Summary of Findings from Long-Term Studies
Manitoba - Long-Term Pesticide Free Production Study
Author(s): Gulden, Robert H.
Summary: A long-term rotation was started in 2000 at the University of Manitoba to investigate the effects of Pesticide Free Production (PFP), a production system where in-crop herbicides were omitted from certain crops in rotation, on weed populations and crop performance in two crop rotations (flax-oat-canola-wheat and flax-oat-alfalfa-alfalfa). Over the long-term, weed seedbank populations were greater in rotations where in-crop herbicides were omitted, but significant yield reductions were only observed in some crops when omitting herbicides in both, the flax and oat crops. Over the 10 years, a crude economic analysis suggests that occasional in-crop herbicide omissions, particularly in competitive crops, may increase net revenues by saving the costs of herbicide while having no major impact on weed populations and crop grain yield.
Citation: Gulden, Robert H. 2012. Long-Term Pesticide Free Production Study at Carman, MB (2000). Prairie Soils and Crops 5:30-35. [http://www.prairiesoilsandcrops.ca]
Manitoba - Potato Rotation Study
Author(s): Mohr, R.M. et. al.
Summary: During the 1990's, Manitoba's processing potato industry experienced a period of unprecedented expansion. The Potato Rotation Study at Carberry, Manitoba was initiated to identify economically and environmentally sustainable rotations that optimized crop yield and quality, while maintaining or enhancing soil quality. Six potato rotations were established in 1998: 1) potato - wheat (P-W); 2) potato - canola (P-C); 3) potato - canola - wheat (P-C-W); 4) potato - oat - wheat (P-O-W); 5) potato - wheat - canola - wheat (P-W-C-W); 6) potato - canola (underseeded to alfalfa) - alfalfa - alfalfa (P-C-A-A). Declines in potato yield were observed in the 2-year rotations in 2007 and continued through 2010.
Citation: Mohr, R.M., Irvine, R. B., Khakbazan, M., McLaren, D.L., Monreal, M.A., Moulin, A.P., Tomasiewicz, D.J., Volkmar, K.M., and Derksen, D.A. (ret'd). 2012. Potato Rotation Study - Carberry, Manitoba (1997-2010). Prairie Soils and Crops 5:36-41. [http://www.prairiesoilsandcrops.ca]
Saskatchewan - Indian Head Long-Term Crop Rotations
Author(s): Lafond, G.P., Campbell, C.A., Lemke, R., May, W.E. and Holzapfel, C.B.
Summary: The Indian Head Long-Term Crop Rotations, established in 1957, consisted of nine different spring wheat based rotations. The rotations studied the effects of nitrogen and phosphorus fertilizer application, legume green manure crops, forage crops, different frequencies of fallow and straw removal. The study was converted from conventional-tillage to no-till in 1990. Applying fertilizers based on soil test recommendations, extending crop rotations and including green manure or hay crops and using no-till all increased grain yield, N and P uptake, soil organic matter content and soil quality, and enhanced nutrient cycling.
Citation: Lafond, G.P., Campbell, C.A., Lemke, R., May, W.E. and Holzapfel, C.B. 2012. Indian Head Long-Term Crop Rotations: Indian Head Saskatchewan. Prairie Soils and Crops 5:42-50. [http://www.prairiesoilsandcrops.ca]
Saskatchewan - Effect of Tillage and Cropping Frequency on Sustainable Agriculture in the Brown Soil Zone
Author(s): McConkey, B.G., Campbell, C.A., Zentner, R.P., Peru, M. and VandenBygaart, A.J.
Summary: In the semiarid Canadian prairies where water availability is the main constraint to crop production, a 2-yr rotation of summerfallow-spring wheat (F-W), with extensive use of mechanical tillage (CT), was the predominant cropping system used for many decades. To enhance net returns and reduce soil degradation, producers have increased cropping frequency and reduced tillage [using minimum- or no-tillage (MT or NT)]. A study was initiated in 1981 on fine sandy loam, silt loam and clay soils to assess the influence of cropping frequency and tillage management on sustainable production.
Citation: McConkey, B.G., Campbell, C.A., Zentner, R.P., Peru, M. and VandenBygaart, A.J. 2012. Effect of Tillage and Cropping Frequency on Sustainable Agriculture in the Brown Soil Zone. Prairie Soils and Crops 5:51-58. [http://www.prairiesoilsandcrops.ca]
Saskatchewan - Old Rotation Study
Author(s): Lemke, R., Campbell, C.A., Zentner, R.P., and Wang, H.
