Potential Economic Return Research Articles

Employing criteria scoring matrix in appraising the economic return of transcending to a circular built environment

PurposeThe circular economy concept emerged as the resolution to the destructive linear economy practices. Nevertheless, the transition to a circular built environment is hindered due to the ambiguities of the economic value of the concept. Conversely, numerous decision-making tools are applied in the construction industry in assessing economic alternatives, even if there is a gap in utilising these tools in appraising circular economic practices. Hence, this study investigates the potential benefits of applying proven decision-making practices, particularly criteria scoring matrices, in developing circular built environments.Design/methodology/approachA qualitative approach was followed to achieve the aim of the study. A conceptual design of a criteria scoring matrix was developed with a comprehensive literature survey. Semi-structured interviews of a three-round Delphi expert survey were employed to assess the matrix qualitatively and develop the matrix further. Data were analysed using the content analysis method.FindingsThe lack of a value assessment tool in economically assessing the circular economy principles is a key barrier to transcending to a circular built environment. In addressing this issue, this study develops a criteria scoring matrix for circularity value assessment during the design stage of a construction project.Originality/valueThis research contributes to the theory by developing a criteria scoring matrix to measure the economic contribution of circular economy principles. Further, this research contributes to the practice by allowing construction alternatives to be selected, balancing the potential economic return options of a project with the project's contribution to a circular economy.

In vitro approaches for the production of aloin: Advancements and opportunities

Aloin, a C-glycosidic derivative of anthraquinone, exhibit immense applications in cosmeceutical industry. It is the main active ingredient of the latex from Aloe vera L., commonly referred as ‘Aloe’ and ‘Ghritkumari’. Aloe is a monocotyledonous, perennial, succulent, herbaceous medicinal plant belonging to the family Liliaceae. Aloe marked its place as a plant of the hour with its versatile uses in pharmaceutical, food, and cosmeceutical industries ensuring a potential economic return. Anthraquinone is the major bioactive component of Aloe and is synthesised via the acetate-polymalonate pathway or shikimic acid-O-succinyl benzoic acid-mevalonic acid pathway. In order to fulfil the industrial demand for enhanced aloin production, methods to complement large-scale Aloe planting techniques must be devised. The conventional method of aloin production is associated with several drawbacks, such as male sterility, insufficient number of planting material, incidence of several diseases and pests of Aloe, ensuing in decline of propagation rate and subsequent aloin accumulation. Hence, biotechnological approaches appear as a better alternative to those conventional systems. The current review focuses on aloin chemistry, its natural biosynthesis, cosmeceutical applications, biotechnological (in vitro) approaches for aloin production as well as highlights the research gaps, unexplored areas, and major obstacles that can be investigated in the near future to ameliorate the production of aloin. To date, reports were emphasized towards direct and indirect regeneration system of Aloe but only a few reports stated the enhancement of aloin production. There is a wide scope for researchers to ameliorate the aloin production via yet-to-be explored synthetic seed technology, elicitation, polyploidization, manipulation of genes involved in aloin biosynthesis pathway, nanotechnology, etc. Hence, this review paves the way forward for Aloe-researchers and scientists associated with research and development at cosmeceutical industries to explore the areas for commercial-scale biotechnological production of aloin.

Estimating the quantity of consumed plastic products and their economic returns in the city of Benghazi1

Abstract
 Plastics recycling has gained significance and popularity over the last few decades due to environmental and economic reasons. Huge quantities of plastic products can be found in Benghazi city in places such as hospitals, restaurants, schools, factories, etc. Rather than accumulating these plastics products in the landfill areas, they can be recycled. Such an action preserves the environment and leads to great financial savings. This study aims to gather data on post-consumer plastic products from different locations and facilities in Benghazi. The plastics products have been classified into five types namely, PET, HDPE, LDPE, PP, and PS. The results revealed that many of the consumed products were PET. The study also reported the potential economic return of these products to some public institutions such as schools, the orphanage, and the homes of the disabled. Also, the study may serve as a starting point to the municipality of Benghazi and other local authorities towards improving the utilization of plastics waste and realizing the significance of their economic return.

Open Innovation moves in SMEs: How European SMEs place their bets?

