Governance, agricultural intensification and land sparing in tropical South America

In this paper we address two topical questions: How do the quality of governance and agricultural intensification impact on spatial expansion of agriculture? Which aspects of governance are more likely to ensure that agricultural intensification allows sparing land for nature? Using data from the Food and Agriculture Organization, the World Bank, the World Database on Protected Areas, and the Yale Center for Environmental Law and Policy, we estimate a panel data model for six South American countries and quantify the effects of major determinants of agricultural land expansion, including various dimensions of governance, over the period 1970–2006. The results indicate that the effect of agricultural intensification on agricultural expansion is conditional on the quality and type of governance. When considering conventional aspects of governance, agricultural intensification leads to an expansion of agricultural area when governance scores are high. When looking specifically at environmental aspects of governance, intensification leads to a spatial contraction of agriculture when governance scores are high, signaling a sustainable intensification process.

Contribution of insect pollinators to crop yield and quality varies with agricultural intensification

Background: Up to 75% of crop species benefit at least to some degree from animal pollination for fruit or seed set and yield. However, basic information on the level of pollinator dependence and pollinator contribution to yield is lacking for many crops. Even less is known about how insect pollination affects crop quality. Given that habitat loss and agricultural intensification are known to decrease pollinator richness and abundance, there is a need to assess the consequences for different components of crop production. Methods: We used pollination exclusion on flowers or inflorescences on a whole plant basis to assess the contribution of insect pollination to crop yield and quality in four flowering crops (spring oilseed rape, field bean, strawberry, and buckwheat) located in four regions of Europe. For each crop, we recorded abundance and species richness of flower visiting insects in ten fields located along a gradient fromsimple to heterogeneous landscapes. Results: Insect pollination enhanced average crop yield between 18 and 71% depending on the crop. Yield quality was also enhanced in most crops. For instance, oilseed rape had higher oil and lower chlorophyll contents when adequately pollinated, the proportion of empty seeds decreased in buckwheat, and strawberries’ commercial grade improved; however, we did not find higher nitrogen content in open pollinated field beans. Complex landscapes had a higher overall species richness of wild pollinators across crops, but visitation rates were only higher in complex landscapes for some crops. On the contrary, the overall yield was consistently enhanced by higher visitation rates, but not by higher pollinator richness. Discussion. For the four crops in this study, there is clear benefit delivered by pollinators on yield quantity and/or quality, but it is not maximized under current agricultural intensification. Honeybees, the most abundant pollinator, might partially compensate the loss of wild pollinators in some areas, but our results suggest the need of landscape-scale actions to enhance wild pollinator populations.

Geranylation of benzoic acid derivatives by enzymatic extracts from Piper crassinervium (Piperaceae)

The ability to carry out geranylations on aromatic substrates using enzymatic extracts from the leaves of Piper crassinervium (Piperaceae) was evaluated. A literature analysis pointed out its importance as a source of prenylated bioactive molecules. The screening performed on aromatic acceptors (benzoic acids, phenols and phenylpropanoids) including geranyl diphosphate as prenyl donor, showed the biotransformation of the 3,4-dihydroxybenzoic acid by the crude extract, and the p-hydroxybenzoic acid by both the microsomal fraction and the crude extract, after treating leaves with glucose. The analysis of the products allowed the identification of C- and O-geranylated derivatives, and the protease (subtilisin and pepsin) inhibition performed on the O-geranylated compounds showed weak inhibition. Electrophoretic profiles indicated the presence of bands/spots among 56-58 kDa and pI 6-7, which are compatible with prenyltransferases. These findings show that P. crassinervium could be considered as a source of extracts with geranyltransferase activity to perform biotransformations on aromatic substrates. (C) 2010 Elsevier Ltd. All rights reserved.

Development of a heavy metal sorption system through the P=S functionalization of coconut (Cocos nucifera) fibers

Lignocellulosic residues are interesting materials for the production of heavy metal adsorbents for aquatic systems. Whole fibers taken from coconut (Cocos nucifera) husks were functionalized with the thiophosphoryl (P=S) group by means of the direct reaction with CI(3)P=S, (CH(3)O)(2)CIP=S or (CH(3)CH(2)O)(2)CIP=S in order to obtain an adsorptive system for `soft` metal ions, particularly Cd(2+). These functionalized fibers (FFs) were characterized by means of elemental analysis, infrared spectroscopy, thermal analysis and acid-base titration. Adsorption isotherms for Cd(2+) fitted the Langmuir model, with binding capacities of 0.2-5 mmol g(-1) of FF at 25 degrees C. (C) 2009 Elsevier Ltd. All rights reserved.

Extraction of cellulose whiskers from cassava bagasse and their applications as reinforcing agent in natural rubber

In this work cassava bagasse, a by-product of cassava starch industrialization was investigated as a new raw material to extract cellulose whiskers. This by-product is basically constituted of cellulose fibers (17.5 wt%) and residual starch (82 wt%). Therefore, this residue contains both natural fibers and a considerable quantity of starch and this composition suggests the possibility of using cassava bagasse to prepare both starch nanocrystals and cellulose whiskers. In this way, the preparation of cellulose whiskers was investigated employing conditions of sulfuric acid hydrolysis treatment found in the literature. The ensuing materials were characterized by transmission electron microscopy (TEM) and X-ray diffraction experiments. The results showed that high aspect ratio cellulose whiskers were successfully obtained. The reinforcing capability of cellulose whiskers extracted from cassava bagasse was investigated using natural rubber as matrix. High mechanical properties were observed from dynamic mechanical analysis. (C) 2010 Elsevier B.V. All rights reserved.

