Partnership solves waste problem
By Len Richardson
California Farmer Magazine
www.CaliforniaFarmer.com
Passage of Assembly Bill 939, the Integrated Waste Management Act of 1989, mandated the state’s cities and counties to either divert 50% of their waste streams from landfills by 2000 or face penalties. This chain of events spurred the Limoneira Co., Santa Paula, to create a partnership with Agromin Corp. in 2004.
Together, the companies developed a 5-acre facility on Limoneira’s land to receive raw green waste from throughout Ventura County. The waste is converted to mulch that is spread in orchards to curb erosion, improve water efficiency, reduce weeds and moderate soil temperatures.
About 200 tons of yard waste, tree limbs and urban wood waste (mainly from construction sites) is received daily at the operation where it is cleaned, ground and converted into 120 tons of finished material.
Limoneira Co. is Ventura County’s largest and oldest grower. Established in 1893, Limoneira currently produces lemons, Valencia oranges, avocados and row crops on 4,000 acres, and provides quality fruits and vegetables for consumer brands such as Sunkist, Calavo, and others sold domestically and internationally.
Agromin Corp. is a manufacturer of premium soil products and the green waste recycler for 15 cities in Santa Barbara, Los Angeles and Ventura counties and unincorporated areas of western Ventura County. Agromin has provided soil amendments and products to Ventura County’s largest vegetable, citrus, avocado and strawberry growers for more than 30 years. It also processes 20,000 tons of urban wood and green waste each month — sometimes up to 1,000 tons a day.
The challenge
Because more than 40% of California’s urban waste stream is compostable organic material, diverting that organic portion can help communities meet their diversion goals. In particular, yard waste (14.6%) and urban wood waste (8.5%) are compostable, green waste materials that can be turned into reusable products.
Annually, more than 10 million tons of green waste and more than 2.5 million tons of urban wood waste enter the urban waste stream in California. Very few communities have figured out how to divert and recycle this waste.
The solution
The only viable economic solution thus far lies in creating strategic partnerships and alliances large enough to:
• Process and compost the mate¬rials into value-added products.
• Maintain enough capacity to use all the materials in ag production.
• Distribute end products to market cost effectively.
Solving these urban recycling needs, meeting sustainable agriculture goals and finding proper scale was a huge problem — until the Agromin-Limoneira solution.
Ventura Mayor Brian Brennan says the Agromin-Limoneira facility has completed an urban-green-waste-to-agriculture-production loop and has allowed Ventura to achieve its goal of being an environmentally progressive city.
Safe and scientific
The Agromin-Limoneira partnership worked with University of California Cooperative Extension to review the potential for disease from introducing urban waste into agriculture. The conclusion was green waste allowed to cure sufficiently would pose no threat. The primary resistance to using urban compost in crop production was defining how to mitigate the risk for farm disease. As a large-scale grower, Limoneira has proved proper composting processes are safe and effective for orchard and crop application.
In particular, erosion was virtually nonexistent in tree blocks where mulch was applied during heavy storms in January and February 2005, keeping pollution-causing nutrients out of washes, creeks and runoff channels that empty into the ocean. In addition, the mulch improves soil fertility without chemical fertilizers: The decomposition and leaching of nutrients from mulch into the soil increases nutrients available to trees. Mulch also bolsters soil biological activity that improves soil structure without additives. By mulching at thicknesses greater than 3 inches, Limoneira has cut weed populations and chemical herbicide needs. | 
