Efeitos de níveis de cobertura do solo sobre a produtividade e crescimento do feijoeiro irrigado, em sistema de plantio direto

The objective of this research was to study the effects of five different treatments of grass (Brachiaria decumbens) straw mulch on common beans (Phaseolus vulgaris L.): 0% (0 t.ha-1), 25% (2,25 t.ha-1), 50% (4,5 t.ha-1), 75% (6,75 t. ha-1) and 100% (9,0 t/ha) designed by randomized blocks, with four replicates. The irrigation was applied when minimum soil water potential were reached about - 30kPa. The water management based on tensiometers and soil water characteristic curve. A microsprinkler irrigation system was used. The experiment was set up at the Experimental Station of Embrapa Rice and Bean (Empresa Brasileira de Pesquisa Agropecuária Arroz e Feijão) at Santo Antonio de Goiás, Brazil, in a Dark - Red Latosol soil. The results showed: the bean yield and his components were not affected by treatments, except grain number/pod,. The mulch increased the water use efficiency and, consequently, decreased the number of irrigations when the mulch reached more than 50% straw mulch. The treatment with 100% of mulching presented the largest leaf area index and dry matter accumulation was not affected by mulching.

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.

Tijolos prensados de solo-cimento confeccionados com resíduos de concreto

In this work results are presented of laboratory tests aiming to evaluate the possibility of using concrete wastes in manufactured soil-cement pressed bricks. Tests of characterization of used soil of the composite of this soil with concrete wastes and of the mixtures of soil cement made with this composite were evaluated. According to results of tests carried out with cylindrical specimens and with soil cement pressed bricks, it was verified that the addition of the concrete wastes improved soil cement mechanical properties, favoring the a reduction of the cement consumption, obtaining pressed bricks with a better quality.

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)

Produção de cebola em solo salinizado

The use of water or soil with a high salt concentration has been the main cause of failure in the yield of many crops. Consequently, this work aimed at evaluating the effects of different salinity levels and soil moisture on onion yield (cultivar Baia periforme). An experiment was conducted in a greenhouse of the Soil Science Department - FCA - UNESP, Botucatu, SP, in pots of 10 L. The soil was salinized with NaCl in order to increase the electrical condutivity of saturation extract of soil from 0.13 to 2; 4; 6 and 8 dS m-1. In each experimental unit 15.2 g of thermophosphate enriched by micronutrients and 1.5 L of organic matter were incorporated. The moisture treatments kept the soil within the limits of 25-50, 50-75 and 75-100 % of field capacity. The plant height the pseudostem diameter and yield of bulbs were evaluated. The results lead to the conclusion that the salinity reduced the vegetative growth and the yield of onion bulbs. Moisture treatment influenced both the diameter and weight of bulbs. The water consumption of the plants decreased with increassing soil salt concentration.

Avaliação de interpoladores estatísticos e determinísticos na estimativa de atributos do solo em agricultura de precisão

The obtaining of the correct space distribution for attributes of the soil is relevant in the agricultural planning, in what concerns to the installation and maintenance of the cultures. The objective of that work was to compare statistical interpolation methods (ordinary krigagem) and deterministic methods (inverse square distance) in the estimate of CTC and V% in a distrophic yellow-red Latossolo. The study was accomplished in the State of Experimental Hands on of the Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural (INCAPER), in an irregular grading with 109 points. The data were collected in the layer of 0 - 0,20 m in the projection of the cup of the plants, in the superior part of the slope. The performance of the interpolators was obtained and compared using the criterion of the medium mistake. The observations are dependent in space until a maximum reach of 14,1 m, considering the isotropy. IDW presented larger mistake in the estimate of the data; however its difference in relation to KRIG was small for both variables.

Efeito de métodos de determinação de parâmetros para o controle da irrigação na eficência do uso da água do feijoeiro, sob três diferentes lâminas de água no solo

The objective of this research was to study three methods of parameter determination for irrigation control under different tensions in common bean (Phaseolus vulgaris L.). The treatments were a combination of three methods of parameter determination for irrigation control (tensiometer, water retention curve, USWB Class A pan) with three soil water tensions (1:-30 kPa; 2:-60, kPa both for the whole plant cycle; 3:-60 kPa for the vegetative phase and -30 kPa for the reproductive phase). The experimental design was randomized blocks, factorial 32 with three replicates. Although no significant effect on water use efficiency was found, a tendency for increasing water use efficiency in treatments with tensions of -60 kPa at the vegetative phase and -30 kPa at the reproductive phase was observed in all methods of parameter determination for irrigation control. Water was saved as less irrigation was applied during the vegetative phase and more irrigation at the reproductive phase. No precipitation was observed from June to September 1995, leading to a high yield and therefore to a higher water use efficiency.

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.