Although Open Innovation (OI) may be a source of opportunities for Small and Medium Enterprises (SMEs), it also represents risks. How SMEs manage the balance between potential benefits and associated risks remains an overlooked topic in the literature. In parallel, recognizing the need for a more fine-grained level of analysis, we introduce the concept of OI moves to disentangle the OI projects of SMEs. An ‘OI move’ is defined as the set of managerial decisions and actions that are executed to reach specific innovation outputs in the framework of a collaboration with a single partner that is conducted as a part of an OI project. An OI move consist of the combination of two building blocks: a) the type of partner chosen to innovate with - ‘who is the SME innovating with’ and b) the exploitation mode - ‘who is exploiting the result’. Using the OI move as the level of the present analysis, we argue that different OI moves have the potential of delivering different benefits, but they also represent different levels of risk. To that end, the aim of our research is to explore how SMEs weigh benefits and risks at the level of OI move.On the basis of a unique data set of 106 in-depth case studies of innovation projects carried out by innovative SMEs located in Europe, 500 OI moves were identified. Clustering the extracted OI moves based on a typology formed by the combination of the type of partners and the exploitation mode revealed: a) benefits sought, b) risks encountered c) the type of partnership chosen.Findings of the study rely on the attention-based view of the firm as it provides an interesting lens through which OI is executed. Three main findings derive from the study. First, an SME initiates an OI move not only on the basis of the potential economic return. Albeit, it is the ‘attention capital’ required to create and capture value that is the SMEs' starting point in considering an OI partnership. Second, we find a ‘paradox’: SMEs tend to practice OI because they lack resources, but it is precisely the lack of resources that makes them reluctant to enter into attention-intensive OI partnerships even if return can be substantial. Third, OI moves involving communities and crowds are a ‘new playing field’ for SMEs. Because of their novelty, SMEs are reluctant to initiate such an OI move even though case-based evidence in our research demonstrates that SMEs using such collaborative forms can be quite successful.

Towards sustainable production of minerals and chemicals through seawater brine treatment using Eutectic freeze crystallization and Electrodialysis with bipolar membranes

European policy encourages the adoption of sustainable systems that promote the efficient use and recovery of minerals and chemicals. In this respect, desalination brines do contain a dramatic amount of valuable minerals and can be valorized through appropriate treatments rather than releasing them into the environment. This paper proposes an innovative brine recovery system for obtaining high purity chemicals through the integration of Eutectic Freeze Crystallization (EFC) and Electrodialysis with Bipolar Membrane (EDBM) technologies. Two separate laboratory-scale experimental campaigns were carried out to validate the potential integration of the two processes. Mirabilite (Na2SO4∙10H2O) has been recovered with a purity of 99.9% using the EFC, and a feed rich in NaCl with low impurities has been further processed in an EDBM unit. EDBM tests with feed solutions simulating EFC effluents have shown that it is possible to produce acidic and basic solutions with high purity (>99%), despite the presence of impurities in the feed. Interestingly, the low EDBM specific consumptions of 0.9–1.1 kWh kg−1NaOH at 100 A m−2 and 1.3–1.6 kWh kg−1NaOH at 300 A m−2 were comparable with and without impurities. In the context of the circular economy strategy promoted by the EU-H2020 Water Mining project, the current study demonstrates that this integrated system effectively minimizes waste, promoting sustainability while providing a potential economic return.

Revalorización del descarte originado por la producción de jugo de manzana como ingrediente funcional en la formulación de premezclas para horneados

This work evaluated the use of apple juice by-product as a functional ingredient in healthy baking premixes. Due to its high fiber content, this raw material was decided to be used as an enrichment strategy for food product formulation. Apple pomace was obtained as a by-product of the juice industry and was dried and ground to obtain apple flour. Premixes for fiber enriched muffins, cakes and biscuits were developed by partially substituting wheat flour for apple flour to obtain a product that could be labeled as “source of fiber”. The products developed were satisfactorily evaluated, but even if fiber had a negative effect on the sensory characteristics of the products, it also caused them to be perceived as healthy. Considering that the cake was the product with the highest acceptability, it was selected to make a comparative study with competing market-leading products. This comparison revealed that the developed premix contributes to the preparation of another product concept, since it was described differently than commercial products, but with comparable acceptability. Finally, it can be said that the development of premixes using apple juice by-product constitutes a new category of functional foods, which satisfies both the needs of consumers and those of the industry, making it possible to transform an environmental problem into a potential economic return for companies.

