Recently in Urban Agriculture Category

"Killer spices" provide eco-friendly pesticides for organic fruits and veggies

Rosemary, thyme, clove, and mint are well-known spices that are emerging as organic agriculture's key weapons against insect pests.

Scientists in Canada are reporting new research on these so-called "essential oil pesticides" or "killer spices." These pesticides have added to the crop-preserving arsenal of organic growers and offer several advantages over their counterparts -- they're readily available and don't require lots of regulatory approval.

And they're safer for gardeners and farm workers, who are at high risk for pesticide exposure.

Murray Isman, Ph.D., of the University of British Columbia is developing these pesticides.

So, just what is it exactly about these spices that allow them to work their magic outside the kitchen? Here's Dr. Isman again:

"It turns out that some of these oils and some of the chemical constituents in the oils are neurotoxic to many types of insects. At least one of their actions, and we're not certain about all of their actions, one of their actions is they interfere with a neuromodulator in insects called octopamine. It's sort of an internal valium for insects, it sort of calms them down so their nervous systems
don't get overstimulated by external stimuli. If you remove that octopamine, which is what
some of these oils do, they get hyperexcited and eventually die."

These pesticides, usually a combination of spices diluted with water, have added to the crop-preserving arsenal of organic growers and offer several advantages over their counterparts. First, they are readily available and don't require lots of regulatory approval. Also, insects exposed to the spices are less likely to evolve resistance to the toxins. And, they're safer for farm workers, who are at high risk for pesticide exposure. 

"Some of these oils, as some other people have mentioned, are very good antimicrobials,
so they could be very useful against food spoilage organisms, for example. They are useful
against certain plant pathogenic fungi and bacteria, and they do have this phytotoxic effect
on plants, so at high concentrations they can be used as natural herbicides."

 

Spiders that live near water may be an effective warning system for contaminants in aquatic ecosystems, according to a new USGS and U.S. Environmental Protection Agency study.

Scientists examined PCB (polychlorinated biphenyls) levels in shoreline-living spiders at Lake Hartwell, a Superfund site in South Carolina, and used this information to map contaminant concentrations in lake sediment.

Spiders are indicators of ecosystem recovery from PCB contamination

Future monitoring studies will use the spiders as indicators of ecosystem recovery from PCB contamination. Researchers also made risk maps for a spider-eating bird, the Carolina wren, which could be exposed to PCBs through eating spiders.

Food Chain Transfers Contaminants

These spiders rely heavily on adult aquatic insects for food and play a key ecological role in the transfer of contaminants between water and land ecosystems. In spite of this, they are underused as a sentinel species at contaminated sediment sites.

SOURCE:  USGS

There are several reasons why urban gardens using containers are effective:

1. They enable us to practice "intensive" gardening method through maximum utilization of limited space.

2. It is easy to practice "intercropping" (planting a variety of plants in one container) which ensures the health of plants due to diversity.

3. It is possible to "conserve" both soil and water as containers prevent run offs of soil and excessive watering.

4. Urban gardens "make use of urban wasteland" (vacant lots, brown fields, unused parking lots, and roof tops)

5. Urban gardening provides "meaningful employment" for persons with limited skills and formal education.

6. Establishing and maintaining an urban garden are very "inexpensive".

7. Urban gardens provide creative ways to "recycle" old tires and other containers that otherwise would be thrown into landfills.

8. Churches and social service organizations can use urban gardening to "rehabilitate, create income generation projects, and provide therapy."

Technology for the Poor publishes a wonderful website that describes effective, low cost ways of developing container gardens that are highly productive. Using wading pools and tires, among other repurposed "technologies" urban residents can sink their toes into the soil in parking lots, on rooftops, in vacant lots and in their tiny urban backyards.  And the productivity isn't just in food -- as delicious as it might be -- it has far ranging quality of life and skill building results.

The purpose of an intensively grown garden is to harvest the most produce possible from a given space.

The Arizona Master Gardener Manual on Intensive Gardening methods examines several ways to grow in small areas.

The practice of intensive gardening is not just for those with limited garden space; rather, an intensive garden concentrates work efforts to create an ideal plant environment, giving better yields with less labor.

A good intensive garden requires early, thorough planning to make the best use of time and space in the garden. Interrelationships of plants must be considered before planting, including nutrient needs, shade tolerance, above- and below-ground growth patterns, and preferred growing season.

Using the techniques described in The Arizona Master Gardener Manual on Intensive Gardening , anyone can develop a high-yielding intensive garden.

Community gardening is a "natural arts" workshop, gallery and experiential spa! This community garden shares a wealth of ideas for revitalizing soul as well as body with fresh air, fresh food and new friendships.

For the Greener Good "Vertical Farming" from National Building Museum on Vimeo.

Urban food security is a rising concern with climate change affecting traditional agriculture with droughts, floods and migratory changes for pollinators. Local regional food production is also a solution for access to fresh foods to reduce obesity and childhood onset diabetes. A major overhaul of our food system is bursting from its seeds.