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Home  > Question of the Week

Question of the Week

Permalink Does leaving green beans in the soil at the end of their life cycle have any nitrogen-fixation benefits?

Answer: Legume plants only fix nitrogen in their roots when the plant is growing. The majority of this fixation occurs prior to flowering. For example, when farmers use legumes as a cover crop to produce nitrogen, they usually terminate it during flowering to get the greatest nitrogen benefit. After flowering, the plant begins to move nitrogen into the seeds. Once in the seeds, the nitrogen is used to build protein. This protein does not decompose as easily as the nitrogen in the plant prior to flowering.

When the plant dies, the nodules in the root no longer fix nitrogen. However, there is still nitrogen in the plant tissues.This is usually a small number compared to the biomass of the plant, perhaps 1 to 3 percent. But there is a nitrogen benefit to the soil if you let the bean plant decompose. As the plant material breaks down, the nutrients in the plant will release to the soil and be available for a subsequent crop.

However, you should balance this nutrient benefit with disease control. Green beans are notorious for having a host of plant diseases. In order to minimize disease pressure, it is often recommended that all plant residue be cleared away at the end of the growing season. If you live in a humid area where disease pressure would be high, you might consider composting your green bean residue. Composting heats the material which helps to kill any disease pathogens and weed seeds.

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Permalink What can you tell me about alternative cattle feeds (concentrates) as supplements for pasture-based cattle production?

Answer: Corn is grown as animal feed on many small diversified farms in rotation with pasture, legumes, or vegetables and is an excellent source of low-fiber energy for grazing ruminants. However, if corn is fed in high quantities, forage intake will decline. Five or six pounds per day for cattle will generally provide enough supplemental energy without decreasing forage intake. Limiting corn supplementation to no more than 0.5 to 1.0% of body weight per day is recommended for cattle on pasture (Sewell, 1993). On high-quality pastures, energy is often the limiting nutrient. Digestible fiber feeds are good for ruminants on high-quality forage because they do not reduce intake and provide energy for protein metabolism. Examples are corn gluten feed (corn gluten meal plus the bran), wheat midds (screenings from wheat flour processing), and whole cottonseed. Others include beet pulp, citrus pulp, dried brewers grain, and soybean hulls. Supplementation with digestible fiber feedstuffs at rates of 0.2 to 0.8% of body weight has yielded favorable results (Bohnert, et al., 2004).

Feed manufacturers use mills to reduce the particle size of feedstuffs. The two most commonly used mills are hammer mills and roller mills. Hammer mills produce feeds with a wide range of particle sizes and are useful for both fiber feedstuffs as well as grains. They are generally more efficient than roller mills but have the propensity to develop more heat, noise, and dust than roller mills. Roller mills are generally more complicated than hammer mills and produce a less uniform feedstuff, but they are energy-efficient and produce much less dust and heat than hammer mills. Roller mills also are not good at processing fiber feeds as are hammer mills (Koch, 2002). When feeds are milled, the particle size reduction tends to increase the surface area of the endosperm in the grain, allowing for better contact of the grain carbohydrates with the animal's digestive enzymes. Milling also allows for easier mixing of feedstuffs for mixed feeds and total mixed rations (TMR) (Goodband, et al., 2002). But when grains are milled too much, and the particle size is too small, the feed process becomes much less energy-efficient and can create dust problems, thus resulting in feed losses. Milling is warranted when feeding whole grains especially for finishing diets for beef cattle and rations for lactating dairy cattle. Wheat, barley, and corn can be rolled or hammer-milled to increase the surface area of the endosperm for aiding digestion. The primary factor to determine particle size is the kind of mill that is used and the size of the screen used. A hammer mill will produce spherical particles with a higher bulk density or weight per unit volume than a roller mill will, whereas a roller mill will produce more irregular shaped particles of a more uniform size (Koch, 2002). The shape of the ridges on the rollers of a roller mill will also impact the particle size of the feed that is milled. Roller mills generally yield feedstuffs that are smaller, more uniform in size, and with a higher calculated surface area (in cm² per gram) than do hammer mills, and are much easier to use than hammer mills. The following is a rough breakdown of the applicability of the two types of mills (Heimann, 2008): Roller Mill Cracking, crimping, minimum fines Coarse grinding, textured feeds Grinding for pelleted feeds: corn, wheat, milo Hammer Mill Grinding for pelleted feeds: corn, wheat, milo Grinding for pelleting feeds: oats, barley, fiber Rendering applications: wood, hulls, etc.

