Main Production Cost Research Articles

Can irrigation systems alter the critical period for weed control in onion cropping?

Weed management is essential in vegetable crops, constituting the main production cost. Cultural control strategies can help minimize weed interference and decrease the critical period for weed control (CPWC) when well implemented. Localized nutrient and water supply may favor crop growth, suppressing weeds, and reducing the CPWC. We hypothesized that the drip system reduces the CPWC compared to the micro-sprinkler system and may be recommended as a cultural control method. To support our hypothesis, the objective was to determine the CPWC in onion cultivated under drip or micro-sprinkler during three cropping seasons. Field experiments were conducted during 2016, 2017, and 2018 to evaluate the effects of drip and micro-sprinkler irrigation had on the CPWC in onion (Allium cepa L.). The coexistence of weed in the onion lifecycle significantly reduced the bulb yield for both irrigation systems. The reduction by weed infestation in relative onion bulb yield for the drip system was 61.8, 80.9, and 97.6% in 2016, 2017, and 2018 seasons, respectively. For micro-sprinkler systems, the reduction was 89.2, 85.2, and 98.6% in the 2016, 2017, and 2018 seasons, respectively. The CPWC varied according to the irrigation system and season. For example, in a drip system, the CPWC was 11, 17, and 74 days for 2016, 2017, and 2018. In the micro-sprinkler system, the CPWC was 18, 53, and 45 days in 2016, 2017, and 2018. The predominant weed community determines the irrigation system (drip or micro-sprinkler) that promotes better cultural weed control and reduction of the CPWC in onion cropping systems.

Еconomic analysis of meat production from two types of Domestic quails

Abstract. There are two types of Japanese quails, reared in Europe – dual-purpose and meat. The aim of the present study was to made an economic analysis of fattening quails from the dual-purpose and heavy production types. Three groups were formed – group 1 (dual-purpose), groups 2 and 3 (heavy type), reared in cages. After quails sexing on the 16th day of age, there were formed six subgroups: 1m, 1f, 2m, 2f, 3m and 3f. Fattening period lasted until 35 days of age. For revenues calculation produced meat and edible offal data per m2, were used. Costs calculation include consumed feed for the period, day-old quail, and other costs. The main production costs were associated with feed and day-old quails: from 80.3 and 82.6% of all costs in the studied groups. The anticipated revenues from produce in group 2 were 10 EUR/m2 higher than those in group 1, and for group 3 – 10.21 EUR/m2 higher than group А. The results indicate that meat type quails fattening is the most economically efficient in quail meat production. Producing quail edible offal is still not developed but could be beneficial for efficiency of quail fattening small farms.

The Determination of the Main Production Cost of Jipang Cake Using the Full Costing Method

<p class="Normal1">The purpose of this study is to determine the main of production cost using the full costing method. The full costing method is one of the methods used in determining the cost of production by taking into account all components of production costs, both fixed and variable costs so that the calculation results are more precise and detailed. This research was conducted in a group of Jipang cake craftsmen in Antajaya Village, Tanjung Sari District, Bogor Regency. The data processed in this study are primary data obtained from the source directly based on real data recorded during the practice or simulation of making Jipang cake at the research location and community service. Based on the calculation, the results of the production cost of Jipang cake based on the full costing method is Rp. 472.15 or rounded to Rp. 500 per pcs.</p>

Flow Shop Providing Frequency Regulation Service in Electricity Market

Electricity cost is one of main production costs for flow shops. Providing frequency regulation services can help electric loads reduce their electricity costs. Previous studies mostly focus on automatic generation control (AGC) strategies for other types of electric loads, such as air conditioners, EVs or battery storage. In this paper, we find flow shops competent to follow regulation signals and avoid interrupts of processing with the help of scheduling optimization. This finding may be an aid for flow shops by availing regulation services to the market and making a profit. Hence, we propose an AGC strategy for optimizing flow shop scheduling, without affecting the operation. To formulate the bidding strategy for flow shops in regulation market, we considered as many relevant factors as possible, including the regulation performance and yield of flow shops, constraints on load power, regulation reserve capacity and machines operation, inventory of each semi-finished product, AGC strategy—as well as the coupling between the bids in both energy market and regulation market. Our case study shows the potential of the methodology proposed in this paper to cut down the electric cost of flow shops and supplies of performance-qualified frequency regulation service.

