Thesis (MSc. (Soil Science)) -- University of Limpopo, 2015 / There exists a considerable level of spatial variability in soil physical and chemical properties within the research block; and the soils are generally shallow. Of all the measured parameters, electrical conductivity, Bray-1 P, exchangeable potassium, calcium and sodium as well as extractable iron and zinc showed a huge percent of variation across the field. Soil variability maps indicated the degree of variability within the research block. The spatial variability of the characterized parameters was significant across the research block. A correlation study was conducted to investigate the relationship between the measured soil physical and chemical properties. Regular soil analyses should be conducted to avoid failure/delay of experiments. It is recommended that inputs such as irrigation and fertilizer application must be varied based on varying soil conditions across the research block. / VLIR project 6 leaders

Orientador: Carolina dos Santos Batista Bonini / Resumo: Sistemas de conservação do solo são capazes de alcançar a sustentabilidade agrícola, juntamente com a integração e diversificação de atividades de manejo. São meios que exploram o sinergismo do sistema, resultado da interação solo-planta-atmosfera. Este trabalho teve como objetivo avaliar de maneira temporal os atributos físicos do solo, sob sistema de integração lavoura-pecuária-floresta, com o intuito de verificar possíveis contribuições na qualidade do solo e na sustentabilidade do sistema. O experimento foi desenvolvido na área experimental da Agência Paulista dos Agronegócios – Polo/Andradina – São Paulo - Brasil. O solo em estudo é um Argissolo Vermelho Amarelo distrófico. O delineamento em blocos casualizados se distribuiu em 4 respectivos tratamentos: T1 – integração lavoura-pecuária, sem o componente arbóreo; T2 – sistema agrossilvipastoril, com sombreamento de 1 linha de eucalipto e densidade de 196 árvores/ha; T3 - sistema agrossilvipastoril, com sombreamento de 3 linhas de eucalipto e densidade de 448 árvores/ha; T4 - plantio exclusivo de eucalipto, as amostras foram coletadas ao longo dos anos de 2014 a 2018, nas camadas de 0-0,05; 0,05-0,10 e 0,10-0,20m, para as avaliações de infiltração de água no solo, resistência à penetração, teor de umidade do solo, densidade do solo, estabilidade de agregado e porosidade do solo. Os resultados revelaram que os sistemas que utilizam integração melhoram e/ou mantêm a qualidade do solo, sem compactar ou influenciar negativame... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Soil conservation systems are capable of achieving agricultural sustainability together with the integration and diversification of management activities. And are means that exploit the synergism of the system as a result of soil-plant-atmosphere interaction. The objective of this work was to evaluate in a temporal manner the physical attributes of the soil, under a crop- livestock-forrest integration system, in order to verify possible contributions to soil quality and system sustainability itself. The experiment was developed in the experimental area of the Paulista Agrobusiness Agency - Polo/Andradina – São Paulo Brasil. The soil under study is a dystrophic Ultisol. The randomized block design was distributed in 4 respetive treatments: T1 - crop-livestock integration, without the tree component; T2 - agrosilvipastoral system, with 1 eucalyptus line of shading and density of 196 trees/ha; T3 - agrosilvipastoral system, with 3 eucalyptus lines of shading and density of 448 trees ha; T4 - exclusive culture of eucalyptus; the samples were collected from 2014 to 2018, in the 0 -0.05 layers; 0.05-0.10 and 0.10-0.20m for the evaluation of soil water infiltration, penetration resistance, soil humidity content, soil density, aggregate stability and soil porosity. The results revealed that systems using integration improve and / or maintain soil quality without compacting or negatively influencing its water infiltration, with changes in its density and total porosity, highlighting t... (Complete abstract click electronic access below) / Mestre