Comparação de métodos para determinação da estabilidade de agregados por vias seca e úmida em diferentes sistemas de uso e manejo do solo

The purpose of the work is to evaluate the stability by dry and humid of theaggregate in different systems or the use and management in Argissolos: agricultural, pasture and torest utilization. This work was realized in agricultural property, in Anhumas city, SR Several analyses including percentage of the aggregate (by way of dry and humid); the weighted mean diameter of the aggregate calculation and statistic analysis. Conclusion: the organic matter content of the A horizon of the soil under forest is 64 % more than the soil under pasture and 79 % more than the soil under annual crop; the WMDA of the aggregate obtained by dry and humid ways of the horizon A and its mean value for the soil decrease in the following sequence: PVAd - forest > PVe -pasture > PVd - annual culture, respectively, with the following values: 1.33560 and 1.445496 (D), 2.81114 and 2.351380 (H); 0.66748 and 1.011830 (D); 2.79642 and 1.624250 (H); 0.32468 and 0.993775 (S), 1.25808 and 0.983135 mm (H); the two methods are equally sensitive to reveal the effect of the soil use and management; the organic matter provides additional stability to the aggregates submitted to humid sieving and clay to the dry sieving: the WMDA obtained by dry and humid ways are statistically different for the soil profiles.

Modelagem em escala regional da erosão relacionada com a evolução da cobertura do solo: Um estudo de caso no sudeste do Brasil

Accelerated soil erosion is, at present, one of the most widespread environmental problems in the world. Geographic Information Systems (GIS) have become an essential tool in soil erosion studies and consequently in the development of appropriate soil conservation strategies. The objective of this paper was to assess the degree of soil erosion associated with land cover dynamics through GIS analysis and to validate the modeling with indicators of soil erosion. Universal Soil Loss Equation (USLE) model, GIS technology and ground-truth dataset (erosion indicators) were employed to elaborate the soil loss maps for four dates at Sorocaba Municipality (SP, Brazil). It was verified that, although the predicted soil loss rate is normally small along the study area, such rate is significantly greater than the soil formation rate. This shows a non-sustainable situation of soil and land cover management. Unplanned urban expansion seems be the main driving force that acts in increasing the erosion risk/occurrence along the study area.

Relação entre a adubação nitrogenada e as condições hídricas do solo para um cafezal de Piracicaba, SP

Although the management of the coffee crop is well established in Brazil, there is still room for its improvement in relation natural resources available in each region, aiming the increase in productivity. Here are presented results regarding the fate of the fertilizer nitrogen (N) applied to a coffee plantation related to the prevailing soil water conditions. Soil water balances are discussed, which allowed evaluation of the root distribution, determinations of the crop coefficient and of the soil water conditions during the development of the crop. Approximately, 60% of the root system was distributed in the 0-0.3 m soil layer and the average crop coefficient was 1.1 for 3 to 5 year old plants. Using an N label, the 15N, it was possible to study the distribution of N in the plant and in the soil and establishes general N balances, which also include losses like leaching and volatilization. After two years of ammonium sulfate application, at rates of 280 (1st year) and 350 (2nd year) kg.ha-1 of N, in four equal application performed during the period of positive growth rate, the recuperation of fertilizer N were 19.1% by the aerial plant part and 9.4% by the roots, 12.6% remained in the soil and 11.2% in the litter; 0.9% was lost by volatilization and 2.3% by leaching; 26.3% was exported through harvesting and 18.2% remained in non evaluated compartments. From the applied 630 kg.ha -1 of N during the two years, 180 kg.ha -1 of N were found in the plant (shoot and root), which corresponds to 28.6%; 150 kg.ha -1 of N remained available for the next years(soil and litter), and only 20 kg.ha -1 of N were effectively lost (volatilization and leaching).

Análise temporal do uso e ocupação do solo na microbacia hidrográfica do córrego da Fazenda Glória, Município de Taquaritinga, SP

The role of environmental concern is important due to the disorganized land occupation and intense exploitation of natural resources which lead to the degradation and exhaustion of the environment. Remonte sensing techniques allow identifying, recognizing and mapping areas modifiers besides estimating the extension of alterations made by man. Thus, the objective of this study was to map land use and occupation in order to evaluate the development of the Gloria Farm Stream watershed in Taquaritinga, SP, Brazil, from 1983 to 2000. The drainage network and agricultural and natural vegetation areas were identified by stereoscopic analyses of 2000 aerial photographs and by data analyses of the field and cartographic documents. The results verified that sugarcane became predominat in 2000 and it is distributed in relatively large areas with detriment to citrus orchards and other crops. The presence of dams, which is not noted in 1983 data, and the increase of forest and natural vegetal fragment areas in the analyzed period was observed. Recovered areas dur to reforestation with native species were identified along the streams and springs of Jabuticabal Mountain Range.

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.

Condições hidrológicas de uma bacia hidrográfica com diferentes usos do solo na região de taquaritinga, SP

In areas where human activities, as agriculture, are developed land use contributes to physical, chemical and biological characteristics of water. This study aimed to identify physical and chemical variations of the water monitoring network in 4 first magnitude watersheds with different land use/occupation in the hydrographic basin of the Glori Farm Creek in the city of Taquaritinga, State of Sao Paulo, from February to July, 2005. The methodology consisted of weekly sample water collections to naalyze turbidity, temperature, dissolved oxygen, pH and electric conductivity. The characterization of the hydrological conditions of the watersheds showed that agricultural activities, including the productive system of the sugarcane cultivation, have affected the quality of water resources.