Alternative Feedstuffs
Rebecca Schafer, Extension educator with South Dakota State University, lists the following factors when looking for alternative feeds: 1. Accurate identification of the alternative feed 2. Availability and consistency of availability 3. Nutrient composition and nutrient availability 4. Consistency of composition 5. Suitability 6. Perishability 7. Freedom from health hazards 8. Special handling, processing, and storage requirements 9. Effect on end product 10. Storage space 11. Legality 12. Cost

Wheat Midds
Wheat midds are a co-product of the wheat milling industry and include screenings, bran, and germ. Protein concentration is often higher than 14% and, depending on the environment in which it was grown, can have an energy content comparable to corn (Dhuyvetter, et al., 1999), although these figures can be highly variable. Wheat midds are a high digestible fiber feed, but since the fiber particle size is small, it is not a good source of roughage and should not be a substitution for forage or other forages in the diet, as the fiber in wheat midds is highly fermentable. Roughage forages are needed to maintain rumen function and health. Introduce wheat midds to cattle slowly to avoid digestive disturbances, up to about 1% of body weight per day (10 to 15 pounds per head per day) to provide protein and energy supplementation on low-quality and winter forages and energy supplementatio0n on high-quality pastures.

Field Peas
Field peas are a nutrient dense feedstuff that can be used as a protein or energy supplement for cow-calf herds. Protein ranges around 23% and energy (TDN) is comparable to corn at 87% (versus 90% for corn). Studies have shown that field peas can be fed either ground, rolled, or whole with no difference on animal performance (Anderson, et. al, 2007). Field peas are particularly suited as a protein supplement for beef cattle on low quality forages. Four pounds of 23% CP field peas per day per head will provide about one pound of protein per day which would be adequate for beef cattle supplementation on low-quality forages.

Anderson, Vern, Greg Lardy, and Breanne Ilse. 2007. Field Pea Grain for Beef Cattle. North Dakota State University. Bohnert, D, D. Chamberlain, S. Filley, R. Hathaway, J. Males, B. Nisley, J. Oldfield, C. Parsons, R. Pawelek, G. Pirelli, M. Porath, and P. Schreder. 2004. Beef Cattle Nutrition Workbook. Oregon State University Extension Service. Dhuyvetter, John, Karl Hoppe, and Vern Anderson. 1999. Wheat Middlings: A Useful Feed for Cattle. North Dakota State University. Goodband, Robert D., Mike D. Tokach, and Jim L. Nelssen. 2002. The Effects of Diet Particle Size on Animal Performance. Kansas State University Agricultural Experiment Station and Cooperative Extension Service. Heimann, Mark. 2008. Advantages and Disadvantages in Particle Size Reduction Techniques. Waterloo, IA: Roskamp Champion. Koch, Kim. 2002. Hammermills and Roller Mills. Kansas State University Agricultural Experiment Station and Cooperative Extension Service. Schafer, Rebecca. 2007. Cattle, Corn, and Alternative Feeds. South Dakota State University. Sewell, Homer. 1993. Grain and Protein Supplements for Beef Cattle on Pasture. University of Missouri Extension.

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Permalink What are my options for controlling spider mites on tomatoes?

Answer: Spider mites on tomatoes can be either web-spinning spider mites, which can be seen with the naked eye, or tomato russet mites, which are invisible to the naked eye but leave plants with a "bronzed" appearance. It would be best to confirm the particular type of mite with a local Extension agent in order to manage it most effectively, since the different types of mites will prefer different hosts and may react differently to control measures.

There are several strategies that can be integrated to limit spider mite populations, including cultural controls, biological controls, and various types of sprays.

Cultural Controls
Dusty conditions can help cause spider mite outbreaks. You can reduce the dust that collects on plants by limiting the speed of vehicles, limiting vehicle access, or watering the roads around the planted area on a regular basis. Providing plants with adequate water also reduces stress on the plants and allows them to better withstand spider mite infestations. Spraying the plants periodically with high pressure water sprays will help to remove both dust and mites.