The removal of vegetation and overburden changes the naturalwater purifying processes and thus decreases the groundwaterprotection in gravel pit areas. The sand and gravel depositsusedfor aggregate extraction in Sweden are also often valuablefor extraction of groundwater as a drinking water resource. TheSwedish legislation requires that gravel pits be restored afterthe cessation of extraction, the aim being to reestablishvegetation and to reinstate groundwater purifyingprocesses. The objective of this study was to improve our understandingof the processes governing groundwater protection andvegetation establishment so that these could be applied toimproving restoration methods for reestablishing naturalgroundwater protection. The focus was on the importance of soilphysical properties of the topsoil for vegetation establishmentand groundwater recharge. Actual field methods for restoration were reviewed.Conflicts between aggregate extraction and groundwaterinterests were common. In many cases the actual restorationcarried out differed from pre-planned specifications in permitdocumentation. Commonly available substrates that might be used forrestoration of gravel pits were investigated. The soils weredescribed as regards texture, organic content, porosity, waterretention and hydraulic conductivity. The way in which acombination of the water retention characteristic and theunsaturated conductivity influenced the behaviour of thesoil-plant-atmosphere system was demonstrated using aprocess-orientated simulation model. Plants with well-developedaboveground characteristics and shallow roots in particularexerted the highest requirements on the soil physicalproperties. Key words:groundwater protection, soil physicalproperties, CoupModel, unsaturated conductivity, waterretention, transpiration, soil evaporation

No description available.

Traditional aerification programs can cause substantial damage to the playing surface resulting in prolonged recovery. A growing trend in the industry involves using aerification techniques that cause minimum surface disruption; however, despite growing interest in new and alternative aerification technology, there is a lack of information in the literature comparing new or alternative technology with traditional methods on warm season grasses. Therefore, the objective of this research was to determine the best combination of new dry-injection (DI) cultivation technology with modified traditional aerification programs to achieve minimal surface disruption without a compromise in soil physical properties. Research was conducted at the Mississippi State University golf course practice putting green and at the Mississippi State University practice football field during. Treatments compared different combinations of hollow tine (HT) aerification and DI from Jun to Aug in 2014 and 2015.

No description available.

Forest areas are particularly susceptible to fires, which are often manmade. Too-frequent fires are likely to adversely affect the soil properties as well as vegetation composition, and possibly lead to soil erosion and desertification. One of the most fire affected forest regions in the world is the Mediterranean. Libya, in the Mediterranean region, has soils that are considered to be arid except in a small area called Aljabal Alakhdar (Green mountain), which is the geographic area covered by this study. It is the wettest part of Libya, and has an extensive forest and many agricultural crops. Like other forests in the Mediterranean it has suffered extreme degradation. This is mainly due to people removing fire wood, or sometimes converting forested areas to agricultural use, as well as fires which may alter several soil chemical and physical properties. The purpose of this research was to evaluate the effects of fires on the physical and chemical properties of soil of Aljabal Alakhdar forest in the north-east of Libya. The physical and chemical properties of soil following fire in two geographic areas have been determined, with those subjected to the fire compared to those in adjacent unburned areas in one coastal and one mountain site. Physical properties studied were: soil particle size, soil water content, soil porosity and soil particle density; and chemical properties studied were: soil electrical conductivity (EC), soil pH, soluble and exchangeable Na, K, Ca and Mg, cation exchange capacity (CEC), soluble Cl, CO3 and HCO3, SO4, organic matter, total N and total P. For the first time in Libyan soils, the effect of burning on the magnetic susceptibility properties of soils was also tested. The results showed that except for the soil water content and magnetic susceptibility, fire has not had a clear effect on the soils¿ physical properties, while there has been a strong impact of fire on most of the studied chemical properties. These results have been used to create an index of burning for such soils in each of the geographic areas, as a step towards creating a model which will enable a subset of soil parameters to be used to estimate how recently a site was burned, as well as defining fire severity at a site. / Libyan Government

