Summer 1995 issue of Remineralize the Earth Magazine.

Soil Remineralization - An Essential Environmental Action: by Frederick I. Scott, Jr.

On May 24, 1994, the U.S. Department of Agriculture (USDA) (Beltsville, MD), the U.S. Bureau of Mines (USBM) (Washington, DC), the National Stone Association (NSA) (Washington, DC), and the National Aggregates Association (NAA) (Silver Spring, MD) co-sponsored a forum on 'Soil Remineralization and Sustainable Agriculture" at the USDA Agricultural Research Station in Beltsville, MD. That forum could represent a mile-stone marking officially sanctioned efforts to implement long overdue action of fundamental importance to human survival, the ultimate reason for environmental concern. It deserves intensive and continuing attention to assure constructive application of the principles addressed.

As outlined by Ronald Korcak (USDA) of the Organizing Committee, the Forum brought together the by-product rock fines generating industry and the proponents of soil remineralization (SR) to explore environmentally sound uses of rock fines and to identify the state of the science supporting their use and the gaps in knowledge that need to be filled. That the accomplishment of such objectives could impact significantly on survival was addressed in substantial measure by other presenters and warrants further attention here.

Keynote speaker, Greg Watson of The Nature Conservancy (Boston, MA), connected the objectives of the proponents of sustainable agriculture, who seek to discover tools and strategies that will allow farmers to reduce the amounts of chemical inputs used to fertilize and protect crops from pests; with the thesis that the naturally occurring gradual depletion of trace minerals from the soil is the major cause of global forest decline and the deteriorating nutritional content of the world's agricultural crops. The primary goals of sustainable agriculture are to encourage farmers to adopt growing practices that 1) preserve the environment and protect biodiversity and 2) are economically viable. From the efforts to build soil fertility through the discovery and use of organic alternatives to chemical fertilizers, the science underlying the organic aspects of soil development has greatly expanded. The publication of John Hamaker's book, The Survival of Civilization, alerted the community to the continuing depletion of inorganic trace minerals that are critically important to the soils, the plants supported by them, and consequently all other life forms that are dependent on plant life. Hamaker (with co-author Don Weaver) demonstrated the outstanding benefits of certain kinds of rock dust in achieving vigorous and healthy growth of plants of all kinds. Watson described larger global context of soil remineralization and discussed the role this concept can play in achieving the goals of sustainable agriculture.

Joanna Campe of the Organizing Committee, editor/publisher of Remineralize the Earth (Northampton, MA), reviewed the history of soil remineralisation efforts extending from the work of Julius Hensel in the 1880's and his book, Bread from Stones (Republished in 1991 by Acres, USA) to the extensive research in agrogeology in Canada (and other places), to the ecological movement concerned with the Hamaker thesis. Highlights from that research include, in Europe for example, a four-fold increase of timber volume after 24 years for pine seedlings remineralized with basalt compared to controls; although no differences between the two were observable for the first six years. The difference was maintained for 60 years from that one remineralization. Similar results were reported in Australia, with five times the growth for some species and potting out time, reduced from five months to six weeks, and, in Michigan, a two and a half times increase in yield of corn without irrigation.

A Material Balance Illustrates the Need for SR

Walter Keller, Professor of Geology, University of Missouri Columbia (Columbia, MO) published papers in the 1940s urging the use of native rocks and minerals as fertilizers, citing research on the benefits obtained. Using a straightforward material balance, he noted that even the unbalanced mineral nutrients supplied by commercial fertilizers fail even to replenish completely the minerals removed by the harvested crop (to say nothing of the essential trace elements not provided in the mix). Application of the record potash production of 1944, for example, would not have replaced the potassium (K20) removed from the soil that year by the corn, wheat, and alfalfa harvested that year. For natural weathering of limestone to have replaced the potash, such weathering would have to occur at the rate of one foot in 218 years whereas the estimated natural weathering rate for the U.S. is one foot in 23,984 years.
That plant growth in general and farming in particular deplete soil of nutrients was attested by Ward Chesworth, University of Guelph, Department of Land Resource Science (Guelph, Ontario, Canada). Early examples of well-developed agricultural systems (Iraq, Pakistan, Egypt, and China) were based on geological delivery systems that provided water and fertile soil for thousands of years. Even so, some of the systems have proven to be unsustainable due to salinization (Iraq and Pakistan) or human intervention (the Aswan Dam built in Egypt in 1964 traps the nutrients that annually renewed the land's fertility). Still, the lesson remains unlearned as the indiscriminate use of dams and intensive irrigation continue.

