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Simulation of Soil Carbon Dynamics under Sugarcane with the CENTURY Model

GALDOS, M. V.; CERRI, C. C.; CERRI, C. E. P.; PAUSTIAN, K.; ANTWERPEN, R. Van
Fonte: SOIL SCI SOC AMER Publicador: SOIL SCI SOC AMER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.49%
Currently there is a trend for the expansion of the area cropped with sugarcane (Saccharum officinarum L.), driven by an increase in the world demand for biofuels, due to economical, environmental, and geopolitical issues. Although sugarcane is traditionally harvested by burning dried leaves and tops, the unburned, mechanized harvest has been progressively adopted. The use of process based models is useful in understanding the effects of plant litter in soil C dynamics. The objective of this work was to use the CENTURY model in evaluating the effect of sugarcane residue management in the temporal dynamics of soil C. The approach taken in this work was to parameterize the CENTURY model for the sugarcane crop, to simulate the temporal dynamics of soil C, validating the model through field experiment data, and finally to make predictions in the long term regarding soil C. The main focus of this work was the comparison of soil C stocks between the burned and unburned litter management systems, but the effect of mineral fertilizer and organic residue applications were also evaluated. The simulations were performed with data from experiments with different durations, from 1 to 60 yr, in Goiana and Timbauba, Pernambuco, and Pradopolis, Sao Paulo...

Using a New Criterion to Identify Sites for Mean Soil Water Storage Evaluation

HU, Wei; SHAO, Mingan; REICHARDT, Klaus
Fonte: SOIL SCI SOC AMER Publicador: SOIL SCI SOC AMER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.38%
Establishing a few sites in which measurements of soil water storage (SWS) are time stable significantly reduces the efforts involved in determining average values of SWS. This study aimed to apply a new criterion the mean absolute bias error (MABE)-to identify temporally stable sites for mean SWS evaluation. The performance of MABE was compared with that of the commonly used criterion, the standard deviation of relative difference (SDRD). From October 2004 to October 2008, SWS of four soil layers (0-1.0, 1.0-2.0,2.0-3.0, and 3.0-4.0 m) was measured, using a neutron probe, at 28 sites on a hillslope of the Loess Plateau, China. A total of 37 SWS data sets taken over time were divided into two subsets, the first consisting of 22 dates collected during the calibration period from October 2004 to September 2006, and the second with 15 dates collected during the validation period from October 2006 to October 2008. The results showed that if a critical value of 5% for MABE was defined, more than half the sites were temporally stable for both periods, and the number of temporally stable sires generally increased with soil depth. Compared with SDRD, MABE was more suitable for the identification of time-stable sites for mean SS prediction. Since the absolute prediction error of drier sites is more sensitive to changes in relative difference in terms of mean SWS prediction...

Spatial Modeling of a Soil Fertility Index using Visible-Near-Infrared Spectra and Terrain Attributes

ROSSEL, R. A. Viscarra; RIZZO, R.; DEMATTE, J. A. M.; BEHRENS, T.
Fonte: SOIL SCI SOC AMER Publicador: SOIL SCI SOC AMER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.49%
Our objective was to develop a methodology to predict soil fertility using visible near-infrared (vis-NIR) diffuse reflectance spectra and terrain attributes derived from a digital elevation model (DEM). Specifically, our aims were to: (i) assemble a minimum data set to develop a soil fertility index for sugarcane (Sarcharum officinarum L.) (SFI-SC) for biofuel production in tropical soils; (ii) construct a model to predict the SFI-SC using soil vis-NIR spectra and terrain attributes; and (iii) produce a soil fertility map for our study area and assess it by comparing it with a green vegetation index (GVI). The study area was 185 ha located in sao Paulo State, Brazil. In total, 184 soil samples were collected and analyzed for a range of soil chemical and physical properties. Their vis-NIR spectra were collected from 400 to 2500 nm. The Shuttle Radar Topographic Mission 3-arcsec (90-m resolution) DEM of the area was used to derive 17 terrain attributes. A minimum data set of soil properties was selected to develop the SFI-SC. The SFI-SC consisted of three classes: Class 1, the highly fertile soils; Class 2, the fertile soils; and Class 3, the least fertile soils. It was derived heuristically with conditionals and using expert knowledge. The index was modeled with the spectra and terrain data using cross-validated decision trees. The cross-validation of the model correctly predicted Class 1 in 75% of cases...

