organic matter – Lee Reich

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GOOD FOR CROPS, GOOD FOR THE EARTH

October 6, 2016/13 Comments/in Gardening, Soil/by Lee Reich

How to be a Good Gardener/Farmer, Simplified

    “The poor farmer grows weeds, the mediorcre farmer grows crops, the good farmer grows soil.” How true, when I think of the good farmers and gardeners I’ve visited over the years. I aspire to be a good farmdener and spend a lot of time trying to grow soil.
   Growing soil isn’t all that complicated. (You do need to start with good drainage of water.)
   First, keep the ground covered. Organic mulches, such as leaves, straw, and wood shavings, keep rain from pounding the surface. The pounding drives small soil particles into pores, sealing the soil surface so water can’t percolate in. Bacteria, fungi, worms, and other soil organisms gobble up organic mulches, releasing nutrients and forming humus, which improves percolation and moisture retention, and makes room also for air in the soil. In my gardens, I never want to see bare ground. Bare, cracked soil
   Live plants likewise protect the ground. The plants might be cabbages, marigolds, carrots, and other garden plants. They might be cover crops, such as rye, oats, peas, or buckwheat, sown specifically to clothe and protect the ground during or at the end of the growing season, and through winter. They might even be weeds — Mother Nature’s way of protecting her soil.
   Second, maintain soil organic matter. Mulches do this, as do growing plants. I go one step further, and import organic matter. Bushel after bushel of leaves that have been raked and bagged by neighbors are collected are unbagged and unraked once they arrive here. Leaves that have been vacuumed into a landscaper’s large truck and then left here in a pile get unpiled here one pitchfork and garden cart at a time.
   I also pitchfork horse manure into the bed of my pickup truck at a local stable. Mostly, that manure is transmuted into compost and then slathered onto beds in the vegetable garden.

Compost, in the making

   I also import — really just transfer — some organic material from one part of my property to another. My small hayfield gets mowed once a year by tractor to keep it from becoming forest but parts of it I periodically scythe, these mowings to feed, along with the horse manure (and kitchen waste, old garden plants, etc.), compost piles.
   The third key to growing soil is to maintain fertility. A soil test can confirm what, if anything, is needed. If the first and second points in growing soil are followed, fertility is probably up to snuff.
   And finally, the fourth key to growing soil: Minimize soil disturbance, avoiding tillage or, at least, excessive tillage. Tillage mixes so much oxygen into the ground that soil organisms go into a feeding frenzy, in so doing gobbling up organic matter too fast. Thus, many of the above benefits, physical, biological, and nutritional, waft away, literally, as carbon dioxide.
   Farming and gardening aren’t “natural.” At their best, they are a balancing act that leans towards emulating natural systems. Which is to say, for instance, that tillage, is not all bad; it can be part of good soil growing if not done to excess and points one, two, and three are followed.
   A measure of “organic matter content” (OMC), from a soil test, provides a rough indication of soil growing progress. Less than 3% means more work is needed. Five percent, or more, is very good. (My vegetable beds are at about 15%.)

Blue-Green Algae Redux

    Last week’s notes about the darker side — and the brighter side — of blue-green algae may have left everyone feeling helpless. After all, you can’t change the hot dry weather that is, in part, responsible for the current blooms. But nitrogen, phosphorus, and other minerals washing into waterways to feed the bacteria also play a role, and it’s something over which we have control.
   Improper septic systems are one culprit.
   More topical culprits are mineral nutrients originating in backyards and farm fields. Too many farmers and homeowners subscribe to the philosophy that “if a little is good, more is better,” when it comes to fertilizer. Not so. Too much fertilizer not only is a waste of money; it damages or kills plants and, with rain, leaches through or runs off the soil to eventually find its way into waterways. A soil test will tell what nutrients, if any, are needed.
   Even better, if fertilizer is needed, is to use an organic fertilizer. Most are not water soluble until metabolized by soil organisms, which means they are less likely to wash through the soil.
   Better still would be to use compost to provide fertility. Nutrients in compost are locked up physically and chemically, waiting to be released by soil life in synch with plant uptake and growth.

Terraced field in Viet Nam

Phosphorus is a plant nutrient that binds tightly to soil granules, but makes its way downhill when rain washes over bare soil to move it downslope. One way to keep this nutrient out of waterways is to keep the soil covered with mulch or vegetation, especially on sloping land. Another way is to avoid exposing soil by tillage. Another way, if tillage is needed, is to till perpendicularly to the fall line of a slope. And yet another way is to alternate tilled areas with grassy strips to catch and hold soil.

Rye cover crop

Do a lot of these recommendations — mulches, cover crops, composts, no-till — for preventing blue-green algae blooms sound familiar? Good gardening and farming practices are also good for the environment.

IT’S ALL ORGANIC, BUT NOT NECESSARILY ALL GOOD

December 11, 2014/7 Comments/in Gardening, Soil, Vegetables/by Lee Reich

Hay, Grass Clippings, Manure, Leaves — Watch Out!

