Orientador: Carlos Roberto Espindola / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-11T10:34:14Z (GMT). No. of bitstreams: 1 BrandaoJunior_Osvaldino_D.pdf: 9518735 bytes, checksum: f14c2b7993a0c94d6d3b6f2034ef17a3 (MD5) Previous issue date: 2005 / Resumo: Os teores de carbono e nitrogênio da biomassa microbiana (CBM e NBM), a respiração basal e o quociente metabólico (qCO2) da microbiota do solo foram avaliados em um LATOSSOLO VERMELHO Distroférrico da Região Norte do Estado do Paraná, sob diferentes sistemas de manejo de solo e das culturas. A área experimental foi instalada em 1988/1989, na Fazenda Experimental da Embrapa Soja, em Londrina, e é constituída de parcelas de mesmo tamanho (7,5m x 30,0m), que se diferenciam pelos diferentes sistemas de manejo do solo e das culturas; o delineamento experimental do ensaio foi em blocos ao acaso com quatro repetições. As coletas do solo, da camada de 0-10 cm, entre linhas de plantas, foram realizadas sempre pela manhã e o material foi coletado das parcelas sob três sistemas de manejo do solo, plantio direto (PD), preparo com cruzador (C) e plantio convencional (PC), sendo que todas as parcelas possuíam os seguintes sistemas de manejo das culturas: rotação (R - tremoço - Lupinus albus/milho - Zea mays/aveia preta - Avena strigosa/soja- Glycine max/trigo - Triticum aestivum/soja/trigo/soja) e sucessão (S - soja/trigo); desse modo, foram coletadas amostras de solo de seis tratamentos: PD (R e S), PC (R e S) e C (R e S). As amostras foram submetidas à análise da biomassa microbiana do solo pelos métodos de fumigação-incubação e fumigação-extração e os dados submetidos à análise de variância com o teste de Tukey (p<0.05). Pode se concluir que, em relação aos teores CBM e NBM avaliados pelo método de fumigação-extração, os maiores valores foram obtidos sob PD, seguidos do sistema de manejo com cruzador e pelo PC; resultados semelhantes foram obtidos pelo método de fumigação-incubação. Em relação aos resultados da respiração basal, os valores encontrados seguiram a seguinte ordem: PD > PC > C. Os qCO2 com e sem a indução por açúcar apresentaram comportamentos semelhantes, sendo que o sistema de PC apresentou maiores valores do que o sistema de PD e com cruzador. O menor qCO2 no PD indica a maior eficiência da microbiota do solo, implicando menor perda de carbono do solo e, conseqüentemente, maior acúmulo de carbono na matéria orgânica ao longo do tempo, nesse sistema. Não houve diferença estatística relacionada aos diferentes sistemas de manejo das culturas (R e S) / Abstract: The microbial biomass carbon (MB-C) and nitrogen (MB-N), basal respiration and metabolic quotient (qCO2) were evaluated in a Rhodic Eutrudox of the North Region of the State of Paraná under different soil and crop management systems. The experimental area was established in 1988/1989 at the experimental station of Embrapa Soja, Londrina, Paraná, and consisted of 7.5m X 30.0m plots under different soil and crop managements; the experimental design was in completely randomized blocks with four replicates. Soil samplings of the 0-10 cm superficial layer, between plant lines were always realized in the morning, from plots under three soil managements, no-tillage (NT), field cultivator (C) and conventional tillage (CT) each with either a crop rotation (R) (lupin - Lupinus albus/maize - Zea mays/black oat - Avena strigosa/soybean - Glycine max/wheat - Triticum aestivum/soybean/wheat/soybean) or crop sequence (S - soybean/wheat); therefore samples were taken from six treatments: NT (R and S), C (R and S) and CT (R and S). Soil samples were analyzed for microbial biomass using two methods, fumigation-incubation and fumigation-extraction and the data were submitted to the analysis of variance and the Tukey test (p<0.05). In relation to the MBC and MBN evaluated by the fumigationextraction method, the higher values were obtained with the NT followed by the management with the field cultivator and the CT; similar results were obtained with the fumigation-incubation method. In relation to the basal respiration, the values obtained followed the order NT > CT > M. The qCO2 with and without sugar induction were higher under CT, followed by the NT and the M managements. The lower qCO2 under NT indicates higher efficiency of the soil microbes, as well as lower losses of soil carbon resulting in higher accumulation of carbon in the soil organic matter with time. No statistical differences were observed related to the different crop systems / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

