Sewage sludge application to agricultural land as soil physical conditioner

Water resource quality is a concern of today's society and, as a consequence, low pollutant wastewaters and sludges are being increasingly treated, resulting in continuous production of sewage sludge. Sewage sludge (SS) can be used as soil physical conditioner of agricultural or degraded lands, due to its organic C component. The objective of this research was to evaluate the long-term SS effects on soil physical quality of properties such as bulk density, porosity, permeability and water retention of degraded soils treated with annual SS applications. The SS rates were calculated according to the crop N demand. The field experiment consisted of three treatments: mineral fertilization, 10 and 20 Mg ha-1 of SS (once and twice the SS quantity to meet the maize N demand, respectively), in annual applications to the surface layer of a eutroferric Red Latosol. SS reduced bulk density, increased macroporosity and decreased microporosity after the third application, but did not significantly alter the soil permeability and physical quality as measured by the S index in the surface layer.

Atlantic Forest succession over calcareous soil, Parque Estadual Turístico do Alto Ribeira - PETAR, SP

The forest succession after abandonment of slash-and-burn agriculture over calcareous soil in Brazilian Atlantic Forest was assessed. This is one of the world's most threatened Biome, with only 8% remaining. The study area is located over calcareous soil inside the Alto Ribeira Touristic State Park (PETAR), southeast Brazil. The phytossociological survey showed a successional pattern dominated by species of Leguminosae, especially Piptadenia gonoacantha (Mart.) J.F. Macbr. This species occurs in calcareous soils as a substitute of Tibouchina pulchra (Cham.) Cogn. (Melastomataceae) that is the most usual dominant tree species in early succession over acidic soil, which is the most common situation in this Biome. These results are important for a better understanding of Neotropical forest biodiversity and characterize a unique genetic bank in this highly endangered Biome. They are also decisive to support actions regarding rehabilitation of degraded lands and a potential tool for Neotropical forest sustainable management, both inside and around the conservation unit.

Leaf micronutrient concentrations and potential photosynthesis in Ochroma pyramidale established in a degraded land

In the Brazilian Amazon, large areas of abandoned lands may revert to secondary forest. In the process, pioneer tree species have an important role to restore productivity in old fields and improve environmental conditions. To determine potential photosynthesis (Apot), stomatal conductance (g), transpiration (E), and leaf micronutrient concentrations in Ochroma pyramidale (Cav. ex Lam.) Urban a study was carried out in the Brazilian Amazon (01o 51' S; 60o 04' W). Photosynthetic parameters were measured at increasing [CO2], saturating light intensity (1 mmol (photons) m-2 s-1), and ambient temperature. The rate of electron-transport (J), Apot,and water-use efficiency (WUE) increased consistently at increasing internal CO2 concentration (Ci). Conversely, increasing [CO2] decreased gs, E, and photorespiration (Pr). At the CO2-saturated region of the CO2 response curve (1.1 mmol (CO2) mol-1(air), J was 120 μmol (e-) m-2s-1 and Apot reached up to 24 μmol (CO2) m-2s-1. Likewise, at saturating C1 g and E were 30 and 1.4 mmol (H2O) m-2s-1, respectively, and P 2 r about 1.5 μmol (CO2) m-2s-1. Foliar nutrients were 185, 134, 50, and 10 μmol (element) m-2 (leaf area) for Fe, Mn, Zn, and Cu, respectively. It was concluded that [CO ] probably limits light saturated photosynthesis in this site. Furthermore, from a nutritional point of view, the low Fe to Cu ratio (15:1) may reflect nutritional imbalance in O. pyramidale at this site.

Biologia do bicho do cesto Oiketicus kirbyi (Lands.-Guilding, 1827) (Lepidoptera, Psychidae) em folhas de Eucalyptus spp

O bicho do cesto, Oiketicus kirbyi (Lands.-Guilding, 1827), inseto extremamente polífago, é praga de várias culturas de importância econômica, principalmente na região sul do Brasil. Sua ocorrência em áreas reflorestadas com eucalipto é freqüente, embora não tenha causado, ainda, danos econômicos de monta. Este trabalho trata da biologia deste inseto em folhas de Eucalyptus spp., com a finalidade de trazer subsídios para o caso de eventuais surtos de O. kirbyi em florestas implantadas. O bicho do cesto foi criado em laboratório em temperatura de 25±3°C, umidade relativa de 70± 10% e fotofase de 13 h. Os seguintes valores médios foram obtidos: período embrionário de 43,1 dias, período larval de 140 dias (machos) e 151 dias (fêmeas), período pupal de 38,2 dias (machos), longevidade dos adultos de 3,0 dias (machos) e 3,9 dias (fêmeas) e período de oviposição 2,1 dias. Foram determinadas, também, as dimensões de ovos, pupas, adultos e das cápsulas cefálicas, o número de ínstares larvais, período de cópula, além da estimativa do dano foliar.

