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Becoming the Good Soil: To Avoid the Most Serious Consequences of Climate Change We Must Have “Negative Emissions”

The growth rate of climate forcing due to human-caused GHGs increased over 20 % in the past decade mainly due to resurging growth of atmospheric CH4, thus making it increasingly difficult to achieve targets such as limiting global warming to 1.5 °C or reducing atmospheric CO2 below 350 ppm. To achieve such targets now require negative emissions, i.e., extraction of CO2 from the atmosphere. If rapid phasedown of fossil fuel emissions begins soon, most of the necessary CO2 extraction can take place via improved agricultural and forestry practices, including steps to improve soil fertility by increasing its carbon content and reforestation (1).

1) Hansen, J, et al, Young People’s Burden: Requirement of Negative CO2 Emissions, Earth Syst. Dynam. Discuss., submitted for Publication (2016)

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Becoming the Good Soil: Role of Soil in Carbon Sequestration

Soils constitute the largest terrestrial organic C pool (~1,500 petagrams* (Pg, 1015 grams ) C to a depth of 1 m; 2,400 Pg C to 2 m depth), which is three times the amount of CO2 currently in the atmosphere (~830 Pg C) and 240 times the current annual fossil fuel emissions (~10 Pg). Thus, increasing net soil C storage by even a few per cent represents a substantial C sink potential (1).
Soil C sequestration is one of a few strategies that could be applied in large scales and potentially at low cost; as an example, the French government has proposed to increase soil C concentration in a large portion of agricultural soils globally by 0.4% per year in conjunction with the Conference of the Parties to the UN Framework Convention on Climate Change (UNFCCC) negotiations in December 2015. This would produce a C sink increase of 1.2 Pg of C per year (1).

1) Paustian, et al. Climate Smart Soils, Nature, 532, 49-57 (2016).

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Becoming the Good Soil: Soil Carbon Sequestration Potential of US Croplands and Grasslands

The first comprehensive assessments of potential soil C sequestration on managed lands for the United States were led by researchers from USDA’s Natural Resources Conservation Service (NRCS) and Agricultural Research Service (ARS) and the Carbon Management and Sequestration Center of The Ohio State University. These syntheses focused on the potential of US soils to sequester carbon with adoption of best management practices under different land uses. Subsequently, more detailed assessments of the technical potential for carbon sequestration at global (1) and US scales generally support these earlier estimates of a significant soil C sink potential, on the order of hundreds of teragrams (1 Tg, equals 1012 (one trillion) grams or 1 million metric tonnes) per year in the United States (45 to 98 Tg for cropland and 13 to 70 Tg for grazing land) and roughly an order of magnitude higher globally (2).

1) Intergovernment Panel on Climate change, Third Assessment Report, 2001.
2) Chambers, A, et al, Soil carbon sequestration potential of US croplands and grasslands: Implementing the 4 per Thousand Initiative, J Soil and Water Conservation, 71, 68A-74A (2016).

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Becoming the Good Soil: Increasing Soil Carbon Will Increase Crop Yields

Increasing soil carbon will increase total soil organic matter (SOM), which is the very foundation for healthy and productive soils (1). Organic farmers often judge and monitor soil health based on the amount of organic matter in each farm field. Active soil organic matter refers to a diverse mix of living and dead organic materials near the soil surface that turn over or recycle every one to two years. Active organic matter serves as a biological pool of the major plant nutrients. The balance between the decay and renewal processes in this biological pool is very complex and sensitive. The populations of microorganisms that make up the biological pool are the driving forces in soil nutrient dynamics. Together they also play a key role in building a soil structure that both retains and freely exchanges nutrients and water—a soil where plant roots thrive (2). Maintaining the concentration of SOM above a threshold level is essential for maintaining soil health, productivity, and sustainability. Loss of SOM leads to degradation of soil structure, reduction in soil water-holding capacity, and exacerbates climatic extremes. Thus, judicious management of the soil carbon pool is necessary (1).

