Campbell, C.A.

Fernandez, M.R.

Gan, Y.

Hamel, C.

Jefferson, P.G.

Lemke, R.

McConkey, B.G.

Selles, F.

Thomas, A.G.

Zentner, R.P.

English

University of Saskatchewan Research Archive

Long-Term Productivity and Economic Performance of SpringWheat Production Systems in Southwestern SaskatchewanR.P. Zentner1, C.A. Campbell2, F. Selles1, P.G. Jefferson1, M.R. Fernandez1, R. Lemke1, C.Hamel1, Y. Gan1, B.G. McConkey1, and A.G. Thomas31  Semiarid Prairie Agricultural Research Centre, Swift Current, SK.2  Eastern Cereal and Oilseed Research Centre, Ottawa, ON.3  Agriculture and Agri-Food Canada, Saskatoon, SK.Key Words: spring wheat, crop rotations, production, costs, net returns, riskIntroduction• Producers in semiarid regions have relied on frequent summerfallowing (F) toconserve water and to maximize available soil N (reduce fertilizer requirements),but this practice has been shown to result in significant soil degradation(Campbell et al. 2002).• Changes in market conditions, together with the development of new crop typesand management methods, may offer wheat (W) producers new opportunities forenhancing farm income or reducing financial risk, while at the same timeimproving environmental sustainability of their cropping systems.• A crop rotation experiment was initiated at Swift Current, SK, to determine themost ideal cropping frequency for wheat in this region and whether flexiblerotations in which fallowing is decided each year based on criteria such asavailable soil water in spring (if water), or the need to control perennial weeds (ifweeds), would be more effective than fixed rotations such as F-W-W.  The studyalso compares the effects of including a legume green manure (LGM) crop in therotation, and the production of Canada Western Red Spring (CWRS) wheat withthe higher-yielding Canada Prairie Spring (CPS) wheat class.Objective• To determine the effects of wheat class, summerfallow frequency, legume greenmanure, and flex cropping on production costs, net returns, and riskiness forwheat-based cropping systems managed with conservation tillage practices in theBrown soil zone of southwestern Saskatchewan.Materials and Methods• Data were obtained from an on-going crop rotation experiment established in1987 at the Semiarid Prairie Agricultural Research Centre (Zentner et al. 2003).• We evaluated 7 cropping systems, five fixed and two flex-crop rotations, over the1988 to 2002 period (Table1).  All rotations have three replicates, with all phasesof each rotation present every year.  The soil is a Swinton loam and had beenunder F-W cropping for the previous 80 years.• The rotations were managed using minimum and zero tillage practices, usingrecommended methods and rates of pesticide application.• All crops were fertilized with N and P based on soil tests (Zentner et al. 2003).The average rates of N applied to wheat grown on fallow or after LGM partial-fallow were 28 to 37 kg ha-1, while wheat grown on stubble received 41 to 52 kgN ha-1.  Wheat plots also received P fertilizer applied with the seed at 9.6 kg Pha-1, while the LGM received only P at a rate of 4.9 kg ha-1.• The LGM crop was Indianhead black lentil from 1987-98, and chickling vetch, cv>AC Greenfix=, thereafter.  The legume seed was inoculated with commercialpeat-based rhizobium culture prior to planting.• The wheat stubble was cut as tall as possible (usually > 30 cm) to enhance over-winter snowtrapping and soil water conservation.• For the economic analysis, all purchased inputs and machine operations werevalued and held constant at their 2003 cost levels (Saskatchewan Agriculture,Food and Rural Revitalization 2003; University of Saskatchewan 2003).• Participation in the Canada/Saskatchewan Crop Insurance Program was assumedto be at the 70% yield coverage for both wheat classes.  The 2003 premium ratesand payout criteria for Risk Area # 10 of Saskatchewan were assumed(Saskatchewan Crop Insurance Corporation 2003).• The net farm-gate prices for CWRS and CPS wheat were taken at their respective10-year (1992/93 - 2001/02) mean values, namely $158 t-1 (STD = $27 t-1) forCWRS wheat (13.5% protein) and $140 t-1 (STD = $29 t-1) for CPS wheat.  Theprice for CWRS wheat was adjusted by treatment, replicate, and year for grainprotein content in accordance with the 2003 protein price schedule as establishedby the Canadian Wheat Board.