Summary: The "Old Rotation" experiment was initiated in 1966 at the Agriculture and Agri-Food Canada Research Centre at Swift Current, Saskatchewan. The overall objectives were to evaluate the influence of rotation length, fallow substitute crops, and nitrogen (N) and phosphorus (P) fertilizers on crop yields, grain protein, N and P uptake, moisture conservation, nutrient use efficiency, incidence of disease, and long-term changes in soil chemical, physical, and biological properties. Economic returns and non-renewable energy use efficiency from changes in the rotations were also determined.
Citation: Lemke, R., Campbell, C.A., Zentner, R.P., and Wang, H. 2012. Old Rotation Study - Swift Current, Saskatchewan. Prairie Soils and Crops 5:59-66. [http://www.prairiesoilsandcrops.ca]
Saskatchewan - New Rotation Study
Author(s): Lemke, R., Campbell, C.A., Zentner, R.P., and Wang, H.
Summary: The "New Rotation" experiment was initiated in 1987 at Swift Current, Saskatchewan. The objectives were to evaluate, under conservation tillage management, the influence of crop and rotation type on crop productivity and grain quality, incidence of plant diseases and weed populations, a suite of soil and environmental parameters, economic performance and energy use efficiencies. The study provided clear evidence that an annual legume green manure (LGM) can be successfully used as a partial fallow replacement for the semiarid Canadian prairies.
Citation: Lemke, R., Campbell, C.A., Zentner, R.P., and Wang, H. 2012. New Rotation Study - Swift Current, Saskatchewan. Prairie Soils and Crops 5:67-73. [http://www.prairiesoilsandcrops.ca]
Saskatchewan - Alternative Cropping Systems Study
Author(s): Lemke, R., Malhi, S., Johnson, E.N., Brandt, S.A., Zentner, R.P. and Olfert, O.
Summary: A long-term, cropping systems study was initiated in 1994 near Scott, Saskatchewan, to develop an enhanced understanding of the role of inputs and cropping diversity in sustaining crop production and soil quality/health as well as preserving biodiversity in the region. Each of three input strategies was applied to three levels of cropping diversity. Organic input systems were based on non-chemical pest control and nutrient management; reduced input systems used integrated long-term management of pests and nutrients utilizing chemicals and no-till practices; high input systems used pesticides and fertilizers "as required" based on accepted recommendations associated with pest thresholds and residual soil nutrient levels from soil tests.
Citation: Lemke, R., Malhi, S., Johnson, E.N., Brandt, S.A., Zentner, R.P. and Olfert, O. 2012. Alternative Cropping Systems Study - Scott, Saskatchewan. Prairie Soils and Crops 5:74-84. [http://www.prairiesoilsandcrops.ca]
Saskatchewan - Re-establishment of Native Mixed Grassland Species into Annual Cropping Land
Author(s): Iwaasa, A.D., Schellenberg, M.P. and McConkey, B.G.
Summary: Approximately 4.9 to 5.0 M ha of cultivated marginal land in Western Canada is environmentally unsustainable and would benefit from conversion to permanent cover from current annual cropping. Since 2001, re-establishment of native grasslands into marginal cropland has been successfully accomplished using conventional seeding technology and a productive and sustainable pasture grazing system has been achieved.
Citation: Iwaasa, A.D., Schellenberg, M.P. and McConkey, B.G. 2012. Re-establishment of Native Mixed Grassland Species into Annual Cropping Land. Prairie Soils and Crops 5:85-95. [http://www.prairiesoilsandcrops.ca]
Alberta - The University of Alberta Breton Plots
Author(s): Dyck, M.F., Roberston, J.A. and Puurveen, D.
Summary: The Breton Plots were established by the Department of Soils at the University of Alberta in 1929. Within the Breton Plots research site, numerous long-term plot experiments have been conducted over the years. This paper summarizes results from the Breton Classical Plots (est. 1930), the Breton Hendrigan Plots (est. 1980), the Breton Tillage Straw Nitrogen plots (est. 1979) and the Breton Nitrogen Immobilization Plots (est. 1982).
Citation: Dyck, M.F., Roberston, J.A. and Puurveen, D. 2012. The University of Alberta Breton Plots. Prairie Soils and Crops 5:96-115. [http://www.prairiesoilsandcrops.ca]
Alberta - Long-Term Grazing Study
Author(s): Douwes, H. and Willms, W.
Summary: The Agriculture and Agri-Food Canada Stavely substation in the native fescue grasslands of south-western Alberta was established in 1949 in response to requests that grassland and range management problems in the foothills area be investigated. Around 42% of the 389 ha site is fenced into 4 pastures where the same stocking rates have been maintained for 63 years to subport long-term range condition research.
