A NOAA Captured image of Lake Erie in 2011 shows the massive algal blooms from nutrient loads – the worst in 10-years

The practice of fertilizing soils for crop nutrient removal while ignoring nutrients already present in the soil or about to be released by biological processes  may be directly contributing to a potentially explosive situation of algal blooms on the Great Lakes – and other places. Images that NOAA has released over a 10-year period for Lake Erie show that in 2011 the algal bloom was the most extensive – worse yet – in the lakes history. Will Brinton traveled to Guatemala in 2011 and observed the  massive algal bloom on Lake Atitlán -  visible in outer-space to NASA imaging:  “The only distinguishing feature in these crises is the source of the nutrients: in Guatemala it’s septage;  in the USA its largely agricultural nutrients.” What makes the USA situation possibly worse than that of Guatemala is that we are doing it in plain day with an arsenal of tools, technology, soil testing and agricultural machinery that is supposed to be the most advanced in the world. “But in fact, it’s just about as primitive from a Nature perspective as dumping raw septage in the waterways”. Since 2002, 15,930 metric  tons of nitrate and a lesser but significant amount of phosphorus has entered Lake Erie. No one is anxious to assume any blame.

A recent Crops&Soils magazine article on the topic quotes agronomist Robert Mullen of the USA Potash Corp: “If no action is taken, there’s a greater likelihood of regulation from the state and federal level” – regulation that many do not want.  Some experts are questioning if we have enough information to stop the problem.  Woods End’s efforts to get a new soil test off the ground that measures the biological ability of soil to release bound nitrogen (and P), is meeting with slow, steady acceptance “but too slow to stem the problem”. says Brinton, developer of the Solvita Soil test.  Presently 32 labs across America and a dozen internationally are offering the test. However, according to Woods End lab, what the soil labs are saying is that farmers are not requesting the new tests – in other words, there is a lack of understanding about the usefulness of the test and why they should do it. This possibly makes soil labs become part of the problem by recommending more-than-enough fertilizer to make for high yields, without accounting for natural sources. Organic-bound N and P is like capital in the bank, and the release each year is the interest coming out.  Modern fertilizing practices appear to be the spend-happy consumer, ignoring  existing capital and the interest it generates.

Failing to measure nutrient potential of soils is not the only source of the problem; the other half is the manner in which soils are prepared and tilled or not-tilled, according to most reports.  Excessive tillage may increase soil washing into waterways from erosion, carrying nutrients with it, but no-tilling is also in the cross-hairs by contributing to surface washing of surface-applied chemicals.  The big perspective must be soil-health starting at home and the soil lab – start appreciating the soil’s intrinsic ability to provide nutrients and stop over-using and over recommending fertilizers based on incomplete soil testing.

1) farmers and soil aficionados gather for soil health discussion 
2) Dave Brandt shows an air-seeder that shoots cover crop seeds into tall corn.
3) Ray Archuleta (NRCS) and assistant demonstrate the power of soil aggregates
4)  Brian Cooley (NRCS) digs the earth to seek worms and “gold”: soil-aggregates

Soil Health is a new paradigm in no-till farming, and very evidently a fast-growing grassroots movement that “threatens” to unite all farmers. Attendees at a farm workshop in Carrol, Ohio said they wished the movement will be recognized not only by no-tillers but organic and conventional farmers as well. More than 300 persons converged on David Brandt’s no-till corn, bean and grain farm on April 10 to learn more about cover cropping, air-seeding, and NRCS Soil Health Tools, a new one of which incorporate Solvita CO2-Burst as the biological component. Down-’n-dirty lessons included soil-clod demos, counting earthworm (and radish) channels penetrating deep into the profile, and watching how to “crush” but, not till, a cover crop for soil improvement.

What’s got participants so excited was “the sense of hope”, according to Jay Fuhrer, Soil Conservationist attending from Bismarck, ND. Hope that USA farm soils so deep in degradation from 50 years of being pushed to massive tillage and soil over-use, can be saved, and returned to economic viability. Some referred to cultivating soil as a form of  “tillage alcoholism” and speculated on the step-wise program needed to slowly restore soil tilth. Intense discussion focused on tools versus vision,  the need to broaden the dogmatic “no-till” messages so other growers can participate, especially how to invite vegetable and organic growers for whom no-till offers (as yet) few practical solutions.

