Atributos físicos do solo e produtividade do milho sob sistemas de manejo e adubações

No-tillage system is an efficient technique in control of soil erosion, when compared with conventional tillage, however, some studies indicate higher compaction under no-tillage, mainly in the surface layer. Strategies that increase the organic matter content, as crop rotation and organic fertilization, can be used to solve the soil compaction. The aim of this study was to evaluate the effect of soil managements (crop succession and crop rotation) and fertilization (organic, mineral and organic-mineral) in the physical properties of the soil, under no-tillage system, from 2006 to 2008. The evaluations were carried out in February 2007, after the summer corn harvest, and in September 2008, after the winter corn harvest. Crop rotation decreased the soil density and soil resistance to penetration and increased the macroporosity and total porosity. The use of organic sources of fertilization did not affect any of the physical attributes of soil. The yield of summer corn was highest in succession crop and mineral fertilization, however, in the winter, there was no difference between the soil managements and among the fertilizations.

Efeito da aplicação de água residuária de suinocultura no solo e na qualidade dos seus lixiviados

This study evaluates the behavior of swine effluent for their effects on soil and the quality of the leachate. In the incubation of soil with effluent were used 48 units in total with experimental application rates of 0, 50, 100 and 150 m(3). ha(-1). The soil pH and leached after the application of different rates remained acid and the values of ammonia in the argisols (Pax; Ultisol) showed minor values than in the witness soil while at the nitosols the values increased due to the application rates. The cation exchange capacity increased with greater intensity in argisols. The carbon/nitrogen relation was low showing a rapid mineralization of organic waste. The values of nitrate in leachate and the first of the phosphorus nitosol were higher than in the argisols, depending on the rate of application.

Produtividade e qualidade de frutos de mamoeiro ‘sunrise solo��� em função de doses de nitrogênio e boro

The study aimed to evaluate the yield and fruit quality of papaya 'Sunrise Solo' as function of nitrogen and boron fertilization. The experiment had a randomized block design with four replications, two plants per plot with a single border. To make up the treatments, we used the experimental array Plan Puebla III, which set the rates for nitrogen (0.0 to 111.2 - 200 - 288.9 - 400 g plant(-1), and B (0.0 - 0.83 - 1.5 - 2.16 - 3.0 g plant(-1)), in a total of ten treatments. The addition of nitrogen increased the yield, average fruit weight and number of fruits per plant. The nitrogen and boron increased the diameter and length of the fruit, amount of seeds and content of soluble solids. The pH of the pulp decreased linearly with increasing doses of nitrogen and boron. It was observed a significant effect of N rates on the level of vitamin C.

Composto e vermicomposto de lixo urbano na produção de mudas de oiti (Licania tomentosa (Benth)) para arborização

Compost and vermicompost, produced from organic fraction of municipal solid wastes were studied as components of potting media for Licania tomentosa (oiti) seedlings production. The objective was to achieve data to amplify the utilization of these products, in order to utilize them to ornamental and urban arborization species. Increasing rates of organic fertilizers were used until the total soil substitution from the potting media. There were no fitotoxic effects. Compost or vermicompost caused higher germination index of seeds and higher growth of plants. The study demonstrated that it is possible to utilize these products in other activities beyond aplication in agricultural soil, and it can generate new markets to this kind of organic fertilizer.

Dinâmica da ocupação do solo bacia do Rio Itiquira, Mato Grosso, Brasil

The study area corresponds to the basin of the Itiquira river high course, totalling 5,361km2. In this area a study of the environmental dynamics was made, applying SIG techniques and satellite images of the years 1966, 1985 and 1996. In 1966 the areas of natural vegetation (forests and groves) occupied 90.64% of the total of the area, which was diminished to 60.57% in 1985 and to only 36.66% in 1996. In this process, 289,382ha of a total of 485,928ha of natural vegetal covering had been lost. At the same time, the agrarian surfaces (agriculture and pasture) that occupied only 0.52% of the total area in 1966, increased to 34.89% in 1985 and to 59.04% in 1996. In 30 years there was an increase of 313,725ha of cultivated lands, corresponding to about 113 times the land occupation of the year of 1966 (2,798ha). The areas classified as urban show a gradual increase since 1966, from 39ha in 1996 to 58ha in 1985, and to 178ha in 1996. The other classes of soil use and occupation (reforestement areas, uncovered and affected by fire and humid areas) added were smaller than 4,27% in 1996.

