Friday, July 18, 2014

Composting - Vital for Better Soil Health, Fertility and Reducing Erosion

Composting reduces waste and builds healthy soil to support local food production and protect against the impacts of extreme weather, from droughts to heavy rainfall. That’s the message of two new reports from the Institute for Local Self-Reliance (ILSR):
State of Composting in the U.S.: What, Why, Where & How <> and
Growing Local Fertility: A Guide to Community Composting<>

Compost is the dark, crumbly, earthy-smelling material produced by the managed decomposition of organic materials such as yard trimmings and food scraps. Compost is valued for its ability to enhance soil structure and quality. It adds organic matter to soil, improves plant growth and water retention, cuts chemical fertilizer use, and stems stormwater run-off and soil erosion. In the U.S., 40 million hectares (28% of all cropland) are eroding above soil loss tolerance rates, meaning the long-term productivity of the soil to support plant growth cannot be maintained.  

It might be worse comparatively in Australia, and China certainly has major problems!

compost production- commercial scale

Applying a meagre 12mm of compost to the all of the severely eroded cropland in the USA would require about 3 billion tonness of compost,” says Brenda Platt, the lead author of both reports and director of ILSR’s Composting Makes $en$e Project. “There is not enough compost to meet that need.  No organic scrap should be wasted.”

Compost also protects the climate:  it sequesters carbon in soil and it reduces methane emissions from landfills by cutting the amount of biodegradable materials disposed. (Methane is a greenhouse gas with a global warming potential 72 times more potent than CO2 in the short-term.) A growing body of evidence demonstrates the effectiveness of compost to store carbon in soil for a wide range of soil types and land uses.

Yard trimmings composting programs are fairly well developed in the U.S.

Of the 4,914 composting operations identified in the U.S. for State of Composting in the U.S., about 71% compost only green waste / yard trimmings (based on 44 states reporting). Food scrap recovery is slowly growing. More than 180 US cities and counties are now collecting residential food scraps for composting, up from only a handful a few years ago.  “There is more demand for composting, especially from businesses and institutions that want to source separate food scraps and not throw them in the landfill,” says Nora Goldstein, Editor of BioCycle, which conducted the state-by-state assessment of composting infrastructure and policies, “We not only need more infrastructure to compost these materials, we need more infrastructure to manufacture high quality compost that our soils — and climate — desperately need.”
compost berm used in erosion control
State of Composting in the U.S. is the first comprehensive review of composting basics, national and state statistics, job generation data, model programs, and policy opportunities.

The report calls for a national soils strategy and for new rules and programs to grow composting, especially at the local community level: including streamlined permitting for facilities, training programs, technical and financing assistance, strong recycling and composting goals, disposal bans, compost procurement policies, and more.  “The beauty of composting is that it can be small-scale, large-scale and everything in between,” says Brenda Platt. “Why send resources out of the community when our neighbourhoods need food and our soils are starved for organic matter?”

I would imagine that the report for Australia and the NT in particular would be quite similar.  However, around Darwin mulched green waste is widely used in domestic areas but much less so commercially and for landscape rehabilitation where it can be especially useful in restarting organic processes on damaged soils.

A sneak peek inside State of Composting in the U.S.: What, Why, Where & How:
·      Section 1, What Is Composting and Compost, describes the composting process, what materials can be composted, composting systems, and the many uses for compost.
·      Section 2, Why Compost?, identifies the key benefits of composting to create jobs, protect watersheds, reduce climate impacts, and improve soil vitality.
·      Section 3, Where Is Composting Happening, provides a national snapshot of composting infrastructure, current policies, and model programs that could be replicated.
·      Section 4, How to Advance Composting, outlines new rules and initiatives to grow composting, and describes the importance of a diverse and locally based infrastructure.

ILSR’s companion report, Growing Local Fertility: A Guide to Community Composting, features successful community-scale composting initiatives, their benefits, tips for replication, key start-up steps, and the need for private and public sector support. 

Produced by ILSR’s Composting Makes $en$e Project and the Highfields Centre for Composting, this guide highlights more than 30 diverse urban and rural small-scale locally based composting programs in 14 states and the District of Columbia.  They include schools, pedal-powered collection systems, worker-owned cooperatives, community gardens, and farms employing multiple composting techniques.

To download both reports, visit

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