Organic materials — that is, things that are or were once living — are the core of “organic” agriculture, and right from the get go, many years ago, I set out pitchfork in hand to gather these materials. Into large garbage pails toted around in my van I loaded manure from nearby stables. Neighbors let me haul away their bags of autumn leaves.

I even convinced city workers to dump a truckload of harvested lake weeds onto the side lawn of my small rented house. (That was in Madison, Wisconsin, where fertilizer runoff from lawns was spurring growth of lake weeds which, besides making swimming hazardous, were, upon their death, causing oxygen depletion of the lakes.)

Me mulching, even as a beginning gardener

Mowings of roadside hay, which I stuffed into the back of the van, were another source of organic matter, used for mulch and for compost. That was before the days of lead-free gasoline, so lead contamination was some concern. Then again, high levels of organic matter in the soil mitigate lead hazards in soils.

More dramatically of concern were bags of grass clippings I once dragged across the yard from my neighbor’s freshly mowed lawn. Hours after I had spread the clippings around my potato’s lush, green vines, their stems twisted and contorted as if screaming in pain — the effect of weedkiller used on the lawn. Perhaps my neighbor was striving for a uniform greensward; perhaps he had inadvertently used a lawn fertilizer laced with weed killer. “Weed and feed” sounds so cheerful and labor-saving. Lawn weedkillers are toxic to broadleaf plants, which means anything but a grass.

The particular weedkiller was probably 2,4-D, also know as Agent Orange (less cheerful-sounding), which is a synthetic category of plant hormone called auxins. At the right concentration and at the right time, whether natural or synthetic, auxins do good things, such as bending plants towards light, initiating root growth in cuttings and in growing plants, and promoting upward growth Otherwise, they can wreak havoc.

I phoned the university extension specialist and was advised to remove the mulch and to adsorb any escaped 2,4-D by mixing activated charcoal into the soil. I did so and subsequent growth was normal.

Home-Grown vs. Imported Hay

I now have the luxury of scything much of the organic material I need from my own one acre field. Early season mowings are succulent and nitrogen-rich, just like grass clippings. Later mowings are hay, dry and carbon-rich. During the growing season, depending on what and when I mow, I can harvest either end of the spectrum, or anything in between.

Wood chips are another good source of organic material, one free of chemicals

I no longer rely on roadside mowings as organic material for my plantings. They are nowadays too finely chopped for easy and fast scooping up with a pitchfork. Even if that were not the case, I would have second thoughts about bringing such hay on-site. Again, weedkillers are the threat, more insidious these days because of use of more persistent ones. So-called pyridine carboxylic acid weedkillers might hang around in the soil or on sprayed vegetation for anywhere from less than 30 days to several years, even in the manure from animals that have eaten sprayed vegetation!

Caution, Testing, & Time to Avoid Problems

I do still occasionally supplement home-harvested organic materials with imported ones. One source is horse manure from a local stable.

A few weeks ago I was pitching forkful after forkful of manure into the bed of my pickup truck when I glanced over at the far side of the pile and noticed some discarded hay, much of it still pressed together in partial bales. “How convenient,” I thought, for mulching, compost, or bedding for my chickens and ducks.

On my drive home I started thinking about that hay riding behind me. Could it be laced with weedkiller?

For the most straightforward answer, I could just ask the stable owner. A stable hand told me that the hay had been shipped from a few hours away. Rather than cross examine my manure donor, I looked closely at the hay to see if any clover, alfalfa, or other broadleaf plants were mixed in. No. Of course, lack of broadleaf plants does not prove that weedkiller was used.

Well-formed leaves indicate that the hay is free of chemical residues

My final recourse was to do a bioassay of the hay, essentially, to plant seeds in it and observe their growth. Two 4-inch flowerpots, one with chopped up, homegrown hay and the other with the chopped up, imported hay, served as growth media, into which went 3 bean seeds each. Long story short: Growth seemed normal in the imported hay although germination was slower, probably because its texture lent itself to more readily drying out.

To put my mind thoroughly at ease about the hay, I’m going to let the pile sit for a few months, where rain, sun, and, eventually warmth, can do their job in splitting apart the insidious weedkiller molecules. The hay is not for my compost, in the dark innards of which weedkillers, if present, would be particularly persistent.

Autumn Leaves, Good Stuff

Just like the old days, I do still import organic materials in the form of bagged autumn leaves — except a lot more these days. They are both weed- and weedkiller-free.

New Video from Last Summer: Grape Training & Pruning

If you’d like to join me on a brief journey back into summer, see www.leereich.com/videos for a new video, I made last summer, about how to prune that quintessential summer vegetable, tomatoes, just like the Godfather.

COMPOST, FERTILITY, & SUSTAINABILITY

October 24, 2014/13 Comments/in Gardening, Soil, Vegetables/by Lee Reich

Compost and/or Living or Dead Organic Material = Sustainable Fertility

Maple leaves already dapple the ground in red and yellow (early this year), one morning showed off what was to come with frost on the windshield, and each day the sun each hangs lower in the sky, yet I’m getting ready for spring planting. Really! Yes, I’d rather do it now than in spring.

