As variaveis relevo e 'solo' na distribuicao desigual da umidade do solo. Avaliacao preliminar.

In a general way the analysis of soil water content enabled one to define which of the colluvium units hold larger water retention capacity. They are: Bela Vista, Piracema I, Campo Alegre, Bom Retiro and Treviso II. These results suggest that the contact zones among alostratigraphic units with high and low water retention capacity are potential zones for the generation of subsurface flow (throughflow). -from English summary

Variaveis da ocupacao do solo e analise multivariada

Photointerpretative and multivariate statistical techniques were applied to variants of soil use measured in 4 hydrological basins of third order ramification, belonging to Tiete basin municipal district of Botucatu, Sao Paulo State. The aim was the grouping of basins of second degree of similarity, as well as to infer spatial distribution representativeness. The hydrological basins were located in 3 physiographic regions, with peripheric depression, cuesta front and cuesta backslope, embracing the following soil units: Regosol intergrade to Red Yellow Podzolic and intergrade to Red Yellow Latosol, Red Yellow Latosol-sandy phase, Litosol basaltic substract phase and Purple Latosol. The results obtained allow the conclusion that soil use not always reflects its fertility. -after English summary

Ensaios triaxiais dinamicos sobre amostras indeformadas de um solo colapsivel

Tests were carried out with samples from two depths of a vertical soil profile. The results indicate that the permanent deformation characteristics of the soil are dependent on their depth in the vertical profile and on their water content. Some practical consequences to the performance of the pavement were considered.

Efeito de parâmetros analíticos sobre a precisão de métodos de extração de zinco do solo

Fifteen soil samples and four extradants (DTPA, Na 2EDTA, HCl and Mehlich 1) were used to study soil extraction methods for available zinc. Each extradant was studied in three soil:solution ratios (1:2, 1:4 and 1:10) and in three extraction periods in the ratio most frequently used. The zinc extracted by DTPA, Na 2EDTA and HCl was not affected by use of soil:solution ratios 1:2 and 1:4, but the amount extracted increased with the 1:10 ratio. In this relation, the variation coefficients increased. With Mehlich, no definite tendency was observed. The increase of extraction period for DTPA extractant, in 1:2 ratio, had little effect on the amount of zinc extracted and on the precision. As to Na 2EDTA extractant in 1:10 ratio, with the increase of extraction time, both increased. As to HCl and Mehlich, both in 1:4 ratio, the increase in extraction period had no effect on the amount of zinc extracted and no definite effect on the precision. Thus, the use of 1:2 ratio for DTPA and Na 2EDTA and 1:4 ratio for acid extractants is recommended. Concerning the period of extraction, 120 min should be used with DTPA and Na 2EDTA, 15 min with HCl and 5 min with Mehlich.

Níveis críticos de fósforo no solo e nas folhas para a implantação de Eucalyptus grandis Hill ex Maiden, em quatro tipos de solos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos de sistemas de preparo do solo no potencial matricial de um Latossolo Vermelho (Oxisol)

The present work aimed to investigate which was the soil tillage system that better fits for conditions of intensive agriculture, on the region of Selviria-MS. The main objective of this paper was to study the conservation and availability of water in the soil profile. In order to evaluate the soil matric potential in field conditions, readings were accomplished, using tensiometers with a mercury gauger. Matric potential was measured at 0.10 m depth, during the vegetative period of Triticum aestivum L. and at four depths 0.10; 0.20; 0.30 e 0.40 m during the vegetative period of Phaseolus vulgaris L. The study areas were located in the municipal district of Selviria, MS, Brazil. The used experimental set-up was entirely random designed, with treatments disposed in strips; three treatments and four repetitions were used. In the different treatments, soil matric potential was determined. Result allow to conclude that the water matric potential was highest for no-tillage and minimum tillage; however, it was also shown that these two tillage systems, allowed to conserve more water in the soil, when compared to the conventional tillage. In the last cycle of the Phaseolus vulgaris L. crop, no-tillage presented smaller storage of water in the soil, compared to the minimum tillage.

Isolamento de fungos produtores de ácido γ-linolênico de solo da Estação Ecologica de Juréia-Itatins, SP

Fungi producing γ-linolenic acid (GLA) were isolated from soil of the Ecological Station of Juréia-Itatins, SP. This essential fatty acid has aroused great interest due to its increasing by applications in pharmaceutical industry. The GLA production by zygomycetous fungi is an alternative way of comparing seed extraction. Thirty-two zygomycetous strains of Mucorales were isolated, most of them belonging to Mucor genus. The GLA production was evaluated after 4 days of incubation at 25°C on a rotary shaker at 150 rpm in medium containing 2% glucose, and 1% yeast extract, following new medium addition (20%) and incubation for an additional period of 3 days at 12°C, without agitation. The GLA production varied according to the microorganism and the strain.

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.

Efeitos do fósforo do solo no desenvolvimento inicial de Genipa americana L.

