6D1-D4 : Annexe D

Contrôle des odeurs en Europe et couvert flottant

BIO-DYNAMIC

AGRICULTURE

An Introduction

by

HERBERT H.KOEPF

Professor, Dr, agr.

Emerson Colege, Forest Row,

Sussex, Englabd

BO D.PETTERSON WOLFGANG SCHUMAN

Lic. Agr Dr. Med, vet.

Jarna, Sweden Bad Vilbel, West Germany

ANTHROPOSOPHIC PRESS

Page 168

75% water, 0.75% nitrogen, 0.35% phosphate, 0.75% potassium, 0.66% lime, and 0.2% magnesium. The amounts of nutrients in farmyard manure are somewhat lower: 75% water 0.4-0.5% nitrogen, 0.3% phosphate, 0.5-0.6% potassium. Depending on the type of stabling and the amount of water used for barn cleaning, 3-5 cubic meters or yards of liquid manure are produced per CU per year .

Reference is here made to the systems of housing and manure handling as they are used by a majority of farms in continental Europe. The aim is to preserve as much as possible of the manuring value of the animaI excrements and to avoid the pollution of ditches, rivers and streams.

The term farmyard manure refers to the solid excrements plus bedding as it is produced in cowhouses with standings and tying (occasionally also in cubicles or free stalls). The dung channel behind the standings includes a gutter for the urine and some washing water; these are collected in a storage tank. ln America the system of separate handling of solid and liquid manures hardly occurs.

The term loafing yard manure refers to covered yards in which enough bedding is spread to absorb both solid and liquid excrements without any effluent running off the manure. The droppings without bedding scraped from yards or free-stall houses are mostly collected in pits and handled as slurry.

Occasionally they are piled up in an uncontrolled fashion and remain exposed to rain or drying by sun and wind. Considerable nutrient losses and pollution hazards occur in this case.

100 hens produce 6 tons of dung per year, containing approximately 90 kg (200 Ibs) of nitrogen, 80 kg (180 Ibs) of phosphate, and 50 kg (140 Ibs) of potassium (Tietjen 1965). Oried chicken dung contains about 12% water, 3.6% nitrogen, 3.5% phosphate, and 1.6% potassium. Chicken dung from deep litter contains 32% water, 1.7% nitrogen, 2.1% phosphate, 1.3% potassium (Advisory Leanet 320, 1969). As these figures show, chickens on a farm produce valuable manure for gardens and fields. If free ranging is required, not more than a few hundred can be kept, however. Runs can be kept relatively green by sub dividing and using the portions alternately. For floor houses for raising broilers an effective step against disease is to submit the litter to a short period of composting before re-opening the house with a fresh batch. As much water as necessary is added to the manure, which is then mechanically turned; a reasonable amount of good, mature bio-dynamic compost is added (Hancock and Escher 1965).

The wellbeing of the animaIs and the quality of the manure are both improved considerably by using appropriate amounts of bedding materials. The question of whether to go over to slurry usually only arises if one is in the process of altering buildings or building new barns. Even if the high cost of investing in slurry techniques is no deterrent, one should take into account that they bring with them far-reaching changes both for the livestock and for the soil life. Technical developments have made the handling of solid manure economically competitive from the labor point of view, so the biological advantages of solid manure can really be made the most of .

The majority of bio-dynamic farms use cowhouses with sufficient bedding material, mechanical barn cleaners and separate storage tanks for liquid manure. The manure is collected outside the cowhouses in flat or conical piles for intermediary storage and treated with bio-dynamic preparations.

The compound preparations, described on p. 206, work weIl in starting the fermentation. When these compound preparations are spread in the barn they help control odor. At the earliest possible opportunity the manure is then transported to compost piles in the fields. The size of the heaps is the same as with other compost. Then they are again treated with the preparations. Soil up to about 5% of the total mass added to the piles greatIy improves the manure. On light soils it is important to add loam or basait meal. The heaps should be covered with potato tops, earth or other litter. The effluent that arises du ring storage near the cowhouses should be collected. Rock phosphate or bone meal can be added to the manure. 50 kg (110 Ibs) per CU/annum is usually recommended. This technique for cowhouses is simple and proven and is even sometimes used where there are free stalls with bedding in the passage.

Loafing yard manure requires the right amount of bedding to prevent the manure from becoming either too dry or too wet. It is treated bio-dynamically in the stable. 6-12 kg (15-30 Ibs) per CU of bedding daiIy are recommended. When weIl fermented, the manure is either taken straight to the fields for heavy feeders or stored in compost piles on the fields. N. Remer (1968) describes more developed composting processes.

ln Scandinavian countries the following additions are often made to manure. Toward the end of fermentation, about 20 kg (45 Ibs) of meatmeal and 10 kg (22 Ibs) of bonemeal are added per ton of manure. It is not possible to use more than 10 kg (22 Ibs) of sulphate of potash magnesia as higher amounts have a detrimental effect on fermentation. For plant composts, up to 40 kg (90 Ibs) lime per ton of plant matter are added.

