Listed below are recent posts across all of CalRecyle's blogs.

  • Celebrating Soil

    This is California Healthy Soils Week, and today is Food Waste and Compost Day. The thin layer of carbon, minerals and microorganisms known as soil provides the basis for life on this planet as we know it, so it is worth celebrating.

    Worldwide, cultivated soils have lost between 50 and 80 percent of their soil carbon. Carbon is the stuff that makes soil look rich and black. In California, we have agricultural soils with critically low soil carbon. Tilling exposes soil carbon to the air, allowing it to vaporize as carbon dioxide. Millions of tons of previously soil-based carbon have moved to the atmosphere, contributing to our global climate problem. Carbon in the soil feeds underground microbial life, a critical component of soil health. High-carbon, high-microbe soils grow healthy, resilient crops that need less water and fertilizer.

    Soil can absorb millions of tons of carbon dioxide from the air worldwide. Building soil carbon is possibly the most effective way to slow and even reverse a changing climate.


    How do we build soil carbon? The fastest and easiest way is by using compost and mulch. The California compost community takes millions of tons of lawn trimmings and food waste annually and transforms these discards into valuable mulches and soil amendments. You can help by putting only clean, biodegradable organics in your “green” bin (if your waste management service provides one), and by purchasing compost and mulch for your yard. You can also compost at home.

    Compost contains about 22 percent carbon, and it also provides a diverse community of micro-organisms. Plants that grow in soil with a diverse and robust microbial life will be bigger and stronger, and will pull more carbon out of the air for photosynthesis. But plants do not use all of the carbon they sequester from the air. They pump some of it into the ground through their roots, attracting friendly soil organisms and growing the carbon pool again.


    Once we understand the environmental power of soil, it makes sense to have a week to celebrate it. In 2015, we celebrated the International Year of the Soil … and 2016 was the International Year of the Pulses.

    A pulse is a legume that produces a dry grain, not a green vegetable. If you are experiencing dwindling yields in your backyard garden, consider using compost and planting a cover crop that includes pulses. A cover crop helps keep roots in the soil at all time, which feeds soil microorganisms. It also protects the soil surface from sun and erosion. When cover crops are cut down, the roots become part of the soil carbon pool. Legumes also take nitrogen out of the air (our atmosphere is about 78 percent nitrogen) and “fix” it into the soil. Some cover crops can fix as much as 200 pounds per acre of nitrogen into soil, helping to fuel next year’s crops.

    It’s time to give the soil the respect and protection it deserves. Compost, mulch, and cover crops are sustainable ways to build healthy soils and help prepare for whatever Mother Nature throws at us next.

    Posted on In the Loop by Robert Horowitz on Dec 6, 2017

  • Organics Recycling Challenge: Invasive Pests

    CalRecycle oversees the state’s recycling and waste management programs to achieve a society that uses less, recycles more, and takes resource conservation to higher and higher levels. More than 30 percent of California’s waste stream is organics like yard trimmings and food waste—materials perfectly suited for value-added products such as compost, fertilizer, and biofuels. Doing so cuts pollution, combats climate change, and creates jobs.

    One of the lesser-known challenges we face in managing organic waste to better and higher uses is something all too familiar to our agriculture industry: invasive pests. Such insects and the diseases they carry can threaten our crops and trees—and when they do, it increases the amount of organic waste we must responsibly manage.

    Palm weevils—a particularly invasive species wreaking havoc on Southern California’s palm trees—are one example. Palm weevils are beetles with large snouts that burrow into the trunk of the palms, eventually causing the crown of the tree to collapse and the tree to die.

    Under laws enforced locally and by agencies such as the California Department of Food and Agriculture, infested organic materials are quarantined and fully composted before leaving the quarantine zone. With a mission to reduce how much organic waste goes to landfills, where it produces harmful greenhouse gas emissions, CalRecycle partners with CDFA to educate Californians on how to prevent the spread of invasive pests in organic materials.

