30 years ago ... a soil test survey by Dr. Liebhardt rocked soil labs nationwide .. and still is exerting an influence ... for the good.

It has been exactly 30 years this spring since Dr. William Liebhardt and colleagues published a carefully crafted survey of 69 USA soil test labs. In the ensuing uproar, some suggested Bill Liebhardt had thrown his career away. Recollecting the events, Bill (retired Ag Scientist, UC Davis CA) told us: “At agronomy meetings where we presented the results, there was standing room only left and out into the halls.” Woods End Labs was one of the 69 commercial labs that received blindly 5 farmer soils, with listed crop histories, and a request for recommendations to grow 125-bu corn. Woods End determined several of the soils were very fertile and required little added fertilizer, but the majority of surveyed labs did not agree.

The problem Liebhardt uncovered was not so much the soil testing per se, although there were disturbing differences such as in measuring soil organic content. The stinging issue was the way labs used (or did not use) test results to construct fertilizer recommendations. And the big one was, then as now, nitrogen. Only 15 labs adjusted N-prescriptions to apparent soil potential and only 3 labs, ours included, pin-pointed the high N-potential soils (rich humus and prior alfalfa in the rotation).

There have been many advances and improvements in soil testing since this time, yet nitrogen remains a challenge. The storehouse of potentially available N is the soil organic matter fraction which has been traditonally overlooked.  Our 1982 soil reports showed some of Liebhardt’s PA soils were richly supplied at 4 – 5%OM. Natural biological release could be counted on to provide a significant contribution. Considering this, for most of the labs, the fertilizer N rates appeared excessive. This burning theme casts a long shadow: a very recent CA study suggests that excess nitrogen fertilizer is straining the state’s ability to deliver quality water.

The fact the majority of soil labs in 1982 did not account for soil’s intrinsic nitrogen potential is not surprising as methods to measure biological response were uncommon, leaving labs to either make potentially inaccurate calculations – or do nothing.  Today, a combination of tools is available (plus soil proficiency programs to monitor testing) all of which may reduce the potential for excessive (and costly) fertilizer, yet the problem of labs not using any tests or tools other than crop requirements persists. Woods End’s Solvita CO2-Burst protocol is one newer means that did not exist earlier and which directly measures microbiological carbon turnover, the kingpin in potential N-release. Accounting for soluble N and adapting local soil and climatic factors will help make the new “soil health” approach a big step forward.   (Copies of the original study and Woods End reports are available by request: lab@woodsend.org). Download references documents HERE

In a first-time feat, composting of a Chip Bag was filmed in time-lapse for 14 weeks, and became a national TV ad. The bag was eventually withdrawn from the market.

The day before Earth Day 2009, fans of American Idol were wowed by a TV ad showing a SunChips bag disappearing and turning into compost, right before their eyes. The ad was genuine. It took stitching together 8,800 individual images shot within a see-through compost chamber, designed and built at Woods End Labs. Frito-Lay declared “the World’s first Compostable Chip Bag,” with full release promised by Earth Day 2010, ushering in — it seemed — an exciting new era for compostable consumer packaging.

Today, store shelves are conspicuously absent of the product — or  just about anything like it.

News buzz in the sustainable packaging industry may partly explain the double act of disappearance. British giant Innovia Films Ltd (IFL), in multiple legal actions filed in the United Kingdom and the European Patents Office, has charged that Frito-Lay’s innovations are the rightful property of IFL. Innovia has successfully petitioned Brussels to block one of Frito’s European patents on the bag, and has pressed for free license rights to Frito’s technologies. (IFL has launched its own version of the compostable chip bag, using metallized cellulose instead of PLA.  ASTM D6400 tests have shown both types of products break down in the same time-frame.)

Even more recently, Frito-Lay has filed a complaint for Declaratory Relief against Innovia, asserting original invention rights. Sustainable packaging advocates are clearly watching the outcome. We are not in a position to comment on the legal merits of the cases. One thing is clear, Frito-Lay was first in the chip marketplace with an authentic PLA-based compostable product.

Postscript: Woods End continues to work with many firms testing and characterizing the unique environmental traits of bioplastics. Yet, interest in compostable films appears to be shifting to higher ground … reusability and carbon footprint. (Research for this article based in part on GreenPatentBlog.com, Foodnavigator-usa.com, Sustainable Packaging Forum, and FoodProductionDaily.com /ps/wfb)

A close relationship of 24hr soil CO2 pulse and nitrogen release by another method: makes soil biology appear more relevant and practical.