Pyrolysis-Gas Chromatography/Mass Spectrometry of Soil Organic Matter Extracted from a Brazilian Mangrove and Spanish Salt Marshes

FERREIRA, Fernando Perobelli; VIDAL-TORRADO, Pablo; BUURMAN, Peter; MACIAS, Felipe; OTERO, Xose Luis; BOLUDA, Rafael
Fonte: SOIL SCI SOC AMER Publicador: SOIL SCI SOC AMER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.33%
The soil organic matter (SOM) extracted under different vegetation types from a Brazilian mangrove (Pai Matos Island, Sao Paulo State) and from three Spanish salt marshes (Betanzos Ria and Corrubedo Natural Parks, Galicia, and the Albufera Natural Park, Valencia) was investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The chemical variation was larger in SOM from the Spanish marshes than in the SOM of the Brazilian mangroves, possibly because the marshes included sites with both tidal and nontidal variation, whereas the mangrove forest underwent just tidal variation. Thus, plant-derived organic matter was better preserved under permanently anoxic environments. Moreover, given the low number of studied profiles and sedimentary-vegetation sequences in both areas, depth trends remain unclear. The chemical data also allow distinction between the contributions of woody and nonwoody vegetation inputs. Soil organic matter decomposition was found to cause: (i) a decrease in lignin contents and a relative increase in aliphatics; (ii) an increase in short-chain aliphatics at the expense of longer ones; (iii) a loss of odd-over-even dominance in alkanes and alkenes; and (iv) an increase in microbial products, including proteins...

Soil Organic Carbon Stocks of Rio Grande do Sul, Brazil

TORNQUIST, Carlos G.; GIASSON, Elvio; MIELNICZUK, Joao; CERRI, Carlos Eduardo Pellegrino; BERNOUX, Martial
Fonte: SOIL SCI SOC AMER Publicador: SOIL SCI SOC AMER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.52%
Robust and accurate regional estimates of C storage in soils are currently an important research topic because of ongoing debate about human-induced changes in the terrestrial C cycle. Widely available geoprocessing tools were applied to estimate native soil organic C (SOC) stocks of Rio Grande do Sul state in southern Brazil to a depth of 30 cm from previously sampled soil pedons under undisturbed vegetation. The study used a statewide comprehensive soil survey comprising a small-scale soil map, a climate map, and a soil pedon database. Soil organic C stocks under native vegetation were calculated with two different approaches: the Tier 1 method of the Intergovernmental Panel on Climate Change (IPCC) and a refined method based on actual field measurements derived from soil profile data. Highest SOC stocks occurred in Neossolos Quartzarenico hidromorfico (Aquents), Organossolos Tiomorficos (Hemists), Latossolos Brunos (Udox), and Vertissolos Ebanicos (Uderts) soil classes. Before human use of soils, most C was stored in the Latossolos Vermelhos (Udox) and Neossolos Regoliticos (Orthents), which occupy a large area of Rio Grande do Sul. Generally, IPCC default reference SOC stocks compared well with SOC stocks calculated from soil pedons. The total SOC stock of Rio Grande do Sul was estimated at 1510.3 Tg C (5.8 kg C m(-2)) by the IPPC method and 1597.5 +/- 363.9 Tg C (7.4 +/- 1.9 kg C m(-2)) calculated from soil pedons. The SOC digital map and SOC database developed in this study provide crucial background information for state-level contemporary assessment of C stocks and soil C sequestration programs and initiatives.; CNPq (the Brazilian National Research Council); FAPERGS (Rio Grande do Sul Research Support Foundation); CAPES (the Brazilian National Coordination for Higher Education Advancement)

