Modeling economic, biophysical, and environmental dynamics of potato production system

The adoption and use of diversified cropping practices has become widely accepted by producers. However, the profitability of an enterprise is dependent on the biophysical and economic factors. The biophysical factors determine the enterprise relationship among the various crops, their interactions with the ecosystem, and how each of them fits into the overall management plan. The economic factors determine the relative advantage of each crop and service in the farm plan. Although there have been experimental studies in Canada examining the impacts of rotations on the agronomics of field crops, there is limited research in modeling economic and environmental dynamics of the potato production system. Potato production in Manitoba has rapidly increased in recent years and became the second largest potato producer in Canada producing about 22.2% of the total Canada's potato production as of 2004. Alberta has had similar expansion with the highest yield per acre in Canada. The expansion of potato industry in these two provinces and other parts of Canada has created some concerns about agro-environmental indicators such as water contamination, soil erosion and long-term profitability of potato production practices. The objective of this study was to address some of these concerns and develop a dynamic model that integrates environmental and economic components of potato production systems and estimates sustainability of some of the agricultural practices. A Stella Modeling framework was developed to provide crop production and environmental input to an economic model of potato rotations. The economic performance of different potato rotations ranging from two to four years in duration, and containing potatoes in combination with oilseed, cereal, forage, and legume crops was evaluated based on standard budgeting techniques. Net income was estimated as the income remaining above cash costs (i.e., seed, fertilizer, chemical, fuel and oil, repairs, crop insurance premium, miscellaneous, land taxes, and interest cost on variable inputs), ownership costs (depreciation, interest on investment, and insurance and housing) for machinery and grain storage, and labour. All annual inputs used in each phase of rotation for each management treatment, the type and frequency of field operation, year and replicate including pre-plant activities, tillage, fertilization, planting, insects and pests control, harvesting, storage, and transportation were included in the analysis. Modelling the economics of irrigated potato rotations required input from an agro-environmental model. This agro-environmental model was developed to simulate nutrient dynamics, soil moisture dynamics, soil characteristics and erosion, soil organic matter content, residue decomposition, and crop growth. The economic model takes into account economic factors and costs that are influenced by yield function, nutrients and crop water thus establishing the link between the agro-environmental module and the economic module. Farm operation costs in our model are divided into two categories: dependent costs and base costs. Dependent costs are costs that are controlled by the agro-environmental module, including yield dependent costs, irrigation dependent costs and fertilizer dependent costs. Base costs were developed through experimental evaluation with E-Views and remain constant throughout the rotation. On the agro-environmental side, the model outputs the changes in soil organic matter, soil loss due to erosion, and carbon dioxide emission due to decomposition and mineralization. Results of the model show that changes in these variables are dependent upon the length of, and the crops involved in, the rotation. The economic model results showed highest average net revenue was found in shorter two-year rotations due to the greater frequency of potato.Crop Production/Industries,

Effects of precision farming, N rate, and temporal trends on wheat yield and productivity

Non-Peer Reviewe

Economics and science of hog manure handling and storage technologies

Non-Peer ReviewedHog production has been growing rapidly in Canada and this growth has created concerns over manure handling and the risk of soil and water contamination. There is limited information available to swine producers as to which technologies and manure management systems would best serve them both economically and environmentally. The objective of this study is to assess hog manure handling and storage systems and outline their environmental advantages and disadvantages. Five main technologies are reviewed which include (1) manure handling, (2) solid/liquid separation, (3) composting, (4) land application, and (5) manure storage. The average cost of hauling liquid manure within 2-3 mile distance is about $0.0125. If the total cost of hauling liquid manure is charged against its nutrients value, the producer cannot afford to haul much more than 2 to 3 miles; therefore, there is a restriction on the distance that manure can economically be moved and the availability of suitable land for manure application becomes a concern. Because of this restriction, manure treatment and the technologies for manure management such as solid/liquid separation or composting become attractive technologies to consider both economically and environmentally. Liquid/solid separation is a step in a complete manure treatment system and it has been utilized to reduce odour and manage phosphorus. There are different technologies available for solid/liquid separation which cost anywhere from$1.22 to $5.38 per pig marketed. Composting could also be utilized in swine manure management but because of high moisture contents, a high carbon source or bulking agent is required. Composting itself could costs anywhere from$4.85 to $13.49 per tonne of raw manure composted depending on type of composting technologies used. Manure storage is also part of integrated manure management system which comes in three main forms: earthen, concrete, and steel. Earthen manure storage systems are the most prominent manure storage systems in Western Canada. The capital cost for earthen manure range from$0.0039 to $0.0953 per gallon depending on availability of equipment and materials and additional costs may also required for adding a liner of clay. Other types of storage system generally cost higher but they might be more environmentally friendly. Operation and maintenance costs of manure storage is mainly limited with seasonal labor for agitation the waste, removal of sludge, and performing pump outs

