Welcome to Agresource's premiere e-newsletter.  In switching from print to an electronic medium, we hope to be able to bring you more current news while saving more of earth's resources.  In this issue, we have four timely articles now that the prime summer gardening and growing periods are underway.  Also, we're taking this opportunity to announce our new comprehensive guide to Topdressing Turf with Compost.  It can be read or downloaded by clicking here.  For more articles and information, please visit our site at www.AgresourceInc.com.

Compost Topdressing Reduces Water Usage

In all portions of the United States there is a steadily increasing demand for clean water. On average, 30% of the total residential water is used for outdoor landscaping. Landscapers and homeowners who wish to maintain healthy landscapes with minimal water usage can use compost to reduce irrigation requirements.

The value of compost used as a soil amendment to improve soil quality has been well established. Compost has many direct benefits on both the chemical and physical properties of soil including increasing the ability of soil to hold water and improving water infiltration. By adding compost to soil during landscape construction, the organic matter content in the soil root zone can be easily adjusted. As the amount of organic matter in the soil increases, the soil has greater ability to hold water.

However for established lawns, sports fields, and turf areas, the addition of large amounts of organic amendment may be more difficult and is best achieved by topdressing. Recent university research (see Johnson et al., 2009 Compost Science & Utilization 17:95-102) has demonstrated that topdressing with compost can have a very significant impact on improving the soil water content and improving turf quality during drought periods. Thus for the homeowner, landscaper, or turf manager who wishes to reduce irrigation, topdressing offers a practical solution without sacrificing a green lawn.

In the United States, there are an estimated 50 million acres of turf and the maintenance of these areas consumes significant amounts of water. Often poor soil quality results in the need for frequent irrigation. The addition of compost to the soil can improve that soil quality and reduce the frequency and volume of irrigation. Research performed at Colorado State University (CSU) has demonstrated that topdressing with compost was effective in reducing irrigation needs by increasing soil water content.

Although the positive impacts of using compost to improve soil’s water-holding ability are already well established, this research was performed to evaluate the effectiveness of topdressing treatments. The CSU study also examined the response of the turf during periods of drought. Researchers evaluated impacts of the topdressing on established Bluegrass plots and measured both the impact on soil water content as well as turf quality and the temperature of the turf canopy.

The results of the CSU research showed that topdressing with compost offered a significant positive effect on soil water content and if followed by core aeration, it was an effective means of water conservation while maintaining “aesthetically appealing turfgrass.” Areas that received topdressing stayed greener longer after periods of drought. Topdressing improved water infiltration even when core aeration was not performed. In addition, compost topdressing resulted in lower temperatures in the turf canopy reducing stress.

In conclusion, the CSU study provides evidence supporting topdressing programs as beneficial to maintaining turf quality and shows that water for irrigation can be reduced without sacrificing a green lawn.

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New Performance Mulch a Success!

Distribution of Agresource’s Performance Mulch expanded considerably during the spring season of 2009. This is mainly due to more people recognizing that compost mulch can be a supplier of nutrients while providing the same benefits as wood-based mulches, such as moisture-holding and weed suppression.

Traditional mulches made with a combination of bark and recycled wood can rob nitrogen from plants. These high-carbon content mulches may need to be removed each year due to the fact that they break down slowly and tend to inhibit plant growth over time. Performance Mulch starts out with the right carbon-to-nitrogen balance so that plants can thrive and the mulch does not have to be removed annually.

For more information on the value of Performance Mulch, go to Newsletters & Articles on Agresource’s web site, or click here to read "Using Compost as Mulch."

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Reduce Greenhouse Gases & Carbon Footprint by Composting

Recently published studies have documented that composting organic residuals is an effective means to reduce the generation of greenhouse gases and reduce our carbon foot print. When compared directly to other disposal options (landfill disposal or incineration), composting reduces the emissions of greenhouse gasses (GHGs), such as carbon dioxide and methane, which are responsible for climate change. A study prepared for Merrimack, NH, showed that landfill disposal generated about 3.4 times more GHG emissions than composting (Beecher, 2009, BioCycle 50:26). Another study, published in 2009 by William Barber (Biosolids Technical Bulletin 14:8), also showed that composting resulted in a net reduction of GHG emissions when the biosolids are co-composted with green waste.

Composting is a widely practiced method for handling organic materials, such as wastewater treatment sludges (biosolids), food and food processing residuals, and leaf and yard wastes. In the composting process, organic matter—primarily carbon—is broken down and stabilized. Greenhouse gasses—primarily carbon dioxide (CO2) but also much smaller quantities of methane and nitrous oxides—are generated in the process. In addition, energy and fuel are consumed to operate equipment to make compost. Depending on the level of technology, these emissions may be significant.

However in order to calculate the GHGs produced and the impact of composting on the overall carbon foot print, consideration must be given to the end use or final stage of the compost. For example, when compost is added to the soil as a soil amendment, the organic carbon is sequestered. In contrast, when the organic residues are incinerated, the carbon is released to the atmosphere as CO2. Organic matter placed in the landfill will be converted to methane, a powerful greenhouse gas and although this methane may be captured and used as an energy source, a significant portion does escape to the atmosphere.

In addition, if compost is used to replace other organic amendments (e.g., peat) and conventional fertilizers, then this replacement will have a positive effect on reducing GHG emissions. The production of conventional fertilizer is very energy intensive using natural gas. Nutrients in compost displace the use of conventional fertilizers and thus result in reduced emissions and a smaller carbon footprint.

In a study performed for the Town of Merrimack, NH, a detailed quantitative accounting was made of energy used and the emissions generated during the process of making and distributing compost. Comparisons were made between the existing in-vessel composting facility operated by the Town and the alternative option of trucking residuals to the nearby landfill. Although composting uses more energy than landfill disposal, the overall impact on greenhouse gas emissions was significantly less for composting. Results of this study have been published in the April 2009 issue of BioCycle (50:26) and a copy of the full study can be obtained at the Northeast Biosolids and Residuals Association website (www.Nebiosolids.org).

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Compost: Good for What You Eat!

Industrial agriculture is all about quantity and speed and low cost. But bringing those heads of lettuce, bushels of apples, and bunches of carrots to your market in greater abundance, as quickly and as cheaply as possible, does not necessarily spell good news for the consumer—at least, not good nutritious news. The growing body of evidence as discussed in Michael Pollan’s book In Defense of Food (Penguin Press, 2008), clearly shows that plants grown with industrial fertilizers as the only soil amendments are “nutritionally inferior to the same varieties grown in organic soils” (p. 119).

It could be because the crops grow too quickly and can’t accumulate all the nutrients of plants grown more slowly and organically; it could be because of the smaller root systems of industrial plants as compared to organically grown crops. And “biological activity in the soil almost certainly plays a role as well; the slow decomposition of organic matter releases a wide range of plant nutrients” (p. 120). Plants grown in soil with high organic matter—a more biologically active soil—have more minerals (up to 30%) than their industrially fertilized counterparts and more phytochemicals, which offer important antioxidants effects when consumed.

Whether tending the family vegetable plot or farming professionally to feed the nation, by growing plants in compost-amended soil, you’ll be bringing more nutritious food to the table.

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