Why Not Compost?

Composting helps stabilize manure and minerals so nutrients are more available to crops — even on the commercial scale

It’s long been known that a plant’s ability to use minerals depends on how the minerals are delivered. There are different sources, all with different nutrient use efficiency. The sulfates, for example, do better than the oxides, while chelated minerals do better yet; it’s not just a numbers game.

Pay Dirt — J. I. Rodale noted that the biological value of compost was superior to the (significant) mineral value.

Regenerative agriculture is all about getting better nutrient use efficiency. The goal is to tap into all the minerals that exist in the soil, plus what has been purchased. How? Biology is the path, with cover crops, using humates with fertilizers, and compost, along with adding certain types of organisms to the soil. These steps take us in the right direction.

I always say that the dumbest idea we humans ever had was putting all the minerals in solution, applying them early in the growing season, and expecting them to be plant-available whenever the plant needs them. They leach, they tie up, and they erode, and then we think we know how many units of NPK are needed to grow the crop.

Another dumb idea is spreading raw manure on hayfields. Cattle don’t eat around manure piles, so coating the whole field with stuff they don’t like makes no sense. Instead, add compost that has added minerals — it’s a no-brainer!

Taxing N?

Gary Zimmer’s farm. The dark green is clover, soon to be corn; the light green is rye planted after corn last fall, with clover frost-seeded this spring, in anticipation of becoming corn next year. The only input besides seed was 1 ton of compost with sulfur and boron on the clover last fall.

As a dairy nutritionist, I got started in soils to create better feeds for livestock. California’s Chico State University did trials recently using compost and gypsum. Their results showed higher yield, greater nutritional value, and increased digestibility. You certainly can’t make a cow more efficient without changing her forage.

Nitrogen is the hardest nutrient to manage because the losses are great, while excess nitrogen causes issues with plant health, burns up carbon, and leaches out available calcium, just to mention a few. Splitting N applications and adding carbon to it with humates (molasses, etc.) will help, but nitrogen is also the only nutrient you can grow yourself. All the rest you have to extract or buy.

I know my statement about nitrogen has never been popular with conventional farmers, but to really change agriculture, we would need to limit its use by taxing it. This isn’t a bad plan, in my opinion. We could use the tax dollars to subsidize the use of cover crops and compost. 1.1 pounds of N per bushel of corn is still recommended, but I work with farmers who are down to using only half a pound of N applied and still get a good crop.

But NPK is not the whole picture. What about the other minerals plants need? We know it takes at least 20. What about soil health? And soil biology? The life found in the soil needs an ideal home, and it needs to be fed.

Farming has changed. We now have large concentrations of animals confined in small spaces and a lot of liquid manure, which is not only costly to spread but can run off hilly and poorly structured soils, causing major issues.

What about Compost?

A compost windrow

So, what about compost? Years ago, when we started Midwestern BioAg, we made compost for farmers. It was hard to do, so we adapted and moved on to making fertilizers that were balanced, not completely soluble, and made from preferred sources. Next came adding humates to calcium, rock phosphate, trace elements, and overall homogenized blends. Then we created fertilizers using byproducts from anaerobic digestors — mostly a fiber source with many of the minerals that are fed to cows plus lots of bug bodies (the short-lived bugs in the cows’ rumen that actually do the work of digesting feed) with minerals added. The rumen is an anaerobic fermentation vat with byproducts of organic acids (acetic, propionic, and butyric) and dead bodies of bugs. The anaerobic digester has different organisms with byproducts of methane and bugs’ bodies. Those dead bugs, I believe, have many benefits for plants and soils, including chelated minerals, hormones, enzymes, and plant stimulants.

Another biological digestive process is aerobic — composting. Anaerobic digestion has problems with compounds given off during the process; the organisms produce methane and leave lots of undigested fibers. Take this and other waste, though, along with poultry manure, add some calcium and other mineral sources, and you can make a great fertilizer. I now make these designer compost mixes with plans to pelletize fertilizer blends in a compost base. The aerobic bugs clean up manures, making complete proteins and reducing pesticides and pathogenic organisms. Compost done right heats up enough to kill weed seeds, while releasing all the nutrients that come from manure and providing lots of biological benefits. Besides, compared to manure, you have a reduced pile — less than half the amount to haul.

I recently acquired a copy of J. I. Rodale’s book Pay Dirt , written in 1945. I enjoy reading old farm books — they have some great ideas and show that lots of what we are talking about in the 21st century isn’t new at all. The book has a lot about composting and other ideas from more than 75 years ago. One comment I like is “it’s not about what’s in compost, but what it does.” Rodale also notes that the value of the biological part of compost is five times more valuable than the minerals — the manure-stabilized nutrients that are more available, the nitrogen-producing organisms, the biological stimulants, the value of the digested carbon along with enzymes and hormones from the bugs.

Compost is also the cheapest way to provide the minerals. We make a blend with dairy and poultry manure and add gypsum. This organic blend has mineral prices comparable to conventional, and the value is twice what you would pay for just the mineral.

Manure on Hay Fields? Or Compost?

Is it wise to put manure on hay fields? Compost is ideal. Harvests are taking off minerals and carbon, so 1-2 tons of a good compost with minerals added will improve your forage quality and yield.

Compost Tea and Compost Extract

Minerals have been added to this pile

There are many companies selling tea products, from hopefully well-made finished compost. A tea-type bag with the compost in it is added to a large water tank, then sugar is usually added and air pumped in. Many other things can be added as well, like humates, biochar, kelp, earthworm compost, montmorillonite clays, or extra organisms for specific functions. Putting that down the furrow when planting, along with other nutrients, is a good way to start your plants off right. Many farmers will then come back and do a foliar. This also works great for hay fields and pastures.

Compost extract is taking a batch of well-made compost, putting it in a tank, adding a liquid to let it soak, then filtering and extracting the soluble nutrients. Other things can be added to the compost, like calcium, sulfur, biochar, kelp, humates, more organisms, different soluble trace element products, plant stimulants, etc. Mixing an extract with tea may also be a good idea. The liquid you soak the compost in can be more than water. The humates can help chelate minerals. You can use a lower-pH product to extract more, such as apple cider vinegar. We are going to experiment with sauerkraut juice, and I’m sure there are many more ways to make a liquid product that will fit many farms.

A Recipe for Better Soils

It may take a few years to completely regenerate the land, but each year it gets better if you cut unnecessary costs like using too much fertilizer, pesticides, and herbicides. Resilience greatly improves, and the cost of production drops. It’s not a new system of farming, but it is the future. We do know how to fix soils by making just a few changes on most farms. Here are a couple of other tips: