Biblioteca do Café
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Item Spatial variability of pores in oxidic latosol under a conservation management system with different gypsium doses(Editora UFLA, 2014-10) Carducci, Carla Eloize; Oliveira, Geraldo César; Curi, Nilton; Rossoni, Diogo Francisco; Costa, Alisson Lucrécio; Heck, Richard JonhSoil structure is modify when subjected to the agricultural process, i.e., a new spatial organization of the pores system is formed, with relation to the physical quality of it. Thus the aim of this work was to visualize and quantify, through X-ray CT scan, the pores distribution in an oxidic Latosol submitted to a conservation management system with different gypsum doses. Three random trenches were dug lengthwise along the plant row in a very clayey gibbsitic dystrophic Red Latosol, subjected to the following gypsum levels: G0: absence of gypsum; G7: 7 Mg ha-1 and G28: 28 Mg ha-1 of additional gypsum, applied to the surface of the plant row. Undisturbed soil samples were collected in plexiglass tubes at depths of 0.20-0.34, 0.80-0.94 and 1.50-1.64 m after six years of coffee cultivation for quantification of 3D pores obtained by X-ray CT scan. The spatial variability of the soil structure was evaluated by semivariograms generated by 3D images in grayscale. Distribution of the detectable pore diameter was conducted by data mining. Statistical analyzes employed packages 'geoR' to semivariogram and 'randomForest' for data mining in R language. A greater spatial continuity of the pores occurred in the G7 at the three depths. The combined effects of the management system promoted a greater spatial variability of the soil structure in the G28 treatment. Based on geostatistical analyses, it can be infer that the adoption of the system under study promoted changes in the pore network in all directions (X, Y and Z), however with better pores continuity in the vertical direction(Z).Item Soil moisture space-time analysis to support improved crop management(Editora UFLA, 2015) Silva, Bruno Montoani; Santos, Walbert Junior Reis dos; Oliveira, Geraldo César de; Lima, José Maria de; Curi, Nilton; Marques, João JoséThe knowledge of the water content in the soil profile is essential for an efficient management of crop growth and development. This work aimed to use geostatistical techniques in a spatio-temporal study of soil moisture in an Oxisol in order to provide that information for improved crop management. Data were collected in a coffee crop area at São Roque de Minas, in the upper São Francisco River basin, MG state, Brazil. The soil moisture was measured with a multi-sensor capacitance (MCP) probe at 10-, 20-, 30-, 40-, 60- and 100-cm depths between March and December, 2010. After adjusting the spherical semivariogram model using ordinary least squares, best model, the values were interpolated by kriging in order to have a continuous surface relating depth x time (CSDT) and the soil water availability to plant (SWAP). The results allowed additional insight on the dynamics of soil water and its availability to plant, and pointed to the effects of climate on the soil water content. These results also allowed identifying when and where there was greater water consumption by the plants, and the soil layers where water was available and potentially explored by the plant root system.Item Variações de curto prazo nas emissões de CO2 do solo em diferentes sistemas de manejo do cafeeiro(Sociedade Brasileira de Química, 2009) D’Andréa, Alexandre Fonseca; Silva, Marx Leandro Naves; Curi, Nilton; Freitas, Diego Antonio França de; Roscoe, Renato; Guimarães, Paulo Tácito GontijoSoil CO2 emissions represent an important component of carbon global cycle. However, information about short-term alterations of CO2 fluxes in soils of tropical regions are scarce. So, the objective of this study was to evaluate such variations in coffee plantations in Latosol (Oxisol). The CO2 emissions were not affected by environmental abiotic factors, such as temperature and soil water evaporation, but they were significantly correlated with the carbon content of microbial biomass (R=0.90, P<0.05). It happens a close relationship between root activity and soil CO2 emission in coffee plantations.Item Indicadores químicos de qualidade da matéria orgânica de solo da sub-bacia do Rio das Mortes sob manejos diferenciais de cafeeiro(Sociedade Brasileira de Química, 2008) Oliveira Júnior, Antônio Claret; Silva, Carlos Alberto; Curi, Nilton; Guilherme, Luiz Roberto Guimarães; Rangel, Otacílio José PassosThis work evaluated the chemical quality of organic matter (OM) of a Brazilian Oxisol cultivated with coffee plants, under organic and conventional managements. Total organic C (TOC), light fraction C (LF-C) and C in humic (HA-C) and fulvic (FA-C) acids fractions was measured. Amongst the evaluated indexes, TOC and LF-C discriminated better OM attributes as a function of management. The stratification ratio (TOC5-10cm/TOC10-20cm) did not show differences between the systems studied. The organic system can contribute to the sustainability of coffee plantations in Brazil, because it maintains the chemical attributes of OM closer to the indexes verified under forest conditions.Item Erosão hídrica em latossolo vermelho sob diversos sistemas de manejo do cafeeiro no Sul de Minas Gerais(Editora UFLA, 2007-11) Carvalho, Ricardo; Silva, Marx Leandro Naves; Avanzil, Junior Cesar; Curi, Nilton; Souza, Fabiana Silva deA erosão hídrica contribui para a redução da sustentabilidade dos sistemas agrícolas. O presente estudo avaliou, sob condições de chuva natural, as perdas de solo, água, nutrientes e matéria orgânica em um Latossolo Vermelho distroférrico típico, com 12 % de declividade, localizado na região de Lavras (MG). O trabalho foi conduzido em parcelas experimentais de perdas de solo. Os sistemas de manejo estudados foram: café sob cultivo convencional, com capina manual (CCC); cultivo convencional, com roçado (CCR); cultivo convencional, com utilização de herbicida (CCH); cultivo orgânico, com capina manual (COC); cultivo orgânico, com roçado (COR); e como referência parcela com solo descoberto (SD). Nos sistemas de manejo em que foi mantida a cobertura da vegetação espontânea (roçado), obteve-se maior eficiência de proteção do solo quando comparado aos sistemas onde houve exposição do solo (capina). No sistema com utilização de herbicida, observou-se um comportamento intermediário. Todos os sistemas de manejo estudados se mostraram conservacionistas quanto à proteção do solo em relação à erosão hídrica, onde o espaçamento adensado merece ser enfatizado.Item Soil phosphorus dynamics and availability and irrigated coffee yield(Sociedade Brasileira de Ciência do Solo, 2011-03) Reis, Thiago Henrique Pereira; Guimarães, Paulo Tácito Gontijo; Furtini Neto, Antônio Eduardo; Guerra, Antônio Fernando; Curi, NiltonResearch data have demonstrated that the P demand of coffee (Coffea arabica L.) is similar to that of short-cycle crops. In this context, the objective of this study was to evaluate the influence of annual P fertilization on the soil P status by the quantification of labile, moderately labile, low-labile, and total P fractions, associating them to coffee yield. The experiment was installed in a typical dystrophic Red Latosol (Oxisol) cultivated with irrigated coffee annually fertilized with triple superphosphate at rates of 0, 50, 100, 200, and 400 kg ha -1 P2O5. Phosphorus fractions were determined in two soil layers: 0–10 and 10–20 cm. The P leaf contents and coffee yield in 2008 were also evaluated. The irrigated coffee responded to phosphate fertilization in the production phase with gains of up to 138 % in coffee yield by the application of 400 kg ha -1 P2O5. Coffee leaf P contents increased with P applications and stabilized around 1.98 g kg -1 , at rates of 270 kg ha -1 P2O5 and higher. Soil P application caused, in general, an increase in bioavailable P fractions, which constitute the main soil P reservoir.