Large-scale pasture restoration may not be the best option to reduce greenhouse gas emissions in Brazil

Cattle ranching accounts for 44% of the greenhouse gas (GHG) emissions from the land use sector in Brazil. In response, Brazil has proposed a massive pasture restoration program that aspires to make ranching more competitive while at the same time reducing associated GHG emissions. Pasture restoration, however, is only one of several intensification options that could be employed to achieve these goals. Here we analyze potential production, economic return and GHG emissions from an intensification strategy based mainly on pasture restoration and compare its productive, economic and GHG emissions performances with intensification options more focused on supplemental feeding (grain-feed supplementation of grazing animals and animal finishing in feedlots). To this end, we developed a multi-sectoral, deterministic simulation model of the ranching system and applied it to Mato Grosso state, the largest producer and earliest adopter of intensive production. To account for GHG emissions, we performed a life cycle analysis of a complete beef production cycle. Our results show that an intensification strategy focused more heavily on pasture restoration does reduce GHG emissions but produces the least favorable economic and GHG emissions outcomes when compared with a range of supplemental feeding alternatives. In view of these results, Brazil should seek a more diversified strategies for cattle intensification in its climate mitigation policy.

354 The effect of OvuGel® administered to weaned sows at proestrus or estrus on reproductive performance

Abstract The use of single-fixed time insemination enhances leverage of genetically superior boars. It is prudent to elucidate the appropriate strategy for using OvuGel® by season and parity given the potential economic return. It was hypothesized that OvuGel® could be used to mitigate seasonal anestrus, in particular for parity 1 sows. The objective was to evaluate reproductive performance of weaned sows administered OvuGel® (OG; n = 1342) that expressed proestrus or estrus on d 4 post-weaning, followed by a single post-cervical artificial insemination (PCAI) 24 h later. This protocol was evaluated as an alternative to treating all weaned sows regardless of estrous behavior. The Control (CO; n = 1530) sows were inseminated via PCAI after they were identified in estrus and again 24 h later if still expressing estrus. Sows were inseminated from May through November 2017. Prior to weaning, within each replicate, sows were equally assigned to OG or CO treatment by parity, genetic line, litter size, nurse sow status and health treatment status. Farrowing rate for OG was not different than CO (86.2 ± 1.2 vs. 86.6 ± 1.2%; P > 0.10, respectively). There was no effect on total born between OG and CO (13.2 ± 0.1 vs. 13.3 ± 0.1; P > 0.10, respectively). However, there was a parity × treatment interaction. Parity 1 OG (86.6 ± 3.0%) sows had greater farrowing rates than CO (74.5 ± 3.0%) sows (P < 0.01), whereas there were no differences (P > 0.05) between treatments for the other parities. These data indicate that producers can administer OvuGel® to sows in proestrus or estrus on d 4 post-weaning, followed by a single insemination 24 h later, and achieve similar performance as sows inseminated multiple times upon detection of estrus.

A Preliminary Investigation into the Feasibility of Gin Blending

The biggest discounts to the grower are for grade, length and micronaire. Since round modules do not blend cotton from multiple parts of a field as conventional modules did, some round modules may fall below base grade. This study was initiated as a preliminary evaluation to determine the effect of gin blending on fiber, yarn and fabric processing performance and quality and the potential economic return to the grower. One lot of irrigated and dryland stripper-harvested seed cotton, with different pre-determined micronaire and length properties, were blended together in four different ratios (80/20%, 60/40%, 40/60% and 20/80%) at the gin and at the textile mill. The resulting two cottons and four blends were carded, ring spun, knitted, scoured, bleached and dyed. Based on the 2016 CCC loan schedule, gin blending can benefit the grower with the biggest economic benefit, about $5 per bale, obtained from the 80/20 and 60/40 blend ratios when using seed cotton with these particular qualities from this one-year study. Processing performance and yarn and fabric quality of the gin blended product were not different from that of the unblended cotton and the mill blended fiber, indicating no serious consequences associated with gin blending, cotton with this micronaire and length range, to the spinner.