Tolerância de perdas de solo na bacia do rio Itiquira, Mato Grosso, Brasil

The geographic area of the present study corresponds to the basin of the Itiquira river high course (Figure 1), in the portion that extends from the tributaries of its source, in the east of the plateau Correntes/Itiquira, in the neighbourhoods the city of Alto Garç as, to the scarp of the São Jerônimo mountain range, toward the west of Itiquira, in the state of Mato Grosso, totalizing 5,361 km 2. The area is placed in the eastern part of the Alto Paraguai basin, in the western portion of the Paraná Sedimentary Basin plateau. Through GIS techniques, it was possible to asses total soil losses from the Itiquira river basin, considering the years of 1966, 1985 and 1996, being based on the Universal Soil Loss Equation. Thus, in 1966 the basin lost 201,546.94 ton of soil, with an average loss of 0.37 ton/ha/year. Considering that the total area of the Itiquira river basin is of 536,100 ha, while in 1985 the soil losses had passed to 1,760,833.40 ton, with an increase of approximately 8.5 times. The average of soil losses in 1985 was of 3.28 ton/ha/year. In 1996 the basin lost 1,662,043.24 ton, with a reduction of only 9.4% in relation to 1985 but, in relation the 1966, the increase continued in the order of 8 times. The average losses per hectare in this year was in the order of 3.10 ton/ha/year (Chart 1). The map of potential of the laminar erosion for 1966 (Figure 3), shows to the highest values in small areas, situated in the northeast of the area, in Alto Garças, with values between 10 the 20 ton/ha/year and some spots in sources of the Itiquira and Ariranha rivers, with values between 1 the 5 ton/ha/year. In a general way, however, the area presents low soil loss for laminar erosion in this year, with inferior values to 1 ton/ha/year. The higher class of erosion, over 10 ton/ha/year, occupied 2,947 ha in 1966. In the year of 1985 (Figure 4), the erosive process spread over the entire studied area, and the class of erosion over of 10 ton/ha/year, already started to occupy 78,437 ha, implying an increase of approximately 27 times in 19 years. A strong increment in the erosive process was noticed in the western part of the area, to along the BR-163 road, exactly where great areas of natural vegetation (open pasture) had been transformed in culture and pasture areas. In the north-eastern part of the area it was also noticed an increment in the erosive process in agreement with the increase of culture areas and reduction of the natural areas, but it was not of so intense form as in the western portion of the area. In the year of 1996 (Figure 5), the class of erosion over of 10 ton/ha/year had diminished for a total of 53.499 ha noticing a retraction of the erosive process in the western part of the area, alongside the BR-163 road. On the other hand, it occurred a strong increment in the northern part of the area, in the neighbourhoods of the city of Alto Garças, alongside the BR-364 road and part of the MT-040 road. In a general way, in the outskirts of the city of Itiquira, in the central part of the area, it was verified an increase of the amount of zones with erosion between 0-1 ton/ha/year, passing to the immediately superior class, of 1-3 ton/ha/year; scarce data of hydrosedimentology in the UHE Itiquira (1999), shows good agreement with the values gotten for the EUPS (Chart 2). Based on the hydric classification proposal for FAO (1967) (Chart 3), it is noticed that areas with high degree of erosion (> 50) in the analysed area are very restricted, occupying 493 ha in 1985 and 332 ha in 1996 (Chart 4). In 1996 appeared as isolated spots in the north of Itiquira and Alto Garças, however beyond limits of the Itiquira river basin. These areas require special cares in its use as agricultural areas. Aiming at identifying and indicating the areas of potential risk of erosion and that need implementation of conservation practices, it was elaborated the map of limit of tolerance to the soil losses. In 1966 (Figure 6), areas with soil losses over of the tolerable were restricted to small spots located in the eastern part of the area, occupying 0.43% of the total of the area; already in 1985 (Figure 7), this percentage passed to 5.86%, spreading for all the area; in 1996 (Figure 8) it is observed a fast reduction of the areas with soil losses over of the tolerance limit, passing 5.43% of the total of the area. All the areas with losses over of the tolerable value must be considered as risk areas and were done in these areas studies for implementation of conservation practices.

