you guys plant as a companion forage to the clover? I'm ok with just adding a little commercial potash every year until the pasture gets back to normal.

Shaz, do you know if that 454 lbs was STP (Soil Test Phosphorous)?
Check out the following article and see if it helps to understand: http://www.sera17.ext.vt.edu/Documents/ ... ations.pdf

Excerpt: "An STP of 300 lbs/A is a good indicator that P build-up in the soil is a valid environmental concern for that particular field. Growers with management alternatives for manure or litter should reduce or totally avoid animal manure or P applications from any source on high P fields. Current scientific evidence is limited on how much P can be tolerated for all fields in all situations. However, it is known that high P fields can require as much as 15 to 20 years of continuous crop harvesting, with no added P during that time, to reduce high STP levels. Therefore, it is to the landowner’s advantage not to let STP build to high levels if he has alternatives for management.
• A STP of 300 lbs/A should not be considered an absolute maximum number for P applications at this time except in specific watersheds that have been determined to have excess P loads harmful to water quality and the environment.
• Growers should be encouraged to make commercial fertilizer applications formulated with N and K2O to meet the forage needs of fields where animal manure is no longer applied. It must be recognized that decreased fertility will result in a loss of forage cover and increased erosion, which could create a greater P problem in runoff than continued manure applications.
Research has shown that when erosion is kept to a minimum, dissolved P is predominant in runoff water, but as erosion increases the percentage of particulate P in the runoff increases."

Thanks,
I've read that article. I think that's were I go the 300lb number.
To answer your question the 454 comes from my last soil test and is given in pounds per acre

 

[lynnmcmahan]

I would have to get another soil sample just to make sure I did my part right and the lab did too.

 

[shaz]

I would have to get another soil sample just to make sure I did my part right and the lab did too.

That's on the agenda this year. They (AL Labs) did six samples for me and the rest were consistent with what I already suspected.
You'd have to see this pasture though. It's become a legume paradise, fescue is mediocre at best and the DH3 ryegrass is doing ok.

 

[Douglas]

Around here land that was in tobacco in the past, is often very high in P and it never comes down much.

Funny you should mention it. It used to be a tobacco field as late as 2003.

That explains it. Tobacco fertilizer formulas always had high P. Most farmers, if they had a good crop 1 year, would just replicate that amount and type of fertilizer every year, and P never leaches away. My readings have been around 300 for P for over 10 years and no tobacco has been on the land since 1995. You will never need to add P on that land in your lifetime.

 

[Jogeephus]

When you go back to using litter you need to alternate applications else you will get in trouble with excess micros as well.