Does grazing corn stalks raise the soil test pH?

[SRBeef]

I was just looking through some soil tests of my strips where I have grazed continuous corn the past few years.

It was surprising that even though I am in an area (SW WI) that normally needs regular lime applications to keep the pH above 6, the pH where I have grazed stalks (and also my rotational grazing pastures) appears to be increasing even though I have not applied lime for several years and 5 years in the corn strips in particular.

Does intensive grazing raise the pH of soils that normal tend to acidic?

Thanks for any responses/experience.

Jim

 

[iowafarmer]

No. Lime does not immediately affect the soil pH it takes several years, so you are probably seeing the results of your last lime application. We test our soil pH about every 5 years and apply lime accordingly.

 

[dun]

No. Lime does not immediately affect the soil pH it takes several years, so you are probably seeing the results of your last lime application. We test our soil pH about every 5 years and apply lime accordingly.

Well put. We test every other year and it's pretty normal for the ph to keep going up for 5-6 years after lime application. Some fields only 2-3 years. We apply lime the first year that it quits going up

 

[thommoos]

I agree with Dun, lime takes 6 to 9 months to strat working and continues for several years depending on the amount rain, especially fertilizer applied. Once it drops apply again quickly.

 

[pdfangus]

it has been suggested that a high level of organic matter and deep rooted crops also serve to enhance general soil productivity including pH.

I would not think that grazing corn stalks would do that unless it was intensely managed. ie strip grazed with a good stocking rate.

 

[SRBeef]

If its not the manure and grazing then I think I am probably seeing a combination of effects. The delayed reaction to earlier applied lome plus the effect of continuous deep rooted corn and an increase in organic matter. Thanks for the replies.

Jim

 

[agmantoo]

Applying chicken litter from a layer house on pasture will raise the PH.

 

[SRBeef]

Applying chicken litter from a layer house on pasture will raise the PH.

Thank you for the reply. I guess what I need to know is what is the pH of the manure dropped while grazing (not fresh).

I have a year old compost pile of manure and hay dropped around the feeders. I will get a garden ph testing kit at the hardware store and test that pile for pH.

Does anyone know what the pH of cattle manure is after it's been spread awhile or composted?

Jim

 

[novaman]

Does anyone know what the pH of cattle manure is after it's been spread awhile or composted?

I believe it is typically around neutral but it can vary depending on the materials in the compost pile.

 

[agmantoo]

novaman is correct with his thoughts on the PH being near neutral.

Here are a few facts on the PH with the animals on different diets. There is a typo in the article as there are two table 1 charts and a table 3. Open all these to get a cheat sheet and findings.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1265955/

 

[SRBeef]

I found this quote in a Penn State publication:

Microbial activity is also affected by pH.
Reported values for pH of manures are 6.9 for cage
layer manure, 7.0 for dairy cattle manure and 7.5 for
swine manure. Addition of waste feed, bedding or
other materials to manure can affect these values.

http://www.abe.psu.edu/extension/factsheets/g/G87.pdf

So even if the manure is neutral 7.0 that would over time raise the pH of my soils. Cornfields in this Dubuque clay soil can be in the 5.0-5.5 range if no lime is applied over a few years. Corn likes a 6.5 pH.

It is also interesting how pH affects the microbial activity which is helping break down the manure and corn residues into useful minerals and organic matter.

Thanks again. Jim

 

[Stocker Steve]

Does intensive grazing raise the pH of soils that normal tend to acidic?
Thanks for any responses/experience.

Sometimes.
Several local grazers who do not apply N, and either pound in residual and/or buy in hay, have reported an upwards trend in both PH and OM. Here we are talking about 5 to 15 years and no lime ever having been added.
Makes sense when you think about it. :cowboy: We have been conditioned that you have to have a fertilizer or lime spreader to improve soil - - but that is just not so. The issue is that this is a slow process unless you have very high stock density.

 

[terra8186]

If you are applying less chemical fertilizers and using the manure as fertilizer, then this could be another factor why you don't need the lime.

 

[SRBeef]

You make a good point - apply less commercial fertilizer (which tends to be acidic) may be part of the reason the pH is not going down as rapidly as it usually does when the corn was not grazed.

However my pH is not just not going down, it is actually INCREASING. My only conclusion is that the manure deposited over 3 winters of grazing is causing the pH to creep up into the high 6's. As mentioned above manure tends to be about neutral at 7.0. This is higher than most crop fields in my area so must be sufficient to raise the average soil sample pH.

Jim

 

[agmantoo]

I got some of my old bills out and researched when the last time I applied lime was in the Spring of 2006. The PH is better now, based on my professionally taken sample that was taken in Dec 2010, than anytime since I bought the place in 1990. No commercial fertilizer has been applied on the existing pastures since 2008. I have access to enough chicken litter from a hatching egg house to only apply litter to only 20 percent of the farm per year. The overall soil analysis indicates I need a little phosphate but not enough to justify running a fertilizer truck over the place. Nitrogen comes from the chicken litter, cattle and the clover. I have been rotationally grazing the acreage since the late 90's and that is about the time I went profitable and my confidence spiked. I started doing a lot of things unconventionally and took on the challenge of year round pasture feeding and no hay. This put a lot of manure on the paddocks and walked a lot of organic material into the soil and distributed cow urine along with the manure. I also bought dung beetles and quit using pesticides that killed worms and beetles. Herbicides are used mostly on fencelines and multiflora roses. I no longer broadcast herbicides on the paddocks. I do not have a weed problem. Here is a recent article that I read and I tend to agree with the findings by observing my place. So yes, intensive grazing raises the pH of soils that normal tend to acidic and at the same time significantly improves the overall fertility improving the quality and quantity of the forage and maximizes the use of the available rain water without increasing input costs. Scroll about 1/2 way down the page after it opens to read the article I referenced.
http://www.extension.umn.edu/distributi ... 01_02.html

 

[SRBeef]

Agmantoo, your post reminds me of walking across my corn strips at night a week or so ago during calving season to get to my calving pasture. I was carrying a flashlight. We had a rain during the day and everything was very wet.

As I walked across the grazing corn strips something seemed odd in the light of my flashlight. Something was moving on the ground ahead of me and as I walked by. I stopped and looked closer and it was almost a sea of nightcrawler worms sticking out of the ground that quickly drew back into their holes as I walked by. Some seemed like 6" out of the ground and maybe 3/8" in diameter.

They were out pulling in corn residue. The sheer numbers of nightcrawlers was very surprising. I have never seen that many per sq yard before.

I do use Round-up or generic Glypho on the RR corn I always grow in these strips for grazing and have for 6 years, 3 years of which has been grazed. I do not however apply any pesticides but plant a bT corn which is naturally resistant to pests. so my conclusion would be the glypho has not hurt the worm population and the bT corn seed has let me raise good corn without pesticides/insecticides. I have never used an insecticide on my farm.

The flourishing worm population is turning corn residue into organic matter and maybe most important in my tight clays, they are getting air into the clay profile and pulling residue which turns into P & K down deep into the soil profile. And with my strip till system being the only tillage, most of their burrows are not destroyed by tillage.

Isn't it neat what nature, along with a little appropriate modern technology, can do if we provide the tools for her to work with and don't mess it up?

Thanks for your post.

Jim