Record ID No. |
3019 |
Author(s) |
Hernandez-Hernandez R M., Castro I., Lozano Z., Bravo C., Gonzalez I., , 2010 |
Affiliation |
Universidad Simón Rodríguez, IDECYT, CEDAT, Caracas, Venezuela, Email: rosa.hernandez@unesr.edu.ve |
Title |
Microbial biomass activity in neotropical savanna soils managed during six years with conservationist cereal-cattle systems |
Source. Vol.(no):Page |
Proceedings of the 19th World Congress of Soil Science, 152-155p. |
Categories |
Mycorrhiza General |
Subjects |
Soil plant relations |
Sub-subjects |
Cropping effect |
Host |
Brachiaria dyctioneura (grass) and Centrosema macrocarpum (legume), Urochloa dictyoneura, Zea mays |
Organism |
Microorganisms |
Country |
Venezuela, S. America |
Abstracts |
In well-drained savanna soils of Venezuelan Central Plains, the changes of microbial activities produced by different agricultural managements for maize were evaluated. The perennial cover crops; Brachiaria dyctioneura (grass) and Centrosema macrocarpum (legume) were established in 2002. Two years later, they were associated with maize cultivated under no-tillage and different phosphorus sources: phosphate rock, diammonium phosphate, native mycorrhizas used as maize inoculum and the phosphorus produced by organic residues mineralization of the cover crops. Temporal variations of the microbial activity were found, showing a significant increase (P<0.05) with the cover crop introduction. Their dynamic patterns during six years of the essay also were different (P<0.05), depending of the phosphorus source-cover crop interaction. Phosphate rock and biofertilizer induced a higher mineralization activity at beginning of maize development, just when there is a major demand. The dynamic variations of metabolic coefficient (qCO2) suggested changes in the efficiency of use of C by the soil microorganisms |