We asked field-day participants what their experiences and challenges were with cover crops. Here’s some of what they had to say:
• A researcher in Hawaii reported using Sudangrass and sunhemp in Maui, where, he reports, all the biomass is aboveground, and labor and input costs remain high.
• A small-scale farmer with just a few acres who produces for her local farmers’ market reported that she has yet to try cover crops. She currently uses composted leaf mulch for weed suppression at the beginning of the growing season and applies it again two to three months into the season when the first application begins to disintegrate. (What few weeds do make it through, she said, diligently get pulled. She also makes her own compost with “kitchen scraps and chicken manure.” )
• Another researcher reported two major challenges in working with hairy vetch and rye: fitting the cover crop into the rotation, and weed-management issues.
• One farmer reminded the group of another great benefit of having a rich microbial community in your soil from good cover-cropping. As microbes complete their life cycle, the exoskeletons they leave behind yield 10-percent nitrogen as they decompose. (Speaking of nitrogen, another farmer counseled, you have to make sure it’s available to your crop plants at the time that they need it.)
• Another farmer reported using Sudangrass to effectively squelch a thistle problem. The fast-growing annual grass also gets cut back (at about 4 feet) and used as a mulch.
• One researcher reported working with grain triticale and vetch in a conventional cropping system. Winter rye, he said, is suitable both as forage and a cover crop. (A West Coast farmer added that rye can come back quickly and become a problem—particularly under irrigation—and that it’s a common allergen.
• A representative from the soil conservation district in Maryland’s Baltimore County reported that her agency was offering cost-share incentives for growing rye for seed because of shortages in supply. The agency is promoting rye as a cover crop because of its ability to hold soil and protect water quality by keeping excess nutrients and agricultural chemicals out of the Chesapeake Bay. A big challenge, she said, is convincing farmers of the economic, as well as the environmental, benefit. “There are a lot of opportunities out there,” she said, “but people just miss it.” (In response, one participant reminded the group that farmers are constantly bombarded with messages from chemical companies and major seed businesses, and are “made to feel like total idiots if they don’t embrace all the technologies…while people are starving.”)
• A home gardener reported using crimson clover, an early-blooming winter annual legume. He enjoys the flowers, then pulls the plants up by the roots and uses it to mulch his vegetables.
• Another home gardener reported using wood chips from his local municipality. (To this comment several people cautioned against the allelopathic properties of certain trees such as black walnut, crepe myrtle and even pine needles).
• An extension agent said she encourages her growers to use rye and rye grass as companion crops for vegetables.
• A conventional farmer reported direct-seeding pumpkins into rolled winter rye. He rolls with a cultipacker and either spins on nitrogen fertilizer or runs it through drip lines, then uses herbicides for weed management.
• A Natural Resources Conservation Service (NRCS) agent reported using newspaper and straw mulch at home in the garden and promoting winter annual cover crops to farmers in New Jersey. Obstacles reported included proper synchronization of the cover crop and cash crop, finding the time to get the cover crop in the ground before a hard freeze, and the lack of a family tradition (i.e. “My father and grandfather didn’t do it, so I’m not going to do it.”). With regard to finding the time to plant a cover crop in the fall, he said, “The farmers’ market is open until Thanskgiving, the help goes back to school, and time is very limited. They know they should be doing it, but they just can’t get it done.”)
• One Extension specialist reported a renewed interest in the aerial seeding of cover crops, particularly canola. “It’s a small seed, you don’t need much seed-to-soil contact, and there’s lots of seed per pound,” he said.
• One farmer reported using buckwheat and Sudangrass at various points in the growing season to assure that the soil is always covered. “I don’t like to leave the soil bare or covered in weeds,” he said. “I don’t get any return [from the cover crops], but I sleep better at night.”
• A woman who, with her sister inherited 112 tillable acres, reported that they transitioned the land to organic and rented it out to a farmer as a “way to make money and pay the taxes.”
• Another farmer reported drilling rye, hairy vetch and “sometimes oats” as cover crops. Problems included “the perpetuity of vetch,” thanks to hard seed that germinates years after it falls. (At that there was some debate about whether vetch was toxic to grazing animals, with the general consensus being that most animals avoid it anyway because of the high tannin content.)
• A gardener reported using dried black beans bought in the grocery store. They germinate fast, he said, and are easily winter killed, adding that they form nodules to fix nitrogen without needing purchased inoculants. He said he plants peppers and tomatoes right into the mat they form.
• Another backyard gardener reported using short white clover very densely in the rows between the vegetables.
• Adaptive equipment, and its cost, was cited as another barrier to utilizing cover crops. To move forward, someone offered, adaptation of equipment already in the tool barn could be a necessity.
• One Extension agent reported that conventional no-tillers are beginning to look at cover crops such as rye and crimson clover. Turbo tilling and managing high levels of residue are strategies these farmers are using as a way to get manure incorporated into a no-till system.
