From Ecology Action
Thanks for all the great questions about how livestock relate to biointensive farming!
Q: How can livestock integrate into the GROW BIOINTENSIVE® system?
A: Livestock can fit into a GROW BIOINTENSIVE system, but it usually takes a larger area. Normally it takes about 40,000 sq ft of grazing land for 1 cow/steer (for milk/meat) or 2 goats (for milk/meat/wool), or 2 sheep (for milk/meat/wool). With GROW BIOINTENSIVE and maximizing the edible calorie output in your diet design, one person’s complete balanced diet can be grown on about 4,000 sq ft—a much smaller area.
The challenge is that 90% of the world’s people by 2014 will only have about 4,500 sq ft of farmable land per person, if they leave and equal area in wild to protect plant and animal genetic diversity and the world’s ecosystems! As you will see from the information that follows on the land requirements for incorporating livestock, this becomes a challenge.
Q: Can you grow food for sheep, goats, or cattle with the system?
Q: How much square footage does it take for each animal?
A: We have not researched the area it takes to feed all animals. The amount and types of food an animal eats is important to know. Animals that can forage, and have a diverse diet, may require more area from which they can obtain total calories, although the percentage of food you have to grow to feed them should be less.
One idea that has been presented in the past is the sharing of an animal for its products by several families, as in Ecology Action Booklet 28, How to Grow All Your Food and Feed by Emmanuel Omondi. In this way each family can cultivate a little extra land, contribute to the feeding of the animal and greatly reduce any unsustainability involved per person
Chickens are the easiest to raise. Their feed can be grown in the least amount of space, their housing requirements are minimal, and their ability to roam freely and supplement their feed with insects, weeds, and other forage gives them appeal in a family food regimen. Backyard Homestead p. 11, Table 3 indicates that 2 eggs per day requires 3 hens eating 120-300 lbs of grain annually, grown on 600-3,000 sq ft, with chicken foraging under supervision. The total amount of grain required for the chickens varies depending on how many weeds and insects they eat while foraging and the yields of the crops raised for them.
Generally, in conventional farming, two gallons of milk daily may be produced by one cow (or two goats) on about one acre (43,560 sq. ft.) Using GROW BIOINTENSIVE fodder raising practices with root crops included in the animal’s diet, special feeding techniques for the animals and special fodder harvesting techniques might reduce this area by 50% or more.
This may be accomplished through:
- Increased GROW BIOINTENSIVE yields;
- The use of weight- and area-efficient calorie-concentrating plants (such as using a certain percentage of rutabaga and/or turnips in the animal diet);
- Multiple, small-amount feeding techniques (see Mackenzie, David. Goat Husbandry. London: Faber and Faber, 1970); and
- Voisin harvesting techniques (Voisin, Andre. Better Grassland Sward. London: Crosby Lockwood & Son, 1960 and Voisin, Andre. Grass Productivity. New York: Philosophical Library, 1959).
No one has yet put all of these methods together—though each one has been tried and most have worked well.
Raising a chicken to 4 lb for 2 lb of meat generally requires 4.2 lbs. of feed per pound of live weight (averages are for the Rhode Island Red roosters and chickens). This translates into an average of 16.8 lbs. of feed per week for a family of 4. Multiply this by 52 weeks in a year and the result is just under 874 pounds of feed. Should half of the feed come from corn and half from wheat, the total area required would amount to 6,940 sq. ft. (69.4 beds).
Q: Does the area scale with the weight of the animal?
A: Yes. Growing food for livestock and people, as well as all the material necessary to keep all this growing space fertile through compost creation, can double to quadruple the area needed to grow a diet, depending on the quantity and type of animal products introduced into the diet. In some cases there can be up to a ten times increase in the amount of land required.
Q: Can you work the manure back into the system, substituting for compost?
A: Manures can be used for a portion of the immature material needed for a pile, but we recommend not exceeding 1/6 the pile's volume in manures—and it is best for the fertility of the soil if it is not used at all1.
The use of manures is complex. Here is an example of how it works: In conventional chemical and organic farming a cow eats the fodder produced on approximately an acre (43,560 sq ft), which contains a “giga unit” of carbon. When the cow eats this fodder, one-third of the carbon is lost through the cow’s metabolism and only two-thirds of a giga unit of carbon is left in the cow’s manure. This manure is composted. In the composting process, another third of the original giga unit of carbon is lost through the metabolism of the microbes in the compost—and only one-third of a giga unit of carbon remains in the cured/composted manure. The composted manure that results is only sufficient to resupply the organic matter lost in one-third of an acre annually, so the soil fertility in two-thirds of an acre is beginning to be depleted.
With GROW BIOINTENSIVE methods, higher fodder yields may occur, but the ratio of humified carbon lost remains the same as when the cow is grazing.
Often, a half-inch layer of animal manure composted without soil (equivalent to approximately 4 cubic feet per 100 square feet) is recommended to be applied to a growing area. However, this is likely to be an over-application of nitrogen which could lead to nitrate toxicity in the crops, nitrate in the groundwater, crop lodging, acidification of the soil, and possibly a loss of soil hummus.
Even more important, adding this amount of soil-less composted manure is insustainable. Annual fodder production for the cow, using GROW BIOINTENSIVE Mini-Farming with zero-grazing techniques, requires (at intermediate GROW BIOINTENSIVE yields) approximately 7,500 square feet of soil (75, 100-sq. ft. beds). The cow produces approximately 220 cubic feet of manure (dry) annually or approximately 110 cubic feet once the manure is decomposed. 110 cubic feet is enough cured manure (without soil) to apply to about 2,750 square feet (or 27.5, 100-sq-ft beds) of soil once per year at the rate described above. Therefore, 4,750 square feet (or 47.5, 100-sq-ftbeds) will not receive compost, and the minerals, as well as humus, will not be replenished. This practice will eventually cause the 47.5 beds to lose organic matter, minerals, fertility and productivity.
Intermediate GROW BIOINTENSIVE Yields
Area required to feed one cow = 7,500 sq ft
Area that will be fertilized with one cow’s manure = 2,750 sq ft
Area that will begin to lose its fertility = 4,750 sq ft