    The transportation of yard waste and woody debris can transfer pests and diseases from one location to another. To prevent or slow the spread of pests, agriculture officials conduct trapping, eradicate pests when found, and enforce quarantines. If not managed correctly, these invasive species can destroy food crops and undermine our economy.

    Every county within California faces unique challenges to prevent the spread of deadly pests and disease. CalRecycle and CDFA recently presented specialized training at CDFA’s annual Pest Prevention University, providing local officials with information on how to safeguard California ecosystems and promote stronger collaboration.

    When clearing organic material from your yard, keep an eye out for unhealthy foliage or pest insects. If you find infested material, cover it immediately with a tarp and contact the CDFA Pest Hotline (800-491-1899).



    Posted on In the Loop by Christina Files on Nov 9, 2017

  • Compost, Home or Away

    Good for the garden, good for the planet

    Here in California, the weather is cooling off, the leaves are turning brown, and thanks to some landmark legislation, compost is finally getting its moment in the sun.

    As organics diversion and commercial organics recycling laws are implemented statewide, local jurisdictions are ramping up “green” recycling programs, including residential curbside pickup. From a materials management standpoint, this is great news, since we need to divert large volumes of organic material from our landfills as quickly as possible to reduce greenhouse gas emissions.

    More than 13 million tons of organic material went to landfills in 2014. If 1 million tons of that material had instead been composted, more than 216,000 metric tons of CO2 equivalent greenhouse gas emissions from landfills would have been avoided.   

    If you don’t live in a jurisdiction that will pick up your green waste—or, if you do any type of gardening and would typically end up buying compost—you might consider home composting, if you aren’t doing so already.

    Regardless of whether you compost your material yourself or let your local waste management company take care of that for you, the benefits are significant:

    • Compost helps soil retain water, so less water is required to grow plants, whether they’re ornamental or agricultural.
    • Compost enriches soil with nutrients, which makes plants healthier and increases crop yields while reducing or eliminating the need for additional fertilizer.
    • Diversion from landfills means organic material won’t be decomposing and generating methane there.

    CalRecycle has several excellent webpages on home composting, starting with a basic primer, including instructions, links, and troubleshooting tips. The Natural Resources Defense Council also has a nice composting wepbage.

    Here are the quick-and-dirty directions:

    • Start with some sort of container, preferably at least 3 feet by 3 feet by 3 feet (one cubic yard).
    • Add “brown” material such as dried leaves, clean straw or hay, or shredded paper products like newspaper and paper towels (“brown” is “high in carbon”). This bottom layer should be at least 4 to 6 inches deep.
    • Add “green” (“high in nitrogen”) material like fruit and vegetable leftovers, used coffee grounds and filters, and grass clippings. This layer should be about half as thick as the “brown” layer.
    • Use a pitchfork or shovel to mix the layer and aerate the pile.
    • Add water until the pile is the approximate consistency of a wrung-out sponge.

    Depending on how diligent you are about your carbon-nitrogen ratios, moisture level, and aeration, (i.e., whether you are a “gourmet” composter or a “casual” composter, according to our primer), sooner or later your organic material will turn into rich, dark, earthy-smelling compost.  While the pile will naturally heat up in the process, careful maintenance can result in temperatures of 120 to 140 degrees Fahrenheit, which will kill most weed seed and speed up decomposition, so compost could be ready in two to three months.

    The regular application of “brown” and “green” material, regular watering, and mixing to add oxygen to the pile, are what basically differentiate composting from the smelly, greenhouse-gas-emitting process that occurs when organic material breaks down in landfills.

    For a more detailed explanation of what’s happening in your compost bin, see LiveScience’s piece titled “How Do Compost Piles Work?” 

    Here are some more compost-related links on CalRecycle’s website:

    You can also check with your local master gardener program if you have specific questions or to meet like-minded gardeners. Occasionally master gardeners have composting workshops or demonstrations at local events like farmers markets. Give it a try!


    CalRecycle RecycleForClimate Compost Home Compost
    Posted on In the Loop by Heather Jones on Oct 12, 2017