A greenhouse experiment was carried out to evaluate the effects of soil phosphorus in the development of plants of Genipa americana L. Five doses of P (0, 50, 100, 200, and 400 mg dm -3) were applied in pots with 10 dm 3 of three Neossolos Quartzarênicos (NQ 1, NQ 2 and NQ 3) and one Latossolo Vermelho (LV), that were used in an experiment with Eucalyptus plants during three months. After this period, the soils were analyzed and a 30 cm height seedling of G. americana was planted in each pot. The experiment design was completely randomized, in 5 × 4 factorial scheme, with five replications. The largest biomass of the stem was obtained with 45 mg dm -3 of P in the soil NQ 1 (9% of clay) and 59 mg dm -3 in the soil NQ 3 (14% of clay). In the LV (40% of clay), the biomass of the stem increased linearly in the band of 3 to 148 mg dm -3 of P. The phosphorus critical level in the soil for 80% of the steam and leaves dry matter production of G. americana at planting phase is 15 mg dm -3, using an anion-exchange resin as extractor.

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.

Retorno de nutrientes ao solo via deposição de serapilheira de quatro espécies leguminosas arbóreas na região de Botucatu - São Paulo, Brasil

The annual litter fall production and the concentrations of macronutrients of four leguminous tree species were evaluated. The experiment was installed in a distrophic red yellow latosol (Oxisol), derivative of the Bauru sandstone group. The studied species were: Leucaena leucocephala. Acacia melanoxylon, L. diversifolia and Mimosa scabrella. The experimental design was randomized blocks, with four treatments (species) and four replications. The litter fall was collected in boxes measuring 50×50×10 cm, two boxes by treatment in each block. The material was collected monthly and dried, weighed and chemically analyzed. The litter fall deposition occurred in the following order: M. scabrella (7,051 kg ha -1 ano -1), A. melanoxylon (2,789 kg ha -1 ano -1), L. diversifolia (1,576 kg ha -1 ano -1) and L. leucocephala (1,389 kg ha -1 ano -1). The content of nutrients obeyed the following order: N>Ca>K>Mg>P>S, with the exception of L. leucocephala that presented a bigger content of S in relation to the P.

Ação de pesticidas em Metarhizium anisopliae no solo

The present study aimed to analyze the action of some acaricides, fungicides, insecticides and herbicides containing different active ingredients on Metarhizium anisopliae Metsch. (Sorokin) inoculated into autoclaved soil. The action of the pesticides was evaluated based on the fungal respiratory activity. The first assessment was done at 48h after inoculation. The pesticides were then added and respiratory activity was determined nine times every 48h and an additional five times every 4 days. Except for the fungicides, no significant effect (P > 0.05) of the pesticides on M. anisopliae was observed. A reduction in CO2 production was observed for the mancozeb treatment from day 4 to day 6 of incubation, and for tebuconazol between days 4 and 6, 8 and 10, and 32 and 36. The same was observed for copper oxychloride between days 10 and 12 and 32 and 36, and for chlorothalonyl between 8 and 10, 10 and 12, and 32 and 36 days of incubation. Identical effect occurred for the acaricides abamectin and fenbutatin oxide, with a reduction in CO2 production between 20 and 24 days of incubation. The herbicides glyphosate, trifluralin and ametrin reduced the respiratory activity of the fungus between days 10 and 12, while the insecticide trichlorfon reduced respiratory activity only from 32 to 40 days of incubation. The results indicate that the toxic action of pesticides on the fungus in soil is small, suggesting that this pest control bioagent can be used in combination with pesticides without compromising its activity.

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.

Orientação geográfica de estufas de polietileno e potenciais de água no solo no cultivo do melão rendilhado híbrido 'nero'

This study aimed to verify the effects of four different minimum soil watler potentials (-30, -40, -50 e -70 kPa) and two different plastic tunnel positions (North-South and East-West) on net melon yield. The results showed that in the East-West position the yield and fruit weight were higher than in the North-South position. The highest yields of melon crop were obtained from -30 kPa. to -40 kPa minimum soil water potential.

Diagnóstico de uma área compactada por atividade minerária, na floresta amazônica, empregando métodos geoestatísticos à variável resistência mecânica à penetração do solo

A quite common problem in the recovery of degraded areas in the mineral exploration understands the compaction of the soil due to the intense traffic of machines and earth movement. The most common problem of the compaction of a degraded surface is: increase of the mechanical resistance to the penetration of the rooats, reduction of the aeration, alteration of the water flow and heat. Thus the present work had the basic objective of diagnosing the compaction of a degraded area by mining in a space way, through the mechanical resistance the way penetration to guide a future subsoiling in the place seeking recovery. Through the studies it was concluded that the kriging method in agreement with the space variation allows the division of the area studies in sub areas facilitating a future work to reduce cost and unnecessary interference to the atmosphere. The method was shown quite appropriate and it can be used in diagnosis of the compaction in a degraded area by mining, foreseeing subsoiling need.