Evaluation of Automotive Varnish as a Coating for Density Measurements of Soil Clods

ALMEIDA, B. G. de; SILVA, A. P. da; RAINE, S. R.; FIGUEIREDO, G. C.
Fonte: SOIL SCI SOC AMER Publicador: SOIL SCI SOC AMER
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.33%
Saran F-310 resin (Dow Chemical Co, Midland, MI) has been widely used to coat soil clods for density and size measurements; however, the manufacturer has recently stopped producing this resin and supplies are difficult to obtain. Hence, we evaluated the feasibility of using Lazzudur 7502 (Sherwin-Williams, Cleveland, OH) automotive varnish to coat soil clods for density measurement. Preliminary evaluations showed that immersion of clods in the varnish did nor affect clod cohesion and that a single immersion in Lazzudur with 30 min of post-immersion drying produced density results nor significantly (P < 0.05) different to those obtained using saran. This technique was tested across seven soils and no significant (P < 0.05) difference was found in the density of the clods measured using the two coating methods. This work suggests that automotive varnish can he used as an alternative to saran resin for clod density measurements.

Soil digital mapping with reduced soil samples under agro-silvo-pastoral systems.

Alexandre, Carlos; Nunes, Jorge; Cortez, Nuno
Fonte: European Confederation of Soil Science Societies Publicador: European Confederation of Soil Science Societies
Tipo: Aula
POR
Relevância na Pesquisa
46.53%
Soil depth (SD), clay content (SCC) and soil organic carbon (SOC) determine land use systems response but are quite expensive to be mapped in high definition. This study uses proximal sensing, tree canopy influence and cokriging (CK) to explore soil sampling reduction in soil digital mapping for low income land use systems. It applies to 5.34 ha of “montado” in central-south of Portugal with rolling morphology and mostly Regosols, Cambisols and Leptosols. Soil probing followed stratified random sampling of areas outside (OC) and under tree canopy (UC), giving 70, 79 and 64 points for SD, SCC(0-50 cm) and SOC(0-30 cm). Soil was surveyed with Dualem1 for ECa. Correlation between ECa, SD, SCC and SOC were 0.687, 0.586 and 0.448. SOC averages differ significantly for UC and OC (83 Mg/ha and 41 Mg/ha). Cokriging with ECa as auxiliary variable was performed for subsamples (N=32, 16, 8 and 4) and results were validated with complementary subsamples (N=32). Completely random and stratified subsampling were applied (slope position and tree canopy influence for SOC). Averaging seven replicas, CK reduced RRMSE (Root Mean Square Error/mean) by less than 0.05 relatively to OK. However, CK allows just a limited increase in RRMSE (<0.05) for SD and SOC when soil subsamples are reduced to N=8...

Correlation Analysis between Time Series of Precipitation and Soil Moisture under a Mediterranean Climate

Sampaio, Elsa; Lima, Júlio; Veiga, Sandro; Corte-Real, João
Fonte: International Soil Tillage Research Organization Publicador: International Soil Tillage Research Organization
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.46%
Rain-fed agriculture in Mediterranean-type environments relies on seasonal precipitation for agro-forestry production. Irregular precipitation rates (P) do influence the spatial-temporal soil-water (SW) distribution to a “critical soil depth” for a “quick” response of the active roots to tap water following a recent precipitation event. We investigated the statistical correlations between time-series of precipitation and soil-water data at depth using the Canonical Correlation Analysis (CCA) technique. Soil-water was measured in a Cambisol Dystic of an experimental plot, located on a smooth hillside in a non-ploughing Portuguese “montado” agro-forestry ecosystem, in a watershed of representative regional geomorphology and land-use of the Alentejo-region, southern Portugal. Soil-water was measured using three time-domain reflectometry (TDR) moisture-sensors since May 12th (2011) at 10-cm, 30-cm and 50-cm depths. Precipitation was measured with a standard rain-gauge (0.1 mm/tip), ca. 8-km of the TDR´s site. We performed CCA on the time-series of hourly data of P and SW recorded from May, 13th to November, 30th. Firstly, CCA involved P and the three variables (each per depth) for SW, considered all together in the model, and...