To use liquid manure successfully, enough storage space must be provided in advance. Existing storage is usually only 3 m (100 ft]) per CU. This should be increased to 5-6 m (170-200 ft). The more recent above-ground storage tanks have proved to be quite usuable and of themselves lead to the two-chamber system, which is most desirable. One tank is used for collection and the other for fermentation, the contents being pumped from pit to tank. The addition of chopped stinging nettles and small amounts of mature composted manure has proved useful in the production of good liquid manure. The bio-dynamic preparations are suspended from a float in porous bags and thus held in the liquid. This treatment is also carried out on mountain grass land farms where there is a shortage of straw and aIl excrements are used as slurry. Vacuum tanks have proved useful for haulage.

The only method that produces no liquid manure is the loafing yard with bedding. ln nearly aIl other cases pits are needed to collect and distribute the liquid manure, which contains a good deal of nutrients as is shown above. How concentrated it is depends on how much water is added. When cattle are out at pasture a proportion of course remains on the meadow. The nitrogen in the urine is in the form of urea, which rapidly decomposes into ammonia and car bon dioxide. As the smell shows, ammonia easily escapes into the atmosphere. Air-tight tanks have been used to avoid this loss, though considerable losses will still occur when the liquid is distributed. ln bio-dynamic farms another system works weIl. Open containers with walls that will withstand frost are less costly. A thin floating cover of chopped straw or stinging nettles on which some rock phosphate or basalt meal is scattered (about 1% of the total content of the pit) does a great deal to prevent the loss. The speed of decomposition of the cover increases as time goes on. Sawdust or wood shavings, which are quite good for fixing nitrogen, can also be used. ln the top layer adjoining the air the excess of carbon compounds gives rise to bacteria that stabilize the rising ammonia. The process can also be improved if, at the start of filling, well-rotted compost is added in an amount of about 5% of the pit contents. An effective fertilizer is thus produced of which the one-sided effects can be balanced by adding rock phophate and basalt meal. But liquid manure is not only valuable because of the nutrients it contains. Because it is a product of animal metabolism it is important for the microorganisms in the soil. Either fresh or fermented it provides a number of physiological effects. The most permanent advantages from liquid manure are achieved if it is applied to the soil with grain stubble or catch crops. However, have to be balanced by intensified humus replacement. Bio-dynamic farms need considerably less lime than others. It is usually found that the amount recommended by the experimental station can be reduced by 30-50% .The reason is that matured farm manure and optimal soil aeration correct acidity; furthermore, minerai fertilizers that accelerate the leaching of lime, thus making it necessary to add more, are not used.

With regard to alI the nutrient sources mentioned above under points 1 to 5, the supply of nutrients to plants is regulated by the soil microorganisms. Nitrogen comes entirely from organic compounds. This is not the case with mineraI fertilizers. These alter the concentrations and ratios of nutrients by by-passing the soil microorganisms. They thus also change the correlation between nutrient ions in soil and plants. This is no great difference seen from the point of view of current ideas about plant nutrition. But for thinking that is concerned with truly biological categories the difference is considerable.

The above gives some of the principles to be considered when attempting to assess the buying-in of fertilizers.

If the supply of nutrients to crops can be achieved in accordance with points 1-3, the result is a self-contained farm organism. There are a number of examples in which this has virtually been achieved.

If the organic commercial fertilizers and sIow-working mineraI substances mentioned under points 4 and 5 are used, then not only the type of fertilizer but also the amount has to be taken into consideration, in addition to the manner in which it is applied, e.g., direct onto the soil or via the compost heap. The more concentrated and easily accessible the nitrogen content is, the greater is the need to take into account the amounts used, in order to conform to bio-dynamic standards. Where the Iimit lie! cannot be stated generally but depends on the individuaI farm and its cultivation, livestock, disease level, soiI conditions, etc. For marketing and production in accordance with the standard of the Demeter trade mark, not only is advice given on crops bul also maximum amounts of fertilizer that may be bought in arc laid down and must be adhered to.

Finally, we must add that general agricultural development with regard to mineraI fertilizing have moved further and furtheJ away from the viewpoints stated here. Sulphate of potast magnesia or basic slag, which have plenty of balast and used to be used much more, may be more favorably assessed thar modern, highly-concentrated single and compound fertilizer offered today for transport and labor reasons.

4 Silica, Clay, Limestone

ln R. Steiner's lectures on agriculture. these terms denote not only three different substances but rather three complex groups of influences from the environment on plant growth. It seems appropriate, therefore to add a few remarks on this theme.

Silica or quartz-rich, that is sandy, soils are poor in nutrients but usually offer favorable conditions for the supply of warmth and air to the root zone. In damp, cool climates. quartz-rich soils usually contain humus that is poorer in nitrogen and tends to be acid. This, however. is not the only point with regard to the significance of silica for growth.

ln a highly diluted solution of Si(OH)., this substance is present in the water in soil and plants and is important as a formative element in plants and their ability to resist fungal and animal pests (Jones and Handreck 1967). The water in soil contains silica in concentrations of 30 to 40 ppm. This amount remains relatively uninfluenced by the chemical processes. particularly the pH range determined by calcium. Iron and aluminum compounds can decrease its concentration in the soil solution. Silica is transported by water into the plant in amounts that roughly correspond to the amount of water taken in and the concentration in the soil. It may be noted, however. that there are definite "silica plants." Among cultivated crops these are the grasses and cereals. Nitrogen and phosphorus fertilizers seem to reduce the intake of silica. Japanese rice farmers like to use silica-rich slag since this helps build up resistance to fungal pests

In a natural state, grasses contain 10 to 20 times as much silica as dicotyledons, particularly legumes. The latter are "calcium