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Archive | Soils

Building Soil Health with Volcanic Basalt

by Rich Affeldt

volcanic-basaltOrganic and sustainable farmers have long relied on rock dust as an all-natural way to improve roots systems, increase yields and promote general plant health in a wide variety of crops and conditions. Yet, it has taken the rapid depletion of our global soils to bring rock dust to the attention of modern agricultural science. The good news is that there is undeniable evidence that rock minerals can help restore soil health, minimize crop deficiencies and boost resistance to pests and disease.

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What is Humus & How is it Formed?

Secrets of Fertile SoilsExcerpt from Secrets of Fertile Soils: Humus as the Guardian of the Fundamentals of Natural Life by Erhard Hennig, published by Acres U.S.A.

by Erhard Hennig

Humus forms as a result of the complicated interplay of inorganic conversions and the life processes of the microbes and tiny creatures living in the soil. Earthworms play a particularly important role in this process. Humus formation is carried out in two steps. First, the organic substance and the soil minerals disintegrate. Next, totally new combinations of these break down products develop, which leads to the initial stages of humus. Humus formation is a biological process. Only 4-12 inches (10-30 centimeters) of humus-containing soil are available in the upper earth crust. This thin earth layer is all that exists to provide nutrition to all human life. The destiny of mankind depends on these 12 inches!

Cultivated soils with 2 percent humus content are today considered high-quality farmland. What makes up the remaining 98 percent? Depending on the soil type, soil organisms constitute about 8 percent, the remains of plants and animals about 5 percent, and air and water around 15 percent.

The remaining 70 percent of soil mass is thus of purely mineral origin. The mineral part of the soil results from decomposition and the erosion of rock. The dissolution of these components is carried out by the lithobionts, which can be seen as the mediators between stone and life. It was Raoul H. Francé who coined the term “lithobiont,” which means “those who live on stone.” The lithobionts are the group of microbes that begin the formation of humus. They produce a life-giving substance from the nonliving mineral. On the basis of this process, living matter, earth, plants, animals and human beings can begin, step by step, to build.

Only soils with an optimal structural state of tilth have a humus content of 8-10 percent. Untouched soils in primeval forests can, at best, reach 20 percent. A tropical jungle can’t use up all its organic waste, so humus can be stored. All forests accumulate humus, but real humus stores only emerge over the course of millennia. Once upon a time accumulations of humus known as chernozem (Russian for black earth) could be found in the Ukraine.

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Nitrogen Fertilizer’s Long-Lasting Legacy

Aerial of intersecting roads in rural IndianaDangerous nitrate levels in drinking water could persist for decades, increasing the risk for blue baby syndrome and other serious health concerns, according to a new study published by researchers at the University of Waterloo. Nitrogen fertilizer applied to farmers’ fields has been contaminating rivers and lakes and leaching into drinking water wells for more than 80 years. The study, published in the journal Environmental Research Letters, reveals that elevated nitrate concentrations in rivers and lakes will remain high for decades, even if farmers stop applying nitrogen fertilizers today. The researchers have discovered that nitrogen is building up in soils, creating a long-term source of nitrate pollution in ground and surface waters. “A large portion of the nitrogen applied as fertilizer has remained unaccounted for over the last decades,” said Nandita Basu, a professor in the Department of Earth and Environmental Sciences and Civil and Environmental Engineering. “The fact that nitrogen is being stored in the soil means it can still be a source of elevated nitrate levels long after fertilizers are no longer being applied.” Their paper presents the first direct evidence of a large-scale nitrogen legacy across the Mississippi River Basin. Professor Basu and her group analyzed long-term data from over 2,000 soil samples throughout the Mississippi River Basin to reveal a systematic accumulation of nitrogen in agricultural soils. In many areas this accumulation was not apparent in the upper plow layer, but instead was found 25-100 centimeters beneath the soil surface.

This article appears in the May 2016 issue of Acres U.S.A.

Interview: Researcher, Author Eric Toensmeier Explores Practical, Effective Carbon Farming Strategies

Real-World Solutions

While this Eric Toensmeier_rgb (2)interview was being prepared a story surfaced on public radio about a couple of enterprising Americans who are taking advantage of changing policy to open a factory in Cuba. Their product? Tractors! The whole idea, the story helpfully explained, was to introduce “21st century farming” to the beleaguered island. By making it easier to tear up the soil. Clearly there is some distance to go before an accurate idea of 21st century farming penetrates the mainstream. It will take people like Eric Toensmeier. His new book, The Carbon Farming Solution, carries enough heft, range and detail to clear away forests of confusion. If the notion of leaving carbon in the soil is going to take its place next to that of leaving oil in the ground, this one-volume encyclopedia on the subject is exactly the kind of deeply informed work that’s required. Reached at his home in western Massachusetts, Toensmeier was exhilarated over finishing a project years in the making, and more than happy to talk about it.

This interview appears in the May 2016 issue of Acres U.S.A.

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Biochar as Substrate for Hydroponic Tomatoes

tomatoes USDA photoAs the use of soilless, hydroponic growing methods becomes more prevalent among crop producers, researchers are looking for new materials that can help growers save money, produce healthy plants and contribute to sustainable practices. The authors of a study in HortScience say that biochar, a charcoal-like material produced by heating biomass in the absence of oxygen, can help “close the loop” when used as a substrate for soilless, hydroponic tomato production. “This method could provide growers with a cost-effective and environmentally responsible green-waste disposal method, and supplement substrate, fertilizer and energy requirements,” said the study’s corresponding author Jason Wargent.

This article appears in the February 2016 issue of Acres U.S.A.

Cover Crops in Grazing Systems

cover crop winter pea, clover, cereal ryeNoble Foundation researchers are studying how cover crops could be part of a year-round grazing system that provides economic and environmental benefits to farmers and ranchers. Noble Foundation research agronomist James Rogers, Ph.D., received a three-year conservation innovation grant from the U.S. Department of Agriculture Natural Resources Conservation Service to conduct the research. The grant will support Rogers in determining how much moisture is used and/or conserved by summer cover crops and how those crops impact production of grasses and legumes consumed by livestock (commonly called forages) during the winter months. Moisture is a key  component of crop and forage production. Sufficient moisture levels boost pasture quantity and provide benefits to soil, which ultimately helps farmers and ranchers. “We need to determine whether the cover crops take moisture away from or preserve moisture for winter pasture,” Rogers said. “Preserving moisture will allow for earlier fall production. However, if the cover crops use up the moisture, winter pasture production is limited.”

This article appears in the February 2016 issue of Acres U.S.A.