February 2, 2004, ARS News Service: American and Russian scientists
collaborating on sustainable methods of farming this
spring will field test a two-pronged approach to growing
dry edible peas.
On one front, they'll coat the legume crop's seed with
an experimental inoculant containing two kinds of yield-boosting
microbes: Rhizobia bacteria and Mycorrhiza fungi. The
bacteria supply the pea plant's roots with nitrogen
"fixed" from the air, while the fungi provide
phosphorus "mined" from the soil, according
to Fred Muehlbauer. He's a geneticist with the Agricultural
Research Service's Grain Legume Genetics and Physiology
Research Unit, Pullman, Wash.
Muehlbauer is collaborating with Alexey Borisov, a
microbiologist at the All-Russia Research Institute
for Agricultural Microbiology in St. Petersburg. A science
division of the North Atlantic Treaty Organization is
funding their three-year project, aimed at improving
pea production as a food crop and as "green manure"
that can naturally fertilize the soil.
Secondly, to get the most out of the approach, researchers
are using the inoculant in concert with pea varieties
especially adept at forming symbiotic relationships
with the Rhizobia and Mycorrhiza. They've developed
five new types of microbe-friendly peas based on careful
screening of 26 total varieties and breeding lines from
ARS and Russian germplasm collections. This spring,
at Pullman and near the Russian city of Orel, they'll
evaluate the new peas' responses--including growth and
yield--to four treatments: rhizobium-only inoculation,
mycorrhiza only, rhizobium plus mycorrhiza, and a control
Pea growers normally inoculate pea seed with the Rhizobia,
but the scientists think a better tactic may be to apply
the bacteria and Mycorrhiza fungi together. Indeed,
in his early field studies, Borisov observed seed yield
increases of up to 30 percent in some, but not all,
of the 26 pea lines he tested. One inoculated pea variety
produced 25 percent bigger seed than fertilized controls.
Read more about the research in the February issue
of Agricultural Research magazine, available online
ARS is the U.S. Department of Agriculture's chief scientific