Harvesting Options Research Articles

Effect of spacing, parental genotype and harvesting cycle on biomass production in two half-sib progenies of Robinia pseudoacacia L.

Abstract This study investigated the influence of spacing, parental genotype and harvesting cycle on woody biomass production in open-pollinated families of the locally selected black locust (Robinia pseudoacacia L.) clones ‘Tsarevets’ and ‘Srebarna’ at specific site conditions. A Nelder experiment with 16, varying along the spokes, nearly-square spacings and two black locust families arranged in alternating sectors, was established in North Central Bulgaria. Alternative harvesting options (‘harvesting cycles’), consisting of one, two or three successive coppicings, were applied and the amounts of dry shoot dendromass collected per plant were accumulated to calculate and analyse the total yield of woody biomass, achievable within 2-, 3- and 4-year periods (‘production period’). The one-coppicing cycle proved superior for both families, regardless of the length of the production period. Biomass yield in the family of ‘Srebarna’ exceeded that of ‘Tsarevets’ at the wider spacings, when 1 and 2 year-old shoots were harvested, while dendromass production of ‘Tsarevets’ was substantially higher in the 4-year-old shoots. The woody biomass yield per plant increased with spacing, and growth tended to saturation at the lowest densities, enabling derivation of optimal planting densities. The total dendromass yield per hectare was maximized at growing space of around 0.5 m2 per plant for the 2-year production period, while spacing of 1.2–2 m2 was required for production periods of 3 and 4 years. If the results from this experiment can be reliably scaled up in practice then short rotation crops of ‘Srebarna’ and ‘Tsarevets’ families at comparable site conditions should be able to produce annual biomass yields of 9–11 Mg.ha−1.year−1 within a 4-year period, given the optimal planting densities and harvesting regimes prescribed.

Steep terrain forest operations – challenges, technology development, current implementation, and future opportunities

ABSTRACTWhile modern fully mechanized ground-based systems are a default option for safe and productive harvesting, they have always been limited by terrain factors such as slope, soil strength, and roughness. There is a limit with regard to the physical feasibility of operating machines on steep slopes because both the weight and also the force from the momentum created during traction loss can affect stability. A huge interest to improve traction of harvesting machines when operating on steep slopes is arising. One way to improve traction and stability on steep slopes is through assisting harvesting machines by winch and cable to anchor locations such as tree stumps or stationary equipment. This technology offers potential for improving the safety, productivity, and efficiency of a harvesting operation, as well as for improving machine mobility and reducing soil disturbance through the reduction of slip. With the exponential development of such technology, an integrated approach must be developed for conducting productive and injury-free mechanical harvesting operations on steep slopes that draws on the skills and accountabilities of the working team. Beyond a certain physical threshold, the only feasible and achievable solution providing some “intelligent behavior” to machines and systems would be the role of mechatronics application. One of the most relevant points could be the possibility to introduce the concept of “teleoperation” using unmanned ground vehicles. Combining teleoperation with winch-assist technology would provide a platform for extending the range of ground-based equipment to previously infeasible terrain conditions.

High Breakdown Strength Schottky Diodes Made from Electrodeposited ZnO for Power Electronics Applications

The synthesis of ZnO films by optimized electrodeposition led to the achievement of a critical electric field of 800 kV/cm. This value, which is 2–3 times higher than in monocrystalline silicon, was derived from a vertical Schottky diode application of columnar-structured ZnO films electrodeposited on platinum. The device exhibited a free carrier concentration of 2.5 × 1015 cm–3, a rectification ratio of 3 × 108, and an ideality factor of 1.10, a value uncommonly obtained in solution-processed ZnO. High breakdown strength and high thickness capability make this environment-friendly process a serious option for power electronics and energy harvesting.

