The Usefulness of a Microcosms System with Acid Soil to Assess the Persistence of Acid Tolerant Alfalfa Nodulating Rhizobia.

WEGENER, C.; DEL PAPA M. F.; BALAGUÉ, L. J.; AGUILAR, O.M.; CASTRO SOWINSKI, S.; MARTINEZ-DRETS, G.; MARTINEZ - ABARCA, F.; TORO, N.; NIEHAUS, K.; PUHLER, A.; LAGARES, A.

Nitrogen Fixation: From molecules to crop productivity. Current Plant Science and Biotechnology in Agriculture.

Springer Netherlands

Año: 2000; p. 477 - 478

The 12th International Congress on Nitrogen Fixation washeld in Foz do Iguaçu, Paraná State, Brazil, from the 12th to 17th ofSeptember, 1999. This volume constitutes the proceedings of this Congress andrepresents a compilation of the presentations by scientists from 38 countrieswho came to discuss the progress made, to exchange views and to collaborate.Since the first meeting in Pullman, Washington, USA, in 1974, this series ofCongresses has been held three times in the United States, four times in WesternEurope, in Australia, Mexico and Russia, and now for the first time in SouthAmerica. Brazil was a most appropriate choice because Brazilian agriculture isespecially dependent on biological nitrogenfixation. An important example isthe soybean crop. The 30 million metric tons of grain produced each year reliessolely on symbiotic nitrogen fixation. N-fertilizers are expensive in Braziland, in the absence of the biological process, this crop would require 4-5 Mtonnes of N at an annual cost of almost 1 billion dollars. Crop rotation, soilreclamation, forestry, forage mixed cropping, intercropping with grasses andlegumes, associative nitrogen fixation with non-legume crops, such assugarcane, and other agricultural practices in Brazil are also dependent onbiological nitrogen fixation. The Brazilian experience with biological nitrogenfixation is a paradigm to be followed by all countries where nitrogenfertiliser is expensive or where present day environmental concerns demand afeasible, efficient and inexpensive alternative to chemical N-fertilizers.