In Europe long-term rotational-tillage farm plot studies reveal soil health can be steadily improved with the right combination of techniques (see Will Brinton’s grad-school days report on comparing Organic and Conventional farm Systems – available on our store).  While old wisdom is undoubtedly at work (see Woods End’s Green Manure guideline from 1985) , growers everywhere need to recognize the new source of inspiration driving farmers to seek practices focused on Soil Health, and applaud Dave Brandt’s motivational message for soil restoration. For more information on Brandt’s farm workshops see Brandt-Soil. To find a lab near you offering the soil CO2-Burst test, go to: Lab-Map.

Comparison of Solvita to Oxymax IR data on CO2 Rates Over Time

A recent research project conducted at Woods End shows that the simple-to-perform Solvita test for compost gives essentially identical information about compost aging as does more expensive IR (infrared) analysis.  The funded research project compares two types of compost (manure vs yard-waste) over a 180-day period, subjecting the piles to quadruplicate tests to see how various indexes change with time.

Like many biological data, CO2 rate versus time fit a power-curve closely.  A noteworthy feature about decomposition is that it drops rapidly in the first month, then very slowly over the next several months. The lab ran infrared CO2-rate on the same samples alongside Solvita volumetric tests,  and the curves were nearly identical (see image). Woods End offers a lab-based version of Solvita so that test labs can offer it to their customers.

What all this means is that expensive lab protocols like IR may not offer any distinct advantages over simple and much less expensive tests like Solvita for routine testing.  There is very little credible published information on how to interpret  IR or Base-Trap CO2-rate tests for compost maturity. In contrast – there is a growing wealth of published data and user-experience with Solvita. “We think labs would prefer a cost-effective method that is also meaningful to their customers, and Solvita fills that gap.” says Brinton, inventor.

Woods End plans to publish the data on indexes of composting later in the year.

CO2 Emissions are readily measured directly in the field with a Solvita CO2-Probe inside an aluminum chamber, covered to prevent CO2 loss or heat-gain from sunlight.

Woods End announced the release of its new Model 700 Solvita DCR  which incorporates upgrades for  new soil test capabilities and improved performance with electronic integration.  The upgrade is being timed with NAPT’s 2013 acceptance of the Solvita CO2-burst test as a provisional lab method. A new channel has been added for field (basal) CO2 respiration testing, coinciding with USDA-NRCS’s new “Soil Quality Kit – Guide for Educators” program.

Field testing enables calculating respiration in terms of pounds of CO2 per acre, or kg/m² - providing an ecological-global carbon picture to soil quality.  ”It’s very clear that soils play an enormous and very active role in global carbon regulation and the test enables one to see it first-hand” – says Will  Brinton. Woods End believes it is the first company to have uncomplicated and inexpensive means to monitor soil carbon emissions in the field.

Special features of  the Solvita DCR700 include a broader CO2 range employed for the official lab CO2-burst protocol and improved light technology for more accurately measuring Solvita color.  These firmware changes have been matched by new software enabling automatic uploads of tests directly into a spreadsheet. In upgrading the handheld spectrometer, Woods End  incorporated a new CO2 range based on current research relating nitrogen-release to CO2-burst after re-wetting soil. The new method is intended for soil labs enabling them to report soil biological activity to growers in addition to normal soil chemistry results.

Brinton and Haney have pursued soil respiration over two decades each and will be reporting in an upcoming 2013 symposia the new diminishing-rate curve for relating CO2-burst to N-release, a curve typical of soil-plant nutrient relationships. “It’s been exciting discovering these biological corollaries for the Solvita test” says inventor Brinton. Dr. John Doran, former SSSA President and a pioneer from the early 90′s in Soil Health monitoring is excited about the advancement: “The Solvita soil test represents one of the most outstanding advancements translating science into practice and interlinking soil science, agronomy, soil testing and crop consultants with farmers, practitioners, and resource conservationists.”  For more info click HERE.

