The CYANOSOILS Project was aimed to establish a realistic, innovative approach for promoting a sustainable increase of overall soil fertility of marginal lands in representative semiarid environments in East and Southern Africa (South Africa, Tanzania and Zimbabwe) by application of indigenous selected strains of soil cyanobacteria fixing atmospheric Nitrogen, and releasing organic compounds (i.e. exopolysaccharides, EPS) able to improve soil structural stability. To achieve these goals, seventeen cyanobacteria strains (over 200 identified in soils of the African countries), able to fix atmospheric N2 and to release ESP in considerable amounts were isolated, purified and grown. Using adequate techniques and procedures, large amounts of cyanobacteria biomass were produced to be applied to poor soils to ameliorate their quality and improve productivity. Laboratory and greenhouse experiments showed that the application of these biomass significantly improves overall soil fertility and crop yield, after the first crop. These results were confirmed by field experiments. In spite of the need of further medium and long-term experiments for finally confirming the relevance and persistence of the beneficial effect, on the basis of the achieved results, the application to marginal lands of selected cyanobacteria strains seems to be a very promising tool for a sustainable improvement of fertility and productivity of degraded soils in semiarid tropics. The project was able to produce protocols for the selection and multiplication of cyanobacteria with suitable characteristics. Moreover, the transfer of methodology and exchange of scientific information in this field of research has been successfully achieved.
Use of indigenous N2-fixing cyanobacteria for sustainable improvement of soil biogeochemical performance and physical fertility in semiarid tropics
2006
Abstract
The CYANOSOILS Project was aimed to establish a realistic, innovative approach for promoting a sustainable increase of overall soil fertility of marginal lands in representative semiarid environments in East and Southern Africa (South Africa, Tanzania and Zimbabwe) by application of indigenous selected strains of soil cyanobacteria fixing atmospheric Nitrogen, and releasing organic compounds (i.e. exopolysaccharides, EPS) able to improve soil structural stability. To achieve these goals, seventeen cyanobacteria strains (over 200 identified in soils of the African countries), able to fix atmospheric N2 and to release ESP in considerable amounts were isolated, purified and grown. Using adequate techniques and procedures, large amounts of cyanobacteria biomass were produced to be applied to poor soils to ameliorate their quality and improve productivity. Laboratory and greenhouse experiments showed that the application of these biomass significantly improves overall soil fertility and crop yield, after the first crop. These results were confirmed by field experiments. In spite of the need of further medium and long-term experiments for finally confirming the relevance and persistence of the beneficial effect, on the basis of the achieved results, the application to marginal lands of selected cyanobacteria strains seems to be a very promising tool for a sustainable improvement of fertility and productivity of degraded soils in semiarid tropics. The project was able to produce protocols for the selection and multiplication of cyanobacteria with suitable characteristics. Moreover, the transfer of methodology and exchange of scientific information in this field of research has been successfully achieved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