Effect of organic N-sources on maize yield components

Maize is one of the main staple crops of the world but needs large amounts of nitrogen (N) to achieve a high yield. Mineral N fertilization is one of the main production costs to cultivation and organic N sources could be a cost-effective alternative to mineral sources. We hypothesized that organic N sources could replace mineral fertilizer whilst maintaining high yields. Therefore, our study examined the effect of N supplied through organic sources on the yield of maize and its components and evaluated the economic viability of using organic N sources in terms of cost savings of energy resources. A field experiment was carried out in the Southeastern region of Brazil (São Paulo state) on a Typical Acrudox soil with a clay texture. The experiment was set out in a complete randomized block design, with six treatments (five N sources + control) and four replicates. The treatments were: (A) mineral source (urea - Ur); (B) a by-product from the food industry (Fby); (C) biofertilizer from swine manure (Bs); (D) poultry bedding (Pb); (E) cattle manure (Cm); and (F) control (Co - without N). The maize yield components evaluated were plant height (V6 and R2 stages), root dry mass and morphoanatomy (R2 stage) and, at harvest, grains in ears, thousand kernel weight (TKW), productivity and crop residues dry mass. Economic viability was assessed by considering the cost of each N source in relation to gross economic revenues from the sale of corn. Overall, the results showed that only Fby produced better yield components and was more productive than urea. This source also provided the highest economic revenue and the lowest fertilizer cost for each unit produced. The Pb and Cm sources were less productive than the mineral source, but were better than Bs, which was slightly better than the control (without N application). The same pattern of results was found for economic revenue and fertilizer cost. Bs was the most expensive N source and consequently gave the lowest economic returns to farmers. In summary, the N efficiency of the organic sources as an alternative to mineral sources for high-yield maize was ranked as follows: Fby >Ur> Pb > Cm > Bs > Co.

Determination of feeding strategies in aquaculture farms using a multiple-criteria approach and genetic algorithms

Since the 1990s, fishing production has stagnated and aquaculture has experienced an exponential growth thanks to the production on an industrial scale. One of the major challenges facing aquaculture companies is the management of breeding activity affected by biological, technical, environmental and economic factors. In recent years, decision-making has also become increasingly complex due to the need for managers to consider aspects other than economic ones, such as product quality or environmental sustainability. In this context, there is an increasing need for expert systems applied to decision-making processes that maximize the economic efficiency of the operational process. One of the production planning decisions more affected by these changes is the feeding strategy. The selection of the feed determines the growth of the fish, but also generates the greatest impact of the activity on the environment and determines the quality of the product. In addition, feed is the main production cost in finfish aquaculture. In order to address all these problems, the present work integrates a multiple-criteria methodology with a genetic algorithm that allows determining the best sequence of feeds to be used throughout the fattening period, depending on multiple optimization objectives. Results show its utility to generate and evaluate different alternatives and fulfill the initial hypothesis, demonstrating that the combination of several feeds at precise times may improve the results obtained by one-feed strategies.

Techno‐economic assessment of carboxylic acids, furfural, and pellet production in a pine sawdust biorefinery

AbstractPine sawdust is an important lignocellulosic waste from the primary industrialization of wood, and its valorization using the biorefinery concept could add new value chains to the forest industry. Compared with large‐scale biorefineries, small‐scale ones involve lower capital and logistics costs, lower risk, and can increase the use of labor in rural areas. A scheme was proposed for the use of the hemicelluloses obtained from the spent liquor of a steam explosion pretreatment of pine sawdust. With the proposed scheme, levulinic acid (LA), formic acid (FA), acetic acid and furfural are obtained from the liquid fraction while pellets are produced from the solid fraction. This pine sawdust biorefinery allows about 747 kg of pellets, 57 kg of LA, 23 kg of FA, 18 kg of acetic acid, and 22 kg of furfural per 1000 kg of dry sawdust to be obtained. The energy used for LA production is one of the main production costs. When 95% of the residual solid is used to generate steam, there is an improvement in the internal rate of return (IRR). The heat integration allows a reduction of 10% in the steam consumption for LA, increasing the capacity for pellet production. The results obtained are therefore essential when seeking alternatives for pine sawdust biorefineries, focusing on the improvement of the production processes, satisfaction of energy requirements, and the reduction of the recovery costs. Three alternatives for the valorization of pine sawdust were analyzed and the best of them obtained an IRR of about 17%. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

Isolation and production of polyhydroxybutyrate (PHB) from isolated strain bacillus sp. using crude glycerol as a carbon source

Polyhydroxybutyrate (PHB) is polyester produced by a range of microbes under unfavorable growth conditions and stored as an intracellular carbon and energy material. PHB production is more expensive than petrochemical polymer production. The main production cost is the cost of carbon substrate. The aim of this study is to produce PHB using a cheap carbon source, crude glycerol, which is a major byproduct in the biodiesel manufacturing process. PHB producing bacteria species were isolated from the soil collected around biodiesel plants and screened by Nile Red staining method. The effects of sources and concentrations of crude glycerol on the biosynthesis of PHB were investigated. The maximum PHB content obtained after 24 hours of batch cultivation was 23.59 % of cell dry weight at initial crude glycerol of 10 g/L and C:N ratio of 1:0.4.

