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Home  > Question of the Week

Question of the Week

Permalink What can you tell me about producing hydroponic fodder to feed livestock?

Answer: Growing fodder for livestock using hydroponics is being done throughout the country, giving farmers in drought-prone areas the ability to grow feed for livestock and also as an alternative high-protein food source for livestock.

Hydroponics is the production of plants in a soilless medium whereby all of the nutrients supplied to the crop are dissolved in water. Using hydroponics to grow fodder for livestock involves sprouting grains, usually using tray systems.

The hydroponic feed is comparable in protein content to commercially available feed containing animal products. This method of feed production requires less land when using vertical trays and also uses less water than most conventional irrigation systems for pasture.

Donnelly Farms in McClure, Ohio, developed a hydroponic fodder system to produce feed for pigs using a SARE grant (see The goal was to produce sustainably raised hogs for a price comparable to conventionally raised pigs. The protein content in commercial feed grows pigs much faster than pigs raised on a diet of corn and hay, considered to be a more natural or sustainable method of farming. But using hydroponic feed allows farmers to grow pigs at the same rate because of the high protein content.

Donnelly Farms was able to grow high-quality fodder in five to 10 days by watering wheat trays once per day, without any special lighting or temperature controls. They were able to produce pigs ready for market in six to eight months with improved taste, reduced costs, and consistent weight gains. The trade-off is increased labor for the farmer or rancher.

One YouTube video features a vertical hydroponic farming operation that produces two tons of barley grass fodder every week. The system is designed to operate 24 hours a day. The system includes a rotating tray system that sprays seed trays for 20 minutes every two hours. The fodder is high in protein and very nutritious. See the video at

You can buy pre-built hydroponic fodder systems to begin producing or build a simple system like the one Donnelly Farms uses. One source is,;ft1_fodder_systems;pg111628.html.

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Permalink Can I grow sweet potatoes in the temperate climate of Washington state?

Answer: You can grow sweet potatoes in more temperate climates with some extra steps and care.

Sweet potato slips need to be planted when the weather has stabilized in the late spring. If the soil temperature is at least 55°F to 65°F (there is conflicting information on this, so you might want to be safe and plant in the 60°F range). Territorial Seeds suggests planting the slip upon arrival. If the soil temperature is less than 55°F, plant the slips in four-inch containers and keep in a warm location. At planting time, select an area in the garden that receives full sun and has well drained soil. Rototill or fork in a two-inch thick layer of compost and plenty of bone meal. In shorter-seasoned areas, a raised bed covered with black plastic makes the best planting environment.

Rows are usually placed 32 to 42 inches apart with in-row spacing of 12 to 18 inches, depending on the cultivar. Closer spacings delay harvest in most cultivars.

Avoid disturbing the roots with foot traffic or deep hoeing. Water thoroughly about every seven to 10 days. If water is provided at transplanting and as necessary for the next 40 days, the plants will probably survive if drought becomes a problem later in the season.

Planting the slips in a deep trench and 'hilling up' the soil as the plants grow will increase yields dramatically. Be sure to keep at least 12 inches of the plant foliage exposed above the soil as you periodically hill it up.

After the weather cools in the fall, carefully loosen the soil around the roots.

Curing should be started within one to two hours of harvest and continued for four to seven days at 85°F and 90 to 95 percent relative humidity with periodic venting. In the absence of better facilities, they can be cured near a furnace to provide warmth. If the temperature near your furnace is between 65°F and 75°F, the curing period should last two to three weeks. You may also be able to do this in a greenhouse or sunroom if you have one. To maintain the required high humidity (85 to 90 percent relative humidity), stack storage crates or boxes and cover them with paper or heavy cloth. Packing in perforated plastic bags will also keep humidity high, and the perforations will allow excess moisture to escape.

After curing, handle carefully and store them at 50°F to 60°F.

For more information on sweet potato production, see the ATTRA publication Sweetpotato: Organic Production at This publication describes advances in organic sweet potato production—propagation, soil fertility and fertilization, tillage and weed management, insect pest and disease management, and curing/handling—and includes an extensive assessment of current and future markets.


Territorial Seed. Sweet Potato Culture.$BE$22$0

B. Lerner. Dig Those Sweet Potatoes. Purdue Department of Horticulture and Landscape Architecture. 10-04-2001

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Permalink What soap is safe to use on organic food crops for insect control?

Answer: Organic farming requires any pest-management materials used be in compliance with USDA's National Organic Program regulations and must be used in the context of organic principles for farming and handling practices.

The Organic Materials Review Institute (OMRI) provides an independent review of products intended for use in certified organic production. After review, if substances are determined safe for organic use they are OMRI Listed.

Safer Soap is OMRI Listed and can be found at most farm supply stores. It can be mixed into solution with chili peppers and sprayed on plants to safely control insects on food crops.

The ATTRA website offers a pest management database that lists different materials by brand name, distributor and whether it is OMRI Listed. You can find the database at

For more information on organic pest management, see the ATTRA publication Integrated Pest Management for Greenhouse Crops at This publication covers IPM for greenhouse crops, both vegetable and ornamental. Monitoring, sanitation, biological controls, biorational pesticides, insect growth regulators, and disease control methods are discussed. Tables include information on the newest biorational pesticides and biological control organisms.

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Permalink How should I space trees in a new pecan orchard?

Answer: The establishment of a pecan orchard by planting trees in rows is how most new growers enter the pecan industry. Trees can be purchased with the cultivar already budded to the top, or planted as a seedling and grafted in the field. (To be "true to name," a cultivar must be propagated asexually, i.e., by budding or grafting rather than propagation by seed.)

The spacing of pecan trees depends on geographical location. In their native and eastern ranges, pecan trees are commonly spaced on a 40-foot x 40-foot grid pattern, which is the equivalent of 27 trees per acre. After about 16 years, trees are thinned by half on a diagonal, leaving 14 trees per acre. At about 25 years old, the third and final thinning will leave a spacing of 80 feet x 80 feet with seven trees per acre.

For a long time, the pecan industry was based on a 35-foot x 35-foot tree spacing. However, recent economic analysis showed an initial 40-foot x 40-foot planting pattern is more profitable because the wider spacing allows the temporary trees more time to produce nuts before they are removed.

In the western range, where sunlight is more intense, trees are planted at 30 feet x 30 feet, which is the equivalent of 48 trees per acre. Ultra-high-density western pecan orchards, spaced at 15 feet x 30 feet, are typically managed by mechanical hedging.

Establishing a Pecan Orchard, a fact sheet from OSU Extension, provides illustrations and details for pecan orchard layout and thinning operations. It is available on the Web at

For more information on growing pecans, see ATTRA publication Sustainable Pecan Production, available at This publication briefly introduces essential knowledge on the basics of pecan culture, such as geography, native versus plantation systems, and economics. This is followed by notes on pecan farming techniques that emphasize sustainable and organic production methods: non-chemical weed control; orchard floor vegetation management using legumes; pecan nutrition with emphasis on organic fertilizer options; and recommendations for organic and least-toxic control of pecan insects and diseases. A selection of pecan literature and Web resources are identified.

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