Critical-point model to estimate yield loss caused by Asian soybean rust

ABSTRACTA model to estimate yield loss caused by Asian soybean rust (ASR) (Phakopsora pachyrhizi) was developed by collecting data from field experiments during the growing seasons 2009/10 and 2010/11, in Passo Fundo, RS. The disease intensity gradient, evaluated in the phenological stages R5.3, R5.4 and R5.5 based on leaflet incidence (LI) and number of uredinium and lesions/cm2, was generated by applying azoxystrobin 60 g a.i/ha + cyproconazole 24 g a.i/ha + 0.5% of the adjuvant Nimbus. The first application occurred when LI = 25% and the remaining ones at 10, 15, 20 and 25-day intervals. Harvest occurred at physiological maturity and was followed by grain drying and cleaning. Regression analysis between the grain yield and the disease intensity assessment criteria generated 56 linear equations of the yield loss function. The greatest loss was observed in the earliest growth stage, and yield loss coefficients ranged from 3.41 to 9.02 kg/ha for each 1% LI for leaflet incidence, from 13.34 to 127.4 kg/ha/1 lesion/cm2 for lesion density and from 5.53 to 110.0 kg/ha/1 uredinium/cm2 for uredinium density.

Analysis on firm innovation boundaries

Innovation has been widely recognized as an important driver of firm competitiveness, and the firm’s internal research and development (R&D) activities are often considered to have a critical role in innovation activities. Internal R&D is, however, not the source of innovation as firms may tap into knowledge necessary for innovation also through various types of sourcing agreements or by collaborating with other organizations. The objective of this study is to analyze the way firms go about organizing efficiently their innovation boundaries. Within this context, the analysis is focused, firstly, on the relation between innovation boundaries and firm innovation performance and, secondly, on the factors explaining innovation boundary organization. The innovation literature recognizes that the sources of innovation depend on the nature of technology but does not offer a sufficient tool for analyzing innovation boundary options and their efficiency. Thus, this study suggests incorporating insights from transaction cost economics (TCE) complemented with dynamic governance costs and benefits into the analysis. The thesis consists of two parts. The first part introduces the background of the study, research objectives, an overview of the empirical studies, and the general conclusions of the study. The second part is formed of five publications. The overall results firstly indicate that although the relation between firm innovation boundary options is partly industry sector-specific, the firm level search strategies and knowledge transfer capabilities are important for innovation performance independently of the sector. Secondly, the results show that the attributes suggested by TCE alone do not offer a sufficient explanation of innovation boundary selection, especially under conditions of high levels of (radical) uncertainty. Based on the results, the dynamic governance cost and benefit framework complements the static TCE when firm innovation boundaries are scrutinized.

Finnish Critical Industries, Maritime Transport Vulnerabilities and societal Implications

Maritime transports are very essential for Finland as over 80% of the foreign trade in the country is seaborne and possibilities to carry out these transports by are limited. Any disruption in maritime transports has negative consequences to many sectors in the Finnish economy. Maritime transport thus represents critical infrastructure for Finland. This report focuses on the importance of maritime transports on security of supply in Finland and for the so called critical industries in particular. The report summarizes the results of the Work Package 2 of the research project STOCA – “Study of cargo flows in the Gulf of Finland in emergency situations”. The aim of the research was to analyze the cargo flows and infrastructure that are vital for maintaining security of supply in Finland, as well as the consequences of disruptions in the maritime traffic for the Finnish critical industries and for the Finnish society. In the report we give a presentation of the infrastructure and transport routes which are critical for maintaining security of supply in Finland. We discuss import dependency of the critical industries, and the importance of the Gulf of Finland ports for Finland. We assess vulnerabilities associated with the critical material flows of the critical industries, and possibilities for alternative routings in case either one or several of the ports in Finland would be closed. As a concrete example of a transport disruption we analyze the consequences of the Finnish stevedore strike at public ports (4.3.–19.3.2010). The strike stopped approximately 80% of the Finnish foreign trade. As a result of the strike Finnish companies could not export their products and/or import raw materials, components and spare parts, or other essential supplies. We carried out personal interviews with representatives of the companies in Finnish critical industries to find out about the problems caused by the strike, how companies carried out they transports and how they managed to continue their operations during the strike. Discussions with the representatives of the companies gave us very practical insights about companies’ preparedness towards transport disruptions in general. Companies in the modern world are very vulnerable to transport disruptions because companies regardless of industries have tried to improve their performance by optimizing their resources and e.g. by reducing their inventory levels. At the same time they have become more and more dependent on continuous transports. Most companies involved in foreign trade have global operations and global supply chains, so any disruption anywhere in the world can have an impact on the operations of the company causing considerable financial loss. The volcanic eruption in Iceland in April 2010 stopping air traffic in the whole Northern Europe and most recently the earth quake causing a tsunami in Japan in March 2011 are examples of severe disruptions causing considerable negative impacts to companies’ supply chains. Even though the Finnish stevedore strike was a minor disruption compared to the natural catastrophes mentioned above, it showed the companies’ vulnerability to transport disruptions very concretely. The Finnish stevedore strike gave a concrete learning experience of the importance of preventive planning for all Finnish companies: it made them re-think their practical preparedness towards transport risks and how they can continue with their daily operations despite the problems. Many companies realized they need to adapt their long-term countermeasures against transport disruptions. During the strike companies did various actions to secure their supply chains. The companies raised their inventory levels before the strike began, they re-scheduled or postponed their deliveries, shifted customer orders between production plants among their company’s production network or in the extreme case bought finished products from their competitor to fulfil their customers’ order. Our results also show that possibilities to prepare against transport disruptions differ between industries. The Finnish society as a whole is very dependent on imports of energy, various raw materials and other supplies needed by the different industries. For many of the Finnish companies in the export industries and e.g. in energy production maritime transport is the only transport mode the companies can use due to large volumes of materials transported or due to other characteristics of the goods. Therefore maritime transport cannot be replaced by any other transport mode. In addition, a significant amount of transports are concentrated in certain ports. From a security of supply perspective attention should be paid to finding ways to decrease import dependency and ensuring that companies in the critical industries can ensure the continuity of their operations.