Made available in DSpace on 2014-08-20T14:37:00Z (GMT). No. of bitstreams: 1 Tese_Daiane_Carvalho_dos_Santos.pdf: 3060772 bytes, checksum: 73cb01bf57d8c16320b8d8d43cdc6255 (MD5) Previous issue date: 2011-03-18 / Few studies evaluate the dynamics and quality of soil organic matter (OM) in agroecosystems of the Pampa Biome. Conservation tillage systems based on the reduction of tillage operations and addition of crop residues, contribute to maintaining and improving soil quality and the environment. In this work, the studies 1 and 2 are related to evaluation of physical fractions of organic matter from the point of view of quantity and quality in the whole soil and in aggregates under areas arenizadas in the southwest of RS, This studies was done in an Paleudult under cultivation of eucalyptus forest homogeneous (FH) system agrosilvopasture (SA) and native (CN). The studies 3 and 4 aimed evaluating quantitatively and qualitatively the physical fractions of organic matter in whole soil and in aggregate in an Albaqualf under cultivation of ryegrass (Lollium multiflorum Lam) + birdsfoot trefoil (Lotus corniculatus), as cover crops in winter and rotation soybean (Glycine max L.) / maize (Zea mays L.) / sorghum (Sorghum vulgare) in the summer in conventional tillage (CT) and no-tillage (NT). As reference area, was sampled an native area (CN). For both studies, soil was collected in the layers from 0.000 to 0.025m and 0.025 to 0.075m depth. The soil was air-dried and sieved at 8.00mm mesh and in aggregate classes (8.00 to 4.76, 4.76 - 2.00, 2.00 to 1.00, 1.00 to 0.50, 0.50 to 0.25 and <0.25mm). The stocks were determined from total organic carbon (TOC) in layers from 0.000 to 0.025m and 0.025 to 0.075m. The physical fractionation and granulometric densimetric SOM were realized to obtain the coarse fraction (CGC), carbon associated with minerals (CAM), free light fraction (FLF), occluded light fraction (OLF) and heavy fraction (HF). The first one study it was concluded that cultivation of FH in sandy soils caused increase in the stock of TOC, total nitrogen (TN) in the soil and fractions CFG, CAM, FLF and OLF when compared to CN in the surface layer. The SA in the soil samples showed more humified OM compared to CN and FH. The OLF, physically protected within the soil aggregates, presented higher proportion of more recalcitrant compounds in relation to FLF. In study 2 concluded that the FH showed the highest values of TOC accumulated in the layer from 0.000 to 0.075m depth in classes of 8.00 to 1.00mm and for the CFG and CAM in theclasses 8.00 to 0,50mm. The FLF was sensitive to changes in land use in the aggregates from 8.00 to 4.76mm at depths from 0.000 to 0.025m 0.025 to 0.075m, and these increments to the FH and CN, respectively. For all systems evaluated (FH, SA and CN), the degree of humification was higher in smaller diameter classes (0.50 - <0.25mm). The OLF showed higher free radical semiquinone, indicating humification. It was concluded from the study 3 that the NT in lowland soils increases the stock of CFG and FLF in comparison to the CT. This effect was restricted to the superficial layer, and these fractions were more sensitive than the TOC to changes in land management. In four years of experiment, te management systems had no effect on the stock of CAM and HF. By Laser Induced Fluorescence (LIF), under CT soil samples showed humified OM compared to the NT and CN. The FLF had a higher proportion of more labile compounds in relation to the OLF. In the study 4 it was concluded that the management systems under CT and NT in lowlands, reduced TOC, FLF and OLF in the aggregates of 4.76 to <0.25mm and a CFG in the classes 12 of 2.00 to <0.25mm compared to CN. Increases in stock of the FLF under NT were obtained in aggregates from 0.50 to <0.25mm in the layer from 0.000 to 0.025m for 0.000 to 0.075m, compared with CT. The largest stock of OLF in the surface layer was observed under NT in the class of the aggregates of 8.00 to 4.76mm. The increases in HF were obtained under the CT. The highest TOC, CGC, CAM, OLF and HF for the CT and NT were found in the classes of larger size aggregates (8.00 to 2.00mm), while a reduction in these stocks declined as the size of aggregates. Through the LIF and the EPR, the humification degree of OM increased with decreased the aggregate classes. / Escassos são os estudos que avaliam a dinâmica e a qualidade da matéria orgânica (MO) do solo em agroecossistemas do Bioma Pampa. Sistemas conservacionistas de manejo baseados na redução das operações de preparo do solo e na elevada e contínua adição de resíduos culturais, contribuem para a manutenção e melhoria da qualidade do solo e do ambiente. Neste trabalho, desenvolveram-se os seguintes estudos: os estudos 1 e 2 estão relacionados à avaliação das frações físicas da MO sob o ponto de vista quantitativo e qualitativo no solo inteiro e em classes de agregados, em áreas arenizadas do Sudoeste do estado do Rio Grande do Sul, em um Argissolo Vermelho sob cultivo de floresta homogênea de eucalipto (FH), sistema agrosilvipastoril (SA) e campo nativo (CN); os estudos 3 e 4 objetivaram avaliar quantitativamente e qualitativamente as frações físicas da MO no solo inteiro e em classes de agregados porém, em um Planossolo Háplico, sob cultivo de azevém (Lollium multiflorum Lam) + cornichão (Lotus corniculatus), como culturas de cobertura no inverno e rotação soja (Glycine Max L.)/milho (Zea mays L.)/sorgo (Sorghum vulgare) no verão em preparo convencional (PC) e plantio direto (PD). Como área de referência, amostrou-se uma área sob campo nativo (CN). Para ambos os estudos, o solo foi coletado nas camadas de 0,000 0,025m e de 0,025 0,075m seco ao ar e peneirado em malha de 8,00mm e em classes de agregados (8,00 4,76, 4,76 2,00, 2,00 1,00, 1,00 0,50, 0,50 0,25 e <0,25mm). Foram avaliados os estoques de carbono orgânico total (COT) e realizado o fracionamento físico granulométrico e densimétrico da MO para obtenção do carbono da fração grosseira (CFG), carbono associado aos minerais (CAM), fração leve livre (FLL), fração leve oclusa (FLO) e fração pesada (FP). No estudo 1 concluíu-se que o cultivo de homogêneo de eucalipto (FH) promoveu o aumento do estoque de COT, NT no solo e nas frações CFG, CAM, FLL e FLO quando comparado ao CN na camada superficial. No SA as amostras de solo apresentaram MO mais humificada quando comparada ao CN e a FH. A FLO, protegida fisicamente no interior dos agregados do solo, apresentou maior proporção de compostos mais recalcitrantes em relação à FLL. No estudo 2 concluíu-se que a FH promoveu os maiores estoques de COT acumulados na camada de 0,000 a 0,075m nas classes de 8,00 a 1,00mm e para o CFG e CAM nas classes que compreendem de 8,00 a 0,50mm. A FLL mostrou-se sensível as mudanças de uso do solo na classe de agregados de 8,00 4,76mm, nas camadas estudadas. Para todos os sistemas de uso avaliados, o grau de humificação foi maior nas classes de menor diâmetro (0,50 a <0,25mm). Concluiu-se pelo estudo 3 que o o PD aumenta os estoques de CFG e de FLL em comparação ao PC, sendo este efeito restrito à camada superficial em curto prazo (quatro anos), neste período, os sistemas de manejo não afetaram o CAM e a FP. O mecanismo mais importante de proteção e estabilização da MO é a interação organomineral, seguido da oclusão e a recalcitrância química. Sob PC as amostras de solo apresentaram MO mais humificada quando comparado ao PD e CN. A FLL apresentou maior proporção de compostos mais lábeis em relação à FLO. No estudo 4 concluíu-se que o PC e o PD em agroecossistema de terras baixas, reduziram os estoques de COT, FLL e FLO 10 nas classes de agregados 4,76 a <0,25mm e de CFG nas classes de 2,00 a <0,25mm quando comparado ao CN. Incrementos no estoque de FLL sob PD foram obtidos nas classes de agregados de 0,50 a <0,25mm, na camada de 0,000 0,025m e para o acumulado de 0,000 a 0,075m, quando comparado a PC. Maior estoque de FLO na camada superficial foi verificado sob PD na classe e agregados de 8,00 4,76mm. O PC contribuiu para o incremento relativo na PF da MO. Os maiores estoques de COT, CFG, CAM, FLO e FP para o PC e o PD, foram encontrados nas classes de agregados de maior tamanho. O grau de humificação da MO aumentou com a redução do diâmetro dos agregados.

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Doctor of Philosophy / Department of Agronomy / Gerard J. Kluitenberg / The Parsons soil has a sharp increase in clay content from the upper teens in the A horizon to the mid fifties in the Bt horizon. The high clay content continues to the parent material resulting in 1.5 m of dense, slowly permeable subsoil over shale residuum. This project was designed to better understand soil-water management needs of this soil. The main objective was to determine a comprehensive hydrologic balance for the claypan soil. Specific objectives were a) to determine effect of tillage management on select water balance components including water storage and evaporation, b) to quantify relationship between soil water status and crop variables such as emergence and yield, and c) to verify balance findings with predictions from a mechanistic model, specifically HYDRUS 1-D. The study utilized three replicates of an ongoing project in Labette County, Kansas in which till and no-till plots had been maintained in a sorghum [Sorghum bicolor (L.) Moench] – soybean [Glycine max (L.) Merr.] rotation since 1995. Both crops are grown each year in a randomized complete block design. The sorghum plots were equipped with Time Domain Reflectometry (TDR) probes to measure A horizon water content and neutron access tubes for measurement of water throughout the profile. Precipitation, evaporation, and perched water depth were determined at the field scale. Drainage was estimated as negligible after performing hydraulic conductivity measurements on the clayey subsoil. Runoff was determined as the residual in this water balance. Cumulative differences in the hydrologic balances as a result of tillage management were found to be minimal over an entire growing season. However, tillage treatment differences were seen in early season evaporation, surface water content, and the resulting residual runoff values. The chisel-disk treatments had greater evaporation leading to reduced runoff when compared with no-till. There was interaction between tillage treatment and time for surface water content measurements. No effect of tillage treatment was found for whole-profile water content. Crop variables were unaffected by tillage other than the first days emergence, and first days tillering being greater for chisel-disk treatments. No correlation between stored water and crop variables could be found. All aspects of field measurement were well supported by the predictions of the HYDRUS 1-D model.

Master of Science / Department of Agronomy / Charles W. Rice / The sequestration of atmospheric CO[subscript]2 into soil through no-till management is an economic and viable method for reducing greenhouse gases, but maintaining no-till practices are necessary to sequester C in the long-term. Our study focused on the effects of a single tillage operation on soil organic C and N and aggregation in no-till soils when no-till practices are immediately resumed after tillage. Three locations in western Kansas were selected that had been in continuous dryland no-till for at least 5 years – Wallace, Tribune, and Spearville. Tillage treatments were administered in 2004 and consisted of no-till (NT), disk plow (DP), sweep plow (SwP), and chisel plow (CP). Treatments were arranged in a randomized complete block design with four replications. Soil samples were taken at 0-5, 5-15, and 15-30 cm depths. Composite samples were taken from each block prior to tillage and tested for whole soil organic C and N. Further soil samples were collected in spring 2005 at approximately nine months after tillage (MAT) and again in fall 2005 at approximately 12 MAT and tested for whole soil organic C and N and aggregate size distribution. Bulk density was measured for each plot and depth prior to sampling at 12 MAT. Twelve MAT samples were also tested for aggregate-associated C and N. The DP tillage had a greater C concentration than NT and CP when averaged over depth and time, but C mass did not vary between tillage systems. Changes in whole soil C and N over time varied by location, but the differences were similar between tillage treatments. Tillage treatments DP and SwP also had a greater mass of macroaggregate (250-1000 [Mu]m) associated C relative to CP (but not to NT) for Wallace in the surface 0-5 cm at 12 MAT. No other differences between tillages in aggregate-associated C were observed. A single tillage event did not have a significant impact on aggregate size distribution. The greatest amount of aggregate-associated C and N existed in the large microaggregate (53-250 µm) fraction. Changes in aggregate distribution or aggregate-associated C or N did not directly correlate to changes in whole soil C and N. We therefore conclude that a single tillage operation using these implements will not result in a measurable loss in sequestered C over time for dryland soils in a semi-arid climate such as western Kansas.

