NO2 emissions from agricultural burning in São Paulo, Brazil

We report here on the application of a compact ultraviolet spectrometer to measurement of NO2 emissions from sugar cane field burns in São Paulo, Brazil, the time-resolved NO2 emission from a 10 ha plot peaked at about 240 g (NO2) s(-1), and amounted to a total yield of approximately 50 kg of N, or about 0.5 g (N) m(-2). Emission of N as NOx (i.e., NO + NO2) was estimated at 2.5 g (N) in 2, equivalent to 30% of applied fertilizer nitrogen. The corresponding annual emission of NOx nitrogen from São Paulo State sugar cane burning was >45 Gg N. In contrast to mechanized harvesting, which does not require prior burning of the crop, manual harvesting with burning acts to recycle nitrogen into surface soils and ecosystems.

Municipal solid waste compost amendment in agricultural soil: changes in soil microbial biomass

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fractal dimension and anisotropy of soil CO2 emission in an agricultural field during fallow

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

Determination of Total Sulfur in Agricultural Samples by High-Resolution Continuum Source Flame Molecular Absorption Spectrometry

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

Fluctuations in Richness and Abundance of Social Wasps During the Dry and Wet Seasons in Three Phyto-Physiognomies at the Tropical Dry Forest of Brazil

The social wasp nests were quantified in three different plant physiognomies (forested Caatinga, shrubby Caatinga, and agricultural systems) to analyze the effect of environmental seasonality and plant physiognomy on the richness, nest abundance, and species composition of social wasps in the region of tropical dry forest of Brazil. The forested Caatinga physiognomy had the greatest richness of species (S = 16), followed by shrubby Caatinga (S 13) and by agricultural system (S = 12). The first axis of detrended correspondence analysis (DCA) explained 67.8% of the variability and shows a gradient of the fauna from agricultural system and shrubby Caatinga to forested Caatinga. In the first axis, wet season scores were much higher than those for the dry season in forested Caatinga. The second axis explained 18.7% of the variability and shows a separation of samples collected during the wet or the dry periods in shrubby Caatinga. This separation was less evident in the agricultural system. Variations in nest abundance were more intense in arbustive caatinga (45% decrease in number of active nests in the dry period), moderate in forested Caatinga (24% decrease in number of active nests in the dry period), and low in agricultural systems (8% decrease in the dry period).

Assessment of Cerdocyon thous distribution in an agricultural mosaic, southeastern Brazil

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

Influence of terrestrial habitat isolation on the diversity and temporal distribution of anurans in an agricultural landscape

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

Effects of research and extension on agricultural growth and equity in Brazil.

Studies the effects of investment in research and extension on total agricultural production and on production of individual crops. Some distributional effects are briefly discussed. Due to the lack of data, the first part of the analysis is restricted to the State of Sao Paulo, and the second part covers the entire country.-from Author

The distribution of agricultural land and the question of agrarian reform in Brazil

Agrarian reform has long been an acute issue in Brazil, where the distribution of cultivable land is extremely unequal. The Land Statute adopted by the military in 1964 constituted a genuine reform programme, which, however, was never implemented as the government chose to modernize agriculture and expand cultivated areas. This has prevented the poorest from having access to the land.-from English summary

Comportamento espacial da cultura canavieira no Estado de Sao Paulo, 1980

Data from the agricultural and Cattle Raising Census for 1980 show that most of the sugar cane producing counties lie in the administrative regions of Campinas, Ribeirao Preto and Sao Jose do Rio Preto. A comparison with the 1975 data shows two important facts; 1) an increase of the cultivated area in 118 counties and 2) an increase in the number of counties with area under sugar cane. There was also an expansion in the sub-regions of Catanduva, Assis and Ourinhos. Nevertheless, Piracicaba, Araraquara, Ribeirao Preto, Jaboticabal and Jau, have continued to be important sugar cane producing nuclei in the State since 1960. -from English summary

Little cicada of sugarcane Mahanarva posticata (Homoptera: Cercopidae). A Brazilian agricultural pest. Morpho-histological study of salivary glands

