Nitrogen and Protein

Nitrogen occurs in a number of ways and in a number of forms.  For the plant to be able to use it, it has to be in “plant available form.”  Grass gets some nitrogen from the air, some from humus, some compliments of a generous nearby legume plant such as clover, which is more capable of “fixing” nitrogen from the air than a grass plant.  But needless to say, the clover isn’t deliberately sharing its hoard of nitrogen with the grass plants.  If there’s enough legumes amongst the grass, say 30% of the plant community in the pasture (known as the “sward”), then there’s usually enough nitrogen from air, legumes and humus to feed the lucky grass plants as well.  My understanding is that the grass receives the most benefit from the legumes when the clover or whatever is sheared (bitten or mowed) whereupon it sheds some roots and root nodules, thereby releasing more nitrogen into the soil.

 

But people with metabolic horses are warned against clover.  A 30-40% legume pasture is frequently high enough in energy to rear cattle and sheep, but it may be off the charts in energy, and possibly poison for a horse.

 

We have a community of clover appearing spontaneously in our pasture now that the growing conditions (rich in minerals) favor germination of seeds.  I can control the mix of legumes and grass through management without using herbicides.  But I still need to provide adequate nitrogen.

 

So if my soil analysis says I’m shy of nitrogen I first need to decide whether this is a “tonnage” issue versus an “adequate nutrition” issue.  Of course as producers of feed for our own animals, our priority is nutrition for the animals, robust health for the pasture and its community of microbes and earthworms, conservative enough not to contaminate ground water and ultimately, be self-sustaining.  This is vaguely in keeping with Allan Savory’s concept of holistic management.  You don’t want to just blast a crop out of the ground. The decision of what type of, and how much nitrogen to use on the crop has broader implications.

 

A couple of other critical considerations in “how much nitrogen” are as follows.  First, if you don’t have that bank of minerals in the soil that biosynthesize the nitrogen into protein, you’ll likely end up with a lot of lush growth without a shred of real nutrition in it.  Lots of photosynthesis products – sugar and starch, but nothing in the way of meaningful protein, vitamins and immune-enhancing nutrients.

 

The other consideration may be more important.  I recently ran across a perfectly fantastic article by Jerry Brunetti of Agri-Dynamics, and published in Acres USA magazine.  The link to the article is http://www.acresusa.com/toolbox/reprints/Brunetti_Protein.pdf

This article is a MUST READ.  In the article Jerry explains the difference between “True Protein” as in amino acids, and “Funny Protein” which is nothing but non-nutritive nitrogen.  The importance to you here is that the Crude Protein value on your hay analysis includes BOTH!  Remember Melamine?  How can we forget!  If you think that the Crude Protein means nutritious amino acids – which is what protein is – you are misled and if you read Jerry’s article, you may discover that there is a hidden health threat to a metabolic horse in this number.

 

Jerry explains that protein on average contains 16% nitrogen.  Based on that average, labs measure only the NITROGEN content of your hay, run it through a simple mathematical calculation and come up with a “Crude Protein” value for your hay report.  Jerry’s article also provides a simple mathematical calculation for estimating what fraction of your crude protein value is protein, and which is non-nutritive nitrogen.  Basically it is a ratio of the recalculated crude protein to the sulphur content on your analysis.  Anything above a 10:1 ratio is “funny protein,” non-nutritive nitrogen. 

 

Our recent hay test was very slightly over 10:1.  This may guide my calculation of how much nitrogen the crop needs this year to meet my holistic goal.  It looks like a little less nitrogen than last year would be ideal.   

 

I’ve run the calculation on some other analyses I have on file.  The dairy alfalfa that my lambs weren’t impressed with was 17:1. 

 

Here’s a little fallout from the non-nutritive nitrogen in forage.  As I understand it, excessive nitrogen can convert to a substance called Blood Urea Nitrogen, or BUN.  BUN can depress magnesium in the blood.  There’s a whole lot more about this in Brunetti’s article, but this should be enough to gobsmack any metabolic horse owner, since we all know that magnesium is a key player in the complex suite of problems called Equine Metabolic Syndrome.

Brunetti stresses throughout the article that the source of this mischief is mineral imbalance in the soil and refers back to Albrecht to correct the problems.  It also clearly lays out the excessive nitrate situation that we know may compound the horse’s problems.

 

As to organic versus conventional inputs for the soil, no matter what form of nitrogen we put on the grass, it’s either going to have to arrive in plant available form or it’s going to have to undergo a reconstruction by soil microbes and chemical reactions to become plant available.  The only sensible way for me to direct you to more information about this is to read about it in Neal Kinsey’s book, “Hands on Agronomy.”

 

If we choose the organic route, the amendments we put on are going to have to go through a deconstruction process to become plant available, because we’ve sort of reversed the process; we’re putting protein on the pasture in many instances to provide nitrogen for the plant.  If you put blood meal on, that’s protein (and of course other blood constituents).  The grass plants aren’t going to descend on blood meal like a pack of coyotes and have a blood fest.  The blood meal is going to have to undergo a transformation to become plant food, and that is going to make it a slow release nitrogen.  One way or another, the nitrogen is only going to end up in the plant in “plant available” form.  It will get there slowly via a sort of digestion process of organic type inputs, or it might get there quickly in a “conventional” input, such as ammonium nitrate.

 

Keep in mind the “digestion” of the blood meal for the use by the grass plant is going to require a voracious community of microbes and earthworms.  Just as with horses and plants and humans and fish and all living creatures, microbes and earthworms die out in the absence of soil minerals.  So if the soil isn’t throbbing underfoot with life by literally tons per square acre, your blood meal, along with all other organic material on the surface, will probably decompose into abnormal materials that may be more toxic than nutritive.

 

As Kinsey explains, there is a head-whirling variety of nitrogen forms available, if you chose the conventional route.  Some are “plant feeders,” some are “microbe feeders” some are slower release, some faster, some volatilize almost instantly, and some stay put.

 

I don’t know everything about “chemical fertilizer” (soil is a collection of chemical, electrical and biological processes, as is all life) and while we are in this soil reconstruction phase, I’ve decided that the soil life needs nitrogen as much as the grass, and having rounded up as much input as I can absorb for the present, I’ve decided a conservative application of a soil-feeding, long acting chemical nitrogen is in my best interest.  As we go along, I will monitor the soil humus level, to make sure the microbes aren’t partying too heavily on the nitrogen and burning up organic matter faster than it’s building or maintaining, and also the legume levels, which are slowly multiplying.  For the life of me, I am not convinced I am doing anything destructive as a result of this decision and my Crude Protein calculation according to Brunetti indicates that the grass plants are pretty much converting all the nitrogen they receive into protein.

 

We each have to make decisions within a frame of reference, and I believe my decision will eventually lead to my holistic goal of fully nutritious horse hay, thrumming soil community, least negative impact and self-sustaining, when the pasture is able to maintain its own nitrogen level without ANY inputs of nitrogen, organic or otherwise.

 

 

Comments

[electrical work]

Everybody should think about pollution, because it negative impact on future of our generation and I think it is really actual for today.

[writing online]

That is so difficult to do everything right.