Reflorestamento compensatório com vistas à retençãode água no solo da bacia hidrográfica do Córrego Palmital, Jaboticabal, SP

This work had as objective to quantify the reforestation for water retention in the Palmital Stream watershed, County of Jaboticabal, SP, by using the methodology of compensatory forestation for retention of water in watersheds. This methodology esteems the retention of water in watersheds considering the world medium value of destiny of the water in the hydrologic cycle, the use/occupation of the soil (forest, pasture and agriculture) and its permeability. The watershed in this study presents an area of 10,625.21 ha, being 237.75 ha at forest, 467.01 ha in pasture and 9,237.57 ha in agriculture. The medium values of the permeability identified in the soils were of 94.81 mm h -1 in forest, 8.99 mm t -1 in pasture and 36.01 mm h -1 in agriculture (sugar cane). Considering that should infiltrate in the soil 20.55% of the water that precipitates on the watershed, and, that the losses of water in forest areas is considered standard, the total estimated volume to compensate the excessive loss that occur in the areas of pasture and agriculture is 12.21 million of m 3ano. The compensatory forestation to retain that volume of loss should contemplate an area of 942.73 ha (8.87% of the area of the watershed). The reforestation can be priority in permanent conservation area or in areas of Legal Reserve.

Variabilidade espacial das propriedades físicas e químicas do solo em áreas intensamente cultivadas

The spatial variability of physical and chemical properties of soil were evaluated to provide subsidies for management of the agricultural input. The chemical variables: P, organic matter (OM), K, Ca, Mg, pH, CEC and base saturation (BS); and physical variables: sand and clay were analysed. Soil samples were collected at two depths (0-0.2 and 0.6-0.8 m) located at irregular mesh of sampling in the region of Monte Alto, in a Yellow-Red Podzol (Alfissolo) (PVA), under different managements, resulting in 88 points in 1465 ha of total area; and at the region of Jaboticabal in a Red Latosol (LV) cultivated with sugarcane, resulting in 128 points in 2597 ha of total area. The chemical and physical soil properties studied showed spatial dependence, except CEC in 0.6-0.8 m layer for LV; Ca and clay at 0-0.2 m layer and P, OM, K, Mg, sand and clay in 0.6-0.8 m layer for PVA. The chemical and physical variables studied were adjusted to spherical and exponential models and some of them showed semivariogram without defined structure. The PVA showed low spatial continuity of chemical and physical properties, mainly in 0.6-0.8 m layer, which suffers less antropic influence. The LV soil showed more homogenous zones of fertility and granulometric composition.

Fontes de potássio não trocável e potássio total em quatro solos do Estado do Ceará

The mineralogical composition of the soil plow layer (0-20 cm) was analyzed for the following soil suborders (according to the Brazilian soil taxonomy): Neossolo Quartzarênico. Argissolo Vermelho-Amarelo, Cambissolo Háplico and Latossolo Vermelho-Amarelo which samples were collected from different regions of the Ceará State. The present study had the objectives of identifying potential sources of both total and non-exchangeable potassium forms for plants located at the different soil fractions. Then highest content of K occurred in the Cabissolo Háplico soil, including both the total and non-exchangeable K forms. In the Neossolo Quartzarênico. Argissolo Vermelho-Amarelo and Latossolo Vermelho-Amarelo, the highest contents of both forms of potassium were impregnated at the sand fraction. The amount of potassium found in the both sand and silt fractions has its origin in the orthoclase mineral which was detected in the mineralogical analysis. In the clay fractio, the origin of the potassium is illite and a inter-stratified mineral (mica+montmorillonite). As compared with the total content, the amount of non-exchangeable potassium is low for all the four soils. It was more concentrated at clay fraction of the Cambissolo soil. The potassium content sequence in the soil was the following: Cambissolo Háplico > Argissolo Vermelho-Amarelo > Neossolo Quartzarênico > Latossolo Vermelho-Amarelo. The results showed that the distribution of the forms of potassium among the soils differ as a function of the nature of the dominating minerals detected in the mineralogical analysis (illite and orthoclase) which was discussed above.