Remediation of a mine soil with insoluble polyacrylate polymers enhances soil quality and plant growth

Guiwei, Q.; Varennes, A.; Cunha-Queda, C.
Fonte: British Society of Soil Science Publicador: British Society of Soil Science
Tipo: Artigo de Revista Científica
Publicado em //2008 ENG
Relevância na Pesquisa
46.52%
We investigated the effects of different application rates of insoluble hydrophilic polyacrylate polymers on plant growth and soil quality from a Pb-contaminated mine soil. The polymer increased the waterholding capacity of the soil from about 250 g ⁄ kg in unamended soil to almost 1000 g ⁄ kg in soil with 0.6% polymer. However, the capacity of the polymer to retain water decreased progressively, presumably as the polymer sorbed Pb. Growth of orchardgrass (Dactylis glomerata L. cv. Amba) was stimulated in the polymer-amended soil. The greatest accumulated biomass over four cuts was obtained in soil amended with 0.4% of polymer. After orchardgrass had been growing for 101 days, the amounts of CaCl2-extractable Pb present in the polymer-amended soil were 15–66% of those in the unamended soil, depending on polymer application rate. The number of bacteria culturable on agar enriched with ‘Nutrient’ and yeast extract, and the activities of dehydrogenase, phosphatase, b-glucosidase, protease and cellulase increased following polymer application. In contrast, urease activity was impaired by polymer application, presumably due to the presence of ammonium as a counter ion. Principal component analysis was used to compare the effects of the different rates of polymer application. Overall...

Quantifying effects of different agricultural land uses on soil microbial biomass and activity in Brazilian biomes: inferences to improve soil quality.

KASCHUK, G.; ALBERTON, O.; HUNGRIA, M.
Fonte: Plant and Soil, The Hague, v. 338, n. 1-2, p. 467-481, Jan. 2011. Publicador: Plant and Soil, The Hague, v. 338, n. 1-2, p. 467-481, Jan. 2011.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
46.53%
Maintenance of soil quality is a key component of agriculture sustainability and a main goal of most farmers, environmentalists and government policymakers. However, as there are no parameters or methods to evaluate soil quality directly, some attributes of relevant soil functions are taken as indicators; lately, an increase in the use of soil microbial parameters has occurred, and their viability as indicators of proper land use has been highlighted. In this study we performed a meta-analysis of the response ratios of several microbial and chemical parameters to soil disturbance by different land uses in the Brazilian biomes. The studies included native forests, pastures and perennial and annual cropping systems. The introduction of agricultural practices in all biomes covered previously with natural vegetation profoundly affected microbial biomass-C (MB-C)?with an overall decrease of 31%. Annual crops most severely reduced microbial biomass and soil organic C, with an average decrease of 53% in the MB-C. In addition, the MB-C/TSOC (total soil organic carbon) ratio was significantly decreased with the transformation of forests to perennial plantation (25%), pastures (26%), and annual cropping (20%). However, each biome reacted differently to soil disturbance...

Microbial biomass and activity at various soil depths in a Brazilian oxisol after two decades of no-tillage and conventional tillage.