Nutritional status of Eucalyptus grandis clones evaluated by critical level and DRIS methods

Nutritional status of eight 1.0 and 4.7 years old clones of Eucalyptus grandis, cultivated in a medium textured Ustults - US - and a Quartzipsamments - PS - soils, in Lençóis Paulista, São Paulo, were evaluated by the Diagnosis and Recommendation Integrated System (DRIS) and Critical Level (CL) methods. Based on multivariate discriminant analysis, the DRIS indices described the nutritional status of trees better in relation to tree age and soil type than in relation to nutrient composition. Spearman's correlation coefficients showed statistically significant relationships between volumetric tree growth and nutrients when applying DRIS indices or foliar nutrient concentrations. However, the DRIS indices indicated a lower number of trees with nutritional deficiencies, in relation to the CL method. According to the CL method, P, S, and Ca were deficient in the majority of the soils and tree age categories. By the DRIS method, Ca was the only deficient nutrient in PS soils, and appeared to be particularly limited in one-year-old trees. In conclusion, the DRIS method was more efficient than the CL method in evaluating the nutritional status of eucalyptus trees.

SOIL ORGANIC CARBON, CARBON STOCK AND THEIR RELATIONSHIPS TO PHYSICAL ATTRIBUTES UNDER FOREST SOILS IN CENTRAL AMAZONIA

ABSTRACT The soil carbon under Amazonian forests has an important roles in global changing, making information on the soil content and depths of these stocks are considerable interest in efforts to quantify soil carbon emissions to the atmosphere.This study quantified the content and soil organic carbon stock under primary forest up to 2 m depth, at different topographic positions, at Cuieiras Biological Reserve, Manaus/ ZF2, km 34, in the Central Amazon, evaluating the soil attributes that may influence the permanence of soil carbon. Soil samples were collected along a transect of 850 m on topographic gradient Oxisol (plateau), Ultisol (slope) and Spodosol (valley). The stocks of soil carbon were obtained by multiplying the carbon content, soil bulk density and trickiness of soil layers. The watershed was delimited by using STRM and IKONOS images and the carbon contend obtained in the transects was extrapolated as a way to evaluate the potential for carbon stocks in an area of 2678.68 ha. The total SOC was greater in Oxisol followed by Spodosol and Ultisol. It was found direct correlations between the SOC and soil physical attributes. Among the clay soils (Oxisol and Ultisol), the largest stocks of carbon were observed in Oxisol at both the transect (90 to 175.5 Mg C ha-1) as the level of watershed (100.2 to 195.2 Mg C ha-1). The carbon stocks under sandy soil (Spodosol) was greater to clay soils along the transect (160-241 Mg C ha-1) and near them in the Watershed (96.90 to 146.01 Mg C ha-1).