Aspects of non-grain part harvesting for corn and sunflower as solid biofuels

Purpose. Identification of promising technologies for harvesting the non-cereal part of the corn and sunflower crops, which provide for the controlled collection of quality products in accordance with the needs. Methods. Analysis of common technological processes of harvesting straw and stem feed, the non-grain part of the corn and sunflower harvest, the synthesis of options for harvesting individual parts of the non-grain part of the corn and sunflower crop and evaluating them by the possible harvest, experimental determination of the full harvest for a particular process. Results. Synthesized and analyzed options for harvesting the non-cereal part of the corn and sunflower crops, which can be used in modern agricultural production. The analysis of the non-cereal part of the corn and sunflower harvest was carried out. The proportion of the non-cereal part of the corn and sunflower crops, which can be collected with various harvesting options, has been established. Experimental studies have been carried out of individual operations of collecting the non-grain part of the corn and sunflower crops. Conclusions. Harvesting the stem mass in a compacted form (rolls, bales) for energy needs is more appropriate than in loose form. Farms that grow corn and sunflower choose the technology of harvesting the non-cereal part of the crop, depending on the area of sowing of crops and needs in the stem mass. The investigated options for harvesting the non-cereal part of the crop provide a complete collection of the stem mass from 3.5 to 85.4%. The final choice of the option of harvesting raw materials is determined not only by the completeness of the collection of raw materials, but also by its technical and economic indicators. Keywords: non-cereal part of corn and sunflower harvest, technology of harvesting non-cereal part, solid biofuel.

Development of a helical coagulation reactor for harvesting microalgae

In this study, an innovative helical coagulation reactor (HCR) was developed for harvesting microalgae by sedimentation with polyaluminium chloride (PAC). The effects of construction and hydrodynamic characteristics on harvesting performance were investigated. Results showed that a higher harvesting efficiency, 96.37%, was achieved for the large and compact flocs generated by the HCR, and the settling rate of flocs was substantially influenced by the velocity gradient (G) and the Reynolds number (Re). When the Reynolds number closed to the transition between laminar and turbulent flow (4000), the flocs settled faster (20.51mh-1), although settling slowed as the Reynolds number increased further because of ruptured flocs. The settling rate of flocs could be further improved to 23.27mh-1by a pulse flow field, mainly due to larger and more compact flocs forming in the plug pipe flow. Furthermore, a comparative investigation of a mechanically agitated vessel and the HCR with the same Camp number (Gt) showed that the HCR achieved higher settling rates and a shorter residence time than those with a mechanical agitator. The HCR provided a uniform dissipation of energy and high velocity gradient while avoiding electrical and mechanical energy consumption, suggesting this reactor is an efficient and economic option for microalgae harvesting.

Scientific and practical justification of haylage harvesting in APC “Levochsky” Novgorod region

There are three options for harvesting haylage: haylage in the trench, haylage with separate packaging, haylage with the preparation of rolls in line. The comparative assessment above the listed technologies of harvesting haylage on the basis of APC “Levochsky” Khvoyninsky district of Novgorod region is given. According to the results of scientific and practical research, the lowest cost of finished products is achieved when using the option of harvesting of haylage with roll packing in line. A wrapper-wrapper is used for this technology.

Productivity and Costs of Two Beetle-Kill Salvage Harvesting Methods in Northern Colorado

Two ground-based timber harvesting methods have been commonly used for beetle-kill salvage treatments after a bark beetle epidemic in northern Colorado. A “lop and scatter” method uses a mobilized stroke delimber to delimb and buck trees at the stump, leaving tree tops and limbs on the forest floor, while a whole-tree harvesting method brings the entire tree to the landing where it is delimbed and bucked, and thus produces logging residue piles at the landing as a byproduct. We conducted a detailed comparative time study of the two harvesting methods to develop productivity and cost models and compared the performance of the two methods under various site conditions. We applied the productivity and cost models to lodgepole pine forest stands totaling 3400 hectares of the Colorado State Forest State Park to estimate salvage harvesting costs for each forest stand and identify the least costly harvesting options. The results show that the estimated stump-to-truck timber production costs were $30.00 per oven dry ton (odt) for lop and scatter and $23.88 odt−1 for the whole-tree method in our study harvest unit. At the forest level, the estimated average stump-to-truck costs were $54.67 odt−1 and $56.95 odt−1 for lop and scatter and whole-tree harvesting, respectively. Skidding distance and downed trees affect the harvesting costs of both methods, but their influence appears to be more significant on the whole-tree method.

