Influência do sistema de preparo e manejo de um latossolo vermelho nas suas propriedades físico-hídricas

The intensive use of the land for agricultural propose causes a series of modifications in attributes, which can take to soil degradation. In this context, the main goal of this research was to evaluate the influence of the soil tillage systems and management on its physical and hydric characteristics. The evaluations were carried out in July of 1999, at experimental plots of a Latossolo vermelho, a clay oxisoil, in the Faculdade de Engenharia Agrícola of the UNICAMP, at the county of Campinas, state of São Paulo. These plots were managed with the following treatments, along a period of eight years: no-tillage, chisel ploughing, conventional system with disk ploughing and revolving hoe. The evaluated physical and hydric parameters of the soil were: soil bulk density, particle density, total porosity, macro-porosity, micro-porosity, soil-water retention curve, hydraulic conductivity and basic infiltration. Significant differences were observed between the treatments on soil bulk density, infiltration, total porosity, macro-porosity and the micro-porosity. The chisel ploughing and no-tillage systems presented the higher values of soil bulk density; nevertheless in these conservationist systems were observed the higher values of basic infiltration.

Potenciais de água no solo na produção de alface

The scope of this experiment is to study the influence of soil water potential on lettuce productivity, particularly in relation to deficit and excess of water. Four lettuce cultivars (Americana, Roxa, Crespa and Mimosa), four minimum soil water potential (-0,001, -0,005, -0,012 and 0,022 MPa) and three replicates in experimental randomized design. The results allowed concluding that the -0,012 MPa has the tendency to produce the highest green mass among her soil water potential applied. The Mimosa showed the tendency to produce the highest evapotranspiration among the cultivars. The cultivars Americana e -0,05 MPa was the best combination (148,33g) the worst was the Roxa and -0,022 MPa minimum soil water potential.

Análise de crescimento em clones de eucalipto submetidos a estresse hídrico

The aim of this study was to evaluate Eucaliptus grandis genotypes (Clones 105 and 433) in relation to drought tolerance, through growth plant analysis. Black PVC pots with 10 liter volume were used for cultivate plants in polyethilene greenhouse oriented east/west. Completely randonmized design with four treatments was used: two clones and two minimum soil water potentials (- 0.03 and -1,5 MPa) and sixteen replicates. Pots were weighed daily in order to evaluate water content and characteristic soli water curve was determined. Plant development was obtained each 15 days from planting until 60 days through total dry matter (DM), leaf area index (LAI), leaf area ratio (LAR), net assimilative ratio (NAR), specific leaf area (SLA), relative growth ratio (RGR) and absolute growth ratio (AGR). Results showed that clone 105 presented less sensibility to water deficit, which qualify it as genetic material for use under dry soil conditons. On the other hand, both clones had similar behavior with no water restrictions.

Análise multivariada de microbacias em relação ao tipo de solo

The objective of this work was to study the dimensional parameters of the drainage net using 12 third-order ramification hydrological watersheds: 4 watersheds per soil unit (LVA, RL and RQ). The soil distinction was realized using ''t'' test to verify the orthogonal contrast among three soil averages and the grouping analysis and mean components. The results showed that the multivariance analysis was not able to discriminate three soils using the dimensional analysis. The t test of this isolated variable allowed discriminating RQ soil from LVA and RL soil units; but it was not sensitive to discriminate the LVA soil and RL unit.

Determinação do índice de estresse hídrico em cultura do feijoeiro com termômetro de infravermelho

In order to calculate the daily stress degree of a bean crop submitted to four water regime applications, cover crop and air daily measurements temperatures were accomplished by using a hand-held infrared thermometer. The treatments did not present crop water stress except the control (without irrigation). The highest yield was obtained by the treatment that received less irrigation frequency, and among the treatments that had the same number of irrigation. The largest yield was obtained with the one that received larger amount of applied water. The largest irrigation frequency did not result in larger productivity. The methodologies used for the irrigation planning were efficient for the replacement of soil water. The daily stress degree index was effective in determining crop water stress; and it was reliable presenting negative values in good water soil condition.

Influência da aplicação de vinhaça na capacidade de Infiltração de um solo de textura franco arenosa

The objective of this study was to analyze effects in different depth in soil water infiltration and to verify the Horton and Kostiakov-Lewis models adequacy in infiltration rate estimate. The treatments were five doses of vinasse (0, 200, 250, 300 and 350 m3?ha1?. The vinasse application reduced the soil erosion risk increasing the possibility of runoff. The Horton model had the best adjustment on the observed data, and the Kostiakov-Lewis model overestimated the infiltration rate values.