• The economic performance of the cropping systems were also evaluated for arange of product prices (representing two standard deviations lower to twostandard deviations higher than their respective mean values) to test the sensitivityof the findings to changes in these price conditions.• All economic results are expressed on a per hectare basis for the complete rotationsystems, which includes the costs and returns for all cropped and fallow portionsof each rotation, and all data were subjected to analysis of variance for split-plotdesigns with rotation as main plot and year as sub-plot (SAS Institute Inc. 1985).Riskiness was assessed using stochastic dominance analysis to compare theprobability density functions of net returns from the rotation treatments forproducers with low, medium, and high risk aversion (Zentner et al. 1992).Table 1.  Crop rotation systems at Swift Current.Crop rotation description AbbreviationFallow-CWRS Wheat-CWRS Wheat F-W-WLegume Green Manure-CWRS Wheat-CWRS Wheat LGM-W-WFallow-CPS Wheat-CPS Wheat F-HY-HYFallow-CWRS Wheat-CWRS Wheat-CWRS Wheat F-W-W-WContinuous CWRS Wheat Cont WContinuous CWRS Wheat (if water)1 Cont W (if water)Continuous CWRS Wheat (if weeds)2 Cont W (if weeds)1 Continuous CWRS wheat unless available soil water in spring is < 7.5 cm, in which case the land isfallowed.  The plots were fallowed in 1988 and 1992 due to inadequate spring soil water.2 Continuous CWRS wheat unless perennial weeds become a major problem, in which case the land isfallowed.  The plots were fallowed in 1994 and 1996 due to high weed densities.Results and DiscussionWeather Conditions• Growing season (1 May - 31 August) precipitation over the 15-year study periodaveraged 231 mm, 9% higher than the long-term mean for this region.• Precipitation levels were more than 20% above normal in 8 of 15 years, nearnormal in 2 years, and below normal in 5 years.  Thus, 1988-2002 represents aperiod of generally favorable growing conditions for annual crops.Grain Yields and Wheat Protein Concentration• Wheat yields during the study period (Table 2) were above the long-term averagefor this region, reflecting the above normal growing conditions.• Yields of CWRS wheat grown on fallow averaged 2524 kg ha-1 and were similarfor the F-W-W and F-W-W-W rotations, while yields of CPS wheat grown onfallow averaged 3286 kg ha-1 (or 30% more), reflecting that CPS wheat wasdeveloped to produce much higher yields but lower grain protein than CWRSwheat (Clarke and DePauw 1989).• CWRS wheat grown on LGM partial-fallow averaged 2173 kg ha-1 over the 15-year period, but in the last 9 years since the LGM crop underwent a change inmanagement, wherein the legume was seeded earlier and turned down earlier inan effort to reduce soil water depletion, subsequent fallow wheat yields weregenerally similar for LGM-W-W and F-W-W (Zentner et al. 2004).• Cropping frequency also did not influence yields of CWRS wheat grown onstubble (Table 2).  Stubble wheat yields averaged 1896 kg ha-1, or 79% ofcomparable fallow wheat yields.  CPS wheat grown on stubble yielded 68% ofcomparable CPS fallow wheat yields and about 18% more than CWRS wheatgrown on stubble.• Grain protein concentrations were highest for CWRS wheat grown on partialfallow and on stubble in the LGM-W-W rotation, and were consistently higher forCWRS than for CPS wheat (Table 2).  The higher grain protein in the LGMsystem was attributed to a gradual improvement in the N supplying power of thesoil (Zentner et al. 2004).Table 2.  Yield and protein content of wheat grown in rotations at Swift Current (1988-2002).Rotation Grain yield (kg ha-1) Grain protein (%)Wheat grown on fallow/partial fallow    F-(W)-W 2491 13.6    LGM-(W)-W 2173 14.9    F-(HY)-HY 3286 11.7    F-(W)-W-W 2556 13.7        Mean 2627 13.5        Sx 70 0.18Wheat grown on stubble    F-W-(W) 1920 12.9    LGM-W-(W) 1977 14.1    F-HY-(HY) 2240 11.4    F-W-(W)-W 1892 13.1    F-W-W-(W) 1910 12.9    Cont W (if water)a 2021 12.2    Cont W (if weeds)b 1659 13.9    Cont W 1892 13.2          Mean 1946 13.0          Sx 44 0.17a   Plots were fallowed in 1988 and 1992 due to inadequate spring soil water.  Data for 1989 and 1993 wereexcluded from the mean values shown.b    Plots were fallowed in 1994 and 1996 due to high weed densities.  