(Invited) Tubular Thermoelectric Generator for Enhanced Power Generation

Thermoelectric generators are interesting energy harvesting option due to its clean nature, silent operation and it harnesses the power from otherwise wasted heat. While most of the research has been directed toward high thermoelectric performance based material innovation, we have focused on its architecture and how to connect hot and cold ends when they are far apart. From that perspective, we have devised an effective integration strategy to roll-up otherwise ultra-thin layers of thermoelectric materials to form tubular architecture and to integrate them in array for high power thermoelectric generator development. We have used widely used thermoelectric materials such as bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3). We also offer an analytical methodology to deduce the effective mechanics of the strain associated with the thermoelectric materials and the used polymeric materials (as stressor and as support layers). Experimentally we have shown seamless 4 cm (and further expandable) tubular arrays of thermoelectric piles. Such a long length allows us to connect to far apart hot and cold end for higher power generation as we also maintain higher temperature difference for longer time. We also compare its effectiveness with solid slab and wire of the same tube from its performance and cost perspective. At the initial stage we report up to 5 μW (8 pairs of p and n-type thermopiles) through a temperature difference of 60 °C. We also show how this can be improved further and potential integration strategy with 2D material system.

Blueberry Producers’ Attitudes toward Harvest Mechanization for Fresh Market

The availability and cost of agricultural labor is constraining the specialty crop industry throughout the United States. Most soft fruits destined for the fresh market are fragile and are usually hand harvested to maintain optimal quality and postharvest longevity. However, because of labor shortages, machine harvest options are being explored out of necessity. A survey on machine harvest of blueberries (Vaccinium sp.) for fresh market was conducted in 2015 and 2016 in seven U.S. states and one Canadian province. Survey respondents totaled 223 blueberry producers of various production sizes and scope. A majority (61%) indicated that their berries were destined for fresh markets with 33% machine harvested for this purpose. Eighty percent said that they thought fruit quality was the limiting factor for machine-harvested blueberries destined for fresh markets. Many producers had used mechanized harvesters, but their experience varied greatly. Just less than half (47%) used mechanical harvesters for fewer than 5 years. Most respondents indicated that labor was a primary concern, as well as competing markets and weather. New technologies that reduce harvesting constraints, such as improvements to harvest machinery and packing lines, were of interest to most respondents. Forty-five percent stated they would be interested in using a modified harvest-aid platform with handheld shaking devices if it is viable (i.e., fruit quality and picking efficiency is maintained and the practice is cost effective). Overall, the survey showed that blueberry producers have great concerns with labor costs and availability and are open to exploring mechanization as a way to mitigate the need for hand-harvest labor.

Growth and yield models for eucalyptus stands obtained by differential equations

The main purpose of this study was to assess nonlinear models generated by integrating the basal area growth rate to estimate the growth and yield of forest stands. The database was collected from permanent sample units, in Paraopeba county, in the state of Minas Gerais, Brazil. The stands were represented by Eucalyptus camaldulensis × Eucalyptus urophylla hybrid trees, with 3 × 3 meters of spacing. The data were divided into two groups: fitting and validating databases. Two nonlinear models (Strategy A and Strategy B) were developed using differential equations to estimate the basal area growth and yield of the sample units. The logistic model was fitted to estimate the volumetric yield as a function of age, site index and basal area. The efficiency of the systems generated by logistic model and models obtained by differential equations (Strategy A and Strategy B) was also compared to the efficiency of the system estimated by the Clutter model (Strategy C). The projection models used to estimate basal area obtained by differential equations were compatible with forest growth and yield, and the logistic model with covariates was compatible with volumetric growth and yield. Strategy A and Strategy B generated different thinning and harvesting options for different site indices, which is biologically consistent.