SOIL COVER AND CHEMICAL AND PHYSICAL ATTRIBUTES IN OXISOL IN THE ATLANTIC FOREST BIOME

ABSTRACT The objective of this study was to evaluate the chemical and physical attributes of different soil cover in a Oxisol with a strong wavy relief in the Atlantic Forest Biome, in which were selected three watersheds, employed with grazing (watershed P), forest (watershed M) and coffee (watershed C). Deformed and not deformed samples were collected in three depths for physical and chemical characterization. The chemical characteristics of soil in different watershed studies presented low levels of fertility. It was observed an elevation of pH in the soil and contents of Ca2+ and Mg2+ in the watersheds P and C in relation to the watershed M. Due to deforestation and the establishment of agriculture and livestock, there was a decrease in the contents of soil organic matter in the watershed P and C, not altering the physical characteristics of the soil in the watershed P. The implementation of coffee plantation is causing a reduction in the soil quality of watershed C in comparison to the watershed P and M, therefore indicating a need to adequate soil management in this area.

GPS receivers for georeferencing of spatial variability of soil attributes

The characterization of the spatial variability of soil attributes is essential to support agricultural practices in a sustainable manner. The use of geostatistics to characterize spatial variability of these attributes, such as soil resistance to penetration (RP) and gravimetric soil moisture (GM) is now usual practice in precision agriculture. The result of geostatistical analysis is dependent on the sample density and other factors according to the georeferencing methodology used. Thus, this study aimed to compare two methods of georeferencing to characterize the spatial variability of RP and GM as well as the spatial correlation of these variables. Sampling grid of 60 points spaced 20 m was used. For RP measurements, an electronic penetrometer was used and to determine the GM, a Dutch auger (0.0-0.1 m depth) was used. The samples were georeferenced using a GPS navigation receiver, Simple Point Positioning (SPP) with navigation GPS receiver, and Semi-Kinematic Relative Positioning (SKRP) with an L1 geodetic GPS receiver. The results indicated that the georeferencing conducted by PPS did not affect the characterization of spatial variability of RP or GM, neither the spatial structure relationship of these attributes.

Soil sampling intensity and spatial distribution pattern of soils attributes and corn yield in no-tillage system

Taking into account that the sampling intensity of soil attributes is a determining factor for applying of concepts of precision agriculture, this study aims to determine the spatial distribution pattern of soil attributes and corn yield at four soil sampling intensities and verify how sampling intensity affects cause-effect relationship between soil attributes and corn yield. A 100-referenced point sample grid was imposed on the experimental site. Thus, each sampling cell encompassed an area of 45 m² and was composed of five 10-m long crop rows, where referenced points were considered the center of the cell. Samples were taken from at 0 to 0.1 m and 0.1 to 0.2 m depths. Soil chemical attributes and clay content were evaluated. Sampling intensities were established by initial 100-point sampling, resulting data sets of 100; 75; 50 and 25 points. The data were submitted to descriptive statistical and geostatistics analyses. The best sampling intensity to know the spatial distribution pattern was dependent on the soil attribute being studied. The attributes P and K+ content showed higher spatial variability; while the clay content, Ca2+, Mg2+ and base saturation values (V) showed lesser spatial variability. The spatial distribution pattern of clay content and V at the 100-point sampling were the ones which best explained the spatial distribution pattern of corn yield.

Effects of vinasse application under the physical attributes of soil covered with sugarcane straw

Areas under vinasse application have been associated to favorable physical conditions for root development, aeration, infiltration and water movement in soil profile. This study aimed to evaluate changes on physical attributes of soil under sugarcane straw after vinasse application in two sugarcane growing areas (Area 1 and Area 2) under mechanized management in the state of Paraíba, Brazil. In each area, the samples were collected in the 0-0.20, 0.20-0.40 and 0.40-0.60m layers of the soil, in 36 points, distributed in a 10×10m mesh, one day before and 40 days after vinasse application. The data were submitted to multivariate analysis with repeated measures and geostatistics. The vinasse application decreased soil density and increased total porosity in both Areas and increased organic matter in Area 2. In Area 1 occurred pure nugget effect for the fractions of sand, silt and clay, independent of soil layer. In Area 2, this effect was verified mostly at superficial layers, except for the fraction of clay that presented a moderate degree of spatial dependence.

