Chemical and spectroscopic composition of humic substances in soil subjected to pig manure applications for ten years
27/ago/2024
ABSTRACT Application of pig manure (PM) in agriculture can influence the amount and composition of soil organic matter (SOM). This study evaluated the changes in contents and stock of C in chemical fractions of SOM and the chemical and spectroscopic composition of humic substances (HS) in a Typic Hapludult (Argissolo Vermelho-Amarelo) after ten years of PM application. Experimental area received 90 and 180 kg ha-1 of N in the form of pig slurry (PS90 and PS180) and pig deep litter […]
Slope position controls prescribed fire effects on soil: a case study in the high-elevation grassland of Itatiaia National Park
28/nov/2023
ABSTRACT There is a need for greater knowledge about the medium- and long-term effects of prescribed fire management on soil in ecosystems prone to wildfires and more vulnerable to climate change. This study examined the short- and medium-term effects of prescribed fire on soil chemical properties and chemical fractions of soil organic matter (SOM) in two positions of the landscape in a high-elevation grassland environment. The ecosystem is located in the mountain peaks of southeastern Brazil associated with the Atlantic […]
Soil macrofauna correlations with soil chemical and physical properties and crop sequences under no-tillage
18/jul/2023
ABSTRACT Soil macrofauna is an important indicator of soil quality, as it is sensitive to changes in the environment as a result of soil management, which includes soil chemical and physical properties and the diversity of cultivated species. This study aimed to evaluate the composition and structure of soil macrofauna under a no-tillage system in different crop sequences, with and without crop rotation, over two growing seasons: a rainy summer and a dry winter. The crop sequences were soybean/corn rotation […]
Reflectance spectroscopy in the prediction of soil organic carbon associated with humic substances
06/jun/2023
ABSTRACT Understanding organic carbon and predominant humic fractions in the soil allows contributes to soil quality management. Conventional fractionation techniques require time, excessive sampling, and high maintenance costs. In this study, predictive models for organic carbon in humic substances (HS) were evaluated using hyperspectral data as an alternative to chemical fractionation and quantification by wet digestion. Twenty-nine samples of Neossolos Flúvicos (Fluvents) – A1, and 36 samples of Cambissolos (Inceptisols) – A2 were used. The samples were also analyzed jointly, […]
Soil properties changing and carbon losses by anthropic drainage in savanna palm swamp (vereda), central Brazil
24/abr/2023
ABSTRACT In the Cerrado, the palm swamps ( veredas ) are characterized by being humid and stable environments that lead to the formation of Histosols ( Organossolos ). and soils with surface horizons of organic constitution, which are fragile and sensitive to anthropic action. This study aimed to evaluate the impact of anthropization (recurrent forest fires and livestock farming) on the chemical, physical and morphological properties of soils in two palm swamps in the Environmental Preservation Area (EPA) of Pandeiros […]
Biogenic and physicogenic aggregates: formation pathways, assessment techniques, and influence on soil properties
24/nov/2021
ABSTRACT: The soil particles can be gathered through physical and/or chemical processes in association with the biological activity, leading to the formation of aggregates. Soil aggregates has several functions in the soil, increasing macroporosity and water circulation – consequently reducing soil erosion and mechanical resistance to root growth, contributing to greater fixation of plants to the soil and absorption of water and nutrients, and protection of intra-aggregate organic matter. The aggregates were initially classified morphologically and in terms of their […]
Forest harvest management systems and residual phytomass affecting physical properties of a sandy soil
05/nov/2021
ABSTRACT Organic carbon introduced in soils, mainly through organic matter, has a relevant role in various soil properties and is particularly important in sandy soils. In these soils, the input of organic material is necessary to ensure the sustainability of production systems. This study aimed to investigate the changes in total organic carbon content and its effect on physical properties in areas under different harvest management systems (HMS) after the harvest of eucalyptus. The study was performed in December 2017 […]
Forms of lime application and use of phosphogypsum in low acid soil in southern Brazil: soybean-wheat yield and soil chemical properties
05/out/2021
ABSTRACT Brazil is currently the leading country in no-till (NT) farming, particularly on Ferralsols (Latossolos), the most abundant soil type. These soils are characterized by subsurface acidity that cannot be effectively corrected by surface application of additives. In this situation, the use of phosphogypsum can be advantageous. This study aimed to assess the residual effects of lime and phosphogypsum application on a clayey Ferralsol, and four soybean and two wheat yields in southern Brazil. The area has been cultivated under […]
Lime and phosphogypsum application management: changes in soil acidity, sulfur availability and crop yield
13/ago/2021
ABSTRACT Oxisols ( Latossolos ) are widely distributed in tropical zones and generally characterized by high levels of surface and subsurface acidity. In Brazil, most Oxisols are managed under no-till conditions with surface application of acidity amendments. This study aimed to evaluate lime application strategies (incorporated and surface) for achieving the desired soil base saturation (BS%) levels (44, 60, 70, and 90 %) and the effect of phosphogypsum + lime application on soil chemical properties as well as wheat and […]
Andic properties in soils with histic horizon “O” in the highlands of Southern Brazil
31/mar/2021
ABSTRACT Soils with andic properties are characterized by a low apparent density, variable charges, large amounts of allophanes, imogolite, ferrihydrite, and/or organo-metallic complexes with Al, and present high phosphate retention. Soils derived from non-pyroclastic materials rich in silicates, formed under a cold and humid climate, a large amount of organic carbon, acid weathering, andic properties can manifest when a large amount of Al is present in the form of organo-metallic complexes. This study aimed to evaluate the characteristics and geographical […]