Effect of Harvest Time and Frequency on Biomass Quality and Biomethane Potential of Common Reed (Phragmites australis) Under Paludiculture Conditions

This study examined the effect of harvest time (from May to September) and dry matter partitioning on biomethane potential and methane yield per unit area of Phragmites australis cultivation under paludiculture conditions. The experimental site is part of a larger experimental platform (San Niccolo, Pisa) located within the Massaciuccoli Lake Basin in Central Italy (Tuscany, IT). The study also took into account the double cut strategy by evaluating the regrowth from June to September. Biomethane potentials ranged from 384 to 315 and from 412 to 283 NL CH4 kg VS−1 (normal liters of methane per kg of volatile solids) for leaves and stems, respectively. About digestion kinetics, maximum daily production rate (R max) was significantly affected by harvest time and not by plant partitioning. Along the harvest season, biomethane yield per unit area was mostly driven by the biomass yield showing an increasing trend from May (1659 Nm3 ha−1) to September (3817 Nm3 ha−1). The highest value was obtained with the double harvest option (4383 Nm3 ha−1), although it was not statistically different from the single harvest carried out in September. Owing to its remarkably lower yields, P. australis cannot be considered along the same lines as crops conventionally used for biogas production, but it may represent an interesting option for paludiculture cropping systems by coupling peatland restoration with bioenergy production. September harvest management seemed the most feasible option, although further investigation on crop lifespan is needed.

Parametric investigation of concrete solar collectors for façade integration

Concrete solar collectors are a cheap and durable option for solar thermal energy harvesting for hot water and space heating applications. They offer a unique facade integrated solar thermal solution, allowing for seamless integration with precast concrete cladding systems. The thermal energy output of a concrete solar collector is dictated by its material (thermal conductivity and specific heat capacity of concrete and pipe), geometry (pipe spacing, pipe diameter, collector thickness, pipe embedment depth) surface finish (absorptance and emittance) and fluid flow. Given the wide range of individual parameter values documented in the literature an investigation into these parameters is required. In this work concrete solar collectors are simulated using an experimentally validated 2D finite element model computed in COMSOL Multiphysics. Outlet fluid temperatures up to 40°C and a daily efficiency of 56% are predicted for a clear summer day in Ireland using the model for a reference case concrete solar collector. Concrete solar collectors compare well with other unglazed collectors (metallic absorber; daily efficiency=62%) and (polymer absorber; daily efficiency=29%). Parameters are investigated individually and compared collectively within the range of values found in the literature. Concrete conductivity and solar absorptance are highlighted as two influential performance parameters which can be improved and are subsequently investigated experimentally. Additionally, geometric parameters, including the embedment depth and pipe spacing are identified as key performance parameters. These material and geometric parameters are limited by practical, economic and aesthetical constraints. These limitations are also examined and summarised.

CFOR: un sistema di supporto alle decisioni per le foreste in Calabria

Abstract: In this work, a spatial decision support system dedicated to forest management in Calabria (CFOR) is presented. The main aim of the tool is to assess wood production under various harvesting options. All functionalities have been developed by Python and R languages for QGIS. Main inputs are digital models, mainly derived from Lidar, and vector shapefiles.

Field test and cost analysis of four harvesting options for herbaceous biomass handling

Abstract : The nature of most biomass materials is a low bulk density as compared to traditional fuel sources. ?High handling cost could be a limiting factor in utilizing biomass feedstock. ?Understanding available harvesting machinery systems and associated costs is critical to future implementation.? Four popular harvesting machinery systems were studied and costs were analyzed based on field measurements and calculations. ?These four systems included (1) round baling and round bale handling systems, (2) large square baling and square bale handling systems, (3) forage harvester and trucking systems, and (4) large square baling plus square bale compression systems. ?Results indicated that a self-loading forage wagon can reduce the cost to harvest a crop but requires more harvest time.? Large square bales were found to reduce cost of handling and transport as compared to round bales.? Further research is needed to determine storage costs and deterioration loss of the two bale types.? Compressed square bales were found to reduce storage, handling and transport costs.? Compressed bale machinery has a high initial cost, which currently makes only valuable for hay export. Keywords: harvesting machinery system, herbaceous biomass, field, cost DOI: 10.3965/j.issn.1934-6344.2011.03.058-068 ? Citation: Douglas Brownell, Jude Liu. ?Field test and cost analysis of four harvesting options for herbaceous biomass handling. ?Int J Agric & Biol Eng, 2011; 4(3): 58

Comparison of “Amicus and COBE Spectra” for autologous peripheral blood stem cell harvest: An Indian experience