Soil remediation using energy and urban wastes, reservoir sediments, and mineral waters were reported on by William Fyfe, University of Western Ontario, Department of Geology, and Michael A. Powell, Department of Earth Sciences (London, Ontario, Canada) and Tripathy, Pollution Control Board, Bhubaneswar, Orissa, India. Noting 19th century reports and recent 20 year studies in the U.K. of the benefits of adding ash to existing soils already capable of supporting growth, the authors determined that mixtures of sludge and ash could support tree (pine, ash, and walnut) and grass (indigenous to India) growth. The trees grew at twice the rate of the controls while the grasses yielded hundreds of times the mass of the controls. Field studies in India of trees planted so that the source of the nutrients could be determined showed that some species planted in mixtures of sludge, ash, and weed are growing at 30-100 per cent faster than trees planted in soils and fertilizers. Experiments in Portugal confirmed that dam sediments provide excellent remediation for depleted soils. Many deep (1-2km) mineral waters, rich in elements such as calcium, magnesium, potassium, etc., have the potential for remineralizing tropical soils (kaolin rich) in regions like the Amazon.

Robert I. Bruck, North Carolina State University (Raleigh, NC) mobilized 200 student volunteers in studying the effects of remineralization on severely declining forest located 5600 feet above sea level in the southern Appalachian mountains. One year after the application of about 1000 lbs/acre of Planters II on 25 acres of the forest, soil and newly flushed tissue samples were analyzed in the spruce/fir zone. (Planters II is a natural sedimentary rock mined at 13,000 feet in the Rocky Mountains, crushed, graded, packaged, and sold as micronutrients by U.S. Soil Co., Salida, CO. It is primarily calcium and magnesium plus 37 trace elements with virtually no nitrogen, phosphorus, or potassium). The most significant preliminary results indicate that tissue levels in both Red Spruce and Fraser Fir of calcium and magnesium have been enhanced from 12-29 percent and soil levels of exchangeable calcium and magnesium have increased an average of 14 percent. Although a significant amount of mortality has taken place, the remineralized plots exhibit 39% fewer dead trees than do the non-treated plots. Observations will be continued during the summer of 1994 as it is too early to establish overall survival and mortality trends for this long-lived system.

David Miller, Oberlin College, Biology Department (Oberlin, OH), evaluated a number of rock dusts including mixed glacial deposits, single mineral types, and some commercial products for their effects on soil nutrient levels, soil microbiology, and nutrient levels of plants grown on treated soils. With the exception of certain cations, changes in available mineral nutrient levels appeared erratic. The results of some standard microbial enzyme assays yielded inconsistent data. From two consistent data sets, the dusts appear definitely stimulatory to microbial activity. First, the addition of dusts to composting materials raises the temperature of the composts. Second, additions of dust increase the rate of decomposition of soil organic carbon, both in field test plots and in pot test experiments. As in investigations by others, tests on poorer soil appear to demonstrate greater potential benefits of rock dust amendments.
Exploring one specific potential benefit of soil remineralization, Orville A. Levander of the USDA's Vitamin and Mineral Nutrition Laboratory (Beltsville, MD), discussed the widely varying selenium levels in soil throughout the world. An essential trace element, yet toxic in excessive amounts, the selenium content of staple grains in different regions has been reported to exceed three orders of magnitude for the same foodstuff. Several approaches have been taken in efforts to remedy the situation including foliar application by spraying crop plants, top dressing of soils with fine pellets, addition to fertilizers used in farming, and the direct addition of selenium to the feed of livestock and poultry. Because many of the biogeochemical processes operating on a global scale to influence the ecological cycling tend to remove this essential trace element from the food chain, active intervention to rebalance its natural flux in the environment may continue to be necessary. Soil remineralization could provide an effective and safe method for doing so.

Organizing Committee member Rick Meininger (National Aggregates Association) recounted the efforts of the NAA in exploring the use of mineral or new product fines in various SR applications. These fines, generally material passing 200-mesh screen (74 um), must be disposed of properly. He urged continued industry cooperation in developing a protocol for physical and chemical testing of them; in the management of a database for information about them; and in coordinating the stockpiling and transporting of different lots of them for a five-year period to aid interested researchers. He was joined in that recommendation by Robert J. Able, Dan Gernatt Gravel, Inc. (Collins, NY).

Lawrence P. Quinlivan (National Stone Association) of the Organizing Committee remarked on the operation of the agricultural lime industry and the potential for the application of some of its products in combination with sewage sludge, compost, yard waste, animal waste, excavation soil, or mineral processing as soil amendments. Aldo F. Barsotti, U.S. Bureau of Mines, Organizing Committee member, provided an overview noting that the estimated but uncertain amount of fines generated, though relatively small compared to other mining operations, may be as much as 200 million short tons annually. Economic considerations will most likely limit bulk quantities for soil replenishment to a local or regional basis. [It should be pointed out, however, that the general application of these fines may literally be a matter of survival for the human species and, as such, would more than warrant efforts, comparable to that of a Manhattan Project for the atomic bomb, substantially beyond regional concerns. That the political effort needed to effect such a commitment would be enormous should not limit the circumspectness with which the undertaking is pursued.]

