Strategies for restoration of degraded pastures in Amazonia examining agronomic, environmental and economic criteria

• Grant number: 00/08239-2
• Support Opportunities: Research Projects - Thematic Grants
• Start date: July 01, 2001
• End date: April 30, 2006
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Carlos Clemente Cerri
• Grantee: Carlos Clemente Cerri
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Pesquisadores principais: Brigitte Josefine Feigl ; Marisa de Cassia Piccolo
• Associated scholarship(s): 03/13742-3 - Development of methodology for the analysis of carbon in soil samples using near-infrared spectroscopy, BP.PD; 03/07033-0 - Evaluation of microbial biomass of the soil and of the root system in pasture under agricultural management in Rondônia, BP.IC

Abstract

Pastures make up the principal use of cleared land in the Brazilian Amazon. Observations show that after 4 to ten years after they are formed, pastures generally begin a process of degradation that characterized by a decline in grass productivity and an increase in the cover of weeds. For both environmental and economic reasons, development of strategies for reformation and restoration of these existing degraded pastures is preferable to formation of new pastures by traditional slash and bum activities. The objective of this project is to examine strategies for recuperation of degraded pastures in Amazonia examining agronomic, environmental and economic criteria. To achieve this objective, we will conduct an experiment on an existing 63-ha area of pasture in the process of degradation located at Fazenda Nova Vida, in Ariquemes, Rondônia. To ensure that this experiment will be located on a representative and homogeneous area of this existing pasture, the area will be characterized for topography, soil physical and chemical attributes, production and nutritive value of existing forage plants, weed infestation and botanical composition, using geostatistical and geoprocessing techniques. The experiment will consist of four blocks (replicates) of six pasture reformation techniques: 1) control, 2) herbicide + NPK + micronutrients, 3) disking + NPK + micronutrients, 4) disking + coplanting of Brachiaria brizantha + PK + micronutrients, 5) plowing + disking + planting of rice + NPK + micronutrients ("barreirão" system), and 6) plowing + disking + rotation of soybean and corn +PK + micronutrients. Before and during the three years following the initiation of the treatments, they will be evaluated for a number of agronomic, environmental and economic criteria, including, i) plant production, nutrient value and digestability of forrage, ii) distribution of the root system, iii) soil quality, aggregation, resistance to root penetration, stocks and fractions of carbon (C), nitrogen (N), phosphorus (P), cation exchange capacity, acidity, availability of nutrients and toxic elements, macrofauna and microbial biomass, iv) chemical analysis of soil solution, including dissolved organic C and N, potassium, nitrate and ammonium, v) fluxes of trace gases, carbon dioxide (C02), nitrous oxide (N20) and nitric oxide (NO), vi) sequestration of C and N, and vii) economic viability. Results will be analyzed by multivariate analysis of variance to determine the treatments that best meet the criteria in each of the three areas and to examine the tradeoffs between these reformation objectives. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CARMO, JANAINA BRAGA DO; PICCOLO, MARISA DE CÁSSIA; ANDRADE, CRISTIANO ALBERTO DE; CERRI, CARLOS EDUARDO PELLEGRINO; FEIGL, BRIGITTE JOSEFINE; SOUSA NETO, ERÁCLITO; CERRI, CARLOS CLEMENTE. Short-term changes in nitrogen availability, gas fluxes (CO2, NO, N2O) and microbial biomass after tillage during pasture re-establishment in Rondonia, Brazil. SOIL & TILLAGE RESEARCH, v. 96, n. 1/2, p. 250-259, Oct. 2007. (00/08239-2)