Humic Substances and Chemical Properties of an Acrisol Amended with Vermicomposted Vegetal and Animal Residues
13/May/2019
ABSTRACT Vermicomposted vegetal and animal residues are rich in nutrients and humic substances and thus can be applied to the soil as a source of functionalized organic matter (OM) and as an alternative to chemical fertilizers. In Southern Brazil, many animal and vegetal residues are easily accessible. Therefore, this study aimed to evaluate alterations in soil chemical properties and OM chemical composition in response to the application of local vermicomposted residues. The vermicomposts of: cattle manure (CM), sheep manure (SM), […]
Corn straw mineralization and carbon, calcium, magnesium and potassium adsorption in mixtures with kaolinite and synthetic goethite
01/Jun/2001
Carbon and nutrients released from the mineralization of organic materials can interact with mineral components changing their dynamics in the soil. In this study, mixtures of corn straw, kaolinite, synthetic goethite, and quartz sand were leached with water after 7, 15, 33, 68 and 113 days of incubation at room temperature. Concentrations of soluble carbon, calcium, magnesium, and potassium were measured and accumulated over time. After 200 days, the total carbon remaining in the mixture was quantified. Total calcium, magnesium, and potassium […]
Carbon and nitrogen mineralization in stored samples of soil planted with sugarcane, with and without N fertilization, over ten years
01/Mar/2001
Carbon and nitrogen mineralization rates were determined in samples from a sandy latosolic Red Yellow Podzolic soil, taken at three depths, 0-20, 20-40 and 40-60 cm, during 10 years of sugarcane cultivation, using plots with and without N fertilization (60 kg ha-1 of N, as urea). N mineralization was measured using the incubation – percolation technique and C mineralization by absorbing the C-CO2 in 1 mol L-1 NaOH. Overall, N mineralization was higher (13%) in the treatment with N fertilization than in that without fertilization during the […]
Use of microwave radiation to evaluate soil microbial biomass
01/Dec/1999
The objective of this work was to determine carbon and nitrogen content in the soil microbial biomass by comparing microwave radiation and chloroform fumigation using the extraction and incubation methods. Two soil samples (Dark-Red Podzolic) were submitted to incubation and extraction after chloroform fumigation and microwave radiation during different periods (2, 5, 10, 15, 20, 30, 40 and 50 min). Two minutes under microwave radiation were sufficient to determine C and N content in the soil biomass using incubation and […]
