According to the time of management implementation, the amount of crop residues added to the soil surface can increase in no-tillage systems (NTS) and promote changes in the chemical and physical soil properties. The objective of this study was to quantify the deposition of plant residues on the soil surface (RSS) and variations in the light organic matter (LOM), in C and N stocks, remaining phosphorus (Prem), the soil physical characteristics (particle density (PD), bulk density (BD) and total pore […]

The land use and land use and management changes are among the main determinants of the stocks of soil organic carbon (SOC). The spatially explicit dynamic modeling is a technique that has been successfully used in evaluations of regional SOC stocks changes. Thus, this study aimed to use the Century 4.0 model associated with geoprocessing and remote sensing techniques to evaluate the effects of agricultural use and soil management changes on dynamics of soil organic carbon (SOC) on farms in […]

In spite of the high amount of N accumulated in high-yielding, short-rotation eucalyptus plantations, no significant or consistent increases in trunk volume have been observed in response to N fertilization. This experiment evaluated the effect of N fertilization on the growth and chemical composition of eucalyptus as well as its role in soil organic matter (SOM) mineralization. The field experiment was carried out in a randomized block design with three replications, in Itamarandiba- MG. Two N sources (ammonium sulphate and […]

The conversion of natural vegetation to cultivated land often results in changes in the quantity and quality of soil organic matter. The magnitude of these alterations varies according to the soil properties, climate, crops and soil management. Soil organic C is not always a sensitive indicator of soil changes. The distribution of C fractions is therefore being used to assess the soil organic matter quality more precisely. This study evaluated the changes in organic C fractions of a Humic Oxisol […]

Pig slurry application as soil manure can alter the chemical properties of the soil and affect its acidity, modifying the environment for crop growth and development. The objective of this study was to evaluate the chemical properties related to soil acidity subjected to successive applications of pig slurry. The experiment was conducted in May 2000, in an experimental area of the Federal University of Santa Maria (UFSM) under no-tillage and lasted until January 2008. Nineteen surface applications of 0, 20, […]

Organic cropping systems with input of fresh organic matter can modify the physical and chemical properties of soils and consequently affect their biological composition. The purpose of this study was to determine the effects of juice grape (Vitis labrusca L.) management on the soil chemical and microbial properties of a sandy-textured Oxisol. In October 2006, soil was sampled from two vineyard experiments set up in 2000, and from a neighboring forest area. The following treatments were evaluated in a 2 […]

Different management systems affect soil C, however decreases in the C stocks of native Cerrado areas converted to pasture have been reported. This calls for further research on this trend, under different management systems and soil-climatic conditions. The objective of this study was to evaluate soil aggregation, C levels and natural abundance of δ13C in a 20 year-old pasture (PA), following nine years of cropping, with signs of degradation compared to soil under native Cerrado (CE) in an adjacent area. […]

This study aimed to evaluate the impact of the eucalypt cultivation at different ages and of phytophysiognomy of the cerrado biome on total organic C stocks and its pools and to verify which one is more sensitive to land use changes. The study was conducted in Brasilia, Distrito Federal, in a Yellow Latosol under eucalyptus after three (PEUC-3), six (PEUC-6) and seven (PEUC-7) years of cultivation, and under savannah strict sensu, dense savannah and open grassland with scattered shrubs. In […]

In the last decades the use of stable isotopes has gained importance in several research areas, e.g., for metabolic flux and pathway analysis and studies on effects of biotic and abiotic plant stresses and on soil organic matter (SOM). Studies on the alterations and dynamics of SOM based on the variation in natural 13C abundance require variations in the C isotopic composition, which are not always observed. One alternative is to label the plant material with 13C by 13CO2 fixation, […]

Soil organic matter (SOM) plays an important role in carbon (C) cycle and soil quality. Considering the complexity of factors that control SOM cycling and the long time it usually takes to observe changes in SOM stocks, modeling constitutes a very important tool to understand SOM cycling in forest soils. The following hypotheses were tested: (i) soil organic carbon (SOC) stocks would be higher after several rotations of eucalyptus than in low-productivity pastures; (ii) SOC values simulated by the Century […]