BABUJIA, L. C.; HUNGRIA, M.; FRANCHINI, J. C.; BROOKES, P. C.
Fonte: Soil Biology and Biochemistry, Oxford, v. 42, n. 12, p. 2174-2181, Dec. 2010. Publicador: Soil Biology and Biochemistry, Oxford, v. 42, n. 12, p. 2174-2181, Dec. 2010.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
46.5%
The advantages of no-tillage (NT) over conventional tillage (CT) systems in improving soil quality are generally accepted, resulting from benefits in soil physical, chemical and biological properties. However, most evaluations have only considered surface soil layers (maximum 0?30 cm depth), and values have not been corrected to account for changes in soil bulk density. The objective of this study was to estimate a more realistic contribution of the NT to soil fertility, by evaluating C- and N-related soil parameters at the 0?60 cm depth in a 20-year experiment established on an oxisol in southern Brazil, with a soybean (summer)/wheat (winter) crop succession under NT and CT. At full flowering of the soybean crop, soil samples were collected at depths of 0?5, 5?10, 10?20, 20?30, 30?40, 40?50 and 50?60 cm. For the overall 0?60 cm layer, correcting the values for soil bulk density, NT significantly increased the stocks of C (18%) and N (16%) and microbial biomass C (35%) and N (23%) (MB-C and -N) in comparison to CT. Microbial basal respiration and microbial quotient (qMic) were also significantly increased under NT. When compared with CT, NT resulted in gains of 0.8 Mg C ha?1 yr?1 (67% of which was in the 0?30 cm layer) and 70 kg N ha?1 yr?1 (73% in the 0?30 cm layer). In the 0?5-cm layer...

Soil fertility, mineral nitrogen and microbial biomass in upland soils of the Central Amazon under different plant covers.

MOREIRA, A.; FAGERIA, N. K.
Fonte: In: INTERNATIONAL SYMPOSIUM ON SOIL ORGANIC MATTER DYNAMICS: LAND USE, MANAGEMENT AND GLOBAL CHANGE, 2009, Colorado Springs, Colorado, USA. Anais... Colorado: 2009 Publicador: In: INTERNATIONAL SYMPOSIUM ON SOIL ORGANIC MATTER DYNAMICS: LAND USE, MANAGEMENT AND GLOBAL CHANGE, 2009, Colorado Springs, Colorado, USA. Anais... Colorado: 2009
Tipo: Resumo em anais de congresso (ALICE)
PT_BR
Relevância na Pesquisa
46.41%
Amazon is the largest State of Brazil and major area of the State is covered by a largest tropical rainforest of the world. Most soils of the Amazon region soils are characterized as acidic and infertile. When the Amazon forest land is cleared for agricultural use by burning the vegetation, the efficient nutrient recycling mechanism are disrupted. However, nutrient contents in the deforested burn land increased temporarily. The objective of this study was to evaluate the soil fertility, mineral nitrogen and microbial activity of carbon (C), nitrogen (N) and phosphorus (P) resulting from the replacement of the primary forest with pasture (Brachiaria brizantha), commercial plantations of rubber (Hevea spp.), cupuaçu (Theobroma grandiflorum), and citrus trees (Citrus sinensis) cultivated in Xanthic Ferralsol and secondary forest under Acrisols Dystric Nitosols. The results showed that ammonium-N predominates in the 0-10 cm soil depth both in primary forest and areas with secondary forest, citrus plantation and pasture. There was no increase in soil fertility with management of the cultivated areas under secondary forest, but in the pasture there was a significant increase in the stock of organic C and total N and high C/N ratios, the inverse of what occurred with the carbon of the microbial biomass. The primary forest had the highest values of C and P of the microbial biomass and the lowest metabolic quotient. Of the successions studied...

The role of soil organic matter in sustainable crop production in the Tropics.