Horse farms are considered the most scenic of estates, but most don’t reuse their own manure which contains herbicide residues, but put it out for disposal (collection by composters and avid gardeners). This is where the residue problems start.

An informal study conducted by Woods End during the past 3 years examining quality of Maine manures used for compost, may have mushroomed into a focus on herbicide carryover specific to horse manures. When Vermont reported a case of compost chemical contamination, Woods End alerted the Chittenden compost facility about carryover risk of herbicides specifically in horse manures and their feedstuffs.  ”The results of all this investigation are possibly more than anyone can handle” says Brinton of Woods End.   Previously, Woods End found horse manures were usually “bioassay-positive,” but at very low levels. In most cases such residues affect plants to only a small degree and sometimes only with massive applications of composts. “The perception is that there is a big problem”.  In fact, the issue is more complex than most believe. Decades of consensus between EPA and industry have led to allowance thresholds for residues of herbicides in farm byproducts.  Perhaps the real need is to re-quantify the risk based on an assumption that these byproducts are not being  farm recycled (which they are designed for). Most herbicides have 1-2 ppm EPA thresholds in feedstuffs (considered safe in the food chain).  Woods End’s strategy to aid composters and growers is to construct risk-pathways for sources — a process analogous to Identity Protocol used to track grain contamination.  This may lead to feeds and hay/straw being seen as as significant indirect sources of residues for farms, especially equine.  A diverse array of information and data mean that any effort  faces “multiple challenges” one being an (odd) perception of being anti-farming. A combination of re thinking safety levels, performing pathway analysis in the short-term to protect growers, and encouraging sustainability for farms not reusing their own residue-laden manures, will have to be implemented. All this against a political backdrop of reduced regulatory oversight of farmers (and composters).

Performing Solvita tests: Best Test Labs owner Stephen Jones (L) with Solvita's Andrew Sparda

Farmers across America have increasing access to soil biology testing thanks in part to Solvita. Presently more than 40 soil labs* now offer Solvita CO2 Respiration as part of their services. Many of these lab are also reporting Solvita data in the ALP program. “The labs are now creatively incorporating Solvita into their reporting programs, showing a diversity that reflects regions, soil types and customer-farmer needs”, says Brinton, originator of the Solvita procedure.  Best-Test Analytical Services of Moses Lake WA has recently added Solvita to their services for growers (see inset). Stephen Jones, lab owner, says this: “Solvita is important in refining our knowledge of organic matter in soils. We are hugely guessing in regard to soil quality. The test provides a tool for farmers which is what we have been trying to do.”  The recent Pacific Northwest Soil Lab tour lead by Bob Miller (ALP) and sponsored by Solvita (Andrew Sparda) included visits to several soil labs: SoilTest Farm Consultants (Moses Lake, WA), Best Test Analytical Services (Moses Lake, WA), AgSource Harris (Umatilla, Oregon), and Kuo Testing Lab (Othello, WA). The tour ended with a special visit to the Lamb Weston facility.

Labs included in the previous Midwest Lab Tour sponsored by Solvita in March 2012 included:  AgSource – LGI Laboratory, AgSource–Harris Laboratory, Servi-Tech Laboratory, Ward Laboratories and a special visit to the NRCS National Soil Survey Center in Lincoln, NE where presentation was made on soil health (for more information on the tours see the SPAC Newsletter at the Soil & Plant Analysis Council.

*For an update on soil labs offering Solvita and for future plans for lab tours for soiltest professionals please contact SOLVITA .

Studies of plant root growth in soils treated with amendments of varying chemical and biological stability reveal that plants respond in a more complex and holistic fashion than customarily believed.  Brinton’s team at Woods End has been using root (rhizotron) chambers to observe how fertilizers such as biochar, mature and immature compost and chemical NPK affect the whole plant’s development.

