Coloring Outside the Lines:
|There are people in our society that rely on the critics to chose which movies they see, political pundits to influence their votes, and they were never caught coloring outside the lines. Russ Nakae is not one of these people - at least when it comes to revegetation. Russ had the good fortune to grow up on the family farm, Twin Peak Orchards near Sacramento, California under the guidance of his father, Howard. It is obvious that he developed his share of intuitive skills when it came to the soil, and like most farmers, a propensity to experiment with new approaches. It is reflected in his approach to restoration.
Many restoration projects are designed by environmental consultants, engineers and landscape architects on computers located miles, or even hundreds of miles, away from the site. While their intentions and objectives are well meant, that critical link with the site, the soil and all the edaphic conditions that influence results are often overlooked. Contractors, on the other hand, develop their standard operating procedures, best management practices and a variety of techniques to mitigate problems and improve performance. This is all well and good, but projects all too often are managed under an engineer mentality, like pouring concrete or installing a drainage channel. The results of this approach are generally less than desirable.
Of all the disciplines associated with revegetation, good old common sense farming remains the closest in protocol. The final objectives may differ significantly. The tools are sometimes shared, but overall are more specialized for each arena. The greatest difference is in the level and length of commitment: farming is a long term commitment to a piece of ground, while restoration only requires involvement until the bonds are released.
Russ and his wife Patty are now principles in Nakae & Associates, a company that specializes in larger projects, such as new highway construction and watershed restoration. And while he has left the farm, the farm hasn't left him. The company prefers to manage under a design/build mandate that enables them to determine the best approach to achieve a well defined end goal. Their approach is one of stewardship, similar in many ways to farming. It enables him to learn what does and does not work in the complex biological, geological and climatic conditions particular to each site. They prefer to include a maintenance clause to assess and reevaluate cultural practices until the end objectives are achieved. They're progressive in theirapproach: testing various methods and materials for each project is part of their management program.
Nakae & Associates, to my knowledge, were the first to go against the opinions of academia and actually incorporate mycorrhizal inoculum in a hydroseeding application. Recommendations have always been to place endo mycorrhizae below the seed to assure proper contact with the roots. They were also the first to combine mycorrhizal inoculum with a healthy dose of controlled release fertilizer. This also ran against conventional wisdom, assuming that high nutrient levels in the soil would be detrimental to the living propagules of fungi. The results of this new approach were not only positive, but also very impressive.
Nakae began experimenting with both procedures on the San Joaquin Corridor Highway along the California coast in Orange County. Research was conducted by the staff on plots installed during the earliest phases of the project. By the time that most of the work was to proceed, they had developed a clear understanding of the soils and conditions and defined a cost effective and well developed approach to the project. The revegetation process not only came in on budget, but ahead of schedule. In certain areas, the return of the California gnatcatcher and cactus wren occurred years earlier than had been anticipated to the restored coastal sage scrub habitat.
The manufactured slopes and disturbed sites common to restoration in the west are generally deficient in nutrients, organics and soil microorganisms. Ideally, all three components would be added to assure a successful outcome. Unfortunately, like farming, input costs must be addressed. Nakae's approach was to assure that an ample level of nutrients were banked into the site and the mycorrhizal component would then more efficiently process plant food for the vegetation. In turn, the crop would begin to produce leaf and root litter, building the organic component and move the site towards ecological sustainability.
More recently, RTI has been involved with Nakae on two new projects: a new highway project in Salt Lake City; and on a new 120 acre plum orchard managed by his father near Sacramento. We had never considered this approach as viable in agriculture, but it became apparent that this particular site in many ways resembled a restoration project. The new orchard had been pasture for several decades. It was a heavy clay/decomposed granite soil, extremely deficient of nutrients and heavily compacted from grazing.
The land was fumigated to eliminate undesirable weeds and then ripped to a depth of six feet with Caterpillar tractors to alleviate the compaction problem. Although soil tests indicated an acceptable level of organic matter, microbial activity and fertility were severely lacking. A root dip was recommended for the bare root plum trees.
Unfortunately, planting was delayed until June, due to a wet spring and problems with the irrigation system. When planting began, temperatures hit 100º F. in the area. The first trees were dipped in the inoculum and then planted with two 10 gram packets of controlled release fertilizer. However, due to the extreme heat, it was decided that the root dipping procedure should be cancelled after 20% of the planting. The remaining trees were planted as quickly as possible.
In spite of the conditions, mortality by the fall was less than 5%. The most phenomenal outcome was the two feet difference between those trees that had been treated with the mycorrhizal root dip and those that had not. The balance of the trees were treated with a biodegradable packet containing mycorrhizal inoculum and, while this will assure that they will eventually receive the benefits of colonization, the root dip appeared to be the best method to inoculate bare root trees.
Nakae is currently working on a perimeter highway around Salt Lake City. In the fall of 1998, they used a specially designed seed drill manufactured by Truax to incorporate controlled release fertilizer, Endo-Net Mycorrhizal Inoculum and a native seed mix on the disturbed areas of the project. Most of the soil was parent material with no organics, marginal levels of beneficial soil microorganisms and no nutrient bank. To complicate matters, any kind of irrigation was out of the question. Precipitation in the Great Basin is sparse and without any organics available to absorb and retain moisture, revegetation would probably be a very difficult challenge.
Nakae decided to drill in the fall, assuring a good cover of seed, inoculum and nutrients. The balanced controlled release fertilizer was formulated to promote aggressive root development. The site germinated this last spring.
"It came up even and thick like rows of little green foot soldiers," Russ commented. By this fall, establishment has been guaranteed and the process of increasing biomass and organics on the site will continue until the ecosystem can function on its own.
The importance of mycorrhizae has been well discussed in recent years and most of the reporting comes from academia. However, recent improvements in inoculum production have created sources of high quality supplies at reasonable costs. It is a tool that may have application on certain sites and not on others. And it is only one of many tools available to the industry. The best method to determine what does and doesn't work is to run plot trials on site. If you are involved in a difficult project, it may be time to take your crayons and step outside the boundaries. You may be surprised at the outcome and you might have fun in the process. L&W
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