• One farmer reported planting pumpkins into rolled rye. He also reported problems with late-season weeds such as pigweed, which he says he generally lets go.
• An NRCS agent from New Jersey reported farmers there experimenting with planting cover crops between black plastic mulch, which is tough on the soil and can cause erosion problems. The cover both controls this problem and adds organic matter. (To this someone reported a farming operation in the northeast using cereal rye and black plastic. They sickle bar the rye and put it over the plastic, increasing the mulch’s use for up to five years.)
• A self-described “conventional guy” said he practices (vertical) turbo tillage through residue. “I think that’s part of the answer. It makes it look a lot nicer so, if nothing else, my neighbors don’t think I’m a ‘garbage farmer.’” He said he plans to get a stalk chopper in order to better incorporate crop residues into the soil. “It’s all a matter of how much money you want to throw at it,” he said, adding that more intensive management meant more equipment on the road, another significant concern, where time, money and safety are concerned.
• Timing is a huge issue, one farmer suggested, adding that he is looking into aerial seeding. “You have to do that cooperatively,” he said. He’s found that “it’s hard to change hearts and minds,” when people are stuck in old paradigms.
• A research agronomist said he put out pans to check the efficacy of aerial seeding and that it was spot-on at a prescribed seeding rat of 14-16 pounds per acre.
• One farmer reported using rye and hairy vetch, and that a customer of his who planted corn into hairy vetch experienced some problems with cutworms.
• Another farmer reported planting wheat into soybeans in the fall. After the wheat comes off, he said, sorghum is planted into the wheat stubble, then that gets tilled in and is followed by either alfalfa or hairy vetch.
• “Most of my cover crop is my crop,” said one animal forage and nutrition expert, who described his system as a perennial polyculture. “Sudex is one of the best summer forage crops you can grow around here” to overcome the summer doldrums of low forage productivity.
• Weed management and soil fertility were listed as top cover-crop attractions for one farmer. “You’re capturing energy from the sun, and you don’t have that bare soil sitting there,” he said. “It just seems like the right thing to do.”
The first thing each of the jigsaw groups identified about soil heath is that it is very much a subjective term. The first step in improving soil heath is to define your parameters and determine what you want to measure. Attendees stressed that it is also important to know what is possible on your own farm (for example, when looking at yield as an indicator, you can grow many more bushels of corn in the Midwest than you can in Pennsylvania.) Most attendees suggested before doing any measurement, you should know your baseline so you can set appropriate goals to which you can aspire.
One woman suggested the very best soil health plans include some additions and some omissions. She said creating healthy soil is really a process of maintaining the structures that naturally exist in the soil.
Sensory cues are one way to see what is happening to your soil. Some good sensory cues are:
Testing is another way to begin measuring the health of your soil. Attendees suggested the following tests:
Once you have your baseline through tests, observation or both, you can then begin to integrate good practices such as the following for improving soil health.
One farmer said when you grow 25 different vegetables it’s hard to keep track of what each plant needs. She said keeping it simple and cost effective are the easiest ways to build the soil health without driving yourself crazy. Whatever you chose to do, everyone agreed, it has to make economic sense. Spending a lot of money on expensive inputs might get you healthy soil quickly, but it might also put you out of business. Improving the health of your soil the smart way requires patience and long-range planning.
Soil building etc.
Fascinating comments. The toughest thing can be finding the time to get cover crops seeded (particularly in a wet season like this one).
Roughly half of our land is maintained under perennial forage cover (hay+pasture). Look in between the forage plants, and you find the surface littered with worm castings. Three weeks after spreading composted sheep manure, it is hard to find much evidence of manure on the surface--I assume the worms have "dragged it down".
Here's a short article prepared for OCIA several years ago, based on our experiences with extending the pasture season. Not exactly a cover crop, but in some ways related.
Kale/ryegrass combination extended grazing season
Forage brassica species are being used by a number of livestock producers to lengthen the grazing season.
We’ve frequently grown a small acreage of fodder kale for our sheep. This crop grows rapidly under cool fall weather conditions, and withstands fairly hard frosts. We’ve had sheep grazing until mid-December, knee-deep in snow and happily munching away on the leafy kale.
Research has shown that kale does best when grown as a row crop. That has also been my experience. Wider row spacing minimizes tramping, and seems to produce more forage than a solid seeding.
Weeds can be a problem with wide row culture. Because kale growth is slow during the hot summer months, weeds can really get ahead of the crop.
Inter-row cultivation will keep weeds in check, but I wanted to look at an alternative approach. Last year, I planted annual ryegrass between the kale rows to smother weed growth. I hoped that the ryegrass would also serve as a palatable addition to the kale pasture.
Approximately four acres were set aside for this purpose. The gently rolling land where the kale/ryegrass combination was seeded varies in texture from a fine sandy loam to a clay loam. The field had been in sod for at least a couple of decades.