A current study with tomatoes grown in a 24″ soil profile revealed that roots respond dramatically – and differently – to varying fertilizers, whether organic or chemical.  Roots were scanned after several months of development, and surface area and root length plus root biomass can be measured. In contrast to untreated, virgin soil where plant roots exhibited fairly harmonious development (but yield was low), the addition of chemical NPK or raw manure strongly influenced morphological changes – particularly with the chemicals (also boosting above-ground yield at the expense of roots). Inorganic NPK was associated with thicker roots and significantly reduced rootlets. Composting the raw dairy manure (7 months) led to harmonious – and significantly enhanced – root development.

Fertilizers have been known to change the relationship of above-ground to below-ground (root) biomass, and therefore clearly influence the entire expression and life-cycle of the plant. Composted manure prompted the greatest amount of rootlet and root-hair development – a fact that is interesting since this could clarly assist drought-resistance, and nutrient uptake. Immature, biologically active manure was somewhat too inhibitory to roots (depending on cultivar) compared to the same material composted. Earlier findings at Woods End indicate that part of this effect is due to exhaustion of soil oxygen by high rates of decomposition (e.g. from immature compost or undegraded organic matter).

When using compost with constructed soil media, the volumetric respiration behavior is the key to good performance.

The compost industry may be promoting stability and maturity tests for compost that are neither current with published science nor consistent with emerging soil markets,- this in a new report by  Woods End Labs presented to Sustainable Sites Initiative.  The report examines the origins of commonly accepted compost stability guidelines in the USA and Europe, highlighting the complete absence of calibration of these tests to relevant horticultural traits. It’s pretty clear numbers were just pulled out of the air. The investigation casts significant doubt as to whether common compost tests are appropriate for soil building, container media and constructed soils.”If you compare so-called “stable” composts to natural soil systems, the discrepancy in biological properties is enormous”, reports principal author Dr. Brinton. Inappropriate compost stability tests may be harmful and could set back the burgeoning interest in areas such as amending disturbed, depleted and manufactured soil ecosystems. “Skills are involved in sourcing materials suitably stable to foster and sustain healthy growing environments”. The paper recollects the dramatic failure of Biosphere 2 (Arizona) due to excessive CO2 production from compost-amended soil, and a recent, highly visible Manhattan project, where unstable compost caused a street to be cordoned-off to allow ammonia to dissipate.

Woods End scientists propose reporting stability as CO2 or O2 exchange per unit volume (g/liter) as an alternative to traditional gravimetric (weight-based) approaches. The new approach is holistic and scientifically-grounded in representing “the behavior of the whole growing media environment”.  Woods End’s Solvita® was designed to do this but has not been sufficiently  appreciated by industry. “Solvita gives a different picture of stability than other tests since it integrates respiration with bulk-density”. Test results show that volume respiration may actually increase slightly with age while apparent gravimetric stability appears to be declining. “Which unit is useful depends on the application”. The report presents charts and tables comparing USDA values for soil respiration to norms for compost and this reveals that stability values accepted in the compost industry, can be 20 to 100 times higher than those encountered in natural soil-ecosystems.

In proposing volumetric respiration, which is the exchange of CO2 for O2 in a standard volume (1-liter) Woods End points out that other useful volumetric tests have been available, such as the Dewar self-heating test and the closed-cress test, but none have been given serious attention in the USA.  “Volumetric tests need to be re-appreciated for their practical application to high-end horticultural applications”.  The essay is available at STABILITY.pdf.

A soil test developed by Woods End Lab measures the CO2 respiration due to soil biological activity. As a soil health test, it will be eligible for EQIP cost sharing.

On the verge of a new growing season, the “what’s new” in soil testing labs is the Solvita CO2-Burst test. Agronomist Bruce Weidner (Weidner Agronomy Services, Illinois) writes “the Solvita test is intriguing because of its potential to be more accurate than other tests, plus the fact that N management is key to my growers’ profits. This is a test that could set me & my business apart”.  Bruce Hoskins, director of the University of Maine soil lab, said “Solvita may be the missing link in my nutrient management plan”. Tom Woodward, a soil consultant, working with Carl Stafford, Ag Extension agent, plan to correlate the Solvita field kit with Brookside Labs PMN test for nitrogen potential. Another leading national soil service, Midwest Labs, has launched “B.R.A.N” (Biological Respiration and Nitrification), a test based on Solvita. Several labs are abandoning the old procedure of calculating N-mineralization potential from the organic matter test – a procedure known to be inaccurate.  Calibration trials evaluating the relationship of Solvita to the 7-day anaerobic N-min test show consistently high correlations.