Recovery of degraded pasture in Rondônia: macronutrients and productivity of brachiaria brizantha

Pasture is the main form of land use in Amazonia. Over time the pasture grass loses vigor and yields decrease, indicating a certain degree of degeneration. The main causes of degradation are lack of pasture maintenance and subsequent weed infestation, the choice of regionally unsuitable forage species and excessive grazing. The main purpose of this study was to evaluate the impact of different recovery managements on soil chemical properties and grass yield of a degraded pasture in Rondônia. For this purpose, an experiment was installed in October 2001, consisting of five treatments: C = control; HA = harrowing + NPK + micronutrients; HE = Herbicide + NK + micronutrients; R = No-tillage rice + NPK + micronutrients; and S = No-tillage soybean + PK + micronutrients. The following N, P and K sources were used: ammonium sulfate for N, calcined phosphate for P and potassium chloride for K. The experiment was arranged in a randomized block design with four replications. The shoot dry matter yield of the grass was analyzed as of the 35th month of experimentation, in a dry and a rainy period. Phosphorus fertilization resulted in significant increases in Ca2+ and Mg2+ and increasing trend of P in the topsoil in the initial months of the experiment in treatments HA and S and increases in Ca2+ and P (trend) in the treatment R. The cumulative production of Brachiaria brizantha, from Sep/2004 to Mar/2005, was 30,025, 28,267 and 27,735 kg ha-1 shoot dry matter in the treatments HA, R and S, respectively. These values differed significantly from treatments C and HE, with 17,040 and 17,057 kg ha-1, respectively. It was concluded that phosphorus fertilization associated to pasture reform was effective to raise the dry matter yield of Brachiaria brizantha. Rice or soybean under no-tillage is recommended as a practice of pasture recovery, due to the residual effect of fertilization.

Inter-relation between soybean yield and soil compaction under degraded pasture in Brazilian Savannah

The Cerrado (Brazilian Savannah) plays an important economic and financial role in the nation, since the pastures of this biome feed cattle for half of the domestic bovine meat productivity, and its agricultural fields produce a third of the country's grain. The variability and spatial dependence between the soil physical attributes and soybean yield were evaluated in a crop rotation planted on a degraded brachiaria pasture, on a dystroferric Red Latosol of an experimental farm of the State University of São Paulo (UNESP), in the 2005/2006 growing season. The linear and spatial correlations between these attributes were also studied, to determine conditions that would allow increased agricultural productivity. In the above pasture area, a grid was installed with 124 plots, spaced 10.0 x 10.0 m and 5.0 x 5.0 m apart, in a total area of 7,500 m². From the linear and spatial point of view, the high grain yield can be explained by the number of grains per plant and soil macroporosity. The high variability observed for most soil properties indicated that the crop - livestock integration system results in environmental heterogeneity of the soil.

Runoff and sediment transport in a degraded area

Gully erosion occurs by the combined action of splash, sheetwash and rill-wash (interrill and rill erosion). These erosion processes have a great capacity for both sediment production and sediment transport. The objectives of this experiment were to evaluate hydrological and sediment transport in a degraded area, severely dissected by gullies; to assess the hydraulic flow characteristics and their aggregate transport capacity; and to measure the initial splash erosion rate. In the study area in Guarapuava, State of Paraná, Brazil (lat 25º 24' S; long 51º24' W; 1034 m asl), the soil was classified as Cambissolo Húmico alumínico, with the following particle-size composition: sand 0.116 kg kg-1; silt 0.180 kg kg-1; and clay 0.704 kg kg-1. The approach of this research was based on microcatchments formed in the ground, to study the hydrological response and sediment transport. A total of eight rill systems were simulated with dry and wet soil. An average rainfall of 33.7 ± 4.0 mm was produced for 35 to 54 min by a rainfall simulator. The equipment was installed, and a trough was placed at the end of the rill to collect sediments and water. During the simulation, the following variables were measured: time to runoff, time to ponding, time of recession, flow velocity, depth, ratio of the initial splash and grain size. The rainsplash of dry topsoil was more than twice as high as under moist conditions (5 g m-2 min-1 and 2 g m-2 min-1, respectively). The characteristics of the flow hydraulics indicate transition from laminar to turbulent flow [Re (Reynolds number) 1000-2000]. In addition, it was observed that a flow velocity of 0.12 m s-1 was the threshold for turbulent flow (Re > 2000), especially at the end of the rainfall simulation. The rill flow tended to be subcritical [Fr (Froude Number) < 1.0]. The variation in hydrological attributes (infiltration and runoff) was lower, while the sediment yield was variable. The erosion in the rill systems was characterized as limited transport, although the degraded area generated an average of 394 g m-2 of sediment in each simulation.

