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A high-protein legume suited for ecological agriculture
The following article grew out of response to one published in Rural Delivery last December. "Danger: Nitrates!," by David Patriquin, told of the work of Basil and Lilian Aldhouse on their egg and grain farm near Lawrencetown, Annapolis Co., N. S., in developing a grain production system without manufactured fertilizers or pesticides.
by Basil Aldhouse and David Patriquin
Fababeans are being promoted as a major crop in western Canada but are relatively unknown in the Maritimes. That's surprising because they were first grown commercially in Canada by a Nova Scotsman farmer, and because by and large, growing conditions are more favorable for them here than in western Canada.
The fababean is a long season legume which cannot be grown everywhere in the Maritimes, but where it can, has much to offer--three tonnes per hectare of high protein seed without use of fertilizer-N.
For reasons we will discuss, it is easier to manage without a lot of intensive inputs then with them, end thus has even more to offer farmers practicing ecological agriculture ("Ecological Agriculture" refers to systems which rely mainly on natural biological processes for the maintenance of fertility and control of pests) or contemplating doing so--or at least we think so. We are not professional agrologists, and our suggestions are not intended to be professional recommendations for growing a particular crop. Rather we want to illustrate some of the principles of ecological agriculture by reference to a particular problem and we hope that this will stimulate more experimentation with ecological tech piques.
The fababean is a small seeded relative of the broadbean (Windsor bean), a garden vegetable familiar to many Maritimers. It is more closely related to vetch than to common garden beans. Pods are borne along the length of strong erect stems, and contain three to four seeds, each about the size of a pea. They are easily threshed.
Protein content of local varieties averages about 26.5 percent. Roughly two kilos of fababeans is the equivalent of one kilo of soybean meal and one kilo of barley. This ratio is useful in feed formulation and for estimating the cash value of the crop. The protein is high in lysine but low in methionine, so that high methionine supplement (e.g. 5 to 12 percent fish or soybean meal) has to be included with the beans in poultry and hog formulations, but not for ruminants. The whole plant can be made into silage. Agriculture Canada Publication 1540, "Growling and Using Fababeans" should be consulted for more precise nutritional information.
As in other legumes, the roots of fababeans are infected by symbiotic bacteria and the resultant nodules "fix" nitrogen from the atmosphere. The fababean is especially good at this, fixing 100 to-200 kilos of nitrogen per hectare. For use as green manure, the plant may be turned in at the flowering stage. By this time it has accumulated 50 to 150 kg nitrogen, part of it coming from the atmosphere and part from the soil.
Two important advantages of fababeans over soybeans are 1) they can be handled with small grain equipment, and 2) special processing is not required. (Soybeans require heat treatment to break down anti-trypsin factors.)
Fababeans require cool to warm, moist growing conditions and are tolerant of late spring frosts. Generally where corn can be grown, fababeans can-;be grown, but unlike corn, they should be planted as early as possible and by about May 15 at latest. Also, fababeans are not as tolerant as corn of high temperatures. During flowering and pod set, roughly from late June to early August, fababeans are very susceptible to heat and moisture stress. In Nova Scotia, soil moisture can be expected to be severely limiting during this period in less than one year out of 10. The plant begins to suffer from heat stress when temperatures approach 306C, a factor which could be critical In some parts of the Maritimes.
Flowering is indeterminate (along the stems) and pods ripen from the bottom of the stem up. By the end of August when bottom pods are just beginning to turn black the plants can be harvested whole for silage. Alternatively they can be left to ripen and dry sufficiently for combining. Most years combining is completed-by the first or second week in October and runs little risk from weather related problems.
The fababean is one of the oldest of cultivated crops. It has been grown in Europe, and in the cooler regions of (or in the cool season) North Africa, South and Central America and in Asia, for food, animal feed, hay, silage and green manure.
Until this century it was the major high protein seed crop in Europe. In 1866 fababeans were grown on 10 percent of tilled land in the U.K. That declined to less than one percent in this century, largely because of the availability of cheap feed protein from overseas. Interruption of supplies and fluctuating prices for soybean and fishmeal in the seventies promoted new interest in the crop in Europe and the U.K.
Rob Warren at Belleisle, Annapolis Co., N.S., appears to have been the first to grow fababeans commercially in Canada, and perhaps the first in North America. Rob has included them in rotations with corn, oats, wheat and hay on tile and mole drained dykelands since 1967. Whether he can continue to do so is uncertain: the fababean is especially salt sensitive, and he is justifiably worried about the effects of Tidal Power manipulation (from the pilot project at Annapolis Royal) on the drainage and salinity of his land.