Improvement of Wood Fuel Pellet Quality Using Sustainable Sugar Additives

The global production and use of wood fuel pellets has increased significantly in recent years. The raw material and the energy required to dry it are the main production costs. Therefore, it is crucial to minimize energy consumption, production costs, and the environmental impact associated with wood pellets. However, these changes should not negatively affect the quality of the pellets. One way to achieve these goals is to use additives. This work investigates how different types of sugar additives affect both the energy needed by the pellet press and the durability and oxidation of the produced pellets. When sugar was used as an additive, the energy use was practically unaffected. When molasses and SSL were added, a small decrease in energy use was observed (6 to 8%) for admixtures up to 1 wt.%; however, when more molasses was added, the energy use increased. Using these additives increased the bulk density (7 to 15 %) and durability (10 to 20 %) of the pellets. The storage of the pellets also caused a small increase in durability (1 to 3 %). Volatile organic compounds were produced as oxidation peaks within the first two months of storage; thereafter, the peaks tapered off.

A control method for agricultural greenhouses heating based on computational fluid dynamics and energy prediction model

As energy heating is one of the main production costs, many efforts have been made to reduce the energy consumption of agricultural greenhouses. Herein, a novel control method of greenhouse heating using computational fluid dynamics (CFD) and energy prediction model (EPM) is proposed for energy savings and system performance. Based on the low-Reynolds number k–ε turbulence principle, a CFD model of heating greenhouse is developed, applying the discrete ordinates model for the radiative heat transfers and porous medium approach for plants considering plants sensible and latent heat exchanges. The CFD simulations have been validated, and used to analyze the greenhouse thermal performance and the priority of fan coil units (FCU) loops under the various heating conditions. According to the heating efficiency and temperature uniformity, the priorities of each FCU loop can be predicted to generate a database with priorities for control system. EPM is built up based on the thermal balance, and used to predict and optimize the energy demand of the greenhouse online. Combined with the priorities of FCU loops from CFD simulations offline, we have developed the CFD–EPM-based heating control system of greenhouse with surface water source heat pumps system (SWSHPS). Compared with conventional multi-zone independent control (CMIC) method, the energy savings potential is between 8.7% and 15.1%, and the control temperature deviation is decreased to between 0.1°C and 0.6°C in the investigated greenhouse. These results show the CFD–EPM-based method can improve system performance with more accurate temperature, more rapid responses and lower energy consumption.

Coolie Drivers Or Benevolent Paternalists? British Tea Planters in Assam and the Indenture Labour System

AbstractThis paper traces the evolution of the indenture labour system in the tea plantations of Assam and, simultaneously, the shaping of the attitudes of British planters towards the labour force. Also explored are: the significant fact that only a small number of British managerial personnel were in charge of a huge migrant labour force; how the need to step up tea production for the competitive world market while keeping down costs—i.e. labour costs, being the main production cost—fostered an exploitative labour system, with planters taking frequent recourse to physical and economic coercion; and the ensuing extra-legal measures needed to keep the labour force under control. The paper also demonstrates that the colonial state was in full cognizance of the injustices of the labour system. Legislation by the government had laid the foundations of the indenture system and, while there were provisions for protecting the interests of labour force, these were on the whole ignored, with the state turning a blind eye to the planters’ use of physical and other extra-legal measures. One instance involved Chief Commissioner Henry Cotton, who attacked the injustices of the system. This attack was silenced swiftly, and the stance taken by Viceroy Curzon as the incident played out is a clear pointer to the government's willingness, to side with tea-industry interests at all costs.

Video Evaluation of Table Olive Damage during Harvest with a Canopy Shaker

Table olives (Olea europaea) traditionally are hand harvested when green in color and before physiological maturity is attained. Hand harvesting accounts for the grower's main production costs. Several mechanical harvesting methods have been previously tested. However, tree configuration and fruit injury are major constraints to the adoption of mechanical harvesting. In prior work with a canopy shaker, promising results were attained after critical machine components were reconfigured. In this study, stereo video analysis based on two high-speed cameras operating during the harvesting process were used to identify the sources of fruit damage due to canopy-harvester interaction. Damage was subjectively evaluated after harvest. Fruit mechanically harvested had 35% more bruising and three times as many fruit with broken skin as that of hand-harvested fruit. The main source of fruit damaged in the canopy was the strike-impact of fruit by harvester rods. Implementation of softer padding materials were effective in mitigating fruit injury caused by the impact of rods and hard surfaces. Canopy acceleration was correlated with fruit damage, thus restricting improvements needed for fruit removal efficiency through increased tine frequency.