RECOVERY OF AN OXISOL DEGRADED BY THE CONSTRUCTION OF A HYDROELECTRIC POWER PLANT

ABSTRACT The removal of thick layers of soil under native scrubland (Cerrado) on the right bank of the Paraná River in Selvíria (State of Mato Grosso do Sul, Brazil) for construction of the Ilha Solteira Hydroelectric Power Plant caused environmental damage, affecting the revegetation process of the stripped soil. Over the years, various kinds of land use and management systems have been tried, and the aim of this study was to assess the effects of these attempts to restore the structural quality of the soil. The experiment was conducted considering five treatments and thirty replications. The following treatments were applied: stripped soil without anthropic intervention and total absence of plant cover; stripped soil treated with sewage sludge and planted to eucalyptus and grass a year ago; stripped soil developing natural secondary vegetation (capoeira) since 1969; pastureland since 1978, replacing the native vegetation; and soil under native vegetation (Cerrado). In the 0.00-0.20 m layer, the soil was chemically characterized for each experimental treatment. A 30-point sampling grid was used to assess soil porosity and bulk density, and to assess aggregate stability in terms of mean weight diameter (MWD) and geometric mean diameter (GMD). Aggregate stability was also determined using simulated rainfall. The results show that using sewage sludge incorporated with a rotary hoe improved the chemical fertility of the soil and produced more uniform soil pore size distribution. Leaving the land to develop secondary vegetation or turning it over to pastureland produced an intermediate level of structural soil quality, and these two treatments produced similar results. Stripped soil without anthropic intervention was of the lowest quality, with the lowest values for cation exchange capacity (CEC) and macroporosity, as well as the highest values of soil bulk density and percentage of aggregates with diameter size <0.50 mm, corroborated by its lower organic matter content. However, the percentage of larger aggregates was higher in the native vegetation treatment, which boosted MWD and GMD values. Therefore, assessment of some land use and management systems show that even decades after their implementation to mitigate the degenerative effects resulting from the installation of the Hydroelectric Plant, more efficient approaches are still required to recover the structural quality of the soil.

Native species indicated for degraded area recovery in Western Paraná, Brazil

Colonization in the State of Paraná has culminated in the devastation of large forest areas in the entire State. Degraded area recovery programs have emphasized the utilization of native species, but often the species indicated for local reforestation areas are unknown, as those areas are little known floristically. This study aimed to survey native species indicated for reforestation of areas in the Western region of the State of Paraná, classify those species as pioneer, secondary, or climactic, and indicate places of occurrence of matrices where seeds of those species could be collected. Bibliographic surveys in the specialized literature and research in the Herbarium Museu Botânico Municipal de Curitiba (MBM) and Herbarium of Universidade Estadual do Oeste do Paraná (UNOP) were conducted to identify potential species for degraded area recovery in the study of Western region of Paraná. In all, 115 species were selected, of which 22 are pioneer, 73 are secondary, and 20 are climactic. The bibliographic surveys suggests that pioneer species are the most indicated for the initial processes in the degraded areas recovery, while secondary and climactic species play a major role in area enrichment.

Recycling of nutrients with application of organic waste in degraded pasture

The utilization of organic wastes represents an alternative to recover degraded pasture. The experiment aimed to assess the changes caused by the provision of different organic waste (poultry litter, turkey litter and pig manure) in a medium-textured Oxisol in Brazilian Savanna under degraded pasture. It was applied different doses of waste compared to the use of mineral fertilizers and organic mineral and evaluated the effect on soil parameters (pH, organic matter, phosphorus and potassium) and leaf of Brachiariadecumbens (crude protein, phosphorus and dry mass production). It was observed that application of organic waste did not increase the level of soil organic matter and pH in the surface layer, and the application of turkey litter caused acidification at depths of 0.20-0.40 m and 0.40-0.60 m. There was an increase in P and K in the soil with the application of poultry litter and swine manure. All organic wastes increased the productivity of dry matter and crude protein and phosphorus. The recycling of nutrients via the application of organic waste allows efficiency of most parameters similar to those observed with the use of mineral sources, contributing to improving the nutritional status of soil-plantsystem.

First record of Anopheles (Anopheles) costai Fonseca & Ramos, 1939 in Espírito Santo State, Brazil

Field collections of immatures and adults of Culicidae were carried out in the Rio Doce Valley, Espírito Santo State, aiming to increase knowledge on the anopheline species of that region. Considering all Culicidae species collected, among other anopheline it is noteworthy the presence of Anopheles darlingi, An. oswaldoi and An. costai. Regarding to An. darlingi, responsible for malaria outbreak in the low lands in that state, it was expected to confirm its presence in the area. The register of specimens of An. costai in the field collections is relevant, increasing the geographical distribution of the species and representing better knowledge of the Series Arribalzagia of the subgenus Anopheles.