Phenolic matrices and sisal fibers modified with hydroxy terminated polybutadiene rubber: Impact strength, water absorption, and morphological aspects of thermosets and composites

The aim of the present work was to investigate the toughening of phenolic thermoset and its composites reinforced with sisal fibers, using hydroxyl-terminated polybutadiene rubber (HTPB) as both impact modifier and coupling agent. Substantial increase in the impact strength of the thermoset was achieved by the addition 10% of HTPB. Scanning electron microscopy (SEM) images of the material with 15% HTPB content revealed the formation of some rubber aggregates that reduced the efficiency of the toughening mechanism. In composites, the toughening effect was observed only when 2.5% of HTPB was added. The rubber aggregates were found located mainly at the matrix-fiber interface suggesting that HTPB could be used as coupling agent between the sisal fibers and the phenolic matrix. A composite reinforced with sisal fibers pre-impregnated with HTPB was then prepared; its SEM images showed the formation of a thin coating of HTPB on the surface of the fibers. The ability of HTBP as coupling agent between sisal fibers and phenolic matrix was then investigated by preparing a composite reinforced with sisal fibers pre-treated with HTPB. As revealed by its SEM images, the HTPB pre-treatment of the fibers resulted on the formation of a thin coating of HTPB on the surface of the fibers, which provided better compatibility between the fibers and the matrix at their interface, resulting in a material with low water absorption capacity and no loss of impact strength. (C) 2009 Elsevier B.V. All rights reserved.

Characterization of banana, sugarcane bagasse and sponge gourd fibers of Brazil

In recent times, increasing attention has been paid to the use of renewable resources particularly of plant origin keeping in view the ecological concerns, renewability and many governments passing laws for the use of such materials. On the other hand, despite abundant availability of lignocellulosic materials in Brazil, very few attempts have been made about their utilization, probably due to lack of sufficient structure/property data. Systematic studies to know their properties and morphology may bridge this gap while leading to value addition to these natural materials. Chemical composition, X-ray powder diffraction, and morphological studies and thermal behavior aspects in respect of banana, sugarcane bagasse sponge gourd fibers of Brazilian origin are presented. Chemical compositions of the three fibers are found to be different than those reported earlier. X-ray diffraction patterns of these three fibers exhibit mainly cellulose type I structure with the crystallinity indices of 39%, 48% and 50% respectively for these fibers. Morphological studies of the fibers revealed different sizes and arrangement of cells. Thermal stability of all the fibers is found to be around 200 degrees C. Decomposition of both cellulose and hemicelluloses in the fibers takes place at 300 degrees C and above, while the degradation of fibers takes place above 400 degrees C. These data may help finding new uses for these fibers. (C) 2009 Elsevier B.V. All rights reserved.

Optimization of fibrolytic enzyme production by Aspergillus japonicus C03 with potential application in ruminant feed and their effects on tropical forages hydrolysis

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

Design and management optimization of trickle irrigation systems using non-linear programming

A non-linear model is presented which optimizes the lay-out, as well as the design and management of trickle irrigation systems, to achieve maximum net benefit. The model consists of an objective function that maximizes profit at the farm level, subject to appropriate geometric and hydraulic constraints. It can be applied to rectangular shaped fields, with uniform or zero slope. The software used is the Gams-Minos package. The basic inputs are the crop-water-production function, the cost function and cost of system components, and design variables. The main outputs are the annual net benefit and pipe diameters and lengths. To illustrate the capability of the model, a sensitivity analysis of the annual net benefit for a citrus field is evaluated with respect to irrigated area, ground slope, micro-sprinkler discharge and shape of the field. The sensitivity analysis suggests that the greatest benefit is obtained with the smallest microsprinkler discharge, the greatest area, a square field and zero ground slope. The costs of the investment and energy are the components of the objective function that had the greatest effect in the 120 situations evaluated. (C) 1996 Academic Press Limited

Evidence of thermostable amylolytic activity from Rhizopus microsporus var. rhizopodiformis using wheat bran and corncob as alternative carbon source

Rhizopus microsporus var. rhizopodiformis produced high levels of alpha-amylase and glucoamylase under solid state fermentation, with several agricultural residues, such as wheat bran, cassava flour, sugar cane bagasse, rice straw, corncob and crushed corncob as carbon sources. These materials were humidified with distilled water, tap water, or saline solutions-Segato Rizzatti (SR), Khanna or Vogel. The best substrate for amylase production was wheat bran with SR saline solution (1:2 v/v). Amylolytic activity was still improved (14.3%) with a mixture of wheat bran, corncob, starch and SR saline solution (1:1:0.3:4.6 w/w/w/v). The optimized culture conditions were initial pH 5, at 45 degrees C during 6 days and relative humidity around 76%. The crude extract exhibited temperature and pH optima around 65 degrees C and 4-5, respectively. Amylase activity was fully stable for 1 h at temperatures up to 75 degrees C, and at pH values between 2.5 and 7.5.