Data for 1995 and 1997 wereexcluded from the mean values shown.Production Costs and Breakeven Conditions• Production costs for the complete rotation systems increased with croppingfrequency; they averaged about $231 ha-1 for F-W-W and LGM-W-W, $242 ha-1for F-HY-HY and F-W-W-W, and $285 ha-1 for Cont W (Fig. 1).• The fact that average total costs were generally similar for F-W-W andLGM-W-W indicates that the added costs for seed and managing the LGM cropwere largely offset by the savings in N fertilizer applied to the subsequent wheatcrops plus savings in costs for weed control (tillage and herbicides) required onpartial- fallow versus the full-fallow areas.• Total costs for the flex-cropping systems were significantly lower (about $22 ha-1less) than for Cont W, reflecting that summerfallowing the land (2 in 15 years)requires lower resource expenditures than cropping it.• The unit cost of producing CWRS wheat on fallow averaged $159 t-1, and $193 t-1when it was grown on LGM partial-fallow (including the cost of summerfallow orLGM partial fallow).  By comparison, the average unit cost for CWRS wheatgrown on stubble ranged between $141 t-1 and $151 t-1, with the cost being lowestfor the LGM system.  The unit cost of producing CPS wheat averaged $130 t-1and $103 t-1 when grown on fallow and stubble, respectively.  These valuesrepresent ‘breakeven prices’, or the minimum wheat prices needed to recoverproduction costs.Figure 1.  Mean production costs for cropping systems at Swift Current (1988-2002).Net Returns• Mean net returns (income remaining after paying for all production costs) werehighest for Cont W ($41 ha-1); intermediate for F-W-W-W, F-HY-HY, and theflex crop rotations (about $15 ha-1 less); and lowest for F-W-W and LGM-W-W(about $25 ha-1 less).  These results contrast to those reported by Zentner andCampbell (1988) for another study at Swift Current conducted during the muchdrier 1967-1984 period wherein F-W and F-W-W were generally more profitablethan Cont W.• On an annual basis, the economic performance of Cont W and the flex–croprotations was significantly higher than for the other cropping systems in 7-8 of 15years, mainly those years with above average growing season rainfall.  In the drieryears, F-W-W and F-HY-HY generally performed best (Fig. 2 and Fig. 3).• Net returns for LGM-W-W were significantly higher than for F-W-W in 5 of 15years, similar in 6 years, and significantly lower in 4 years, the latter yearsoccurred mainly prior to the change in management of the LGM crop in 1993(Fig. 2).• Net returns for F-HY-HY were higher than for F-W-W in 5 of 15 years, but theywere significantly lower in 4 other years.• Increases in the price for CWRS or CPS wheat favored the more intensivelycropped systems, while lower wheat prices favored the rotations that includedfallow (data not shown).Figure 2.  Annual net returns for fallow-based cropping systems at Swift Current.Figure 3.  Annual net returns for continuously cropped systems at Swift Current.Riskiness• Income variability increased as cropping frequency increased (Fig.4).  Riskinesswas lowest for F-W-W and highest for the continuously crop systems.• Surprisingly, the flex-crop systems displayed higher income variability than ContW, in part because no income is generated in years when the land issummerfallowed due to inadequate spring soil water or high weed infestations,and in part due to the all-risk crop insurance program which offsets years withlow grain yields (and income), thereby helping to increase and stabilize income(or minimize the losses) in these years.• Producers face a tradeoff between the potential to earn higher net returns and theneed to accept higher risk or income variability (Fig. 4).• Based on a risk analysis of the probability distributions of net returns for thecropping systems (and with all-risk crop insurance), producers with low riskaversion (i.e., those most willing to gamble or accept risk) would choose Cont W,while more conservative producers (i.e., those less willing to gamble) wouldchoose the F-HY-HY or F-W-W-W systems (Fig . 4).• Without all-risk crop insurance, producers with low to moderate risk aversionwould choose F-W-W-W or Cont W (if water), while producers with higher riskaversion would choose F-W-W (Fig. 5).Figure 4.  