Woods End and its partner,  the USDA-ARS soil lab in Temple, Texas have been running comparison of soil respiration and nitrogen mineralization using a number of traditional methods. One test called 7day N-min, has shown surprisingly good correlations to the rapid CO2-burst method that Solvita and USDA have developed (see figure). The 7-day N-min measures microbial activity and nutrient-release in an indirect, time-consuming process, and labs are hesitant to use it, or if they do, they have to charge more than farmers may be willing to pay. “Yet the information is vital to understanding how to save costly nitrogen fertilizer- without loosing any yields – plus it shows you something important about soil biological health”- Brinton of Woods End states, who invented the test in 1996, but has seen this many years go by in realizing the application.

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 25 years. The new protocol puts the measurement of soil microbial activity into the realm of the practical and is cost-effective for commercial soil labs to perform.

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.

RELEASE of “FREE” NITROGEN: Measuring microbial activity is not the same as determining total organic matter (SOM) or  total-C, and then estimating the potential release of nitrogen – a method which some labs have relied upon, but which can give remakably inaccurate results. 7d N-min will actually measure the nutrient release but under harsh circumstances of 40°C anaerobic incubation. Other tests the team has used are direct 28-day mineralization of nitrate and ammonium, showing similarly good correlations. Added to the roster are crop uptake studies which are showing that the amount of nitrogen present in unfertilized crops- called “controls” – closely corresponds to the amount predicted by the soil biology test. “There is a great deal of interest in showing how this biological function behaves in different growing regions” says Brinton.

Popularly called "Biochar", Europeans suggest re-naming to "Plant Charcoal" - A 2009 study shows even with massive mobilizing of 10% of all biomass to biochar only 1.6% of Germany's carbon footprint would be offset."Is it even worth the effort?"

The re-discovery of “Terra Preta” in the Amazon Basin marked for soil scientists a possible turning point: the idea that an ancient practice could provide insight into correcting CO2 build-up and staving soil decline.  “Millions of Euros have been spent now on biochar studies”: conference organizer for the Berlin October 2011 ANS-Symposium intoned.  Far from the near-panacea biochar in USA presents for saving climate and soil, the European lab tests along with tough EC climate regulatory debate  ”cast doubt that significant progress will be made until many questions are answered”. The Institut für Agrarrelevante Klimaforschung presented data showing variable carbon-stability and summarized  soil-plant studies confirming that negative effects are almost as common as positive effects. The big topic was lab tests which suggest biochar carbon has as little as 35% stability or possibly “climatologically irrelevant”. Editor Dr. Kehres (Journal “Humus and Agriculture“) summed up the symposium: “Biochar appears over-rated … the biochar claim to 1,000 yr stability is revised downwards to 10-100 years, roughly the same as compost”.  Details on the fractions of carbon from pyrolysis, HTC and other carbonizing  methods weighed against the lack of  method standards, plus rankling over carbon legislative validation,  suggest a biochar future “if even economical”  faces many hurdles. The symposium eventually turned to name calling: it was proposed to drop the prefix “bio” from biochar, a “technical misnomer” – and a source of confusion in Europe where “bio” means certified natural farming. What’s the name to be?- “Plant Charcoal”- (“Pflanzenkohle – its more accurate”).

A new biological plastic (L) shows obvious biodegradation compared to polyethylene (R). Polyethylene gave a half-life on 48-years in the studies, but the bioplastic reduced the half-life to only 11-months.

For one year, marine biodegradation tests have been underway at Woods End and are revealing “important and interesting differences” in behavior of polyethylene (PE) compared to biological plastic such as PLA (polylactic acid) and PHA  (polyhydroxyalkanoate) polymers. Test protocols include ASTM 7081 and ASTM-6691 which require quantifying disappearance and also use marine phytoplankton to rule out ecotoxicity effects. Decay constants determined for PE showed that it had a half-life of 48 years, according to Dr. Brinton who is leading the studies. PLA cut this in half but “that does not disappoint us since it is designed to degrade in hot composts”.  The studies at Woods End are a follow-on to aerobic composting tests conducted by Woods End labs for a wide array of clients who are developing novel bioplastics for consumer markets. “There are reports that the oceans now contain 100-million tons of non-degraded plastic trash, so working towards plastics that degrade in marine environments is a big step”. The marine studies are being especially supported by Pepsico and FritoLay, who developed with Woods End the world’s first PLA-compostable chip-bag. “The big excitement” according to Woods End is how some other new bioplastics perform under marine conditions. Switching from polyethylene to PHA reduced the marine half life from 48 years to 11-months, the study reports. The researchers plan to present full results at upcoming marine biology and sustainable packaging events.