Beds of spent vegetables have been cleared. Okra plants, in this cool weather, just sat in place, hardly producing any new pods. So out went the plants. I severed the main roots with my hori-hori knife (www.oescoinc.com) and yanked out each stem. When corn is finished, it’s finished. Beds of early corn got replanted with endive, lettuce, and other late vegetables, but the latest beds of corn were harvested too late for replanting. Clearing away old vegetable plants not only clears the deck for next spring but also takes offsite some pests and diseases that might otherwise lurk around next year to do their evil work.

Clearing bed of all weeds and plants in preparation for its layer of compost.

With spent vegetable plants cleared away — tomatoes and peppers are still yielding fruits, so they remain for now — I remove weeds. Ideally, all of them. Left in place, annual weeds spread seeds and roots of perennial weeds grab more tenaciously and deeper into the soil. A single pigweed plant, for instance, can drop 120,000 seeds, poised and ready to invade next year’s garden. That, and the 36,000 seeds on every plantain plant, the 39,000 seeds of each lamb’s-quarter plant, and the 8,000 seeds clustered in a crabgrass seedhead prompts me to pull these weeds now, before more seeds mature.

Of course, some weeds escape my notice, so the final step in preparation for spring is to suffocate these: I slather each planting bed with a one inch depth of mostly weed-free compost. A temporary 2X4 at each edge of the bed keeps the compost neatly in place until patted down firmly.

The compost does more than snuff out overlooked weeds. Its biotic life helps protect plants against pests and diseases. It helps soils hold water and air. And it feeds plants a smorgasbord of nutrients.

On a Garden, Farmden, or Small Farm, Fertility Simplified

Did I mention spreading fertilizer, “organic” or otherwise, in getting the soil ready for spring planting? No. A one-inch depth of compost supplies all the nutrients needed to grow vegetables, even in beds with closely spaced plants. Paraphrasing the Beatles lyrics, “All you need is . . .compost, da, da, da-da da.”

Bed in middle has been lathered with an inch depth of compost, left on surface.

A garden is not Mother Nature left to her own devices; nonetheless, I try to emulate her as much as is practical. She does not spread fertilizer. Plants are naturally nourished as organic materials, such as leaves, stems, wood, roots, and dead animals, decompose to release whatever nutrients gave them life. I enjoy making compost and make enough to spread that required one-inch depth over all the beds.

Next best would be to spread some concentrated source of the most needed nutrients, that is, “fertilizer,” on the ground and supplement it with a mulch such as wood chips, straw, hay, or other organic material. Here, an organic fertilizer, such as soybean or alfalfa meal, has the advantage over a chemical fertilizer in that nutrients become available over a long time and are made so in response to temperature and moisture, in synch with plants’ needs.

Two advantages of maintaining fertility with compost rather than mulch plus fertilizer are that seeds are more easily planted directly in the compost and compost, if made from a variety of feedstuffs, provides a wider spectrum of nutrient for the plants.

Cover Crops, Used Correctly, for Even Large Farms

A wheat farmer in Montana is not going to be spreading an inch of compost on his 1,000 acres, or even soybean meal and a mulch of straw. Agriculture is a balancing act, again, not Mother Nature but not disrespecting her either. In the case of a wheat farmer, or any large scale farm, cover crops are a practical route to healthy soil.

Cover crops are plants grown specifically to maintain or improve a soil. Cover crops may occupy the ground for part or for the whole season. As they grow, their roots push through the soil to break it up and, upon their death, leave channels for air and water. Roots exude natural compounds that stimulate a a wide population of beneficial microbes and release nutrients from the soil’s rocky matrix. Leguminous cover crops garner nitrogen from the air into a form that plants can gobble up. And once dead, deliberately or with age, cover crops can maintain or increase all important soil organic matter.

Oat cover crop in one of my beds.

The devil is in the details. Killed too young, while still lush and green, a cover crop adds nothing in the way of soil organic matter (but does protect the soil surface from erosion). Tilling a cover crop into the soil, a common practice, might burn up more organic matter, by giving the ground a big burst of oxygen, than is added by the cover crop, whether the cover crop is young or old. And then there is the choice of cover crop itself for regional adaptability, for shading out weeds, or for beefing up a poor soil.

How about this? Set aside a separate area for cover cropping each year. Or set aside a separate area for cover cropping, but mow the plants one or more times through the growing season to provide mulch or feedstuff for compost. With enough land and suitable mix of cover crops, including legumes for nitrogen.

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“Sustainability” is a buzzword these days. Nourishing the ground with nothing more than annual sprinklings of chemical fertilizer not sustainable in terms of long-term soil health and because synthetic fertilizers require fossil fuels in their making. At he other end of the scale, primitive slash and burn agriculture, where land is cleared and burned, crops planted for a few years, then the site abandoned for a new site, is sustainable. But you need enough land to be able to leave time for the soil to naturally regenerate before another slashing and burning. In our “advanced” culture, recycling organic materials back to the land is also sustainable. It’s just a matter of getting the materials back into the soil, as compost or more directly, but not to a landfill or an ethanol (gasahol) factory.