Slide 1

Soils in Urban Agriculture and Community GardensChallenge: Growing food in degraded urban soil

Healthy soil is fundamental to agriculture.

For there to be significant improvements in access to healthy food through urban agriculture soils must be productive.

Urban agriculture often takes place on a small scale and will need to make use of dense planting techniques which require excellent soil fertility.

Challenges Healthy soilUrban soil has often been both damaged and neglected. Urban populations have generally low environmental literacy and even less understanding about soils.

Compaction?Low Nutrients?Poor Drainage?Contamination?

Whats a busy urban dweller to do?

The single best solution to the problem of urban soil is to Add Organic Matter (anything that was once alive, containing carbon)

Urban centers generate a wide range of organic residuals that have potential utility as soil amendments, including: municipal biosolids yard trimmings and food scraps

Add Organic Matter Urban Residuals

Organic Residuals

Annually, each person in the US generates an average of: 22 dry kg municipal biosolids (treated sewage) 88 kg yard trimmings and (grass clippings, leaves, etc.)79 kg food scraps (NEBRA, 2007; USEPA, 2006)

Approximately 50% of the biosolids, 98% of the food scraps and 45% of the yard trimmings are currently disposed of or landfilled.

Organic Matter really works to improve urban soilAdding organic matter:Will support an increase in production for urban agriculture by increasing available nutrients and building soil tilth and fertility.

Phosphorus is an essential plant nutrient On left: Beets grown with biosolids On right: Beets grown without biosolids

Organic Matter really works to improve urban soilAdding organic matterWill improve how quickly water infiltrates the soil reducing surface water runoff and allowing water to get to plants.

Also improves the soils ability to hold water

Organic Matter really works to improve urban soilAdding organic matter:Will store carbon - sequestering carbon in the soil and providing food for soil microbial communities.

This also takes it out of the atmosphere where we have an excess and puts it back in the soil where it becomes food for plants. When 7

Besides urban soil: Other benefits to recycling ResidualsReduces the importation of valuable organic matter from rural areasCreates sustainable end-uses for urban residualsMany urban gardeners are new to gardening available soil products will allow gardeners to have greater success.

A little background on whats happening in Tacoma TAGRO Class A biosolids produced by the City of Tacoma.TAGRO has been utilized by the community for decades.WWTP upgrade in 1991 officially made the product Class A safe for use with no restrictionsHistorically, TAGRO was available in a liquid form for farmland this is still done but availability is limitedDeveloped dry products beginning in 1995Diversified product range in 2004

Program has worked to build relationships and gain public support creating a market

Community Gardening in Tacoma increasing demand

Pink existing prior to 2008Yellow new since 2008

The vast majority are using TAGRO products

The combination of urban gardening and urban residuals is contributing to incredible success for gardeners, government, and the environment.

Education another incredible opportunity

Demand for this information is explodingThere is a window of opportunity to connect people to their food supply/environmentAlso an opportunity to educate people about waste and urban nutrient cycling

What is needed now

Investments in Urban residuals and incredible urban resources that is too often treated as waste and disposed of.

Educational resources made available lack of urban-appropriate resources about both gardening and residuals

Support from municipal infrastructure for urban agriculture as a productive use of urban land low cost way to care for vacant land.

Questions?

Questions? Comments?

Kristen McIvor, PhCCommunity Garden Coordinator, Tacoma/Pierce CountyCascade Land Conservancy

kristenm@cascadeland.org253.363.1846