Tradeoff between increases in net return and increases in riskiness, assumingparticipation in the Canada/Saskatchewan all-risk crop insurance program.Figure 5.   Tradeoff between increases in net return and increases in riskiness, withoutall-risk crop insurance.Conclusions• Wheat yields for these N and P fertilized systems, managed using conservationtillage practices, were above normal for the region, reflecting the generallyfavorable growing conditions during the study period.• Wheat yields were not influenced by cropping frequency, with yields of CWRSwheat grown on stubble averaging 79% of fallow CWRS wheat yields, and withyields of CPS wheat grown on stubble averaging 68% of fallow CPS wheatyields.• Grain protein content of CWRS wheat was highest when grown in the LGMsystem, and was little affected by cropping frequency.• Total production costs increased with cropping frequency; however, the cost perunit of wheat produced displayed the reverse trend.• Net returns were generally highest for Cont W, intermediate for the flex-croprotations and for F-HY-HY and F-W-W-W, and lowest for F-W-W andLGM-W-W, again reflecting the good growing conditions which favored moreintensive cropping systems.• Net returns from the production of CPS wheat, with its higher yield but lowergrain protein content and market price, averaged about $10 ha-1 higher than fromthe production of CWRS wheat grown in comparable fallow-based rotations.• The use of a legume green manure crop as a summerfallow replacement wasgenerally more profitable than full-fallow, but to be successful the LGM cropmust be planted early (mid to late April) and its growth terminated in early July(before reaching full bloom) to minimize soil water depletion by the legume.• The economic performance of the flex-crop rotations was superior to the fallow-based fixed rotations, but lower than for Cont W when participation in all-riskcrop insurance was assumed.• But, without all-risk crop insurance, Cont W (if water) was the preferred croppingsystem by producers with low to moderate risk aversion, while producers withhigh risk aversion would choose F-W-W.ReferencesCampbell, C.A., Zentner, R.P., Gameda, S., Blomert, B., and Wall, D.D.  2002.Production of annual crops on the Canadian Prairies:  Trend during 1976-1998.Can. J. Soil Sci. 82: 45-57.Clarke, J.M., and DePauw, R.M.  1989.  ERDA semi-hard wheat agronomy project.Final Report.  Agriculture Canada Research Centre, Swift Current, SK. 138 pp.SAS Institute, Inc.,  1985.  SAS user=s guide: Statistics version 5 ed. SAS Institute, Inc.Cary, NC, 956 pp.Saskatchewan Agriculture, Food and Rural Revitalization. 2003.  Farm machinerycustom and rental rate guide 2003.  Financial Programs Branch, SaskatchewanAgriculture, Food and Rural Revitalization, Regina, SK. 36 pp.Saskatchewan Crop Insurance Corporation.  2003.  Premium tables - 2003 crop year.Risk Area #8, Saskatchewan Crop Insurance Board, Melville, SK., 5 pp.University of Saskatchewan.,  2003.  Prairie crop protection planner. Version 2 [CD-ROM].  University of Saskatchewan, Saskatoon, SK. Available:http://paridss.usask.ca/crop_planner.Zentner, R.P, and Campbell, C.A.  1988.  First 18 years of a long-term crop rotationstudy in southwestern Saskatchewan – Yields, grain protein, and economicperformance.  Can. J. Plant Sci. 68: 1-21.Zentner, R.P., Campbell, C.A., Biederbeck, V.O., Selles, F., Lemke, R., Jefferson, P.G.,and Gan, Y.  2004.  Long-term assessment of management of an annual legumegreen manure crop for fallow replacement in the Brown soil zone.  Can. J. PlantSci. 84: 11-22.Zentner, R.P., Campbell, C.A., Selles, F., McConkey, B.G., Jefferson, P.G., and Lemke,R.  2003.  Cropping frequency, wheat classes and flexible rotations:  Effects onproduction, nitrogen economy, and water use in a Brown Chernozem.  Can. J.Plant Sci. 83: 667-680.Zentner, R.P., Selles, F., Campbell, C.A., Handford, K., and McConkey, B.G.  1992.Economics of fertilizer-N management for zero-till continuous spring wheat in theBrown soil zone.  Can. J. Plant Sci. 72: 981-995.

Long-term productivity and economic performance of spring wheat production systems in southwestern Saskatchewan

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Long-term productivity and economic performance of spring wheat production systems in southwestern Saskatchewan

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