Biological Controls
If chemical sprays are not used, the spider mite's many natural enemies will generally provide good control. Perhaps the most important natural enemies are predatory mites of various types. These mites are about the same size as spider mites, but they move about more quickly on their longer legs. Predatory mites are commercially available and information about insectaries that sell them in your area can be obtained from: California Department of Pesticide Regulation, P.O. Box 942871, Sacramento, CA 94271-0001; (916) 324-4100. Ask for a free copy of "Suppliers of Beneficial Organisms in North America," or download it from the Web at

Other natural enemies of spider mites include general predators such as minute pirate bugs, bigeyed bugs, and lacewing larvae. Mite-specific predators include the sixspotted thrips, Scolothrips sexmaculatus; the larvae and adults of the spider mite destroyer lady beetle, Stethorus picipes; and larvae of certain flies including the cecidomyid Feltiella acarivora. In order to maintain significant populations of these beneficial insects on your farm, there must be sufficient habitat for them--pollen and nectar sources as well as prey on which they can feed. Options for providing such habitat are described in more detail in the ATTRA publication, Farmscaping to Enhance Biological Control, available at

Applied Materials
There is a range of commercially available materials that are formulated to be applied to foliage and control mite populations. Care should be taken not to use soaps or oils on water-stressed plants or when temperatures exceed 90°F (1). Both of these materials may be phytotoxic to some plants and should be tested out on a portion of the foliage several days before applying a full treatment. Most of the products listed below must contact mites to kill them, so excellent coverage, especially on the undersides of leaves, is essential, and repeated applications may be required. Sulfur dust or spray can be used on some vegetables but will burn cucurbits. Do not use sulfur dust if temperatures exceed 90°F, and do not apply sulfur within 30 days of an oil spray (1).

Sulfur dusts are skin irritants and eye and respiratory hazards. Always wear appropriate protective clothing.


1. UC Pest Management Guidelines. 2000 (revised 2011). Spider Mites.

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Permalink What can you tell me about controlling fiddleneck in my pasture?

Answer: Fiddleneck (Amsinckia spp.) is a native annual herb in the borage family. Fiddleneck is known to be toxic to horses both in its fresh form as well as in hay (Weed Board, 2010), and this toxicity is likely caused by alkaloids in the plant tissues (Merck, 2008).

The presence of high numbers of weeds like fiddleneck is a sign that something is happening in the field that may weaken grasses and decrease productivity. As long as a grass stand is maintained intact through proper management, the grass community will thrive. However, when some kind of disturbance occurs, the grasses often have a hard time bouncing back without weed populations becoming established. Weeds take advantage of a niche left open by grasses as they disappear. Grass plants cannot occupy the available niche as easily as weeds can, because weeds have evolved to be very competitive for nutrients and have adapted to soil conditions that most grasses have not. If a soil is disturbed through compaction (the destruction of soil structure due to animal impact or machinery), or if it has become infertile due to intensive cropping and harvesting of nutrients, weed species will find a comfortable home. This is nature's way of correcting imbalances because deep-rooted weeds can scavenge non-available nutrients, translocate them to their leaves and stems, and return them to the soil when they die. This is, in effect, a way of soil building in degraded soils. After the soil has become porous due to the rooting of weeds, and nutrients have been returned to the soil, natural plant succession can take over and the grasses will begin to return (Cocannouer, 1950). However, without human intervention, this succession can take decades to occur.

So, weeds are good indicators of soil nutrient deficiencies and excesses. For instance, fiddleneck tends to occur in soils that are low in calcium and very high in magnesium, potassium, and manganese (McCaman, 1994). Fiddleneck can often be found on soils that are low in humus and low in soil porosity. The presence of this high numbers of this plant might suggest that soil calcium is limited and should be brought into balance with other nutrients, including carbon in the form of compost or manure.

