Azolla-Anabaenaas a Biofertilizer for Rice Paddy Fields in the Po Valley, a Temperate Rice Area in Northern Italy

Stefano Bocchi,Antonino Malgioglio

doi:10.1155/2010/152158

Abstract

Azollais a floating pteridophyte, which contains as endosymbiont the nitrogen-fixing cyanobacteriumAnabaena azollae(Nostocaceae family). Widely cultivated in the Asian regions,Azollais either incorporated into the soil before rice transplanting or grown as a dual crop along with rice. To examine the feasibility of its use in flooded rice fields sited in the Temperate European Areas, we carried out a series of experiments in PVC tanks during 2000–2002 in Po Valley (northern Italy) conditions, to study the growth-development dynamics and the resistance/tolerance to low temperatures and to commonly used herbicides of several differentAzollastrains. Three out of five strains tested survived the winter, with an increase in biomass from March to May producing approximately 30–40 kg of nitrogen. One of these strains, named “Milan”, emerged as the most resistant to herbicide and the most productive. Of the herbicides tested, Propanil permitted the survival of growingAzolla.

Highlights

Azolla is a heterosporous pteridophyte, with seven species
The main areas of cultivation are in the western part of the Po valley in Northern Italy and in the river delta areas, Ebro and Guadalquivir, in Spain
This research presents a first attempt to evaluate the possibility of using Azolla-Anabaena in rice fields in the Po Valley, as a source of mineralized organic Nitrogen

Summary

Introduction

Azolla is a heterosporous pteridophyte, with seven species. Together these represent 84% of the total European cultivated area of about 400,000 ha of rice Cultivation centers such as Vercelli or Lomellina (Italy), Camargue (France), Ebro and Guadalquivir (Spain) tend to possess distinct “rice-related” characteristics: agronomic (specialization, simplification), landscape (“rice landscape”), natural resources (intensification of the resource use), economy and culture. These rice districts are located in reclaimed, marshy areas/ wetlands of high environmental value which are highly vulnerable, creating a need for sustainable and environmentally sound management techniques

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Conclusion