FAGERIA, N. K.; FERREIRA, E. P. B.; KNUPP, A. M.
Fonte: In: INTERNATIONAL SYMPOSIUM ON SOIL ORGANIC MATTER, 3., 2011, Leuven. Organic matter dynamics - from soils to oceans: book of abstracts. Leuven, Belgium: European Science Foundation, 2011. Publicador: In: INTERNATIONAL SYMPOSIUM ON SOIL ORGANIC MATTER, 3., 2011, Leuven. Organic matter dynamics - from soils to oceans: book of abstracts. Leuven, Belgium: European Science Foundation, 2011.
Tipo: Resumo em anais de congresso (ALICE) Formato: p. 195.
EN
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46.33%
Soil organic matter has long been recognized as important indicator of soil productivity.; 2011

Modelling and digital soil mapping of the organic carbon stock in the topsoil (0-10 cm) of Rio de Janeiro State, Brazil.

MENDONÇA-SANTOS, M. L.; SANTOS, H. G.; COELHO, M. R.
Fonte: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 3, 30 Sept. - Oct. 3, 2008, Logan, Utah. Bridging research, production, and environmental applications: papers. Publicador: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 3, 30 Sept. - Oct. 3, 2008, Logan, Utah. Bridging research, production, and environmental applications: papers.
Tipo: Artigo em anais de congresso (ALICE) Formato: 10 p.
EN
Relevância na Pesquisa
46.53%
A soil database with 431 soil profiles of Rio de Janeiro State was used in the scope of a research project entitled ?Quantifying the magnitude, spatial distribution and organic carbon in soils of Rio de Janeiro State, using quantitative modeling, GIS and database technologies? (Projeto Carbono_RJ, funded by FAPERJ - Carlos Chagas Filho Foundation for Research Support in Rio de Janeiro State). Considering that these soil data were collected to other purpose, there was only a few sparse data to soil bulk density, which is essential to estimate of soil organic carbon (SOC) stock. To face this problem, pedotransfer functions (PTFs) were estimated to be used in the modeling of organic soil carbon of topsoil (0-10 cm), using s.c.o.r.p.a.n model. The following environmental correlates were used as predictor variables: satellite data, lithology and soil maps, DEM (Digital Elevation Model) and its derivatives as source of information for these variables. This dataset, that represents the best organized soil dataset in Brazil, is working as a trial for learning/teaching of Digital Soil Mapping (DSM) using a variety of methods for predicting soil classes and their properties. The "f" of the equation was modeled by means of multilinear analysis and regression-kriging. Seven different models were built and compared through statistical methods. In a general way...

Growth of aerobic rice in the presence of biochar as soil amendment: short-term effects in a clayey Rhodic Ferralsol in the Brazilian savanna (Cerrado).

CARVALHO, M. T. de M.; MADARI, B. E.; BASTIAANS, L.; VAN OORT, P.; HEINEMANN, A. B.; SILVA, M. A. S. da; MAIA, A. de H. N.; MEINKE, H.
Fonte: In: JOINT SSA AND NZSSS SOIL SCIENCE CONFERENCE, 5., 2012, Hobart. Soil solutions for diverse landscapes. Hobart: SSA: NZSSS, 2012. Publicador: In: JOINT SSA AND NZSSS SOIL SCIENCE CONFERENCE, 5., 2012, Hobart. Soil solutions for diverse landscapes. Hobart: SSA: NZSSS, 2012.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
46.48%
Abstract: Increasing yields in aerobic rice systems (ARS) is a challenge in the Brazilian savannah (BS), where rice is grown under unfavourable conditions characterised by well drained and low fertile soils. Management options that could increase soil water availability and nitrogen (N) use efficiency would probably lead to higher grain yields in ARS. One promising option under consideration is the use of ?biochar?, a by-product of charcoal made of hardwood, as a soil amendment. Biochar is high in resistant (pyrogenic) carbon (70 to 80% of the material), which influences some processes in soil, depending on the amount applied and its interaction with the soil properties. Yet there are no conclusive field studies that quantify the effect of hardwood biochar application on grain yield of ARS in the BS. Here, we report single season effects of biochar application coupled with N fertilisation on aerobic rice growth and grain yield in a clayey Rhodic Ferralsol in the BS. At 72 days after sowing, leaf area index and total shoot dry matter of aerobic rice was negatively related to biochar rates above 16 Mg/ha. This effect might be related to changes in soil properties due biochar application, such as increased soil nitrate availability.We found that biochar applications did not influence grain yield. The effect of N fertilisation on yield followed a quadratic pattern...