Orientador: Morel de Passos e Carvalho / Banca: João Antonio da Costa Andrade / Banca: Gener Tadeu Pereira / Resumo: O milho é um dos cereais mais cultivados e consumidos no mundo. Para silagem é a forrageira de melhor qualidade, muito utilizada na alimentação bovina. Por apresentar sistema radicular com alto potencial de desenvolvimento, os atributos físicos do solo são de extrema importância à sua produtividade, uma vez que, em condições adversas, podem dificultar a penetração das raízes e, conseqüentemente, limitar o adequado aproveitamento dos nutrientes e da água disponível. No ano agrícola de 2005, na Fazenda Bonança (Agropecuária Dahma), município de Pereira Barreto (SP), Brasil (20o40'12'' latitude S; 51o01'50'' longitude W), foram analisadas a produtividade de forragem do milho safrinha outonal (MSF), no sistema plantio direto irrigado, as densidades da partícula (DP) e do solo (DS), as porosidades totais determinada (PT) e calculada (PTc), os teores de areia (AR), silte (SI) e de argila (AR) de um Latossolo Vermelho Distrófico (Acrustox Háplico) local, nas profundidades 1 (0-0,10 m), 2 (0,10-0,20 m) e 3 (0,20-0,30 m). O objetivo foi estudar a variabilidade e as correlações lineares e espaciais entre os atributos da planta e do solo, visando selecionar um indicador da qualidade física do solo de boa representatividade para a produtividade da forragem. Foi instalada a malha geoestatística para a coleta dos dados do solo e da planta, contendo 125 pontos amostrais, numa área de 2500 m2 e declive homogêneo de 0,025 m/m. No geral, os atributos estudados, além de não terem revelado distribuição aleatória, apresentaram variabilidade entre média e baixa. Seguiram padrões espaciais claramente definidos, com alcances da dependência espacial entre 6,8 e 46,8 metros. Assim, o maior alcance que poderá assegurar extrema semelhança em magnitude para qualquer atributo estudado, e que poderá alimentar os pacotes ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Corn is one of cereals most cropped and consumed in the world. At silage is the best green crop, very employed in the bovine nutrition. Once it has roots with high growth capability, the soil physical attributes are very important to his productivity, so that, in adverse conditions, they can inhibit the roots penetration, and thus restrict the suitable absorption of plant nutrients and available water. The forage productivity of autumnal corn (FP) in no-tillage and irrigated, and the particle (PD) and bulk (BD) densities, the determined (TPd) and computed (TPc) total porosities, the contents of sand (SA), silt (SI), and clay (CL) soil attributes, in depths 1 (0-0,10 m), 2 (0,10-0,20 m), and 3 (0,20-0,30 m), in a Haplic Acrustox of Bonança Farm (Dahma Agricultural Company) in Pereira Barreto County, Sao Paulo State, Brazil (20o40'12'' latitude S; 51o01'50'' longitude W), were analyzed in the agricultural year of 2005. The purpose was to study the variability and linear spatial correlations among the attributes (plant and soil), aiming to select an index of soil physical quality with good capacity to represent the forage productivity. A grid geostatistical to collect soil and plant data was installed, with one hundred and twenty five sample points, in a area of 2500 m2, with homogeneous slope steepness of 0.025 m/m. Yonder not changed randomly, the studied attributes showed median to low variability, with excellent spatial performances, and ranges between 6.8 and 46.8 meters. Therefore, the farthermost range at to guarantee high similitude in size, at every-one soil researched attribute, and however it will be used in the computational software of precision agriculture, must be of 46.8 meters. The FP will be estimated through equation of multiple linear regression, from the TPd1 and TPd2 attributes. The Core Method must determine the TP advantageous. Although the ...(Complete abstract click electronic access below) / Mestre