1) Magdoff, F and Van ES, H, Building Soils for Better Crops, Sustainable Soil Management, SARE Outreach Publications, Brentwood, Md, 2009.
2) Keith R. Baldwin, Crop Rotations on Organic Farms, North Carolina Cooperative Extension Service (2006), www.cefs.ncsu.edu.

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Becoming the Good Soil: Supplementation of Cropland with Compost Increases Productivity

A review of the use of organic supplements to cropland indicated that application of long-lasting organic amendments increased organic carbon by up to 90% versus unfertilized soil, and up to 100% versus chemical fertilizer treatments. Furthermore, regular addition of organic residues, particularly composted ones, increased soil physical fertility, mainly by improving aggregate stability and decreasing soil bulk density. The best agronomic performance was obtained with the highest rates and frequency of applications. Crop yields increased by up to 250% after long-term applications of high rates of municipal solid waste compost (1).
Compost is the end of product of a controlled aerobic decomposition of organic wastes (such as yard waste, food waste, animal manures, and other materials that come from recently living organisms). Compost has readily available and other slow-releasing plant nutrients, as well as a high organic matter content, which helps to feed the microbes in charge of creating a well-rounded environment for life to flourish.
The reason that compost is so effective in increasing crop yields is that compost is more slowly decomposed compared to fresh plant residues, with composts typically having mean residence times several times greater than un-composted organic matter (2).
A single application of composted green waste to California rangeland significantly increased forage production from 40 to 70% over three years (3).
Compost has also been shown to increase yields for field crops. In a six year field experiment studying the effect of farm compost amendment on a crop rotation of potato, fodder beet, forage maize, and Brussels sprouts demonstrated that farm compost increased soil quality and crop yields establishing a causal relationship between soil quality and crop production (4).
Finally, it has been estimated that an increase in the SOC pool within the root zone by 1 t C/ha/year could enhance food production in developing countries by 30 to 50 Mt/year including 24 to 40 Mt/year of cereal and legumes, and 6 to 10 Mt/ year of roots and tubers (4).

1) Diacono M, and Montemurro, F, Long-term effects of organic amendments on soil fertility. A review, Agron. Sustain. Dev. 30, 401–422 (2010).
2) Paustian, et al. Climate Smart Soils, Nature, 532, 49-57 (2016).
3) Ryals, R., and W. L. Silver. 2013. Effects of organic matter amendments on net primary productivity and greenhouse gas emissions in annual grassland ecosystems. Ecological Applications 23:46-59.
4) D’Hose, et al. The positive relationship between soil quality and crop production, Applied Soil Ecology 75, 189– 198 (2014).

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Becoming the Good Soil: Other Ways That Compost Helps Mitigate Climate Change

To make compost, organic materials are necessary, like yard waste, food waste, wastewater treatment plant residuals, animal manures, or others. Currently, some organic wastes are finding their way to the landfill, where they decompose anaerobically (without oxygen) and methane is emitted—a greenhouse gas contributing to climate change. Landfills contribute 20% of the total methane emissions generated in the US (https://www.epa.gov/ghgemissions/overview-greenhouse-gases). The EPA estimated that in 2014 the trash contained approximately 22% food by weight (https://www.epa.gov/smm/advancing-sustainable-materials-management-facts-and-figures-report ). In North Carolina alone, it is estimated that just over 8% of the excess food generated is recovered from the landfill through composting, anaerobic digestion, food donations, and animal feeding (NCDEQ 2012 and 2016 reports — http://deq.nc.gov/conservation/recycling/composting/composting-resources). Composting itself produces carbon dioxide as a byproduct of the respiration of the composting microorganisms, and it could produce methane and nitrous oxide if the pile is not managed correctly; however, when compared to the traditional method of organic waste disposal—landfilling—composting is regarded as a way to avoid the generation of methane (http://faculty.washington.edu/slb/docs/CCAR_Composting_issue_paper.pdf). Therefore, just the act of diverting organic waste from the landfill can prevent significant quantities of methane from being generated, helping to mitigate climate change in its own way.