Encouraging results from field trials with fababeans in western Canada in 1972, combined with increased costs of soybean meal, led to serious and continuing efforts there to establish fababeans as a mayor prairie crop. By the late 'yes they were being grown on more than a hundred thousand hectares. However, the crop has not been the immediate success that had been hoped for. Yields in excess of four tonnes per hectare are not uncommon, but averages are often much lower (one to two tonnes), due to heat or moisture stress during flowering, or to suboptimal temperatures early in the season. It is anticipated that an intensive breeding program established in Manitoba will produce varieties better suited for the prairies.
In spite of the generally more favorable climatic conditions for fababeans in much of the Maritimes, and of its early commercial start here, fababeans are grown by only a handful of farmers. More experimented with the crop in the seventies, but obtained bad yields or had other problems with it.
At Belleisle, and at Tunwath (see RD December 1984) in Lawrencetown, N.S., good yields were obtained initially and seed yields have in most years been two and one half to four tonnes per hectare or better.
Below we discuss six possible reasons for poor performance of fababeans. We assume first of all that the soil has a pH of six or greater, and that K and P are adequate. Fertilizer-N is not normally applied to fababeans, even as "starter."
1. Poor nodulation: the fababean is a legume, and to grow properly, the roots must be infected by a particular type of soil bacterium. If they aren't, plants are likely to be stunted and yellow. It is conventional practice to inoculate legume crops the first time they are grown. After that you shouldn't need to inoculate because they multiply tremendously in the process of nodule formation and decay and then survive between crops in the soil.
Regardless of whether you inoculate the crop, it's a good idea to pull up some flowering plants to see whether they have good nodules (see Fig.). If they don't and you did inoculate, then the inoculant may not have been good. It's a good idea to keep some of the inoculant stored in the fridge, so that it can be later tested if it did not appear to be effective.
2. Chocolate Spot: This fungal disease is not likely to be a problem except in excessively moist regions. Rob Warren had a problem one year when he planted the MINDEN variety on his dykeland where there is a lot of fog. Subsequently he used the MARIS BEAD variety which is quite resistant to Chocolate spot, and had no recurrence of this problem.
3. Herbicide residues from previous cereal or corn crops, or drift, can be especially detrimental.
4. Residual fertilizer-N from previous crops can make stems succulent and plants difficult to combine. This isn't a problem if plants are cut for silage.
5. Aphids. These have frequently been cited as a reason for crop failure. They can be controlled by insecticides, but application must be timely for control to be effective, and so as not to interfere with bee pollination (plants are typically 70 percent self-fertilized, and 30 percent cross-fertilized by bees).
6. Weeds. It is often stated that beans encourage weeds or do not compete well with weeds. Treflan was registered for use with beans but is not effective against some of the broad-leaved weeds. The current (1984) "Guide to Chemical Weed Control" contains no reference to fababeans.
Sometimes it can be difficult to obtain inoculant for fababeans or the inoculant may not be completely effective. This is not too much of a limitation in the Maritimes because probably a third or more of the soils contain the fababean nodule bacterium in sufficient abundance to give good nodulation without use of inoculant. Probably most soils contain it in at least low numbers. A good indication of its presence is the occurrence of vetch, which is infected by the same type of bacterium.
Sometimes the first planting of fababeans gives plants that are highly variable in size and nodulation. The bigger plants may have abundant nodules at the top of the tap root while smaller plants have no nodules, or nodules are restricted to the lateral roots (see sketch). In such cases, the right type of organism was in the soil (or was established by inoculation), but not in sufficient amount to give a uniformly good crop the first year. This first planting will result in great proliferation of the organisms, and there should be good nodulation in that field if beans are planted there the next year.
One way to multiply organisms in this way without wasting a lot of seed is to make a light planting (e.g. 25 kilos per hectare, broadcast or drilled) the year before a regular seeding. This could be done in August after a winter crop is harvested, for example, or seed could be mixed with that of a summer crop.
Seeds could be inoculated if you suspect or have previously determined that the proper organism is not present. The inoculant organism and/or organisms present in low numbers in the soil will multiply with this light seeding and there should be uniformly good nodulation when a regular seeding is made the next spring.