Findings of the significant benefits of soil remineralization add further perspective to the documented direct ingestion of soil by mammalian and avian species throughout the world. Bernadette M. Marriott, Acting Director Food and Nutrition Board, National Academy of Sciences (Washington, DC) explored the meaning of geophagy or soil eating. The behavior transcends culture, geographic location, and socioeconomic class. Although there are conflicting hypotheses as to the nature and rationale for the behavior, there seem clearly to be nutritional and physiological benefits derived from the practice.

Tara Zadeh, General Counsel for the Commonwealth of Massachusetts Department of Food and Nutrition (Boston, MA), brought the sobering reminder to the advocates of soil remineralization that the majority of individuals in the regulatory and environmental communities are totally unfamiliar with the concept of soil remineralization. The use of a unique process for manipulating the environment may implicate existing local, state, and federal environmental land use laws or prompt legislators and regulators to create new laws and regulations. Thus, as with advocates of any new concept, proponents of renourishing the soils through remineralization should be prepared to answer a range of questions.
She advised advocates of re mineralization to anticipate generalized skepticism and opposition from regulators and activists un familiar with the sound basis for the practice by developing and bringing that information effectively to their attention. Data addressing a wide variety of concerns including run off; leaching, accumulation in water bodies, possible damage to aquatic and plant life, endangered species, protection of water supplies and wet lands impacts should be collected and made available in easily understandable formats.
In addition, the research community exploring remineralization will need to address more practical legal and regulatory issues relating to the actual commercial use of remineralization and the products grown in mineral treated soils. These issues include environmental impacts, worker protection, public health, and consumer concerns. She believes it to be essential that sufficient scientific data exist to substantiate any particular labeling claims (such as increased soil fertility, increased nutritional values, or pesticidal properties).
That well-meaning observation, along with the statement that good information will lead to intelligent debate which should lead to intelligent regulation, fails to acknowledge the protective role that western science plays in shielding Euro-American civilization from reality. Unless some circumstance such as the increasingly pervasive awareness of doom forces a revision of the generative kernel of western culture, the initiative for a substantial soil remineralization effort will fail. One ought to note, however, that the soils that have nourished the human race and all of the species on the planet for several million years were made of rock dust, so it cannot be all bad. While the conditions for optimal use of rock dust can be determined, it is unlikely that we recently arrived scientists and other inhabitants, who seem unable to stop fouling the planet, can do a better job of specifying criteria for permitting its use.

James W. Schmitt, Granite Rock Company (Watsonville, CA), summarized industry's perspective and necessary activities if the use of new product fines and related materials is to be commercially successful in soil remineralization. More information is needed on the benefits of aggregate fines. How quickly and for how long do they work? What mechanisms are responsible for their success? What is the range of compatibility of soils, crops, and fines? What is the availability of nutrients from the fines?

The industry needs to systematically determine the composition, properties, and nutrient availability of each of its aggregate fines and to learn the language of agronomy and the needs of the new customer base. He urged the industry to cooperatively develop technologies, test methods, and quality standards. This will require changing the mind set regarding fines including educating staff about the opportunities and soliciting help from it to meet the challenges. Aggregate fines represent a large reserve of compositionally consistent naturally occurring co-product generated by the processing of sand and gravel or crushed stone into construction aggregate. Their application to agricultural land is only one of the markets that the industry should get organized to explore.

W. Doral Kemper, USDA/ARS National Program Staff (Beltsville, MD) reviewed the research needs posed by the interest in using rock dust in agriculture. While expecting to more fully define those research needs based on information presented at the meeting, Kemper viewed the starting point as the need to know where there are significant or incipient deficiencies of these nutrients in plants, animals, and/or humans. He noted that maps have been developed on a few of these elements such as zinc and selenium and that others may be in preparation. With defined areas of deficiency and chemical analyses of rock dusts available within reasonable hauling distance of the area of deficiency, greenhouse and field studies using dusts with the most potential for providing the deficient element should be conducted. With this best fit established, an economic analysis of its use should follow. With such information, industry should be able to establish rock dust as a viable product line.

The Promise and Problem or Soil Remineralization

As outlined by Counselor Zadeh, unfamiliarity with the concept and background of soil remineralization on the part of the public and its legislative, regulatory, and environmental representatives may en gender much caution and concern in the community. Indeed, the advocates and practitioners of soil remineralization must present the case fully and persuasively. They must proceed judiciously to develop the technical, logistical, and financial information for the application. As suggested earlier, however, neither the crucially important promise nor the culturally threatening problem posed by soil remineralization have been addressed. Handicapped from the outset because it appears to be too simple, the probability for the success of soil remineralization efforts will sink further if those considerations are not addressed.