Volume 31, Number 6, 2007

Nitrogen is an essential nutrient for common bean. However, there are still doubts about which source and level should be used to supply crops with this nutrient via sidedressing application in no-tillage systems. The objective of this work was to evaluate the influence of sources and doses of sidedressed nitrogen on common bean nutrition and grain yield (Phaseolus vulgaris L.) under no-tillage, on a Rhodic Nitisol. It was used a randomized complete block design with four replications, in a 2×4 […]

On the main island of the Archipelago of Fernando de Noronha, the dry tropical climate with oceanic influence and the parent material of volcanic origin are responsible for low soil weathering. The peculiar conditions are of particular scientific interest with a view to the improvement of the Brazilian Soil Classification System (SiBCS). For this purpose, the morphological, physical, chemical and mineralogical attributes of seven representative soil profiles (two Lithic Neosols, one “Saprolithic” Neosol, three Regolithic Neosols and one Fluvic Neosol) […]

Restinga is a typical vegetation on quartzitic, sandy, nutrient-poor parent materials along the Brazilian coast. Soils under restinga vegetation on the Ilha do Cardoso (SP) were studied to understand their genesis and to improve the Brazilian Soil Classification System (SiBCS). Thus, a physical, chemical and detailed morphological characterization was carried out. The results evidenced aquic, sandy, very acid soils with variable organic matter content, in which podzolization is the main pedogenic process. Sulphidric materials also occur due to the influence […]

Restinga is a typical vegetation on quartzitic, sandy, nutrient-poor parent materials along the Brazilian coast.. Podzolization is the main pedogenic process in restinga soils and Spodosols and Quartzipsamments with incipient podzolization are the most common soils. Podzolization is frequently studied in cold climate regions, while mineralogical studies of Spodosols in tropical climate on quartzitic parent material are scant. In this work, soils under restinga vegetation on the Ilha do Cardoso-SP, Brazil were studied to identify the mineralogical assembly of silt […]

The low reactivity of lime below the application layer is mainly due to its low solubility, to the increase in soil negative charge in the applied zones, and to the short permanence of anions of added anions in the soil solution. This study was carried out to evaluate the effect of anions added as potassium salts on increasing the reactivity of surface-applied limestone. The experiment was carried out in 2005 on a Haplumbrept (360 g kg-1 clay, 60 g kg-1 organic matter, and […]

Soil is an essential natural resource for life. Its overall capacity to function as substratum for plants, as environmental filter and regulator of gas, water and energy flow is defined as soil quality. An soil quality index can be used to monitor the effects of agricultural use on the soil attributes. The objective of this study was to determine a soil quality index (SQI) for the subsurface horizons of a cohesive argisolic Yellow Latosol (LAx) of Coastal Plains under natural […]

The advance of the agricultural frontier, characterized by the conversion of natural ecosystems into cultivated areas, was intensified in the last decades. Most of the practices used to manage soils cause changes in the soil quality and soil organic matter (SOM) dynamics. Studying the impact of different management systems is essential to choose the most adequate soil management practices. This study aimed to evaluate different SOM fractions and carbon and nitrogen storage of a very clayey typic dystroferric Red Latosol […]

Microbial biomass carbon and organic carbon were measured in a long-term field experiment (20 years) in Planaltina, DF, Brazil, under corn-soybean crop rotation. Six management systems were selected: disk plow before planting (ADPP); disk plow after harvesting (ADPC), no-till after disk plowing in the first year (PDAD); moldboard plow before planting (AVPP); moldboard plow after harvesting (AVPC), no-till after moldboard plowing in the first year (PDAV) and an undisturbed area of Savanna type vegetation, Cerrado (CE) as a reference. Soil samples […]

Sediments in agricultural areas represent a significant source of pollution of aquatic environments. There are many different sediment sources at the level of a rural catchment (e.g. crop fields, pastures, forests, river banks, and roads), with different magnitude of contribution and contaminant potential. The identification of the sediment origin is important to understand the sediment transport rate and the management of sediment eroded at the catchment scale. The goal of this work was to identify the main sediment sources of […]