Variabilidade dos atributos de um latossolo vermelho sob plantio direto no cerrado brasileiro e produtividade da soja

The spatial variability of several soil attributes (bulk density, penetration resistance, water content, organic matter content and pH) as well as soybean yield have been assessed during the 2007/08 growing season, in Selviria (MS) in a Hapludox (Typic Acrustox), under no tillage. The objectives were to assess the spatial variability of soil and plant parameters at the small plot scale and to select the best soil attribute explaining most the variability of agricultural productivity. Soil and plant were sampled on a grid with 121 points within a plot of 25,600 m 2 in area and slope of 0.025 mm -1 slope. Medium and low coefficients of variation were obtained for most of the studied soil attributes as expected, due to the homogenizing effect of the no-till system on the soil physical environment. From the standpoint of linear regression and spatial pattern of variability, productivity of soybeans could be explained according to the hydrogen potential (pH). Results are discussed taken into account that the soybean crop in no-tillage is widely used in crop-livestock integration on the national scene.

Influência de Manejos de irrigação sobre aspectos de Ecofisiologia e de produção da videira cv. Syrah / Paulsen 1103

O manejo de irrigação pode influenciar o comportamento ecofisiológico e a produção da videira. O objetivo desse trabalho, conduzido em 2010 em Petrolina – PE, no Submédio do Vale do São Francisco, foi avaliar a influência de diferentes estratégias de manejo de irrigação no potencial de água na folha e em aspectos qualitativos e quantitativos das uvas do primeiro ciclo de produção da videira cv. Syrah/Paulsen 1103. O sistema de irrigação utilizado foi gotejamento e a lâmina de água foi estimada com base na evapotranspiração da cultura. O delineamento experimental utilizado foi o de blocos casualizados, em 4 repetições e com 3 tratamentos: irrigação plena, realizada durante todo o ciclo de produção; a irrigação com déficit, onde a aplicação de água foi interrompida na fase fenológica de cacho fechado; e a irrigação com déficit controlado, onde a irrigação, também interrompida na fase de cacho fechado, foi eventualmente realizada após a interrupção, de acordo com o monitoramento da água no solo. A imposição de déficit hídrico às plantas favoreceu uma maior concentração de açúcares e a redução da acidez nos frutos, contribuindo para a melhoria da qualidade das uvas para vinificação.

Fracionamento da fertirrigação e seu efeito na produção da alface sob ambiente protegido

Buscando quantificar o efeito do parcelamento da fertirrigação no desenvolvimento da alface, esta pesquisa procurou verificar o número de parcelas de fertirrigação que apresentasse o melhor desempenho no crescimento da cultura. O experimento se deu em blocos casualizados, com três repetições, quatro tratamentos de fertirrigação e três lâminas de irrigação (L1, L2 e L3). Em um dos tratamentos de fertirrigação (F1), toda a adubação necessária se deu no início do plantio; no tratamento F2, a metade da adubação se deu no início do plantio e a outra metade no meio do ciclo da cultura, uma vez planejada a colheita em 40 dias após o plantio; o tratamento F3 foi fracionado: 1/3 da adubação no início do plantio, 1/3 depois de 13 dias e o ultimo terço após 26 dias do plantio; o tratamento F4 seguiu o mesmo raciocínio, fracionando a aplicação em 4 partes, de 10 em 10 dias. Logo, os quatro tratamentos de fertirrigação receberam a mesma dosagem de fertilizantes. Os resultados permitiram concluir que a aplicação F1 resultou no pior desempenho, com massa fresca de 135,06 gramas por planta, enquanto o melhor resultado se deu no tratamento F2, com massa fresca de 161,40 g. Em todas as lâminas, o parcelamento F3 resultou em sistema radicular mais desenvolvido. O tratamento L1 apresentou em média maior desenvolvimento das raízes, seguido do L2 e L3. O tratamento L1 apresentou menor condutividade elétrica no extrato da solução dos vasos, sendo o único tratamento que diferiu estatisticamente dos demais.

Planilha eletrônica para auxilio à tomada de decisão em manejo de irrigação

The irrigation scheduling is basically the adoption of pre-established criteria to define the time and the amount of water to be applied through irrigation systems. Hence, the objective of this work was to develop and test a spreadsheet of easy comprehension, handling and interpretation by growers, which uses as inputs the physical-hydric soil attributes and tensiometer readings to the determination of irrigation depth and time. The spreadsheet enables the grower to make reading and to know in a fast way how much water to apply into the soil. The test of the spreadsheet was performed in an irrigated orchard of grapevines in Petrolina, State of Pernambuco, Brazil. Soil water retention curves and tensiometer readings from the effective rooting depth were used as a basis for obtaining the soil water matric potential, soil water content, water availability, soil water content to be replaced, net and gross irrigation depth and irrigation time. The analysis of the use of the irrigation scheduling spreadsheet resulted in a shorter time for irrigation in relation to the irrigation scheduling based only on the crop evapotranspiration. The spreadsheet can be helpful to growers adjust irrigation depth when irrigation scheduling is based only on crop evapotranspiration.

