How Maize Evolves When It Is Bred Under Biodynamic/Organic Conditions And Selected For Improved Nutritional Value And Nitrogen Efficiency.

Summary

"A breeding program for maize for biodynamic/organic farmers has taken place in at the Mandaamin Institute. The program began in 1989 and entails summer nurseries in Wisconsin, USA and winter nurseries in Puerto Rico and Chile. Emphasis has been on improving adaptation, productivity, nutritional value, and nitrogen (N) efficiency/N2 fixation. Methods include pedigree breeding , development of synthetic populations, and selection under N limited conditions. A co-evolutionary approach is taken to optimize interactions between the maize populations, the breeder, and associated microbes, under N limited biodynamic/organic environments . Results have been shifts in protein quality and better adaptation to N limited conditions. Emergent evolutionary processes a) increased the occurrence of mutants with soft grain possessing higher protein quality; b) improved chlorophyll content and N efficiency, and c) resulted in the appearance of densely branched rooting systems in the top layers of the soil for N efficient inbreds and hybrids. Grain yields for the best hybrids have been competitive with conventionally bred hybrids, especially under N limited conditions. Grain quality of the resulting hybrids averaged 16 % more protein, 30 % more methionine, and 16 % more lysine than for conventional hybrids. Under poultry feeding conditions where some synthetic methionine is fed, the monetary value of the grain was 14 % higher because it reduced the need for soymeal in feed. Outcomes of the program are populations, inbreds, and hybrids which are now in wider spread strip plot testing on organic farms in Wisconsin, Illinois, Indiana, and have entered initial commercial production in conjunction with Foundation Organic Seed (Onalaska, WI). We will also report results from ongoing farm trials that assess relationships between rooting, N uptake, N mineralization of organic matter, N2 fixation, and protein production in grain."