Compactação do solo e intervalo hídrico ótimo no crescimento da parte aérea e produtividade da cultura do milho

The aim of this work was to evaluate the effect of soil compaction caused by tractor wheel traffic on the limiting water range (LLWR), shoot growth and levels of compaction and four replications in a completely randomized experimental design. Soil samples with preserved structure were collected in the layers: 0.02-0.05; 0.08-0.11; 0.15-0.18 and 0.22-0.25m to determine macroporosity, microporosity, total porosity, bulk density, resistance to penetration and LLWR. The evaluated corn parameters were: plant and first spike height, steam diameter, number of spikes per plant, plant dry matter, dry matter of 1000 seeds and seed productivity. The soil compaction restricted all corn parameters except the number of spikes per plant and dry matter of 1000 seeds. The LLWR was reduced by the soil resistance to penetration, even in the tilled soil with bulk density of 1.12 Mg m-3. Only the treatment with 11 Mg tractor, repeated four times on the area, demonstrated bulk density above critical bulk density in the LLWR that was 1.37 Mg m-3, where the seed productivity was significantly smaller.

Atributos químicos e físicos de um solo tratado com biossólido industrial e cultivado com milho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise das condições hidrológicas em bacias hidrográficas com differentes uso e ocupação do solo

The analysis of the physical medium in hydrographic basins requires knowledge of the processes involved and characteristics of variables at different geographic scales. Considering the principle that the micro-basins can be categorized, they are then considered territorial units of ideal work for the analysis of hydrologic conditions. The objective of this work was to compare water resources of four hydrographic basins' with different land use and occupation. Five sampling points along the drainage network of hydrographic basins of first order of magnitude and a sampling point in the river mouth of M1 and M4 micro-basins were established. The water collections occurred at monthly intervals from August, 2006 to August, 2007. Temperature (°C), turbidity (NTU), odor, pH, electric conductivity (μS cm-1), dissolved oxygen (mg/L), total dissolved solids (ppm) and total phosphorous (mg/L) were the variables evaluated in the study. The highest variability of the parameters was found in hydrographic basins M2 and M3. The characterization of the hydrologic conditions of the hydrographic micro-basins indicated that agricultural activities, including cultural practices of anthropic activities affect water resources.

Índice de Qualidade da Água (IQA) do reservatório Tanque Grande, Guarulhos (SP): Análise sazonal e efeitos do uso e ocupação do solo

The Tanque Grande Reservoir is located at the Serra da Cantereira, Guarulhos (SP), and provides 3% of the municipal drinking water. In the last years, the urban zone has expanded towards the reservoir and has significantly altered the land use. In this work, water samples from three stations were monitored from August/2007 up to July/2008 in terms of the Water Quality Index (IQA) adopted by CETESB. The waters were usually classified in the band Good during the study period. Nevertheless, termotolerants coliforms, BOD and total phosphorus have exceeded the legal limits several times. Such occurrences may be related to the economical activities at the sub-watersheds in addition to changes in the land use of the surroundings of the reservoir.

Custos e rentabilidade do milho em função do manejo do solo e da adubação nitrogenada

Agronomic practices that help farmers to raise yield and reduce costs must be studied to ensure agricultural sustainability. Thus, the objective of this study was to analyze economically the effect of soil management and nitrogen fertilization in maize crops. Treatments consisted of a combination of 3 soil management techniques (plow harrows + floating harrows, chisel + floating harrows, and no-tillage), 5 periods of nitrogen fertilization (control - 0 kg ha -1 N; 120 kg ha -1 after sowing (S); 120 kg ha -1 in the V 6 stage; 30 kg ha -1 (S) + 90 kg ha -1 in V 6; 30 kg ha -1 (S) + 45 kg ha -1 in V 4 + 45 kg ha -1 in V 8 The total operating cost (TOC), gross revenue (GR), operating profit (OP), profitability index (PI), break-even yield, and break-even price were estimated. It was concluded that the no-tillage system, after 11 years of management, associated with nitrogen fertilization promotes positive PI and OP, being useful to farmers.

Métodos de interpolação para estimar o ph em solo sob dois manejos de café Arábica

There are many methods used to estimate values in places no sampled for construction of contours maps. The aim of this study was to use the methods of interpolation kriging, inverse of the square of the distance and polynomial in the representation of the spatial variability of the pH of the soil in the organic and conventional management in the culture of the coffee plantation. For that, irregular meshes were built for soil sampling in the depth of 0-0,10 meters, totaling 40 points sampling in each area. For gauging of the interpolation methods they were solitary 10% of the total of points, for each area. Initially, the data were appraised through the classic statistics (descriptive and exploratory) and spatial analysis. The method inverse square of the distance and kriging has low error in estimating dados. The method of kriging presented low variation around the average in different managements.