If you are not in a hurry to harvest a regular crop, much can be learned by hand sowing a number of small plots (e.g., two to three meters squared) on several fields, including some inoculated ones if you can. The stature and nodulation of plants can be compared at flowering, and seeds can be collected in September to give an estimate of potential per hectare yields (Assuming 40 seeds are planted per square meter, 30 plants mature, and seeds are collected from 15 plants, the per hectare yield in kilos per hectare will be 20 times the weight of those seeds in grams).
Problems three through six are most easily dealt with in an ecologically managed system. To begin with you don't have herbicide residues. Secondly, it would be normal to plant beans after a non-leguminous crop in which case there should not be an excess of free N in the soil.
At Tunwath, beans are planted after winter wheat. The wheat residues are incorporated by rotovating followed by ridging in the fall. In conventional systems, wheat residues are often burned or removed because they can inhibit subsequent crops through phytotoxic effects, and by tying up N.
Fababeans do not seem to be bothered by the phytotoxins, presumably because of their large seeds. The tying up of nitrogen and release of carbon dioxide by microorganisms growing on the decomposing straw actually enhance nodule formation and nitrogen fixation.
Viewed ecologically, an aphid problem is indicative of too much uniformity in a system. The solution is to break that uniformity up, both in time, and spatially. A variety of habitats should be provided so that a healthy balance of predators and potential pests can be established.
At Tunwath, black aphids invariably invade a few or many plants on the periphery of fields in July, and occasionally it looks as if they will do the crop in. But just as invariably, they are followed by predators and parasites and disappear as fast as they appeared. The low levels of weeds that are purposely tolerated on the farm appear to be important in this process, and so are the crop rotation, the smallish fields, and the interspersion of those with woodland, meadows and streams.
Weeds do not have to be a problem in legume crops. The legume's use of atmospheric nitrogen gives them a natural advantage over weeds--provided there is not a great deal of free nitrogen in the soil to stimulate the weeds. The fababean has two further advantages: 1) it can be planted early (the earlier the better), allowing it to get a jump on some of the more difficult weeds and 2) it has an erect habit which will shadow the weeds if plants are seeded closely.
At Tunwath, beans are drilled (three inches depth) in seven inch rows at a rate of 224 kilos per hectare (200 lbs. per acre). This results in 25 to 35 plants per square meter at maturity. The fields are harrowed, weather permitting, about seven days after planting using a coil spring harrow (a less aggressive version of the spike tooth harrow) working about an inch deep -- this (hopefully) avoids damage to the growing tip. They can be and often are harrowed again with the same harrow when about three inches high.
The fababean is quite tolerant at this stage and sustains little damage. Even with this treatment, the crop may look weedy towards the end of June. But unless there is residual fertilizer-N present, the legume soon takes over, and by mid-July forms a closed canopy.
Fababean seed is expensive. Add to that the general lack of familiarity with the plant in this region, and the peculiarities involved in the nodulation process, it makes sense to grow it on a limited area the first time round. As well, it makes sense to give it at least a second try if the first is unsatisfactory. In the process, more seed can be grown, and potential problems such as those discussed above, identified.
Fababean seed is available through a number of seed houses. However, as it is not a regular item for many dealers it is a good idea to order seed and inoculant early.
Because of their nitrogen-fixing capabilities, legumes are a cornerstone of ecological agriculture. Where it can be grown, we think the fababean is a particularly good legume for ecologically minded farmers, and we do think it could be grown and used more widely than it is. However, it will not be suitable for all soils or all farmers. There are many other legumes that can and are being used in the Maritimes, and there are many ways to incorporate them in an ecological farming system. For further information and ideas on ecological farming, we recommend the following:
"Earthcare: Ecological Agriculture in Saskatchewan." $13 plus postage from Earthcare, Box 1048, Wynyard Sask. SOA 4T0. This an invaluable guide to ecological farming, incorporating extensive scientific literature, and documenting experiences of ecological farmers. It is written from the West, but there is much in it that is applicable to the East.
"The Rest Of The Story," by Dr.Harold Willis, available from the author (Box 692, Wisconsin Dells, Wisconsin 53965). Corn and western oriented but a lot of basic principles of use anywhere.
Two monthlies dealing exclusively with ecological agriculture are The New Farm, 33 East Street, Emmaus, PA 18049, ($15 Canadian per year), and Acres, USA, 10008 East Terrace, Raytown, Missouri 64113 ($15.50 US per year).
Copyright © 1985 Rural Delivery. All rights reserved.
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