Orientador: Itamar Andrioli / Banca: William Natale / Banca: Renato de Mello Prado / Banca: Eurico Lucas de Sousa Neto / Banca: Alberto Carvalho Filho / Resumo: Objetivou-se com esse estudo avaliar o efeito de diferentes combinações de leguminosas arbóreas em sistema de cultivo em aleias, com quatro anos, sobre os atributos químicos e físicos do solo e a diversidade e dinâmica populacional de plantas infestantes. O experimento foi constituído por cinco tratamentos com oito repetições em delineamento experimental em blocos casualisados: Leucaena leucocephala + Clitoria fairchildiana; Leucaena leucocephala + Acacia mangium; Gliricidia sepium + Clitoria fairchildiana; Gliricidia sepium + Acacia mangium e o controle (sem leguminosas). Foram avaliados no solo: matéria orgânica, pH em CaCl2, P, K, Ca, Mg, H + Al, Na, Al, densidade, porosidade e estabilidade dos agregados e calculadas a soma de bases (SB), a capacidade de troca catiônica (CTC) e a saturação por bases (V%), As plantas invasoras foram avaliadas quanto a: família, espécie, número de indivíduos e fitomassa, sendo estimados a abundância, a frequência, a dominância e o Índice de Valor de Importância (IVI). A avaliação da diversidade florística foi realizada através do Índice de diversidade de Shannon-Wiener (H'). Na camada de 0 - 10 cm todos os tratamentos afetaram a concentração de magnésio. Para a densidade e a porosidade do solo, não houve diferenças significativas entre os tratamentos. Quanto à estabilidade de agregados, os valores para diâmetro médio ponderado (DMP) variaram estatisticamente entre os tratamentos na camada de 10-20 cm, as combinações L. leucocephala + A. mangium e G. sepium + A. mangium obtiveram os maiores valores. Foram identificadas 32 espécies de plantas, pertencentes a 16 famílias. As famílias mais representativas foram Poaceae, com seis espécies, seguida por Cyperaceae e Malvaceae, com quatro espécies cada. A espécie Cyperus lanceolatus apresentou o maior IVI. Leucena + sombreiro e gliricídia + acácia apresentaram maior diversidade. Em relação à fitomassa das plantas ... / Abstract: The objective of this study was to evaluate the effect of different combinations of legumes tree in alleys cropping systems with four years on the chemical and physical properties of the soil, and the diversity and dynamics of weed population. The experiment consisted of five treatments with eight replications in a randomized block experimental design: Leucaena leucocephala + Clitoria fairchildiana, L. leucocephala + Acacia mangium, Gliricídia sepium + C. fairchildiana, G. sepium + A. mangium and control (without legumes). The following soil properties were evaluated: organic matter, pH in CaCl2, P, K, Ca, Mg, H + Al, Na, Al, density, porosity and stability of aggregates and calculated the sum of bases (SB), the cation exchange capacity (CEC) and base saturation (V%). The weeds were evaluated for: family, species, number of individuals and biomass and estimated abundance, frequency, dominance and the Importance Value Index (IVI). The floristic diversity was analyzed using the diversity index of Shannon-Wiener (H '). At depth 0-10 cm all treatments affected magnesium concentration. For density and porosity of the soil there were no significant differences between treatments. For the aggregate stability, the values for mean weight diameter (MWD) varied between treatments in the 10-20 cm layer, the combinations L. leucocephala + A. mangium and G. sepium + A. mangium presented the highest values. Thirty two plant species belonging to sixteen families were identified. The most representative families were Poaceae, with six species, followed by Cyperaceae and Malvaceae, with four species. The specie Cyperus lanceolatus presented the highest IVI. Leucaena leucocephala + Clitoria fairchildiana and Gliricidia sepium + Acacia mangium presented greater diversity. Regarding the biomass of weeds, there were differences between treatments with the highest value observed for the control treatment. There were no significant differences between ... / Doutor

