Archive for January, 2010

Value-Added Management

Something I really enjoy doing is describing how and why agroecological farmland management adds value. Farmland LP sets land-use rotation standards.  This benefits specialty producers by creating synergies with other farmers to lower disease risks and increase yields.  For example, a vegetable farmer will work land that has been managed for several years by a pasture specialist.  In this way we capture both the advantage of specialist expertise and diversification.

Crop rotation diagramImage caption:  A diagram of the basics of land-use rotation that uses pasture to build fertility and different classes of annual crops to keep soil healthy.

Here are descriptions of pasture, seed, vegetable and cover crops, and their properties and functions.

Pasture

Pasture provides the foundation for soil health.  Composed of many long-lived plant species, their deep roots associate with fungi and mobilize minerals from soil layers inaccessible to annual plants.  These minerals are brought to the surface in leaves, eaten by animals, and become part of the topsoil as manure decomposes.  Pasture legumes build soil nitrogen stores, and sod-forming grasses develop soil carbon.  Land not suited to annual cropping is placed in permanent pasture, while the highest quality land rotates through pasture to be restored.

Key Characteristics

  • Field duration:  5-15 years
  • Life history:  Long-lived perennial plants and livestock
  • Soil impact:  Deeply restorative
  • Percent land-use:  30-40%
  • Financial risk/reward:  Low risk/steady return
  • Examples:  perennial rye grass, forage tall fescue, chicory, white clover, subclover

Seed crops

Seeds provide portable, storable and concentrated forms of carbohydrates, proteins and oils.  Seed diversity keeps disease in check, replenishes soil carbon, and permits response to changes in market demand.  Grains make straw that can be used for animal bedding and compost.

Key Characteristics

  • Field duration:  3-10 years
  • Life history:  Annual
  • Soil impact:  Partially restorative to moderately depleting
  • Percent land-use:  30-40%
  • Financial risk/reward:  Medium risk/modest return
  • Examples:  wheat, rye, oats, sunflowers, buckwheat, flax, lentils, pintos, cover crop seeds

Vegetables

Vegetables are important for vitamins, minerals, fiber, and to make meals tasty and interesting.  Composed mostly of water, they are more difficult to store, process and transport than other crops, and hence can sell for a comparative price premium.  The great diversity of species and varieties available makes vegetable cultivation a knowledge and labor intensive practice.

Key Characteristics

  • Field duration:  1-5 years
  • Life history:  Annual to biennial
  • Soil impact:  Moderately to highly depleting
  • Percent land-use:  5-10%
  • Financial risk/reward:  High risk/high return
  • Examples:  tomatoes, squash, green beans, cabbage, lettuce, garlic, onions, sweet corn

Cover Crops

Cover crops serve three major functions—protection of soil from erosion between seasons, restoration of soil carbon and nitrogen levels, and disruption of pest, disease and weed lifecycles.  Once well established, a cover crop can be used like a pasture for part of a year.  They are usually planted in the fall after a summer harvest and last until a new crop is sown the following spring or until the subsequent fall if a field needs a good rest and full nitrogen replenishment.

Key Characteristics

  • Field duration:  6 months to 1 year
  • Life history:  Annual to biennial
  • Soil impact:  Restorative
  • Percent land-use:  10-20%
  • Financial risk/reward:  Low risk/low return
  • Examples:  annual rye, small grains, vetch, field peas, bell beans, clovers

Biodiversity that Pays

The wasps are only 1 or 2 millimetres long fully-grown but they have an ability to paralyse and destroy other insects, including many of the most destructive crop pests, by delivering a zombie-inducing venom in their sting.

http://www.independent.co.uk/news/science/voodoo-wasps-that-could-save-the-world-1868569.html

I love stories like these.  Two years ago I remember standing over a patch of carrots I let go to flower and counting twelve species of wasps.  Carrots and their relatives, such as parsnips, cilantro, lovage and fennel, produce small flowers that tiny insects such as these wasps can get.  You can think of the nectar as the wasp version of an “energy drink” and the other insects they prey upon as a “protein shake.”  Organic farmers use these feeding relationships to keep pests at bay.  Having some wild spaces among the farm landscape where favored flowers can bloom helps grow food.

Image caption:  A predatory wasp sips nectar from a plant in the carrot family.

Plant diversity in the farmscape is also critical for pollinating crops.  Some intriguing research has just been released.

The decline of honeybees seen in many countries may be caused by reduced plant diversity, research suggests.

Bees fed pollen from a range of plants showed signs of having a healthier immune system than those eating pollen from a single type, scientists found.

http://news.bbc.co.uk/1/hi/sci/tech/8467746.stm

This specific line of study is fairly new, but the general principle is well established.  Dietary diversity for many animals gives them a range of metabolically important chemicals.  If you feed animals on a narrow diet, they typically get diseased.  We know this about pets and livestock, and now we are discovering its importance for honey bees.

I recently spoke to a graduate student studying bumble bees in the Willamette Valley of Oregon and was glad to hear that both native and honey bee populations are thriving.  She said that her professors suspected, and were analyzing some data to confirm, that high crop and landscape diversity in the area meant that bees were well fed throughout the summer.

The organic system plan required by the National Organic Standards includes a description of how the farm will protect and enhance biodiversity.  By growing many kinds of crops, restoring native habitats, and even creating artificial structures like hedgerows, a positive pay back accrues when it comes to lowering pest pressures and increasing pollination rates.

Less is More with Antibiotics

Twenty-five years ago, Norwegians were also losing their lives to this bacteria. But Norway’s public health system fought back with an aggressive program that made it the most infection-free country in the world. A key part of that program was cutting back severely on the use of antibiotics.

Now a spate of new studies from around the world prove that Norway’s model can be replicated with extraordinary success, and public health experts are saying these deaths – 19,000 in the U.S. each year alone, more than from AIDS – are unnecessary.

http://www.physorg.com/news181461239.html

Why do I bring attention to news from the medial industry in a blog about agriculture?  Because the same solution to an unnecessary problem, use less antibiotics and you won’t need many antibiotics, applies in farming as well.

Consider this article from mid 2009 for comparison.

Researchers say the overuse of antibiotics in humans and animals has led to a plague of drug-resistant infections that killed more than 65,000 people in the U.S. last year – more than prostate and  combined. And in a nation that used about 35 million pounds of antibiotics last year, 70 percent of the drugs – 28 million pounds – went to pigs, chickens and cows. Worldwide, it’s 50 percent.

http://www.physorg.com/news181238071.html

I am not sure why one article indicates that 19,000 deaths occur from antibiotic resistant bacteria in the U.S. each year while another says “more than 65,000″ but the statistic that really caught my attention was that over 2/3 of antibiotics go to livestock.  And as I commented upon previously, organically managed poultry given no antibiotics have the lowest levels of contamination.

The bottom line is that livestock producers need to learn from the Norwegian public health and hospital specialists–when it comes to antibiotics, less does more.    This isn’t anything new to those of us involved in organic farming, but as the public becomes more aware of this topic and desires healthier food, we will be here to provide it.