Amazon landforms and soils in relation to biological diversity

Thirteen main landform units are distinguished for the whole of the forested Amazon region, each with its specific soil pattern and vegetation structure. These landform-soil-vegetation units are delineated on a small-scale map and illustrated by a schematic cross-section. Floristic diversity of the gamma type is to be highest on the steepland-and-valley complexes of the Andean fringe, on the crystalline shield uplands, on the inselberg complexes, and on the eutric variant of the western sedimentary plains. Endemism is expected to be highest on the sandy plains, and parts of the table lands and inselberg complexes. Speciation, linked to the concept of forest refuge areas, is likely to be highest on the sandstone table lands, on the stretches of Amazon planalto, and in the areas of relict valleys, in view of the prolonged geomorphological stability of these units.

Diversity of the land resources in the Amazonian State of Rondônia, Brazil

Conflicting opinions are recorded in the literature concerning the suitability of Amazon lands for sustainable agriculture following deforestation. This article has been written to shed light on this question by summarizing climate, landform, soil and vegetation features from the findings of a land resource study of the Brazilian state of Rondônia in south-west Amazonia. The work, which followed the World Soils and Terrain Digital Database (SOTER) methodology, was financed by the World Bank. During the course of the survey special emphasis was given to studying soils; 2914 profiles were analyzed and recorded. The study identified a complex pattern of land units with clear differences in climate, landform, soils and native vegetation. Forested areas mosaic with lesser areas of natural savannas. The latter occur on both poorly-drained and well-drained, albeit nutrient deficient sandy soils. The tallest and most vigorous forests or their remnants were seen growing on well-drained soils formed from nutrient-rich parent materials. Many of these soils could, or are being used for productive agriculture. Soils developed on nutrient-poor parent materials support forests that are significantly lower in height, and would require large lime and fertilizer inputs for agriculture. Low forests with high palm populations and minor areas of wet land savannas cover the poorly drained soils. It is evident that forest clearing in the past was indiscriminant; this cannot be condoned. The diversity of land conditions found throughout Rondônia would suggest that many past studies in the Amazon have simply been too broad to identify significant soil differences.

Protected environments and substrates for production of genipap seedlings

Genipap (Genipa americana L., Rubiaceae ) is a native Brazilian species and can be used in the recovery of degraded forest areas or for food supply. In order for the species to reach its potential, production of high quality seedlings is essential. The objective of this study was to evaluate genipap seedlings in protected environments and different substrates. The environments tested were: (1) a greenhouse with polyethylene film in the top, with aluminized screen (Aliminet®) of 50%-shading under this film, and lateral sides covered with 50%-shading nylon net (Sombrite®), (2) a shaded hut, all sides covered with 50%-shading nylon net (Sombrite®), and (3) a nursery shelter, with all lateral sides uncovered and the roof covered with leaves of buriti (Mauritia flexuosa). In these environments the following substrates were tested: 50% cattle manure + 50% cassava foliage, 50% cattle manure + 50% Vida Verde®, 50% cattle manure + 50% vermiculite, and 25% cattle manure + 25% vermiculite + 25% of cassava foliage + 25% Vida Verde®. Because there was no repetition of the growth environment, the effect of environment was examined using statistical procedures for analysis of combined experiments. Within environments a completely randomized design was used with five replications. All substrates are suitable for the formation of genipap seedlings, where the recommended substrates are: 50% cattle manure + 50% cassava foliage and 50% cattle manure + 50% Vida Verde® for the greenhouse and the substrates composed of 50% cattle manure + 50% vermiculite and 25% cattle manure + 25% cassava foliage + 25% Vida Verde®+ 25% vermiculite for the shaded hut. The buriti shelter is not recommended for production of genipap seedlings.

Ecologia da ictiofauna de um córrego de cabeceira da bacia do alto rio Paraná, Brasil

Ecological studies were conducted in the ichthyofauna of Cedro, a small headwater stream located in a degraded area of State of São Paulo, Brazil, situated in the upper Paraná River basin. These are the results of two non-consecutive years observations and collections in two biotopes of that stream: a pool and a rapid. The ecological characteristics studied change in space and time. The present richness of species is high (21 species), nine of which are constant, six accessory and six accidental. The diversity is low (0.69 to 2.38), and the numeric predominance, from one to three species, occurred in both biotopes. The most frequent species are Poecilia reticulata (Peters, 1859) (28.1%), Corydoras cf. aeneus (Gill, 1858) (20.3%) and Hypostomus cf. ancistroides (Ihering, 1911) (19.8%). The density ranges from 0.7 to 19.8 specimens/m³. The similarity index indicates high similarity between the ichthyofauna (45.0% to 95.0%) inside the same or contiguous biotopes. The evenness (0.46 to 1.0) is comparable to those found in similar studies carried out in other streams.