Variabilidade espacial de perdas de solo, do potencial natural e risco de erosão em áreas intensamente cultivadas

The objective of this work was to identify the spatial variability of the natural erosion potential, soil loss and erosion risk in two intensely cultivated areas, in order to assess the erosion occurrence patterns. The soil of the area located at Monte Alto, São Paulo state, was classified as Paleudalf (PVA) with moderately slope, with different managements. The soil of the area located at Jaboticabal, São Paulo state, was classified as Haplortox(LV) with gentle slope and cultivated with sugarcane. A irregular grid was imposed on the experimental areas. Soil samples were obtained from 0-0.2 m depth at each grid point: 88 samples in Monte Alto area (1465 ha) and 128 samples at Jaboticabal area (2597 ha). In order to obtain the values of the studied variables USLE was applied at each grid point. Descriptive statistics were calculated, and geoestatistical analyses were performed for defining semivariograms. Kriging techniques to develop map showing spatial patterns in variability of selected soil attributes were used. All variables showed spatial dependence. The PVA soil showed higher erosion risk due to the slope and atual management compared to the soil LV.

Atributos químicos do solo e produtividade do milho afetados por corretivos e manejo do solo

A field experiment was carried out in the Lageado Experimental Farm belonging to the São Paulo State University - UNESP, Campus of Botucatu, SP, in a distrophic Nitosoil in 1997/98. The objective was to compare the effects of magnesium termophosphate; termophosphate + lime; termophosphate + phosphogypsum + sugarcane vinnace application on the chemical characteristics of the soil and on the corn (Zea mays L.) yield cultivated in no-tillage and conventional tillage systems. The Crotalaria juncea was cultivated as mulch-producing to make possible the establishment of the tillage systems. The mean modifications in the soil fertility were due to aplication of the magnesium termophosphate. The differences between the two tillage systems, related to crop productivity, were associated to the smaller N content in the corn leaf in the no-tillage system.

Intervalo hídrico ótimo e produtividade de cultivares de soja

The objective of this study was to determine the optimal water interval and its relationship with soybean yield. For this study, an experiment was carried out in Jaboticabal, São Paulo State, Brazil, in a Haplustox medium textured soil. The experimental design consisted of a completely randomized with subdivided plots (six compaction levels and four soybean cultivars), with four replications. The soil compaction levels were: T 0 = 0, T 1* = 1, T 1 = 1, T 2 = 2, T 4 = 4 and T 6 = 6 strides of a 11 ton tractor, on the same place, side by side on soil surface. In T 1* the compaction occurred when the soil was dry. In December, 2003 the soybean (Glycine max), cultivars IAC Foscarin 31, MG/BR 46 (Conquista), BRS/MG 68 (Vencedora) and IAC 8 - 2 were sown. After sowing, indeformed soil samples were collected in layers of 0.03-0.06, 0.08-0.11, 0.15-0.18 and 0.22-0.25 m for determination of soil water content and resistance to penetration curve and the optimal water content. According to model, the critical soil bulk density (Dsc) for soybean yield varied between cultivars from 1.56 to 1.64 Mg m -3. The soil bulk density at which the yield of soybean cultivars decreased was greater than the Dsc.

Resistência à penetração de um solo em recuperação sob sistemas agrosilvopastoris

In the Research and Teaching Farm of the State University of São Paulo (UNESP) - Campus of Ilha Solteira, located in Selviria, in Mato Grosso do Sul State, a study was conducted with the objective of investigating the resistance to penetration of a highly degraded soil due to construction of a Hydroelectric Power Plant. The experimental design was a completely randomized, with five treatments and five replications. The treatments were constituted of the following uses and managements: area in advanced state of degradation; area under regeneration cultivated 13 years with Pinus; area under regeneration cultivated 11 years with green manure and pasture; degraded area with natural regeneration; and area with natural vegetation (savanna). The system where the area was under regeneration with Pinus cultivation and the niches with natural regeneration were the closest to natural condition (savanna). Except for the natural area (savanna), all others presented a higher resistance to penetration in the layer of 0.20-0.40 m, which represents serious limitations for growth of plant roots.

Correlação da produtividade do feijão com a resistência à penetração do solo sob plantio direto

The soil mechanical resistance to penetration (PR) has great influence on vegetative development as the root growth and the crop productivity change in inverse proportion. Thus, the objective of this research was to study correlation between the bean grain productivity and the PR in an Oxisol cultivated for four years in no-tillage system at FEIS/UNESP. The attributes PR and yield were determined in a regular grid with 119 sample points. The PR was determined in the layers of 0-0.05, 0.05-0.10, 0.10-0.15, 0.15-0.20 and 0.25-0.30 m. The results were submitted to procedures of descriptive statistics, linear correlation and geostatistic analysis. The linear correlation between the yield and PR was practically null, as in all soil layers investigated it showed determination coefficients (R2) smaller than 0.03 and not significant. The geostatistic analysis showed moderate structure of spatial dependency for PR in the layers of 0.05-0.10 and 0.10-0.15 m, and strong for yield; however, the conjugate spatial analysis of such attributes showed no correlation, therefore, the spatial variability of PR did not influence the yield.