Background: Adequate collection of peripheral stem cells from the patients depends on the disease condition, efficient mobilization and the equipment used for PBSC harvest. COBE Spectra has been the major platform for collecting these PBSC for more than 2 decades. Now with introduction of PBSC harvest option with Amicus cell separators (which was used primarily for plateletpheresis) in India, it is worth while comparing both the platforms for stem cells collections. Materials and Methods: Our study is a retrospective analysis of autologous PBSC harvest procedures done at our centre. The study included the data of autologous PBSC collections from January 2015 to June 2016. Total 61 patients underwent 85 autologous PBSC harvests for both haematological and non haematological indications. Results: Out 61 patients, 40 patients collected their target number of cell in a single harvest, 18 patient required dual harvests and 3 patients required three consecutive days of harvest. Pre-Apheresis WBC, platelets and CD45/CD34 cell counts were comparable. COBE Spectra collects significantly higher product volume and higher number of platelets in the apheresis product. Whereas WBC counts of the product, total CD45/CD34 cell dose and collection efficiency (CE2) and collection ratio (CR) were comparable on both the platforms. Conclusions: Amicus took more time to harvest the anticipated number of cells in the graft as well as COBE Spectra resulted in higher platelets loss during the process of cell collection. Our analysis is first of its kind from Indian subcontinent and indicates that with gradual phasing out of COBE spectra from the market Amicus offers a comparative platform for PBSC harvest.

Decision-support tool for management of miombo woodlands: a matrix model approach

Rational forest management planning requires information on the present forest state and on future development. However, forest management planning in Tanzania has often been done without any information on forest development because appropriate tools are lacking. This study presents a matrix model that combines distance-independent growth and mortality models, area-based recruitment models, and allometric models for prediction of volume and biomass. In this way forest development can be simulated according to different treatment options. A short-term (seven years) test of the matrix model using independent data from permanent sample plots showed that the overall difference between predicted and observed basal area was small (6.5%). Long-term simulations (1 000 years) with the model showed that it was able to attain, irrespective of initial conditions, similar steady-state conditions (i.e. basal area, volume and biomass of 13 m2 ha−1, 130 m3 ha−1 and 90 t ha−1, respectively), which also correspond well to biological expectations in the ‘real’ miombo woodlands of the country. The flexibility of the model as a decision-support tool was demonstrated by simulating three harvesting options aiming at different combinations of charcoal and timber production. The model complexity is well adapted to the data quality and abundance, and it is dependent on proxies of some main drivers of the dynamic processes. The development of the matrix model is a step forward facilitating better decisions in the management of miombo woodlands. However, data ranges used for calibrating the submodels are limited in time and space, and future efforts should focus on tests and recalibrations based on extended data ranges. Presently, therefore, applications of the matrix model should be limited to the data ranges of the modelling data from the Iringa and Manyara regions.

Annual bioenergy crops for biofuels production: Farmers' contractual preferences for producing sweet sorghum

Dedicated annual sorghum crops, such as sweet sorghum or energy sorghum, may provide an option for farmers to supply cellulosic feedstocks for biofuel production and help the industry meet government mandates. Kansas farmers are poised to be major producers of sweet sorghum for biofuels due to favorable agro-ecological conditions. The purpose of this paper is to assess Kansas farmers' willingness to grow sweet sorghum under contract as a feedstock for biofuel production. The paper examines farmers' willingness-to-pay for contract attributes and the impact of socio-economic factors on their willingness-to-pay for these attributes. A stated choice survey was administered to Kansas farmers to assess their willingness to grow sweet sorghum for biofuels under various contracting scenarios. Results show that farmers may be willing to grow biomass for bioenergy under contract, but may have varying preferences for the importance of contract attributes such as net returns, contract length, insurance availability, government incentives, and potential for biorefinery harvest options based on socio-economic characteristics of growers.