Effects of atrazine on female Wistar rats: Morphological alterations in ovarian follicles and immunocytochemical labeling of 90 kDa heat shock protein

Fertility in female mammals may be affected by a variety of endocrine disrupters present in the environment. Herbicide atrazine is an example of endocrine disrupter employed in agriculture, which disrupts estrous cyclicity in rats. Aiming to characterize morphologically the effect of low and sublethal doses of atrazine on the ovaries of Wistar rats, in an effort to determine the possible intrafollicular target site through which this herbicide acts adult females were submitted to both subacute and subchronic treatments. Additionally, immunocytochemical labeling of 90 kDa heat shock protein (HSP90) was performed in order to evaluate the role played by this protein in the ovary, under stressed conditions induced by herbicide exposure. The results indicated that atrazine induced impaired folliculogenesis, increased follicular atresia and HSP90 depletion in female rats submitted to subacute treatment, while the subchronic treatment with low dose of atrazine could compromise the reproductive capacity reflected by the presence of multioocytic follicle and stress-inducible HSP90. © 2007 Elsevier Ltd. All rights reserved.

Seedling growth of Schizolobium parahyba on different substrates and irrigation levels

The present study aimed to assess the behavior of seedlings of Schizolobium parahyba (Vell.) Blake growing on different substrates and irrigation levels, and to study the use of urban waste compost in substrates. The experiment was carried out in the College of Agricultural Sciences, Universidade Estadual Paulista (UNESP), Department of Agricultural Engineering, Jaboticabal Campus, state of São Paulo, Brazil. The experimental design used was completely randomized, consisting of 30 treatments in a factorial design with 15 substrates and two irrigation levels in four replicates. The substrates were composed of different materials: urban waste, Plantmax®, dry cattle manure, vermiculite and soil. For the study of seedling growth, the following characteristics were evaluated: height (H), root-collar diameter (D), number of leaves, shoot dry weight, root dry weight, total dry weight, H/D ratio, Dickson's quality index, and the ratio between height and shoot dry weight (H/SDW). Assessments of the first three characteristics were carried out 20, 35, 50 and 65 days after sowing. Results showed that urban waste compost increased the growth of Schizolobium parahyba. There were significant differences for the irrigation levels tested; with better results for 150% ET compared to 100% ET irrigation level.

Infrastructure, transport and production development in an agricultural region: a case in Argentina.

The development of the agricultural area in central and northern Argentina was analysed in a recent ECLAC study. More than 80% by volume of the country's agricultural exports pass through the ports in this area. Exports by the agroindustrial complex account for 58% of the total value of Argentine sales.It is known that investments in infrastructure generally help to reduce the costs of enterprises and to enhance productivity. The main idea presented in this study is that investments in transport infrastructure are a necessary condition for the productive development of a region, especially in relation to external trade through ports and navigable waterways.In the case of Argentina, a positive relationship has been observed between the development of port and waterway services (with reduced costs and operating times, improved reliability and new services), and expansion of the agricultural border, growth of productivity and agricultural production, and its industrialization.

Evaluation of Meteorological Elements and Lettuce (lactuca Sativa, L.) Yield Related to Geographic Orientation of Polyethylene Greenhouses

O experimento foi realizado na área experimental do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas – Unesp/Botucatu, Estado de São Paulo, em duas estufas dispostas em diferentes orientações geográficas, Leste/Oeste e Norte/Sul. A alface (Lactuva sativa L.) cv. Elisa foi cultivada em ambas estufas, sendo semeada em 05/05/99, transplantada em 29/05/99 e colhida em 31/06/99. Utilizou-se tensiômetros para monitorar o potencial de água no solo para realizar o manejo do sistema de irrigação por gotejamento. Microevaporímetros eqüidistantes de 3 m e colocados em 3 alturas, 0.50, 1.00 e 1.50 m, termohigrógrafos e tanques Classe “A” foram instalados nas duas estufas. Através de análise geoestatística, não se observou dependência espacial nem variabilidade espacial da evaporação nas duas estufas. Entretanto, a altura dos evaporímetros apresentou diferenças significativas: a evaporação à altura de 1.50 foi menor que nas outras duas.As médias de temperatura, umidade relativa e déficit de pressão de vapor do arnão diferiram estatisticamente entre as estufas e o ambiente externo. Os valores médios de evaporação de água no tanque Classe A instalado fora das estufas diferiram estatisticamente quando comparados com os instalados no interior das estufas, porém, entre as orientações não se constatou diferença significativa. Pôde-se verificar que não houve diferença significativa das características agronômicas da alface em ambas orientações estudadas. No entanto, houve diferença significativa para essas características entre os canteiros no interior das mesmas, havendo variância espacial para os dados de matéria fresca apenas na estufa N/S.

Seasonal variability of a conditional stability constant and the characterization of sedimentary humic substances from typical agricultural and urban areas

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