Foreground: continuous cotton, no legumes, over 126 years; background cotton- 3 yr rotation includes winter legumes

The  “Old Rotation” trial at Auburn University, AL has been continuously managed since 1896 (126 years) and is one of 3 of the oldest running research plots in the USA (in Europe, the Rothamsted plots have been running 160 years). Recent monitoring of the Auburn plots reveals the great value to soil quality (and nutrient mineralization potential) of inclusion of soil building crops (winter legumes) in the rotation. Without proper crop and nutrient management, the study shows soil quality and crop yields will decline steadily to very low levels. The more remarkable feature is the fact that soil degradation is as slow as soil building – in other words, good soil care and rotations (which might include composts or farm manure as do the Rothamsted plots) takes time to improve soils. According to published reports, soil organic carbon (SOC) was  “dramatically affected by conservation tillage and crop rotations”. Woods End’s Brinton visited the plots and previously worked on long-term trials in Sweden as part of his Masters in Agriculture. Brinton stressed the value of the long term studies to understand realistically the benefits of organic matter to soil quality.  Woods End plans to work with scientists on the long term plots to show how soil respiration is an excellent overall indicator of soil quality improvements. Sadly, continuance of the long term plots is threatened by budget cuts.

www.solvita.com

Public and private USA soil labs are lining up to offer Woods End’s latest protocol: a soil test that simulates the biological CO2-burst following moistening of dry soil. The phenomena of a respiration spike has been observed by  soil scientists to correlate with soil microbial biomass carbon (SMBC), the soil’s living storehouse. The simple, inexpensive test accurately measures the magnitude of the CO2 burst. One application is that it serves to indicate N-release potential. Lab and field trials have shown a high correlation to 7- and 28-day nutrient mineralization. USDA found in a survey of soils that the Solvita CO2 burst was proportional to yields from unfertilized control plots – meaning it accurately represents the soil’s indigenous reserve that is naturally released to crops each year. “The pressing issue today is that most soil labs still ignore the contribution of N that comes from humus, and therefore fertilizer recommendations are invariably excessive – a primary cause of continued water pollution but more importantly a careless use of farmer’s money”.   Land Grant Soil labs that have recognized the value of the procedure and which are now offering the Solvita CO2-Burst test include:

1. Rutgers University Soil Testing Lab
2. University of Maine Orono
3. Washington State University – Prosser
4. University of Rhode Island
5. Montana-State University-Northern
6. University of Delaware (Carvel Research Center)
7. Auburn University, AL (trials underway)

Private USA labs offering the test include: Brookside (OH), SoilTest Farm Consultants (WA), Spectrum Analytic (OH), AV Labs (WA), Kuo Testing Labs (WA), Western Labs (ID), Ag Resources Consulting (MN), Energy Labs (MN)  GMS Labs (IL), AgVise, (ND), Texas Plant & Soil Lab (TX). Foreign: Creation Innovation Labs (Australia), Quantum Labs (New Zealand).

The CO2-burst test is calibrated for soils in the range of 0 – 5% OM and reads 0 – 120 ppm CO2-C corresponding to a N-mineralization potential of 0 – 120 lbs/a or more.  A film about the new test is found at:  Solvita CO2-Burst

From seedling to market - Ornamentals on a "life-support" system of chemicals and non-renewable resources.

Modern market theory applied to growing plants  relies on controllable non-renewable or man-made ingredients and programs to achieve “customer satisfaction”. This includes peat and perlite – both “nutrient-inert” which require being drenched with imported chemical mixtures to obtain the appearance of a healthy plant prior to market.  Nothing about this approach is really authentic and it is debatable if  raising plants in this fashion is sustainable.  From an ecologic perspective there are no naturally recycled normal soil nutrients in the plants. Just how environmentally sound it may be is likely to become a focus of life-cycle analysis (LCA) and other methods,- a challenge to operations that by nature of chemical containment are claiming they are “green” and sustainable. In a related event, a recent report out of California found commercial and home turf care to be less sustainable and more environmentally damaging than industrial farming. While some groups have challenged the CA study as unduly influenced by the farm lobby, a recent New Jersey study arrived at the same conclusion, when tracking the cause of marine estuary contamination leading to ecological collapse.  One explanation, according to Woods End,  is that the horticultural and entertainment landscaping  industries are nearly unregulated and management choices that ultimately affect plant quality and the environment are simply being left up to market forces and personal preferences –  in the absence of sound science”.