Little cicadas are homopteran insect pests of sugarcane plantations. As these insects suck out the sap from the leaf parenchyma, they inoculate a toxic saliva that damages the plant vessels, thus promoting the loss of glucose by the affected plant. The morphological and histological analyses of the salivary glands of the little cicada Mahanarva posticata, revealed that these glands are formed by 2 portions: one portion comprises a group of acini and has been denominated as the principal gland; the second portion is filamentous in nature and has been denominated as the accessory gland; it is formed by very long and fine filaments. The acinous portion of the gland can be subdivided into 2 lobes: an anterior lobe formed by 3 lobules (I, II, III), and a posterior lobe formed by lobule IV and the excretory duct. Histologically, the salivary glands showed that the filaments are empty sutructures composed by several internal channels with secretion granules being observed in the cytoplasm of the cells of the secretory filaments. Lobules I and II of the principal gland are characterized by being highly basophilic and for accumulating a large amount of secretion in both the cytoplasm of the cells and inside secretion vesicles. Histochemically, we verified that the secretion produced by these glands is lipidic and protein in nature, with the production of polysaccharides being very low. The differences in stain and appearance of the different regions of the salivary gland lead us to believe that the final glandular product is lipoproteic in nature.

Assessment of anaerobic sewage sludge quality for agricultural application after metal bioleaching

The effects of metal bioleaching on nutrient solubilization, especially nitrogen and phosphorous, from anaerobically-digested sewage sludge were investigated in this work. The assessment of the sanitary quality of the anaerobic sludge after bioleaching was also carried out by enumerating indicator (total coliforms, fecal coliforms, and fecal streptococci) and total heterotrophic bacteria. The experiments of bioleaching were performed using indigenous sulphur-oxidizing bacteria (Thiobacillus spp.) as inoculum and samples of anaerobically-digested sludge. Nitrogen and phosphorous solubilization from sewage sludge was assessed by measuring, respectively, the concentration of Total Kjeldahl Nitrogen, ammonia, nitrate/nitrite, and soluble and total phosphorous before and after the bioleaching assays. At the end of the experiment, after 4 days of incubation (final pH of 1.4), the following metal solubilization yields were obtained: zinc, 91%; nickel, 87%; copper, 79%; lead, 52%; and chromium, 42%. As a result of sludge acidification, the viable counts of selected indicator bacteria were decreased to below the detection limit (4 × 103 cfu 100 ml-1), followed by an increase in the mineral fraction of nitrogen (from 6 to 10%) and in the soluble fraction of phosphorous (from 15 to 30%). Although some loss of sludge nutrients can occur during solid-liquid separation following bioleaching, its beneficial effects as metal removal and reduction of pathogenic bacteria are sufficient to consider the potential of this treatment before sludge disposal onto agricultural fields.

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.

Water table effects on bean yield and nitrate distribution in the soil profile

In order to evaluate the bean yield under different water table levels as well as the moisture and nitrate distribution in the soil profile, a field experiment was carried out in the experimental area of the College of Agricultural Sciences - UNESP, Botucatu, SP, Brazil. Beans were grown in field lysimeters under five water table depths: 30; 40; 50; 60 and 70 cm. The moisture in the soil profile was determined gravimetrically using samples collected at 10; 20; 30; 40; 50; 60 and 70 cm deep. The water table depths of 30cm and 40cm showed the highest productivities (3,228.4kg.ha-1 and 3,422.1kg.ha-1, respectively), with no statistical differences between them. The highest productivity was related to the two highest water table levels (30 and 40cm), which provided the highest moisture average values on the basis of volume in the soil profile (33.3 e 31%) as well as the consumptive use of water (416 and 396mm). The nitrate content during the bean cycle at the extraction depth of 60cm was below the safe drinking limit of 10mg.1-1 for water table depths of 30; 40; 50 and 60cm, which shows the denitrification efficiency as a way of controlling nitrate pollution in water tables. The management of water table can lead to high levels of bean yield and to a better control of nitrate pollution in underground water.