ABSTRACT: Vale do Rio Doce shoot dieback (VRDSD) is an anomaly whose cause seems to be associated with hypoxic conditions and their consequences (excess Mn and Fe) triggered by elevation of the water table in areas with poor drainage. Different plants have distinct survival strategies under this form of stress. The objective of this study was to understand the physiological responses involved in the differential tolerance of eucalyptus clones to VRDSD and their relationship to hypoxia and excess Mn. A […]

ABSTRACT: Currently, the Brazilian savanna (Cerrado) represents the main agricultural area of the country, comprising a great variety of landscapes and soils, geological formations and vegetation patterns, as well as the major watershed. We studied the hydropedology and morphometry of a representative catchment (Frutal river), on a high tableland (Chapada) in the Triângulo Mineiro region, Brazil, describing the soil-water-landscape relationships to understand land use and water resources. To this end, we applied physical, chemical, micromorphological, and morphometric methods. When dry, […]

ABSTRACT: The parent geological materials and formation factors influence the chemical, physical, and mineralogical properties and composition of the soil. Therefore, the aims of this study were to determine the chemical and some physical and mineralogical properties of the soil useful for agricultural practice; to determine the natural contents of the semitotal metals in soils of the state of Rio Grande do Sul (Brazil); and to suggest use of the quality reference values (QRVs) in accordance with Resolution 420/2009 of […]

ABSTRACT: Eucalyptus forests in southern Bahia (BA) are planted in soils with a sandy surface layer and humid tropical climate, conditions that lead to soil carbon (C) decomposition. Recent studies have shown that nitrogen (N) may be important for soil C stabilization. The aim of this study was to evaluate the contribution of Eucalyptus harvest residues and nitrogen fertilization to C stabilization in Ultisols of southern BA. The experiment was conducted in Eucalyptus clonal plantations cultivated in two regions of […]

ABSTRACT A first large-scale systematic survey of natural radioactivity contents of soils of the state of Rio de Janeiro is presented, focused on the establishment of Quality Reference Values (QRVs). Undisturbed soil samples were collected from 243 areas and analyzed by gamma spectrometry. The activity contents varied largely, ranging from 12.2 to 1,029 Bq kg−1 for 40K (geometric mean of 111.1 Bq kg−1), from 3.5 to 99.8 Bq kg−1 for 226Ra (geometric mean of 29.7 Bq kg−1), and from 5.4 […]

ABSTRACT Improvement of fallow vegetation can have a positive impact on the productivity of slash-and-mulch systems in eastern Amazonia. Phosphorus fertilization can increase biomass and nutrient stocks in the fallow phase, thereby improving nutrient cycling and crop productivity. Here, we compared biomass and nutrient stocks under three fallow management strategies: (1) natural fallow (regrowth vegetation) – NF; (2) NF vegetation improved with leguminous trees (Sclerolobium paniculatum Vogel and Inga edulis Mart.) – IF; and (3) NF vegetation improved with leguminous […]

ABSTRACT The identification of areas with greater erosive potential is important for planning soil and water conservation. The objective of this study was to evaluate the physical characteristics of rainfall events in the state of Rio de Janeiro, Brazil, and their interactions with rainfall patterns through multivariate statistical analysis. Rainfall depth, kinetic energy, 30-min intensity (I30), duration of rainfall events, and the erosivity indices KE >10, KE >25, and EI30 in 36 locations (stations) were subjected to principal component analysis […]

ABSTRACT For the development of nutrient budget models to recommend lime and fertilizers for agricultural and forestry crops, curves of plant growth and nutrient accumulation are required. Information about how nutrients are partitioned between the different plant organs is also necessary, but still scarce for pine in Brazil. This study evaluated the growth, biomass partitioning, and nutrient dynamics in pine forests in southern Brazil. To this end, we assessed unthinned 2, 4, 6, and 8-year-old stands of Pinus taeda L. […]

Abstract Nicotine concentration is a key index and directly affects the industrial quality and availability of flue-cured tobacco (FCT). Seedlings transplanted at different times were subjected to different climatic conditions, which were closely correlated with the growth, development, and nicotine synthesis of FCT. An appropriate transplanting time is imperative for ensuring high-quality tobaccos. Hence, a 15N tracing experiment in the field (which included three treatments: FCT seedlings transplanted on 5th, 15th, and 25th May) was carried out to evaluate the […]

ABSTRACT The Jaguarí River Basin forms the main water supply sources for the São Paulo Metropolitan Region and other cities in the state. Since the kinetic energy of rainfall is the driving force of water erosion, the main cause of land and water degradation, we tested the hypothesis of correlation between the erosive potential of rainfall (erosivity) and geographical coordinates and altitude for the purpose of predicting the spatial and temporal distribution of the rainfall erosivity index (EI30) in the […]