Diffusion du coton génétiquement modifié en afrique du sud : des leçons pour l'afrique zone franc

Cotton production in South Africa derives mainly from commercial farming, it is not so much correct to present the so-called success of its adoption of Genetically Modified Cotton (GMC) as an example of successful GMC use by smallholding farmers. With reference to a fluctuating if not declining cotton production, the so-called success is debatable as it is clear that a mere technology introduction cannot ensure production increase. Other factors matter, in particular the institutional ones. Focusing exclusively the debate on the GMC issue has diverted the public attention from dealing with these factors.Cotton sector has suffered from severe instability whose negative effects impacted mainly smallholders. The last stage of the institutional evolution within this sector, oriented towards further intensification secured by irrigation, encompasses a risk of debarring most smallholders from producing cotton if the new approach cannot further scale up. It seems that this questionable evolution of the agriculture in the Makhatini Flats has been concealed by the exclusive debate about GMC.The results of our research complement the existing ones by pointing out bad profitability in an unfavorable climatic and institutional context. This reminds us that rain-fed agriculture remains sensitive to climatic hazards and that adoption of new technology might increase its financial risk. Wholly speaking, the outcomes of the GMC use in South Africa are unstable at a very low yield level. Change in the production cost structure should be emphasized since expenses on seeds becomes the main cash production cost. Today, only a few countries in Francophone African countries benefit from institutional stability which is favorable to GMC introduction. Such an introduction calls for preparation notably to negotiate favorable economic conditions of biotechnology transfer and to reorganize seed distribution in compliance with farmers' interests. This preparation would not be easy and adoption of GMC should not be precipitated..

Diffusion du coton génétiquement modifié en Afrique du Sud : des leçons pour l'Afrique Zone Franc.

Si l’utilisation du coton genetiquement modifie (CGM) en Afrique du Sud, depuis 1996-1997, est le plus souvent presentee comme un succes d’adoption d’OGM par les petits paysans de pays en developpement, c’est une presentation qui occulte le fait que la production cotonniere est d’abord celle des fermiers blancs. Le succes du CGM dans ce pays est aussi tout relatif car la production continue a decliner et la part des petits paysans noirs reste toujours aussi faible. Le cas de l’Afrique du Sud montre que la seule introduction d’une technologie nouvelle ne suffit pas pour assurer la progression de la production a l’echelle du pays. Des facteurs d’ordre institutionnel interviennent, mais la focalisation exclusive sur le CGM les occulte. Nos travaux fondes sur une enquete recente mettent en evidence une mauvaise rentabilite dans une annee defavorable sur le plan climatique et institutionnel. Dans des conditions plus favorables, la rentabilite est meilleure, mais avec un risque financier accru. Rares sont les pays de l’Afrique Zone Franc presentant aujourd’hui une stabilite institutionnelle favorable a l’introduction du CGM. Celle-ci necessite preparation notamment pour negocier des conditions economiques favorables de transfert de la biotechnologie et pour une reorganisation de la distribution de semences preservant les interets des paysans. Les difficultes associees a cette preparation mettent en garde contre une adoption precipitee.

Energy saving potential of greenhouse climate control

As energy costs are one of the main production costs many efforts were made to reduce the energy consumption of greenhouses. One possibility is the development of new control strategies (e.g. wind-dependent control [B.J. Bailey, Wind development control of greenhouse heating, Acta Hort. 174 (1985) 381–386]). But in most cases the energy saving potential of control seems to be overestimated. In this paper the main influences of control strategies on energy saving are discussed. For example calculations of energy consumption were made for several control strategies. The results elucidate that there are only minor differences in heat consumption for the investigated control strategies and therefore energy saving potential of control is also small. For online optimisation of control it is more important to increase the yield in order to maximise the net income of the grower. As the heating costs are about 10% of the total production costs a reduction in yield of 1% must be compensated by more than 10% energy saving.

Energy Saving Potential of Greenhouse Climate Control

As energy costs are one of the main production costs many efforts were made to reduce the energy consumption of greenhouses. One possibility is the development of new control strategies (e.g. wind dependent control, Bailey 1985). But in most cases the energy saving potential of control seem to be overestimated. In this paper the main influences of control strategies on energy saving are discussed. By example calculations of energy consumption were made for several control strategies. The results elucidate that there are only minor differences in heat consumption for the investigated control strategies and therefore energy saving potential of control is also small. For online optimisation of control it is more important to increase the yield in order to maximise the net income of the grower. As the heating costs are about 10% of the total production costs a reduction in yield of 1% must be compensated by more than 10% energy saving.