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Caring for Our Common Home: Composting (updated blog from December 28, 2015)

By composting at home and the church, we can: 1) reduce the amount of garbage we generate, 2) create valuable compost for home and church gardens, and 3) decrease our carbon footprints by sequestering carbon in the soil.
As part of our goal to achieve “zero waste” on our church campus, Nativity uses a composting service, Food FWD (http://foodfwdnc.com/), which distributes sustainable and compostable single-use items like cups and plates, utensils, take out boxes, and other products for people looking to use earth-friendly items. FWD has provided the church with two collection bins, which they pick up weekly.
Also on our church campus, we have two compost bins just inside the fence of the Nativity Community Garden (NCG). The finished compost is used in the garden. Parishioners are welcome to add compostable materials from their homes to the bins in the NCG). Please only add new raw material to the right hand bin. For what to compost and what not to compost, see lists below.
Another option to keep compostable material out of the landfill is to sign up for a household composting service like CompostNow (http://compostnow.org/).

What to Compost:
Kitchen greens, fruit scraps, chewing gum, vegetable scraps, house plant trimmings, coffee grounds, rice, pasta, eggshells, tea bags, fresh flowers (not woody), plant trimmings (not woody), leaves (not as thick matt), coffee filters, stale bread, paper napkins, paper towels, dryer lint (not containing synthetic fibers), hair, fur from brushed animals.

What not to Compost:
Meat, fish, bones, dairy products, oils and fats, sauces, ashes, pet waste, diseased plants, weeds (especially with seeds), grass clippings.

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Nativity’s Becoming the Good Soil Project Has Received Support from the Episcopal Church

The news release below was published today by the Diocesan House, The Episcopal Diocese of North Carolina

Nativity, Raleigh, Among Recipients of Stewardship of Creation Grant

The Episcopal Church recently announced the awarding of 16 grants totaling $123,910 in the second round of grantmaking managed by the Advisory Council for the Stewardship of Creation and approved by the Executive Council.
Among the recipients is Nativity, Raleigh, awarded $10,000 toward its work, Becoming the Good Soil, of reducing the serious effects of climate change by engaging in regenerative agriculture through carbon farming, specifically by supplementing land with compost. In simple terms, one goal of carbon farming is to increase soil organic matter (SOM) to help draw carbon out of the atmosphere and sequester it in the ground.
In addition to the implementation of carbon farming to local soil, Nativity will work to help educate individuals and congregations learn more about regenerative agriculture through, among other channels, the development of a white paper to be made available to all churches.
The Diocese will follow the development of this work, but you can learn more about carbon farming now and stay connected with Nativity’s environmental efforts on its Creation Care blog at nativityonline.org.

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The Soil Story

This short video beautifully explains the science behind the carbon farming concept, and why to avoid the most serious consequences of climate change we need to encourage greater adoption of this conservation agricultural practice.

http://search.aol.com/aol/video?q=the+soil+story&s_it=video-ans&sfVid=true&videoId=C22C04611FF665D9A04FC22C04611FF665D9A04F&v_t=client97_searchbox-ac

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Becoming the Good Soil: A Life of Grace for the Whole World

In conjunction with Nativity’s efforts to serve as a catalyst for launching carbon farming in NC (see Caring for Creation blog posts on August 28 and December 3, 2016), Nativity is offering a series of events beginning on April 22 (Earth Day) and going to the end of May. The first event will be a potluck supper and Holy Eucharist at 5 pm on April 22 (Earth Day). The next day, beginning at 10:15 am on Sunday, April; 23, and for the next 5 Sundays, Environmental Stewardship will present a program called A Life of Grace for the Whole World. These events are a direct response to the Episcopal House of Bishop’s call “to acknowledge the urgency of the planetary crisis in which we find ourselves, and to repent of any and all sets of greed, overconsumption, and waste that have contributed to it”, and further, “to take steps in our individual lives, and in community, public policy, business, and other forms of corporate decision – making, to practice environmental stewardship and justice. We hope you will join us. Everyone is welcome