Trees and grass contribution to soil organic carbon in agroforestry systems.

TONUCCI, R. G.; GARCIA, R.; NAIR, V.
Fonte: In: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa, 2015. Publicador: In: WORLD CONGRESS ON INTEGRATED CROP-LIVESTOCK-FOREST SYSTEMS; INTERNATIONAL SYMPOSIUM ON INTEGRATED CROP-LIVESTOCK SYSTEMS, 3., 2015, Brasília, DF. Towards sustainable intensification: proceedings. Brasília, DF: Embrapa, 2015.
Tipo: Resumo em anais de congresso (ALICE)
EN
Relevância na Pesquisa
46.44%
Agroforestry systems have the potential to enhance carbon (C) sequestration in soil compared with treeless (agricultural) systems (Montagnini & Nair, 2004). When one type of vegetation is replaced with another, stable isotope contents (?13 C) values can be used to identify soil organic carbon (SOC) derived from residues in the native vegetation and the new vegetation based on discrimination between C3 and C4 plants. The present study aimed to assessing the impact of difference land-use systems on C3 and C4 contribution to SOC. The experimental area is located inside the Cerrado biome. Soil samples were taken from six different land-use sites: (i) native local forest; (ii) Eucalyptus forest (EF) established in 1985 (OEC); (iii) EF established in 2004 (NEC); (iv) pasture of B. decumbens; (v) Agroforestry System (AF) established on 1994 (OAF); and (vi) AF established on 2004 (NAF). The establishment on AF was placed first with the eucalyptus planted and rice (Oryza sativa), soybean (Glycine max) and braquiaria grass (B. Brizantha cv. Marandu) in between trees rows. Soil was collected from four depths (0-10; 10-20; 20-50 and 50-100 cm). For stable C isotope analysis, whole soil was analyzed mass spectrometer. The percentage of SOC derived from the Brachiaria ssp....

General soil map of Florida

Caldwell, R. E ( Robert Edward ), 1915-; Johnson, R. W; United States -- Soil Conservation Service; University of Florida -- Soil Science Dept
Fonte: U.S. Dept. of Agriculture, Soil Conservation Service ( Washington D.C.? ) Publicador: U.S. Dept. of Agriculture, Soil Conservation Service ( Washington D.C.? )
Tipo: cartographic Formato: 1 map : col. ; 81 x 81 cm. folded to 21 x 28 cm.
Publicado em //1982 ENGLISH
Relevância na Pesquisa
46.41%
"U.S. Dept. of Agriculture, Soil Conservation Service in cooperation with University of Florida, Institute of Food and Agricultural Sciences and Agricultural Experiment Stations, Soil Science Dept."; "100,000 meter Transverse Mercator grid, zone 16 an 17."; "4-R-24748; Base 4-R-37036."; Includes inset map of "Majorland and resource areas."; On verso: text and charts of soil classifications.; (Funding) Funded in part by the University of Florida, the Florida Heritage Project of the State University Libraries of Florida, the Institute for Museum and Library Services, and the U.S. Department of Education's TICFIA granting program.; (Statement of Responsibility) by R.E. Caldwell ; R.W. Johnson.

The use of GIS and additional information to check soil classification maps.