A liberal coating of composted manure was applied to the land during a narrow window of good April weather. After that, the trials and tribulations of the growing season began. May was unusually cold, and wet enough to keep us off the land until the last week of the month.
Once conditions improved, the manured sod was moldboard plowed. Then came the drought! For the next six weeks, the only moisture we received was dew. I cultivated the freshly plowed sod, but it was simply too bone dry to risk seeding.
We received a good rain in early July. By the middle of the month, I was finally able to plant the four acres. That was about three weeks later than normal.
The kale was seeded through the grain drill’s grass seed box at approximately 4 pounds per acre. The appropriate runs were blocked off to produce 28-inch row spacings. The common annual ryegrass seed went through the grain box at 10 pounds per acre. (The grain box runs over the kale rows were blocked, of course.)
The ryegrass germinated quickly, but kale emergence was slower and more erratic. The weather turned dry again after seeding, and stayed that way right into September.
By mid-September, a reasonable stand was established. A month later, we had a lush stand of forage. The ryegrass was waist high. The kale plants were even taller in the best parts of the field. The later-emerging kale was behind, but still promised a fair amount of grazing.
Winter was starting to flex its muscles by the third week of October. This was the third year in a row that winter had started early. We decided to turn the sheep in before November, as had been originally planned.
Electrified polywire was used to strip graze the field in eight replications. The four acres provided 3-1/2 weeks of lush grazing for 160 bred ewes. I had hoped for more production from the seeding. However, the late-season pasture did keep the sheep out of the hay mow for almost a month. With a better seedbed and more favourable growing conditions, production could probably be doubled.
Conclusions and suggestions
The ryegrass did an excellent job of suppressing weed growth. Sheep readily consumed both the kale and the grass.
The common ryegrass seed used last year must have been the hay (Westerwolds) type, because its stems elongated and it put on seed. It would be better to use the Italian type of annual ryegrass, which tends to remain vegetative.
Mid-June would likely be an ideal time for seeding this combination. The ryegrass might put on too much growth if planted earlier. Kale and ryegrass both grow slowly during July and August, then take off with the arrival of cooler fall weather.
The direct expenses associated with this annual pasture combination included land preparation and seed. We already had the fencing materials on hand. By my calculations, total costs worked out to $30 per ton of dry matter. That’s a pretty reasonable price for high quality forage. With higher production under more favourable growing conditions, the cost per ton of forage would be further reduced.
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Cover crops for subtropical climates
Any ideas on this ? My father in law has some few acres in Mexico in an area growing a lot of sub tropical products like coffee, banana, and other subtropical fruits, but the basic staple is maize. Any suggestions as to cover crops in that kind of environment ? Currently they are simply not used at all. So when the rains come, away goes a lot of the top soil. Terrain is mountainous so equipment access is limited, no tractors and so on! What is causing the most problem is a question of pure economics, and what I am trying to correct is the use of very expensive chemical fertilizers which are every month more expensive. Needless to say my father in law is not convinced ! No herbicides or pesticides are used. But a lot of hand labour. And they plough the land with oxen to prepare for planting the maize which is quite expensive as well. There is a dry season which runs from October through April with the last two months really horrifically dry, often drought. (April or May to October is a time of really heavy almost monsoon like rains, and is the growing season traditionally.) The drought leaves no food for farm animals: this year we planted as a trial half the large plot with maize, and then 1/4 with habas (broad beans with nitrogen fixing capability and an edible and saleable product) and the remaining quarter with oats. Two months of drought left us with the maize and oats very severely checked and the beans gone ! When the rains came, the maize caught up very quickly and provided the hurricanes dont blow the maize down, that will give a reasonable crop, and the oats recovered enough to give some animal food but really not much. The soil really needs organic matter to retain the moisture better.
The peasants in Mexico(in general) have never been given more than free or heavily subsidized chemical fertilizers. So they simply dont understand the importance of composting or of cover crops. In years gone by, a simple sulphate of ammonia was enough, but now they need an NPK type fertilizer, which I suppose shows that the soil has been losing minerals over the years, apart from washout of topsoil.
I read your Rodale letter with enthusiasm and wish you all the very best. I realise that Pennsylvania conditions are hardly comparable, because of the high rainfall in the rainy season. But maybe someone has some ideas ?
In the rains, the weeds grow like nobody's business.
Oh and if you believe that this is an unprofessional letter, I am from the UK, educated in Mediaeval History (which should help me in the campo !) but have lived here for thirty years ! Though I do come from an agricultural background, I have never been more than a keen gardener !
cover crops
I just read your question ...www.echotech.org seems to have a lot of helpful information for growing crops in difficult areas of the world. I hope you have found some help.
Re: Rye as a winter cover-crop
Since rye is so useful in helping to crowd out weeds like quack grass. In heavy soils should the season get away because of excess spring moisture you can follow the rye with buckwheat this I feel makes an excellent strategy to re-establish and re-invigorate weedy ground.
It may also be of interest to note that quack grass is host to the organism that causes ergot in the rye.
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