A decision support model for individual tree stump harvesting options based on criteria for economic return and environmental protection

ABSTRACTBased on principles of multi-criteria analysis techniques, a model (MAPStump-E) for decision support on stump harvesting at stand level was developed. The model applies the concept that each stump can be attributed production values (economic) and environmental values (here soil protection and water quality). Individual tree stump information was incorporated directly from the production reports of harvesters and combined with high-resolution Geographical Information System data on topography and soil type to create a production submodel and a soil and water vulnerability submodel (SWM). To test the model, it was applied to a 45-ha study forest in south-central Sweden and the outcome of nine scenarios with varying bioenergy prices and environmental protection levels was examined. Combined analysis of the effects of production and environmental criteria on total dry mass of harvestable stumps at the study site showed that biomass prices had a stronger influence than environmental criteria. Conflict stumps were defined as stumps suitable for harvest based on production criteria, but unsuitable based on soil and water protection criteria. In a “medium” price scenario, the proportion of conflict stumps at the study site ranged from 6% to 18%, depending on protection level set.

Assessing and Mitigating the Hydrological Impacts of Urbanisation in Semi-Urban Catchments Using the Storm Water Management Model

Urbanisation causes a range of adverse impacts on stream physical and ecological conditions due to increases in catchment runoff caused by increased imperviousness. Developing ways to reduce these impacts on in-stream ecosystems is a major challenge and requires innovative catchment specific, high-time-resolution modelling methods. We employed a combination of high-time-resolution data collection, analysis and modelling methods to understand the underlying hydrological processes and evaluate a potentially significant management option – stormwater harvesting. A set of sensitive parameters of the Storm Water Management Model (SWMM) were optimised using an automatic calibration method and hourly data in eight catchments in South East Queensland, Australia. Systematic investigation of the effects of urbanisation and its mitigation through stormwater harvesting was achieved by modelling the impacts of increasing impervious area for three of the relatively undeveloped catchments. As the extent of impervious areas across the catchments increased we typically found increases in the duration of high flow spells together with increases in mean flow and the frequency of runoff events. However, many hydrologic responses to increasing imperviousness were specific to the physical characteristics of catchments, and to the spatio-temporal pattern of urbanisation. By implementing stormwater harvesting options the hourly flows were reduced by up to 60 % but the maximum flow was unchanged. Thus the option was able to reduce, but not totally ameliorate, the negative hydrological impacts of increasing imperviousness.

Using forest ecosystem simulation model EFIMOD in planning uneven-aged forest management

Uneven-aged forest management is suggested to be a sustainable management alternative in boreal forests, but knowledge on applicable harvest intensities is very limited as majority of the studies has focused on even-aged management practices. The ecosystem model EFIMOD was used to assess the effect of selection cuttings on ecosystem production, carbon sequestration and volume increment in spruce stands. The model was calibrated and validated against experimental data from 20 permanent forest plots in southern Finland where stand responses to uneven-aged management had been monitored for 25years. The simulated scenarios started with planting trees on bare land, simulation of first decades according to even-aged management, and a subsequent transformation into uneven-aged stand structure and management. Simulated selection cutting scenarios contained variations of both harvest interval (10–30years) and postharvest stand density (basal area 8–16m2ha−1). We hypothesized that longer harvest intervals and higher post-harvest basal areas will positively affect the net ecosystem production, nitrogen use efficiency, and forest carbon sequestration. The results presented here are for a period of 90years. Simulations showed that net ecosystem production (NEP) increased from 0.25 to 0.5kgm−2a−1 of carbon with longer harvest intervals and higher postharvest density, and was generally less than that at undisturbed development. Nitrogen use efficiency (NUE) varied from 100kg NPP per kg consumed N for heavy cuttings to 300kg NPP per kg consumed N for light removal of trees. Changes in soil carbon stocks were negative for most scenarios (5–20% decline in terms of total soil C), and the decline was most pronounced with lowest postharvest density and short harvest intervals. The volume of harvested timber was between 320 and 400m3ha−1 for a 60-year period. Longer harvest intervals resulted in increased timber production. Stem volume growth (5–7m3ha−1a−1) was equally affected by both harvesting parameters. The cumulative volume of deadwood of 80–120m3ha−1 was substantially higher with the longest harvest interval (30years) than with the shorter alternatives where it comprised 40–60m3ha−1. The simulations provide novel results on different harvesting options for uneven-aged forest management of boreal Norway spruce stands. These results fill a gap in knowledge on ecosystem responses to alternative management regimes and support the development of sustainable management practices.