Fiddleneck does not compete well with grasses. A dense, highly productive pasture with fertile soil and good grazing management is the best defense against annual weed infestation, including fiddleneck. Highly productive pastures can be inherently resilient and maintaining a dense, productive pasture includes fostering plant diversity and managing defoliation through mowing or grazing to benefit beneficial plants while discouraging weeds.

The presence of weeds in an established pasture is usually a sign of a management problem. Fertility, proper planting procedure, and harvest management are the most effective ways to maintain dense, productive pastures. Ensure adequate soil fertility and optimum pH with nitrogen-fixing legumes and applications of lime as per soil test. When establishing new pastures, ensure that you use weed-free seed on a well-prepared seedbed, or use a no-till drill at the appropriate time. Also, be sure to practice good harvest management, whether grazing or haying, by leaving enough forage standing after harvest to allow for regrowth. It is especially important to rest pasture plants after grazing to allow full regrowth, thereby ensuring plant health and productivity.

Fiddleneck should be controlled by mowing. A single summer mowing is usually beneficial after flowering but before the seeds set. However, additional clippings will be required if later summer rain results in significant lush fiddleneck regrowth. Mowing after flowering but before seed set will reduce weed seed production and decrease the amount of weed seeds in the soil for the following year.

Cocannouer, Joseph A. 1950. Weeds Guardians of the Soil. The Devin-Adair Company.

McCaman, Jay L. 1994. Weeds and Why They Grow. Sand Lake, MI.
Merck. 2008. Pyrrolizidine Alkaloidosis: Introduction, The Merck Veterinary Manual. Merck & Co., Inc. Whitehouse Station, NJ.

USDA-NRCS Plants Profile, Amsinckia Lehm (fiddleneck)

Weed Board. 2010. Fiddleneck. Stevens County Noxious Weed Control Board, Colville, WA.

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Permalink What can you tell me about gooseberry and currant production?

Answer: Gooseberry and currants are closely related (both are Ribes spp. ) and have relatively the same management requirements. Currants have three different distinct varieties--black, red, and white. Gooseberry varieties range from greenish-white to red. While they will tolerate a wide range of soils, a well-drained soil high in organic matter will bring the highest yields.

Plant gooseberries four to five feet apart. Currants and gooseberries have relatively little pest pressure. White pine blister rust used to be a big problem with Ribes species, but there are resistant varieties available now (see below). Mature plants will yield four to five pounds of fruit per bush. Gooseberries have thorns and this should be a consideration in the harvesting of fruit.

General Pest Management Issues
Birds can be a significant problem on small fruits. Netting, raptor perches, and bird alarms are effective tactics for managing birds in fruit orchards.

It is critical to create a space that has very little weed pressure, since the perennial nature of these crops will make cultivation difficult. This can be done through cover cropping before planting, and mulching the shrubs annually after planting. Mulching also helps to keep the soil cool and moist during the typically dryer and hotter months of summer, and gooseberries and currants would respond well to this.

Goosberry Varieties
There are several thousand varieties of gooseberries: 3004 red, 675 yellow, 925 green, 280 white. In general, gooseberry varieties fall into two categories: the small fruited but mildew-resistant American gooseberry (Ribes hirtellum) and the larger European gooseberry (Ribes uva-crispa). However, most varieties in the U.S. are hybrids of the above two species, one American and one European.

Some Gooseberry Varieties Resistant to White Pine Blister Rust
Hinnomaki Red is a dark red, medium-sized fruit from Finland, with an outstanding flavor. Its outer skin is tangy, while the flesh is sweet.

Amish Red is a new large-fruited and flavorful variety with excellent disease resistance.

Poorman originated in Utah, the result of an American X European type cross, and was introduced in 1888. Don't let the name fool you as it is one of the larger, better flavored, fresh-eating type of gooseberry. It is equally good for pies, jams, and other processed products.

Additional Resources
Thomas, Andrew. 2008. Elderberry Trials Bear "Fruitful" Results. Southwest Center Ruminations Newsletter. University of Missouri Agriculture Experiment Station. Jan–Mar. Vol. 14 No. 1.

New Crops Opportunities Center. 2008. Gooseberries and Currants. University of Kentucky Cooperative Extension Service.

California Rare Fruit Growers Association. 1996. Gooseberry. California Rare Fruit Growers Association website.

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