Management zones definition using soil chemical and physical attributes in a soybean area

Several equipments and methodologies have been developed to make available precision agriculture, especially considering the high cost of its implantation and sampling. An interesting possibility is to define management zones aim at dividing producing areas in smaller management zones that could be treated differently, serving as a source of recommendation and analysis. Thus, this trial used physical and chemical properties of soil and yield aiming at the generation of management zones in order to identify whether they can be used as recommendation and analysis. Management zones were generated by the Fuzzy C-Means algorithm and their evaluation was performed by calculating the reduction of variance and performing means tests. The division of the area into two management zones was considered appropriate for the present distinct averages of most soil properties and yield. The used methodology allowed the generation of management zones that can serve as source of recommendation and soil analysis; despite the relative efficiency has shown a reduced variance for all attributes in divisions in the three sub-regions, the ANOVA did not show significative differences among the management zones.

Magnetic susceptibility in the prediction of soil attributes in two sugarcane harvesting management systems

This study aimed to investigate the potential use of magnetic susceptibility (MS) as pedotransfer function to predict soil attributes under two sugarcane harvesting management systems. For each area of 1 ha (one with green sugarcane mechanized harvesting and other one with burnt sugarcane manual harvesting), 126 soil samples were collected and subjected to laboratory analysis to determine soil physical, chemical and mineralogical attributes and for measuring of MS. Data were submitted to descriptive statistics by calculating the mean and coefficient of variation. In order to compare the means in the different harvesting management systems it was carried out the Tukey test at a significance level of 5%. In order to investigate the correlation of the MS with other soil properties it was made the correlation test and aiming to assess how the MS contributes to the prediction of soil complex attributes it was made the multiple linear regressions. The results demonstrate that MS showed, in both sugarcane harvesting management systems, statistical correlation with chemical, physical and mineralogical soil attributes and it also showed potential to be used as pedotransfer function to predict attributes of the studied oxisol.

Chemical attributes of soil and dry mass accumulation of maize fertilized with cassava wastewater

The aim of this study was to evaluate chemical attributes alterations of a clay-loam textured soil and dry mass accumulation of maize submitted to application of cassava wastewater doses in three assessment periods. The experiment was conducted under greenhouse using a completely randomized experimental design in a factorial 5 × 3, with four replicates. The analyzed factors of research were doses of cassava wastewater (0; 12.6; 25.2; 50.4; 75.6 m3 ha-1) andassessment periods (20, 40 and 52 days after germination). The following parameters were determined: electric conductivity of soil saturation extract, pH in water, content of available P, content of exchangeable K+, Ca2+, Mg2+ and Na+of soil, dry mass of leaves and stem. The application of cassava wastewater on soil enables increase of pH, electric conductivity of saturation extract, contents of available P, contents of exchangeable K+ and Na+ and dry mass of leaves and stem. However, only pH and content of exchangeable K+ of soil, the electric conductivity of saturation extract and dry mass of leaves and stem are influenced by assessment period.

Soil physical attributes in chemigated banana plantation with wastewater

ABSTRACT The feasibility of using sewage wastewater as a water and nutrient source for plants is an alternative to harness agricultural natural resource, observing its influence on the organic matter dynamics and soil energy. Our objective here was to evaluate the effects of applying different doses of effluent from a sewage treatment plant, in Janaúba – MG, Brazil, over the physical attributes of a soil grown with “Prata Anã” banana. From soil sample collection at depths of 0-20, 20-40, and 40-60 cm, we determined the following soil properties: soil density, total porosity, macroporosity, microporosity, organic matter, clay dispersed in water and stability of soil aggregate. The experimental design was in randomized blocks with four repetitions. Wastewater raising doses promoted increase in suspended solids, contributing to macroporosity reduction at 20-40 and 40-60 cm depths; as well as a reduction in organic matter within 0-20 cm layer. Clay dispersal was observed in the depths of 0-20 cm, being derived from an increase in sodium content. Concurrently, there was a reduction of soil aggregate stability.

Physical attributes of a pasture soil in southeast Goiás determined by geostatistics

ABSTRACT This study aimed to evaluate the spatial dependence of physical attributes in a soil cultivated with Brachiaria grass. A 12-m regular sampling grid was established within an area of 3.500 m2. Thirty-five soil samples were collected at 0-30 cm depth for particle density, bulk density, texture and total porosity analysis. These data were evaluated using statistical methods of indicator kriging and the GS+ software. The GS+ software was used to develop three-dimensional maps and evaluate semivariograms. The spatial dependence was evaluated using experimental semivariograms. The analyzed attributes indicated the occurrence of spatial dependence when fit to the exponential model. Areas with higher porosity occurred in the regions with lower bulk densities and higher particle densities.