Intercropping of maize, millet, mustard, wheat and ginger increased land productivity and potential economic returns for smallholder terrace farmers in Nepal

Low nitrogen inputs, low crop yield, and low land productivity are major challenges associated with cereal-based sole cropping systems in Nepal. Crop intensification and diversification by introducing legumes as intercrops could help alleviate these challenges. With the presence of diverse crops and cropping systems, particularly in hilly topographies, a range of intercrop options is required. We compared 10 intercrop combinations to native sole cropping systems in the mid-hills of Nepal for two cropping seasons (2015–2017) to identify the most productive and economic intercrop combinations for smallholder terrace agriculture. In the spring-summer season (i.e., mid-March to mid-July), cowpea (var. Makaibodi and Suryabodi) and bean were intercropped with maize in 1:1 rows, whereas soybean, blackgram, and horsegram were broadcast with millet (30:70 ratios) during the rainy-autumn season (i.e., mid-July to mid-November). Pea and lentil were used as pre-winter/winter intercrops (i.e., mid-November to mid-March) in mustard (30:70 ratios), while wheat was planted with pea. Ginger was planted with maize in 1:1 rows during the spring-summer season in which the maize rows were replaced by soybean and lentil during the rainy-autumn and pre-winter/winter season, respectively. Plots were analyzed for yields of individual crops as well as other agronomic indicators including land equivalent ratio (LER), total land output (TLO), harvest index (HI), and potential economic return.Maize + cowpea var. Makaibodi appeared to be the most productive and economic intercrop combination for the spring-summer season (LER – 1.58 and TLO – 4.26 t ha−1, 21% higher than the maize sole crop with an increase in potential economic return by 67%) whereas millet + soybean appeared to be the best combination for the rainy-autumn season (LER – 1.40 and TLO – 2.21 t ha−1, 26% higher than the millet sole crop with a 288% increase in potential income). For the pre-winter/winter season, wheat + pea and mustard + pea combinations appeared to be productive (wheat + pea: LER – 1.31 and TLO – 2.90 t ha-1 i.e., 16% higher than sole wheat with a 54% increase in potential income; mustard + pea: LER – 1.36 and TLO – 2.14 t ha−1 i.e., 30% higher than sole mustard with a 15% increase in potential income). The year round intercrop system (i.e., ginger + maize-soybean) displayed a LER value of 2.45 with increased TLO (21.8 t ha−1 i.e., 2% higher compared to sole ginger) which increased potential economic return by 6%. We conclude that legume intercropping was a robust option across seasons and locations confirming that it could be a promising ecological practice for intensification of cereal-based sole cropping systems on smallholder terraces. Also, it is important to note that soybean and pea provided higher potential net income to farmers as sole crops compared to when they were grown with millet and wheat as intercrops, respectively. It is important that we promote these options to smallholder farmers and disseminate the advantages of legume integration on land productivity, soil fertility management, and income.

Linking crop structure, throughfall, soil surface conditions, runoff and soil detachment: 10 land uses analyzed in Northern Laos

In Montane Southeast Asia, deforestation and unsuitable combinations of crops and agricultural practices degrade soils at an unprecedented rate. Typically, smallholder farmers gain income from “available” land by replacing fallow or secondary forest by perennial crops. We aimed to understand how these practices increase or reduce soil erosion. Ten land uses were monitored in Northern Laos during the 2015 monsoon, using local farmers' fields. Experiments included plots of the conventional system (food crops and fallow), and land uses corresponding to new market opportunities (e.g. commercial tree plantations). Land uses were characterized by measuring plant cover and plant mean height per vegetation layer. Recorded meteorological variables included rainfall intensity, throughfall amount, throughfall kinetic energy (TKE), and raindrop size. Runoff coefficient, soil loss, and the percentage areas of soil surface types (free aggregates and gravel; crusts; macro-faunal, vegetal and pedestal features; plant litter) were derived from observations and measurements in 1-m2 micro-plots. Relationships between these variables were explored with multiple regression analyses. Our results indicate that TKE induces soil crusting and soil loss. By reducing rainfall infiltration, crusted area enhances runoff, which removes and transports soil particles detached by splash over non-crusted areas. TKE is lower under land uses reducing the velocity of raindrops and/or preventing an increase in their size. Optimal vegetation structures combine minimum height of the lowest layer (to reduce drop velocity at ground level) and maximum coverage (to intercept the largest amount of rainfall), as exemplified by broom grass (Thysanolaena latifolia). In contrast, high canopies with large leaves will increase TKE by enlarging raindrops, as exemplified by teak trees (Tectona grandis), unless a protective understorey exists under the trees. Policies that ban the burning of multi-layered vegetation structure under tree plantations should be enforced. Shade-tolerant shrubs and grasses with potential economic return could be promoted as understorey.