Resposta produtiva do feijoeiro comum a diferentes manejos de irrigação

The objective of this work was to analyze the most appropriate management to achieve higher productivity for carioca beans (phaseolus vulgaris) and pearll cultivar. The research was developed in the Demonstrative and Experimental Area of Irrigation (ADEI) of FCAV/UNESP, Campus of Jaboticabal, SP. Four treatments were used: T1- irrigation with base in ETo estimated by the method of Class A pan; T2- irrigations based on the readings of tensiometers installed at 0,20 m and 0,40 m of depth; T3- irrigations carried out with base in ETo estimated by the method of Penman-Monteith and T4- witness. The results were submitted to analysis of variance. To compare the averages the test Turkey was used at 5% of probability. The treatment T3 had smaller applied water depth than the treatments T1 and T2, and also smaller productivity. The conclusion is that the treatments irrigated with larger frequency showed higher production of grains.

Porosidade e infiltração de água do solo sob diferentes sistemas de manejo

Management systems affect soil structure, causing changes in porosity that can influence water infiltration into the soil. This study aimed to evaluate the effect of different management systems on the porosity and water infiltration in Distroferric Red Nitosol with clay texture. The management systems were: conventional with disc plow + two soft harrowing, conventional with heavy disc harrow + two soft harrowing, no tillage and fallow. The following attributes: porosity, pore shape and water infiltration velocity into the soil were determined. Management systems such as no-tillage, conventional with disc plow and heavy disc harrow, and fallow modify the porosity and the shape of pores of a Distroferric Red Nitosol, influencing water infiltration, which was favored in no-tillage for the greater presence of elongated pores.

Propriedades físico-hídricas, desenvolvimento radicular e produtividade da soja em dois tipos de manejos de solo

The soybean culture is part of crop rotation used by irrigators from the southwestern region of São Paulo State that perform no-tillage soil management as a form of sustainable soil use. The objective of this work was to evaluate the effect of this conservationist practice on physicalhydric properties, soil compaction, root development, and soybean culture production components in relation to the conventional management. The experiment was conducted at the Buriti-Mirim Farm, Angatuba, SP, in Brazil, using an area irrigated by a center pivot system divided into two types of soil management: conventional and no-tillage. Although the no-tillage management presented higher soil density, lower water available and lower soil resistance to penetration, both soil managements showed no difference in relation to root development.

Manejo da Irrigação Para Otimização da Produtividade E Qualidade de Frutos de Tomateiro em Sistema de Plantio Direto

There is much information on the adequate soil water matrix potential for returning irrigation in conventional soil tillage systems; however there is not enough information on the best soil water matrix potential for no-tillage production systems. This work aimed to study the effect of five irrigation levels on yield, soluble solids, and fruit acidity of the Hypeel tomato, cultivated for industrial processing and cropped on no-tillage system in Yellow Latosol. The experiment was carried out on a randomized block design with five treatments and four replications. The treatments consisted in different soil water matrix potentials for returning irrigation (m at 13cm of soil depth): -15, -30, -45, -60 and -75 kPa. The results obtained showed that the soil water matrix potential of -28.5 kPa resulted in maximum yields for tomato crop; whereas the value of -50.8 kPa resulted in the maximum fruit soluble solids concentration.

Produção e Qualidade Física dos Frutos do Abacaxi sob Diferentes Lâminas e Frequências de Irrigação

The objective of this study was to evaluate the performance of pineapple cultivar Smooth Cayenne as the physical production and the quality of the fruit when subjected to different frequencies of water dpeth and soil water in Triângulo Mineiro - Uberaba-MG. The experimental area soil is Oxisol, clay loam sandy and soft undulating local relief. A randomized block design in a factorial 4 x 2 with four levels of soil water depth (50%, 75%, 100% and 125%) of crop evapotranspiration (ETc) and two irrigation frequencies (1 day and 3 days = F1 = F2) and four replications was utilized. The crop productivity, number of seedlings, mean weight, diameter, and hardness of the fruit, plus water use efficiency were evaluated. Productivity was not significantly affected by the water depth and by the frequency of water applied; however the fruit shell resistance, the efficiency of water use, and ratoon seedlings were significantly influenced by irrigation, the water depth of 50% of the crop evapotranspiration (ETC) provided greater efficiency of water use for the production of pineapple fruit.