Master of Science / Department of Agronomy / Johnathon D. Holman / Kraig L. Roozeboom / Replacing fallow periods with cover crops can provide many benefits including soil quality improvements and reduced nitrogen fertilizer requirements. Field experiments were established near Garden City, KS with winter wheat and fallow phases as main plots, thirteen legume or non-legume cover crops, continuous winter wheat, and fallow as subplots, and cover crop termination method as sub-subplots. Treatments containing triticale had greatest water use efficiency (19.9 kg ha[superscript]-1 mm[superscript]-1) and aboveground biomass (3550 kg ha[superscript]-1), but subsequent winter wheat yields were reduced due to a reduction in volumetric water content. Increased soil residue through greater cover crop biomass resulted in increased precipitation storage efficiency during the fallow period, but water requirements to produce biomass depleted soil moisture more than growing a low biomass crop or fallow. In years of above-average precipitation, low biomass cover crops might be grown with little to no negative effect on subsequent wheat yields. A second field experiment was established near Manhattan, KS with fallow, double crop soybean, and four cover crop treatments planted after wheat harvest in a winter wheat-grain sorghum-soybean no-till cropping system, with five nitrogen treatments applied to the sorghum crop to estimate nitrogen contribution of the cover crops. Greatest above ground biomass production and nitrogen accumulation was observed with sorghum-sudan grass. At the 0 kg ha[superscript]-1 N rate, grain sorghum yields were reduced 1200 kg ha[superscript]-1 following sorghum-sudan grass, while all other cover crop treatments provided a 20-30 kg ha[superscript]-1 N equivalent benefit. Sorghum yields might be reduced following large biomass producing cover crops when nitrogen is limiting, but a small nitrogen benefit might be realized following low C:N ratio cover crops. Cover crop productivity and their subsequent effects on grain sorghum performance were evaluated in field studies established near Manhattan and Hutchinson, KS in 2008 and 2009. Sixteen summer or fall cover crop species were planted in no-tillage winter wheat stubble and evaluated for biomass production, nitrogen concentration, and nitrogen accumulation. Summer annual grass species produced the greatest biomass, 3392 kg ha[superscript]-1 and greater, and legume species accumulated the greatest amounts of nitrogen, averaging 43 kg ha[superscript]-1. Grain sorghum yields were 867 kg ha[superscript]-1 greater following summer cover crops compared to fall cover crops. Cover crops had a significant effect on sorghum performance, with yields 1240 kg ha[superscript]-1 greater following legume cover crops.