Developing an Economic Estimation System for Vertical Farms

The concept of vertical farming is nearly twenty years old, however, there are only a few experimental prototypes despite its many advantages compared to conventional agriculture. Significantly, financial uncertainty has been identified as the largest barrier to the realization of a ‘real' vertical farm. Some specialists have provided ways to calculate costs and return on investment, however, most of them are superficial with calculations based on particular contextual circumstances. To move the concept forwards a reliable and flexible estimating tool, specific to this new building typology, is clearly required. A computational system, software named VFer, has therefore been developed by the authors to provide such a solution. This paper examines this highly flexible, customised system and results from several typical vertical farm configurations in three mega-cities (Shanghai, London and Washington DC) are used to elucidate the potential economic return of vertical farms.

Economic evaluation of an industrial high temperature lift heat transformer

Heat transformers are closed cycle thermodynamic systems which allow waste heat energy to be recycled by increasing its temperature. TAHTs (Triple stage heat transformers) are capable of increasing the temperature of supplied heat by up to ∼140 °C. This paper attempts to analyse the industrial attractiveness of such cycles by conducting a case study on the potential installation of a TAHT in a small Irish oil refinery, examining various different natural gas price scenarios. The choice of waste heat energy being recycled is shown to be pivotal to the success or failure of the installation. TAHTs are demonstrated to show most benefits when applied to waste heat streams with large quantities of latent heat. The usage of more efficient and cost effective equipment instead of conventional shell and tube heat exchangers within the system dramatically increases the potential economic return from the heat transformer. At the present gas price, the capital cost of (conventional) equipment is too high to make this investment financially attractive for the current industrial example, with excessive payback periods predicted. However a return to natural gas price levels observed in 2008 and 2009 would make the unit economically viable.

Ecosystem Services of UHE Carlos Botelho (Lobo/Broa): a new approach for management and planning of dams multiple-uses

The aim of this study was to identify and make an initial accounting of the ecosystem services of the hydroelectric power generation plant, UHE Carlos Botelho (Itirapina Municipality, São Paulo State, Brazil), and its most extensive wetlands--total of 2,640 ha--and also identify the drivers of change of these services. Twenty (20) ecosystem services were identified and the estimated quantitative total value obtained was USD 120,445,657.87. year(-1) or USD 45,623.35 ha(-1).year(-1). Investments on restoration of spatial heterogeneity along Tietê-Jacaré hydrographic basin and new technologies for regional economic activities must maintain ecological functions as well as increase marginal values of ecosystem services and the potential annual economic return of ecological functions.

Croatian Food Industry By-Products: Co-Digestion with Swine Manure vs. Use as Liquid Animal Feed