Crescimento inicial do cafeeiro irrigado com água salina e salinização do solo

The coffee crop is expanding to new areas with not enough studies about its response to saline irrigation water. The initial growth of coffee plant was evaluated, in greenhouse at the Engineering Department of the Federal University of Lavras (UFLA), under different levels of irrigation water salinity. The completely randomized design was used with 6 treatments (S0 = 0.0 dS m -1, S1 = 0.6 dS m -1, S2 = 1.2 dS m -1, S3 = 1.8 dS m -1, S4 = 2.4 dS m -1 and S5 = 3.0 dS m -1) and 4 replications. The irrigation was accomplished according to soil water retention curve and resistance block reading, restoring the soil water content to its field capacity. It was verified that water salinity affected the plants characteristics significantly. The water salinity above 1.2 dS m -1 caused damage to plant development resulting, in some cases, in death of plants. The leaf area of plant was the variable most affected by salinity of irrigation water. By the end of the experiment, the soil was classified as saline-sodic.

Características físicas e fisiológicas na qualidade industrial de cultivares e linhagens de trigo e triticale

The physical, physiological and rheological characteristics of cultivars and lines of wheat CD (COODETEC) 103, 104, 105, 107, 108, 109, 110, 111 and CD 2017 and CDFAPA 2036 lines and triticale (EMBRAPA 53), for quality of flour for bread making were studied. The weight of hectliter (HW), weight of thousand grains (WTG), percentage of germination, total protein and farinography, in a completely randomized experimental design, with four repetitions, except the farinography (with two repetitions) were analyzed. The means obtained were compared by the Scott Knott test at 5%. The cultivars were different regarding the tested parameters. The PH value were compatible for commercialization, but not always the higher PH value corresponded to the greater weight of thousand grains. Only the CD 108 and 111 cultivars may be destine for French bread considering the stability parameter. About the index of tolerance for the mixture, the cultivars and lines were not different, but only the flour of 2017 line would attend the values that were established for French bread-making and fermented cookies. The CD 104, 108 and 11 cultivars and the CD 2017 and CDFAPA 2036 line obtained the ideal index also for fermented cookies. The cultivars which presented better weight of thousand grain gave the best index of tolerance for the mixture. There was no positive relation between total protein and the farinography.

Dinâmica da regeneração do subsolo de áreas degradadas dentro do bioma Cerrado

The objective of this research was to evaluate the physical and chemical conditions of revegetated subsoil in degraded areas in a Cerrado biome and to verify which plants promote better conditions for soil recovery. The research was conducted in the remaining area of the hydroelectrical plant site at Ilha Solteira (SP). The experimental design was a completely randomized with five treatments and three replications. The treatments consisted of: natural regeneration area, brachiaria area, Pinus sp. area, exposed soil area and Cerrado grassland (used as control). The following soil characteristics were appraised: porosity; density, stability of aggregates, infiltration rate, temperature, exchangeable cations, organic matter, pH and potential acidity. The results show that Pinus is not a good species to recover the chemical attributes of the subsoil. The revegetated areas need to be improved in their physical attributes to allow a better development of the vegetation. Brachiaria and the natural regeneration were the most promising treatments, presenting results similar to natural Cerrado.

Comportamento contrátil de barreiras selantes de solo estabilizado para base de lagoas de tratamento

Liners were proposed as subsoil contamination protection devices for waste disposal sites. In the rural environment, they can be used to construct pond bottoms for liquid waste treatment, but the construction needs to be quick and cheap. A good technical solution for these situations is the use of local soil compacted with low quantities of cement or lime, obtaining good properties for this purpose. These barriers need special care about their contraction behavior which may compromise its use. This work shows the results of contraction tests in sandy soil specimens and others stabilized with lime and with cement. Soil structure changes during cure time were checked using electronic scan microscopy. Results show maximum soil contraction of 0.648% for specimen with 14 days cure process. After twenty eight days of cure the contraction values were lower than 0.5%, which classifies the material as of low contraction. Electronic scan image shows significant material structure alteration up to seven days cure. Results show that studied mixtures had appropriate contraction behavior for liner usage.