Will Brinton, the inventor of the test, says “we are happy with this evaluation process… we see individual labs innovating around the test and seeking regionally appropriate linkages to reach their growers.” Solvita is unique since, unlike most soil tests, it is not a chemical extraction method. Soil microbes produce the test result – a burst of CO2 captured in a simple, overnight process. Enthusiasm is bolstered from reported high correlations observed of the Solvita test vs. actual nitrogen (and also phosphorus) mineralization from soil humus. “That’s free fertilizer” says USDA-ARS  scientist Rick Haney, a soil-respiration pioneer who has coached Woods End on developing the CO2-burst as a test. By itself, the Solvita test serves as a biological indicator of soil health and, according to several NRCS sources,  should qualify for cost sharing under EQIP in the Nutrient Management Code 590 category.

Solvita soil results from participating labs will be monitored in 2012 within the ALP Soil Proficiency program, and several NAPT labs are also offering Solvita.  Speaking about the test, Bob Miller, technical director of ALP said, “The Solvita method is robust. It isn’t that soil respiration can’t be used to assess nitrogen-mineralization. It is just that we the labs haven’t used it in such a way.” Solvita is a new approach. Lowell Rheinheimer, farm resources manager for Organic Valley LLC, a large dairy farm coop, spoke about Solvita during a recent (Feb 2012) farm conference in La Crosse, Wisconsin: “perhaps 5% of people in this room realize how revolutionary this method really is”.

Soil microbes number up to 10-million per gram soil, and release free fertilizer for plants.

According to Will Brinton, soil labs may be reluctant to adopt soil biology tests due to complicated outdated (and costly) methods. “It’s too bad since this is impeding the country getting on with much needed soil quality assessment”. One older method, still sometimes used, measures microbial biomass by an indirect process called fumigation-incubation (FI). FI is complicated and requires use of toxic chloroform first to kill soil microbes, then inoculation, then a 10-day incubation for microbes to re-establish themselves, then a period of capture of CO2. “Talk about a convoluted,  costly way  to measure the microbial traits of a soil”. Will Brinton has worked with soil respiration since the late 1970′s and developed the breakthrough Solvita test, which allows soil microbial activity to be rapidly measured within 24hrs. Microbes are important since their activity releases free fertilizer that labs are not accounting for in their fertilizer recommendations.

PARTNERSHIP: The new soil Solvita CO2-burst protocol is a unique collaboration of Government and Private Lab: Woods End Laboratories and Dr. Haney’s USDA-ARS soil lab in Temple, TX, both centers that had been pursuing soil quality for the last 20 years. The new protocol puts the measurement of soil microbial activity into the realm of the practical and is extremely cost-effective from a commercial soil lab perspective. The simple method combines a pre-calibrated CO2-trap and a soil drying-and re-wetting step which simulates the natural potential to spring into activity, following a severe event (but not as severe as killing with chloroform).  Recent published research shows that 24h  CO2-burst  corresponds closely to bacterial biomass results, so it should be no problem to move forward with the new system. The thrust of the new work however is focused on nutrients released by microbes:

WHY TEST SOIL MICROBES: The quantity of active soil microbes – fungi and bacteria- can be represented by actual living carbon associated with “respiring (live) cells producing CO2 within a soil systems” – from Dr Haney and Brinton. This living microbial consortia is associated with many positive properties such as transforming chemicals, aiding pesticide degradation, facilitating the release of nitrogen from organic matter and contributing to soil aggregation. The latter property alone may account for more than 50% of soils ability to resist erosion.

ACTIVE not STATIC CARBON: Measuring microbial activity is not the same as determining total organic matter (SOM) or  total-C, both determined by combustion. “Those show the quantity but not the quality” of  the soil carbon. Woods End hopes that by making testing more streamlined and accessible, agronomists, farmers and soil scientists will be able to routinely include biological measures in explaining soil fertility.