Food industry by-products such as spent brewer's yeast and whey from cheese production are being amended with nutrients and used as a feed source in the Croatian swine sector. However, as interest in energy production and anaerobic digestion of animal manures has increased, co-digestion of these materials with manure could improve the economic viability of on-farm digesters. To determine the feasibility of this approach, consideration should be given to whether food industry by-products provide a better economic return as a low-cost animal feed or as an anaerobic digester feedstock. In addition, while slaughterhouse wastes are not used as an animal feed, this article also considers the use of this material as a co-digestion feedstock. The economic information and substrate selection presented in this article are based on by-products available to a swine farm in Croatia and production data from the facility while feeding with by-products. Biochemical methane potential (BMP) assays were used as a fast, inexpensive method to determine the potential methane production rates for the various substrates. Using BMPs, the potential methane production rates for various combinations of spent brewer's yeast, whey, slaughterhouse waste, corn silage, and swine manure were also determined. Results of the BMP assays were used to compare the potential economic return of using the food wastes to produce methane in the digester to the value of these materials as feed ingredients for swine production. Based on live production data, liquid feeding of food industry by-products was calculated to provide a $6.89 savings per finish pig produced over a 90-day period at the Croatian facility. Since the facility produces 14,000 finish pigs every 90 days, this represents a cost savings of $96,000 per turn, or over $307,000 per year considering that the facility finishes 3.2 turns of pigs per year. Using cheese whey or spent brewer's yeast as a co-substrate in the proposed swine manure digester has the potential to provide an additional income via electricity generation of $26,000 and $34,000 over a 90-day period, or $83,000 and $109,000 annually, respectively. These values were based on the value of the substrate, assuming that either a digester or liquid feeding system already existed. Based on the data, the economic return is better when the by-products are used as a feed ingredient. However, if the swine digester is amended with all available co-substrates, including whey, spent brewer's yeast, slaughterhouse waste, and corn silage, the potential additional income is $168,000 per 90-day turn or $538,000 per year. The data presented in this article include substrate characteristics, potential methane production normalized on the basis of mass of substrate volatile solids, estimated electricity generation potential, and economic data.

A variable-rate decision support tool

Profitable precision or variable application of inputs depends on many factors; however, the inherent variability in a soil and or crop property and the relative responsiveness of yield to fertilizer inputs at different soil concentration levels are the most important factors in influencing economic gain. Generally, the greater is the spatial variation in the property influencing the input rate, the greater is the potential economic return from precision application compared to uniform application of an input. Based on a quantitative assessment of the spatial variation in soil properties that influence rates of input, a variable-rate decision support tool (VRDST) was developed to: (1) assess the potential profitability of variable-rate compared to uniform application and (2) identify the economic optimal uniform application rate if this is selected. The VRDST was evaluated using spatially distributed soil data from selected fields in North Carolina. Net return from variable-rate application and the economically optimal uniform rates are illustrated. Varying fertilizer cost, crop price and sampling costs greatly influenced net return from variable-rate application.

Indigenous livelihood systems in industrial tree-plantation areas in West Kalimantan, Indonesia : economics and plant-species richness

An ‘integrated tree plantation’ approach combining indigenous livelihoods and industrial wood production is being implemented in West Kalimantan, Indonesia. In this study the economics of land-use was investigated in villages within the plantation scheme. The effect of three alternative land-use scenarios and costs and benefits of each land-use type were studied using linear programming. The scenarios were based 1) on the current land-use, 2) on the integrated tree plantation system with incentives and government regulations, and 3) on a financially optimal land-use distribution. Additionally, plant species richness in different land-use types was surveyed. The scenarios had different kinds of effects on villages varying in respect to their possibilities for land-use intensification. In villages with extensive land use, establishment of tree plantations without any land-use regulations increased the potential economic return on land, resulting in conversion of natural and man-made semi-natural forests into swidden fields. In villages with more sedentary agriculture, the plantation scheme did not create pressures towards remaining forests even in the case of financially optimal land-use distribution. Incorporation of land-use regulations prevented further deforestation but also decreased households' economic returns. The results also showed that conversion of Imperata grasslands to any other land-use increased species richness. Incentives, restrictions or regulations aiming at conserving natural and semi-natural forests are needed to ensure conservation of biodiversity and long-term improvements in local livelihoods. It can be concluded that tree plantations can be combined with other land-use practices: They can improve the economic return on land without further degradation of the environment.