Research tasks. To accomplish the research objective, the following tasks were set: 1. To establish the effect of long-term reduced tillage on soil productivity (physical, chemical and biological properties); 2. To determine the conditions of agrocenosis components’ competition for solar radiation; 3. To identify the influence of tillage intensity on weed incidence in a crop stand; 4. To ascertain the impact of tillage of different intensity on the productivity of agrocenoses (yield, 1000 seed weight, etc.) and on biometric indicators (plant height, maize ear length). / Tyrimų uždaviniai. Tyrimų tikslui pasiekti numatyta nustatyti: 1. Ilgalaikio žemės dirbimo supaprastinimo įtaką dirvožemio derlingumui (fizikinėms, cheminėms ir biologinėms savybėms); 2. Agrocenozės komponentų konkurencijos dėl saulės spinduliuotės sąlygas; 3. Žemės dirbimo intensyvumo poveikį pasėlio piktžolėtumui; 4. Skirtingo intensyvumo žemės dirbimo poveikį agrocenozių produktyvumo (derlingumas, 1000 sėklų masė ir kt.) bei biometriniams rodikliams (kukurūzų augalų aukštis, burbuolių ilgis).

Lauko eksperimentas buvo vykdomas nuo 1999 metų pagal šią schemą: A veiksnys: Šiaudų įterpimas: šiaudai pašalinti (-Š), šiaudai susmulkinti ir paskleisti (+Š). B veiksnys: Žemės dirbimo sistemos. Eksperimentas buvo atliktas Lietuvos žemės ūkio universiteto bandymų stotyje. Eksperimentas vykdytas 2010 metais. Atlikus tyrimus nustatyta, kad šiaudų įterpimas ir žemės dirbimo sistemos neturėjo esminės įtakos piktžolių daigų skaičiui. Daugiausiai daugiamečių piktžolių daigų rasta sekliai purentuose variantuose, o mažiausiai – tiesiogiai sėjant į neįdirbtą dirvą. Trumpaamžių piktžolių daigų kiekiui esminės įtakos turėjo šiaudų paskleidimas (+Š). Trumpaamžių piktžolių daigų skaičius buvo 43 procentais mažesnis nei dirvoje, kur šiaudai buvo pašalinti (-Š). Nustatyta, kad šiaudų paskleidimas neturėjo esminės įtakos vasarinių rapsų piktžolėtumui, nustatytam prieš derliaus nuėmimą. Esminių skirtumų buvo rasta skirtingose žemės dirbimo sistemose, sekliai purentuose laukeliuose. Palyginus seklųjį purenimą kultivatoriumi plokščiapjūviais noragėliais ir lėkštiniais padargais (KL) bei seklųjį purenimą rotoriniu kultivatoriumi (RK) su giliu arimu (kontrolė) (GA), piktžolių kiekis padidėjo 1,5 ir 1,6 karto. Daugiamečių piktžolių esmingai padidėjo laukeliuose, kur buvo sekliai arta (SA). Šiaudų paskleidimas turėjo esminės įtakos trumpaamžių piktžolių kiekiui. Dirvoje su šiaudais, palyginus su laukeliais be šiaudų, trumpaamžių piktžolių sumažėjo 1,3 karto. Esmingai trumpaamžių piktžolių kiekis... [toliau žr. visą tekstą] / Field experiment was carried out since 1999, as follows: Factor A: Insert a straw: straw removal (-S), straw, shredded and spread (+S). Factor B: tillage systems. The experiment was carried out in Lithuanian University of Agriculture Experimental Station. The experiment was conducted in 2010. It was determined that straw incorporation and tillage system had no significant effect on the number of weed seedlings. Most perennial weed seedlings found in shallow scratch in the treatments, while at least - when sown directly into uncultivated soil. Short-lived weed seedlings had a substantial impact on the quantity of straw spreading (+S). Short-lived weed seedling density was 43 percent lower than in the soil, where straw was removed (-S). It was found that the spreading of straw had no significant effect on weed control in spring rape, before the harvest. Significant differences were found in different tillage systems, shallow scratch boxes. Compared shallow scarification autum cultivator tines and implements Disc (KL) and a rotary cultivator shallow scarification (RK) with deep plowing (control) (GA), weeds grew 1.5 and 1.6 times. Perennial weeds has increased substantially in the fields, where it was shallow plowing (SA). Spreading straw had a substantial impact on short amount of weed. The soil with straw, as compared with the boxes without straw, weeds, fallen short 1.3 times. Substantially short amount of weeds growing through tillage systems. Studies have shown that both... [to full text]