O solo é um importante sumidouro de carbono (C) atmosférico, uma vez que concentrações de CO2 da atmosfera podem ser atenuadas através de mecanismos de sequestro de C no solo. Nesse contexto, solos sob clima semi-árido estão sendo atualmente avaliados como potenciais sequestradores de C, sobretudo no processo de recuperação de áreas degradadas. No entanto, ainda há carência de informações referentes aos mecanismos envolvidos no sequestro de C. Adicionalmente, há incertezas nas estimativas dos estoques de C pela falta de conhecimento sobre sua variabilidade espacial devido à complexidade dos processos físicos, químicos e biológicos que influenciam o ciclo do referido elemento. As variações espaciais do C no solo estão relacionadas a fatores naturais e induzidos pelo homem e essas variações apresentam-se em diferentes escalas espaciais. Por tais motivos a presente pesquisa teve como objetivo avaliar a variabilidade espacial do C e de outros atributos físicos, químicos e biológicos do solo numa área de 100 ha destinada ao reflorestamento na região semi-árida do Rio Grande do Norte. Para tanto, foi estabelecida uma grade regular de 644 pontos amostrais espaçados de 40 m numa área localizada no município de Angicos (RN), pertencente à Universidade Federal Rural do SemiÁrido. Foram coletadas 1932 amostras de solo nas profundidades 0-0,1; 0,1-0,2; e 0,2-0,3 m para determinações de C, areia, silte, argila, pH, Na, P, Ca, Mg e K. Para determinar o C da biomassa microbiana (Cmic) foram utilizadas 156 amostras referentes à camada 0-0,1m. Com relação à densidade do solo (Ds) foram coletadas 246 amostras nas três profundidades mencionadas anteriormente. Adicionalmente, foram efetuados os seguintes cálculos: estoques de C, saturação por bases (V %), CTC (CTC(T)), saturação por Al (m) e soma de bases (SB). Os resultados foram submetidos à análise estatística descritiva clássica, seguida de análise geoestatística. O solo da área apresenta predominância de textura muito arenosa, baixa CTC e teores de C e Cmic; altos valores de Ds, acidez elevada e médios teores P e bases disponíveis. Estes resultados são comuns em solos de região semi-árida sob Caatinga em decorrência das condições climáticas desfavoráveis. Na análise descritiva a maioria dos atributos avaliados apresentou normalidade na sua distribuição. Os coeficientes de variação (CV) foram classificados como médios para a maioria dos atributos, a dependência espacial foi moderada com média geral dos alcances de 135 m. A maioria dos atributos ajustou-se ao modelo esférico. Na avaliação da eficiência dos modelos ajustados, tanto a validação interna como a externa apresentaram comportamentos semelhantes. A modelagem aplicada permitiu estimar o alcance e a magnitude das dependências espaciais. Por meio da krigagem foi efetuada a interpolação dos dados e gerados os mapas de variabilidade espacial para os atributos físicos, químicos e biológicos estudados. Os resultados obtidos nesta pesquisa ressaltam a importância do entendimento da variabilidade espacial do C e outras propriedades do solo, informações que servem como ponto de referência inicial (linha de base) e tem implicações importantes para futuras avaliações do impacto no sequestro de C e do potencial produtivo de Jatrofa na região semi-árida do Nordeste Brasileiro. / Soil is an important carbon (C) sink, since atmospheric CO2 concentrations can be attenuated by soil C sequestration. In this context, soils under semi-arid conditions are being evaluated as potential soil C sinks, mainly considering the process of rehabilitation of degraded areas. However, little information is available on the mechanisms associated with soil C sequestration. Moreover, there are uncertainties on soil C stocks estimates because of the lack of knowledge about its spatial variability due to the complexity of physical, chemical and biological processes that directly influence soil C cycle. Soil C spatial variability is associated with a series of natural and human-induced factors and those variations can be expressed in different spatial scales. Therefore, the main objective of the present study was to evaluate the spatial variability of C and soil physical, chemical and biological attributes in a 100 ha area destined to reforestation in the semi-arid region of Rio Grande do Norte (RN), Brazil. In order to do that, a regular grid (40 x 40 m) of 644 sampling points was defined in an area located in the city of Angicos (RN) that belongs to the Universidade Federal Rural do Semi-Árido. Samples from the 0-0,1; 0,1-0,2; e 0,2- 0,3 m soil layers were collected in each sampling point totalizing 1932 soil cores that were used for the following analyses: C, sand, silt, clay, pH, Na, P, Ca, Mg and K. For microbial biomass C, 156 samples were used from the 0-0,1 m soil depth. Samples for soil bulk density (total of 246 samples) were collected in the three mentioned soil layers. Additionally, the following calculations were performed: soil C stocks, base saturations, cation exchange capacity and aluminum saturation. The results were analyzed using classical descriptive statistics and geostatistics. The soil at the studied area is very sandy and presented low values of cation exchange capacity, C content and microbial biomass; high values of bulk density and soil acidity and medium values of P content and available bases. Those results are typical for soils under native vegetation at the semi-arid region due to unfavorable climatic conditions. From the descriptive analyses, the majority of the studied attributes presented normal distribution. The coefficients of variation (CV) for the majority of the studied attributes presented medium values; the spatial dependence was moderated with mean range value of 135 m. The majority of the attributes were fitted by the spherical model. Assessment of model adjustment efficiency was performed through internal and external validations and both presented similar trends. The application of modeling technique provides estimations of the range and the spatial dependence magnitude of the evaluated soil attributes. Using kriging techniques, analytical results were interpolated and maps were generated to show the spatial variability of the soil physical, chemical and biological properties. The results from the present study stressed the importance of adequately understand C and other soil properties spatial variability. Such information has important implications for future assessments of soil C sequestration and is useful for potential production of Jatropha in the semi-arid condition of the Brazilian northeast region.