Examples of strategies to analyze spatial and temporal yield variability using crop models

Process-oriented crop growth models simulate plant growth over homogeneous areas. The advent of precision farming has resulted in the need to extend the use of point-based crop models to account for spatial processes. Spatial processes include surface and subsurface water flow and spatial and temporal interaction of plant growth with soil water, nutrient and pest stress and management practices. Our research has focused on developing methods to account for spatial interactions in the CROPGRO-Soybean and CERES-Maize models. These methods introduce new challenges for accurately and economically defining spatial inputs for the models. In spite of these challenges, both models have been used to evaluate causes of spatial yield variability with reasonable success. The purpose of this paper is to present several examples of strategies that we have found useful in using these models to assess spatial and temporal yield variability over different environmental conditions and to analyze economic return of prescriptions. Strategies to overcome spatial resolution in point-based crop models include calibration techniques to run point-based models at small scales within a field, using remote sensing to target measurements of models inputs to areas of similar plant response, and linking point-based models to three-dimensional water flow models to better represent water transport. Each strategy is demonstrated using case studies and comparison of simulated and measured data are presented. A method to estimate break-even costs associated with variable soybean cultivar placement in a field is outlined and presented as a case study as well. Crop models can provide useful estimates of potential economic return of prescriptions, as well as estimate the sensitivity of a prescription to weather. They can also estimate the value of weather information on management prescriptions.

Nitrogen Fertilization of Dryland Grasses in the Northern Great Plains

Dryland grass production is an important agricultural commodity in the Northern Great Plains. Nitrogen (N) fertilizer can increase dry matter production and forage quality, yet there are relatively few rangeland and improved pasture managers who utilize fertilization practices to optimize production. Two trials (1972-1975 and 1978-1981) with 10 common grass species used a single application of 0, 56, or 112 kg N ha-1 and 0, 112, or 224 kg N ha-1 to evaluate long-term grass performance to N fertilization. Dry matter production in each trial was measured annually for 4 years. Yields increased on average 1,340 kg ha-1 with the application of 56 kg N ha-1, and 1,662 kg ha-1 with 112 kg N ha-1 in Trial 1. In Trial 2, yields increased 3,499 and 5,140 kg ha-1 with applications of 112 and 224 kg N ha-1, respectively. Responses to applied N were evident 4 years after application for some species, most likely due to the combination of improved grass vigor and recycling of fertilizer N immobilized in organic forms. Single applications of N were effective in improving dry matter production of some common grasses for multiple years, when water was suitable. The magnitude of response and potential economic return from fertilization were species dependent.

THE COOPERATIVE DEVELOPMENT OF THE GOBE OIL FIELDS

The proposed Gobe Petroleum Development Project includes the development of two separate oil fields, SE Gobe and Gobe Main. The fields are located, respectively, in the northwestern area of Petroleum Prospecting License (PPL) 56 and the southeastern area of PPL 161 in the Gulf and Southern Highlands provinces of Papua New Guinea, approximately 500 km northwest of Port Moresby, 80 km northwest of the town of Kikori and 85 km southeast of the Kutubu oil fields.The Gobe anticline, on which the discovery wells were drilled, is a large east-southeast trending ridge situated at the leading edge of the Papuan Fold Belt. The surface of the anticline was formed by folded limestone which has weathered to produce a rugged terrain characterised by intense pinnacle karst topography. Dense rainforest covers all of the project area. The crest of the anticline is in excess of 1,300 m above sea level, with the hydrocarbons occurring between approximately 900 m and 1,200 m below sea level.The Gobe Main Field is located entirely within PPL 161 which is operated by Chevron Niugini Pty. Ltd. The SE Gobe Field is located within both PPL 56 and PPL 161. The PPL 56 license is operated by Barracuda Pty Limited. Both of the fields are situated approximately 15 km from the existing Kutubu oil export pipeline. Development planning for the two fields is now at a mature phase and the two license groups are preparing to submit Petroleum Development License Applications (PDLA) to the PNG Government. Initial production is targeted for December of 1997 and the fields are forecast to produce at a combined peak rate of approximately 50,000 BOPD.The potential economic return to participants and the state will be optimised by developing these fields in a cooperative manner with shared production facilities. Similarly, utilisation of the nearby Kutubu oil export pipeline will yield benefits to both the field developers and pipeline owners. The Gobe development serves as an example of how the economics of two 'marginal' field developments can be enhanced by employing existing infrastructure and sharing of facilities. This paper will provide an overview of this cooperative approach to development.