Comparison of fractional excretion of sodium, uric acid and urea nitrogen in diagnosis of pediatric acute prerenal failure

Background and aim: various factors, in terms of faster diagnosis of acute renal failure have been studied so far, but these studies have been done mostly on adults. Therefore, in this paper we made a comparison of fractional excretion of sodium (FeNa), uric acid (FeUa) and urea nitrogen (FeU) in acute prerenal failure in children to find out which one is more sensitive in diagnosis of acute prerenal failure. Material and Methods: In a cross-sectional study, 5 CC blood was taken from 29 children of 1 month to 15 years old, diagnosed with acute pre-renal failure; the amount of creatinine, sodium, uric acid and urea nitrogen was measured in their plasma. After taking a standard urine specimen, all the mentioned items were measured in patients' urine and put into the formula of FeNa, FeUa and FeU and compared. Results: In this study, 75.8% FeU, 68.9% FeUa and 58.6% FeNa are agreeable to prerenal criteria and the most sensitivity is assigned to FeU. Among the three groups, FeNa is more affected by treatment with diuretic. The difference between FeNa in the receiver group of normal saline and the receiver group of diuretic is more than those groups which did not receive any. Conclusion: Fractional excretion of urea nitrogen in children, especially in the receivers of diuretic is more sensitive in diagnosis of acute prerenal failure. Moreover, this index is more sensitive in diagnosis of acute prerenal failure than the other indexes

Economic assessment of pulse crop rotations in western Canada

Non-Peer ReviewedPulse crops have become essential to farming practices in the Northern Great Plains, but little has been studied how rotation systems with different crop mixes affect the economic returns. Initiated in 2010, a four-year crop rotation study was repeated at Swift Current, Saskatchewan, and Brooks, Alberta to identify effective crop rotation length and frequency of pulses in a rotation and to evaluate the economic returns for individual crop and for the entire crop rotations in western Canada. Rotation systems that included one or two lentil crops in the 4-year sequence lead to greater and consistent revenue gains at all sites. Wheat monoculture resulted in the lowest net return due to higher cost and lower product prices compared with other crops in the rotation

Residual effects of preceding crops on wheat yield and profitability

Non-Peer ReviewedA four-year cycle crop rotation study (cereal crop with a range of legumes and oilseeds at different frequencies and sequences in rotation) was established from 2010-2018 at three locations in western Canada to evaluate the effects of legume and non-legume preceding crops on wheat yield and profitability. Preceding legume crop residues significantly influenced the average yield and annual net revenue of the following cereal crop wheat; however, the residual effects on wheat were not uniform among legume crops. Effects of legume and non-legume preceding crops on the following crop wheat will be presented and discussed

Modelling soil dynamics and the effect of nitrogen levels on potato yield function

Non-Peer ReviewedCrop yield is maximized when optimal levels of nutrients, water, and other inputs are available to the crop and the influence of disease and weeds has been minimized. While each crop has differing responses to nutrient availability, modelling soil dynamics and the effect of nitrogen levels on potato yield is very important. The objective of this study was to model several environmental components of potato yield function including soil characteristics and organic matter content, soil nitrogen, temperature component, moisture component, solum and nitrogen mineralization, nitrogen fertilizer, and nitrogen sufficiency. The interaction of these components with moisture availability and nitrogen sufficiency was shown to impact potato yield