VIANA, J. H. M.; AVELLAR, G.
Fonte: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 2., 2006, Rio de Janeiro. Book of abstracts... Rio de Janeiro: Embrapa Solos, 2006. Publicador: In: GLOBAL WORKSHOP ON DIGITAL SOIL MAPPING, 2., 2006, Rio de Janeiro. Book of abstracts... Rio de Janeiro: Embrapa Solos, 2006.
Tipo: Artigo em anais de congresso (ALICE)
EN
Relevância na Pesquisa
46.41%
The aim of this work was to check the limits of the soil classification map using GlS tools and additional information. The information from the geology map, the digital elevation model, Aster images and the detailed soil classification map was used to establish the criteria for automatic classification, using some classification attributes as local elevation, slope and pixels values in images. The new reclassified soil map was compared to the original, and sampling was performed in points in field where the maps didn't match to access the quality of results. The results showed that this method is a promising tool to obtain better quality in digital soil information and to direct sampling, but the accuracy may be limited by the resolution of the available data, and field validation is necessary.; 2006

Long-term Effect of a Single Application of Organic Refuse on Carbon Sequestration and Soil Physical Properties

Albaladejo Montoro, Juan; López, J.; Boix-Fayos, Carolina; González Barberá, Gonzalo; Martínez-Mena García, M. Dolores
Fonte: American Society of Agronomy; Crop Science Society of America; Soil Science Society of America Publicador: American Society of Agronomy; Crop Science Society of America; Soil Science Society of America
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
46.46%
Restoration of degraded lands could be a way to reverse soil degradation and desertification in semiarid areas and mitigate greenhouse gases (GHG). Our objective was to evaluate the long-term effects of a single addition of organic refuse on soil physical properties and measure its carbon sequestration potential. In 1988, a set of five plots (87 m2 each) was established in an open desert-like scrubland (2–4% cover) in Murcia, Spain, to which urban solid refuse (USR) was added in a single treatment at different rates. Soil properties were monitored over a 5-yr period. Sixteen years after the addition, three of the plots were monitored again (P0: control, P1: 13 kg m–2, P2: 26 kg m–2 of USR added) to assess the lasting effect of the organic addition on the soil organic carbon (SOC) pools and on the physical characteristics of the soil. The SOC content was higher in P2 (16.4 g kg–1) and in P1 (11.8 g kg–1) than in P0 (7.9 g kg–1). Likewise, aerial biomass increased from 0.18 kg m–2 in P0 up to 0.27 kg m–2 in P1 and 0.46 kg m–2 in P2. This represents a total C sequestration of 9.5 Mg ha–1 in P2 and 3.4 Mg ha–1 in P1, most of the sequestered C remaining in the recalcitrant soil pool. Additionally, higher saturated hydraulic conductivity...

Oxygen transport to plant roots: Modelling for physical understanding of soil aeration

Knight, J; Cook, Freeman John
Fonte: Soil Science Society of America Publicador: Soil Science Society of America
Tipo: Artigo de Revista Científica
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A model that couples the diffusion of O2 to plant roots at the microscale to diffusion of O2 through the soil at the macroscale is derived. The solution is complex, but if the length scales (Zr and Zm; see APPENDIX for list of symbols) are equated a simple analytical expression can be obtained. This model is used to investigate relationship between a critical air-filled porosity (θm) and the other parameters; viz temperature (T), O2 concentration in the bulk soil (C*), O2 concentration at the root surface (Cr), root length density (L), the ratio of root radius (a) to the water film radius (R), microbial respiration (Mo), and length scales (Zm and Zr) related to the depth to which microbial and plant respiration are active in the model using sensitivity analysis. The model shows that θm is not very sensitive to the O2 concentration at the root surface (Cr), or the ratio of root radius (a)I water film radius (R), but is sensitive to all the other parameters in some part of their range. The results indicate that indices used to define soil aeration; O2 diffusion rate (ODR) or O2 flux, O2 concentration, or air-filled porosity, which have been previously used, are related and a single critical value for these is unlikely. If a constant critical value exists for one of these indexes it cannot exist for the other two. It is also shown that it is highly unlikely that a universal critical parameter related to soil aeration exists for any of these parameters. It is concluded that more parameters than ODR...