Substrato e solução nutritiva desenvolvidos a partir de efluente de biodigestor para cultivo do meloeiro

Looking for the sustainability of a small farming enterprise, the present study focused the benefit of the biodigestor effluent resulting from the anaerobic fermentation of the bovine manure in a soilless melon plant experiment. The research was conducted in Jaboticabal, in the State of Sao Paulo, Brazil, at latitude of 21° 15' 22'' S and a longitude of 48° 18' 58'' W. The melon plant (Cucumis melo L. cv Bonus n° 2) was grown with substrate, seedling obtained in 10/2003. An experimental design was adapted in a randomized block with 16 treatments and 5 replications in a factorial 4 x 4 (4 substrates and 4 nutrient solutions). The 4 substrates were made up of different proportions in volume of the blend composition taking into consideration both the solid part of the biodigestor effluent and the washed raw sand. The 4 nutrient solutions were made up of the liquid part of the biodigestor effluent (biofertilizer) in substitution to the mineral water soluble fertilizers. The addition of the effluent in the sand led to a more rapid vegetative growth, a more precoceous crop with heavier fruits and a much better yield of melon crop. The mineral water soluble fertilizers used in the cultivation of plants in substrates can be partially replaced by the biofertilizer studied.

Atividade microbiana em um Latossolo degradado tratado com lodo de esgoto

The degraded soil shows, in general, poor biological activity, considering its physical characteristics, low fertility and organic matter, mainly due to removal or degradation of its superficial layer. The sewage sludge, due to its high content of easily decomposed organic matter can be an alternate source of organic residues and combined to its high content of the principal nutrients for the plants can be an important factor to promote biological activities in degraded soil. In order to study the actions of the sewage sludge in the recovery of a degraded Latosol, the carbon in the microbial biomass (C mic), the carbon released CO2 (C-CO2) and the relation between microbial and organic carbon (Cmic/Corg) were used as indicators of the effects. To do so, two doses (30 and 60 Mg ha-1) of sewer slime applied in topdressing and incorporated together with a mineral fertilizer treatment, using the eucalyptus as a test crop. A completely randomized design with 4 treatments and 4 repetitions was used. The sewage sludge promoted increase of liberated C-CO2 and the C mic, which constitute the adequate quality indicators for monitoring the soil recovery.

Estimativa do padrão de preferência térmica de matrizes pesadas (frango de corte)

Female broiler breeder productivity is based on the principles of thermal comfort that are directly related with the microclimate inside the housing. This research had the objective of monitoring the behavior of female broiler breeders, using the technology of radio-frequency, injectable transponders and readers in different existing microclimates inside a small scale distorted housing model. Eight birds with electronic identification were used. Three readers were used, in three different points inside the model: on the floor of the nest, in the passage besides the lateral wall and below the water facility. Dry bulb (DBT), wet bulb (WBT) and black globe (BGT) temperature were measured continuously. The results point out a distinct behavioral pattern of the birds regarding the environment exposition during the experiment. Three probabilistic models of behavior were developed from the recorded data: probabilistic model for the passage use: FP = 1.10 - 0.244 ln(DBT), probabilistic model for the water facility use: FB = 0.398 + 0.00866(DBT), and probabilistic model for the nest use: FN = 2.22 - 0.272 DBT + 0,011 DBT 2 - 0.000144 DBT 3.

Enxertia e água de irrigação carbonatada no transporte de 15N e na produção do tomateiro

The effects of CO2 application through irrigation water, and of grafting in transport of 15N and in the tomato production, were studied. These treatments were arranged in a 2 x 2 factorial scheme (with and without CO2 in irrigation water and grafted and non-grafted tomato), in a completely randomized design, with four replications. The injection of CO2 into the water began at 34 days after transplant of seedlings (DAT) and continued for all irrigations. The application of the sulfate of ammonium with abundance in atoms of 15N of 3.13% in plants destined to analysis was done at 45 DAT when the plants were in the middle of fructification. After 14 days of fertilizer (15N) application the plants were harvested, washed, dried and sent for analysis of 15N in plant tissue. The results demonstrated that CO2 and the grafting did not alter the transport of 15N in the plant. The production of commercial fruits was larger when CO2 was applied in water.

Desempenho operacional de semeadora-adubadora em diferentes manejos da cobertura e da velocidade

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Vulnerabilidade à erosão do solo da Região do Alto Rio Pardo, Pardinho, SP

This study aimed at the elaboration of a database with information and a map of erosion vulnerability for ecological zoning for the upper Pardo River, Botucatu, SP, by using the Geographical Information System - SPRING. The map of erosion vulnerability was made from spectrally homogeneous regions, producing a grid of zone averages, which was then subdivided, resulting in a vulnerability map to erosion. The results allowed us to conclude that digital imaging produced valuable information for mapping of soil use and database formation. The GIS - SPRING was efficient at identifying soil and vulnerability erosion classes and 95% of the basin presents a moderately stable vulnerability degree, through the presence of medium young soils in gently waring reliefs and covered by 49.27% of pasture and 29.88% crops.