Residual effects of preceding crops on wheat yield and profitability

Non-Peer ReviewedA four-year cycle crop rotation study (cereal crop with a range of legumes and oilseeds at different frequencies and sequences in rotation) was established from 2010-2018 at three locations in western Canada to evaluate the effects of legume and non-legume preceding crops on wheat yield and profitability. Preceding legume crop residues significantly influenced the average yield and annual net revenue of the following cereal crop wheat; however, the residual effects on wheat were not uniform among legume crops. Effects of legume and non-legume preceding crops on the following crop wheat will be presented and discussed

Economics of mixed farming under rotational grazing with low input system

Non-Peer ReviewedThis study was conducted at the Manitoba Zero Tillage Research Farm (MZTRA) located 17.6 kilometres north of Brandon, Manitoba. The objective was to evaluate new farming systems designed to improve economic return, sequester carbon, and reduce inputs, energy use, and greenhouse gas emissions of mixed production systems. Yield and net revenue varied across MZTRA landscapes due to spatial and temporal variability of soil fertility and biophysical properties. Relative to studies with conservation tillage in the Canadian Prairies, producers can expect to achieve higher crop yields with most crops under zero tillage. Compared to crop yields reported for conventional tillage (CT) in Thin Black soil zone of Saskatchewan, spring wheat was 11 to 32% higher, winter wheat 41 to 66% higher, pea 27% higher, and flax was comparable. There were no significant differences in total input cost among annual crop rotation. Our results indicated that small-scale mixed crop and livestock operations had higher operating costs, the success of which depended on animal and environmental conditions as well as management. Hay and grazing systems also had higher risk. Among annual crops, although net revenue was higher for canola and peas, risk was also higher due to higher net revenue variation for these two crops. The findings showed that the use of zero tillage with low inputs has the potential to save energy use and improve energy use efficiency. The use of zero tillage provided significant energy savings (compared to CT reported by Zentner et al. (2004)) in on-farm use of fuel and in machine operation and manufacture. The ratio of grain, oilseed and pea yield to emission of CO2 (kg yield per kg CO2 emitted) varied considerably between crops. This ratio was similar for winter wheat and spring wheat, but not for canola and flax. Canola ratios were higher than flax (2.03 compare to 1.92 kg of flax). Peas had a higher ratio (8.47 kg), due to low fertilizer rates. Alfalfa had the highest ratio (17.8 kg yield kg CO2, due to low inputs of fertilizer and pesticides. Overall the crops and rotations studied were highly energy efficient and reduced the calculated contribution of GHGs to the environment especially when legume and N-fixing crops were incorporated

The economics of potato crop rotations in southern Manitoba

Non-Peer ReviewedRapid expansion of the potato industry in Manitoba has led to increased potato production in Manitoba. While the introduction of potatoes into current cropping systems may provide an opportunity for producers to increase the profitability of their farming operation, development of economically and environmentally sustainable production systems is key to the long-term success of the industry. Currently, little information is available about the economic and environmental impacts of such crop rotations with respect to potato production in Canada. Recognizing the importance of sustainable production systems, in 1998, a potato crop rotation study was established at Manitoba Crop Diversification Center (MCDC) at Carberry to develop recommendations for irrigated potato management in southern Manitoba. Six crop rotations ranging from two to four years in duration, and containing potatoes in combination with oilseed, cereal and/or legume crops, were included in this study. Each phase of each rotation was present in each year making a total of 18 treatments. This paper discusses the economic return of these six different crop rotations. The data with respect to all the production practices, including storage, transport and marketing for the period of 1998 to 2001 were collected and analyzed using a computer model developed for this purpose. Econometrics View software was used to develop this model, and the model takes into account the whole system for each rotation when analyzing the data. The preliminary results suggest that, for the period of 1999 through 2000, both potato-canola and potato-oat-wheat rotations appeared to be promising rotations. However, the poor potato yield of the potato-oatwheat rotation in 2001 resulted in low average net income for that rotation. The higher net benefit of the potato-canola rotation during the time period analyzed was primarily the result of a higher proportion of the tuber yield being of marketable size, not for higher gross tuber or canola yields. It is, however, difficult to make firm conclusions at this point of time as to which rotation will be most profitable in the long term. This is mainly because of the rotation treatments have only been in place since 1998 and, as such, observed differences among rotations may be a function not only of the rotation but also of environmental conditions and management within a given year