Citation: Douwes, H. and Willms, W. 2012. Long-Term Grazing Study at Stavely, Alberta. Prairie Soils and Crops 5:116-122. [http://www.prairiesoilsandcrops.ca]
Alberta - Productivity of Long-Term No-Till Plots
Author(s): Smith, E.G., Larney, F.J., Nakonechny, D.J., Barbieri, J.M. and Lindwall, C.W.
Summary: A long-term no-till study was initiated in 1968 at the Lethbridge Research Centre. The study was initiated at the infancy of no-till management to better understand the long-term implications and the management problems that could arise with no-till. The crop rotations in this study included fallow-wheat or fallow-wheat-wheat/flax. Three tillage systems were selected for the study: (1) wide blade (cultivator) that leaves most of the crop residues on the surface after tillage, (2) heavy duty cultivator that buries more crop residues than the blade cultivator, and (3) no-till (chemical control of weeds during the fallow and crop year).
Citation: Smith, E.G., Larney, F.J., Nakonechny, D.J., Barbieri, J.M. and Lindwall, C.W. 2012. Productivity of Long-Term No-Till Plots - Lethbridge Alberta. Prairie Soils and Crops 5:123-131. [http://www.prairiesoilsandcrops.ca]
Alberta - Long-Term Cattle Manure Plots
Author(s): Hao, Xiying and Benke, M.
Summary: A field experiment was started in 1973 to determine the safe loading capacity of soil with cattle feedlot manure. Manure was applied annually at 0, 30, 60, and 90 tonne ha-1 (wet weight) under rainfed and 0, 60, 120, and 180 tonne ha-1 under irrigated conditions. The long-term manure applications resulted in increased levels of organic matter, N, P, salt and trace minerals in soil. This increased straw yield at all manure rates, but reduced grain yields at higher rates and affected crop quality.
Citation: Hao, Xiying and Benke, M. 2012. Long-Term Cattle Manure Plots. Prairie Soils and Crops 5:132-138. [http://www.prairiesoilsandcrops.ca]
Alberta - Long-Term Erosion-Productivity Relationships: The Lethbridge Soil Scalping Studies
Author(s): Larney, F.J. and Janzen, H.H.
Summary: Soil erosion by wind or water removes valuable topsoil and decreases soil productivity. What is the value of this topsoil in terms of maintaining crop yield? When restoring eroded soils, how long do the effects of one-time applications of soil amendments last and is the magnitude or longevity of these effects influenced by the level of erosion? This study was conducted to answer these questions and ascertain the effects of simulated erosion on soil productivity and methods for its amendment. Incremental depths (0, 5, 10, 15, and 20 cm) of surface soil, or cuts, were mechanically removed to simulate erosion at two sites (one dryland, one irrigated) in southern Alberta in 1990.
Citation: Larney, F.J. and Janzen, H.H. 2012. Long-Term Erosion-Productivity Relationships: The Lethbridge Soil Scalping Studies. Prairie Soils and Crops 5:139-146. [http://www.prairiesoilsandcrops.ca]
Alberta - Rotation ABC
Author(s): Smith, E.G., Ellert, B.H., Janzen, H.H. and Nakonechny, D.J.
Summary: Rotation ABC was established in 1911 at the Lethbridge Research Centre. The rotation study has been and continues to be used to evaluate the long-term impacts of cropping systems on soil quality, productivity, and the broader environment. The non-replicated study includes three wheat-based rotations, rotations that were considered feasible in western Canada. The rotations were continuous wheat (A), fallow-wheat (B), and fallow-wheat-wheat (C). In 1967 and 1972 the plots were divided to impose four fertility treatments within each plot by applying all combinations of two rates of nitrogen and phosphorus fertilizer. In 2010, six plots of Rotation T, land adjoining Rotation ABC and in a fallow-wheat rotation since the 1950's, were used to replicate Rotation ABC.
Citation: Smith, E.G., Ellert, B.H., Janzen, H.H. and Nakonechny, D.J. 2012. Rotation ABC - Lethbridge, Alberta. Prairie Soils and Crops 5:147-154. [http://www.prairiesoilsandcrops.ca]
Alberta - Rotation 120
Author(s): Smith, E.G., Ellert, B.H., Janzen, H.H. and Nakonechny, D.J.
Summary: Rotation 120 was initiated in 1951 at the Lethbridge Research Centre to evaluate the sustainability of common and potential crop rotations for the area. The rotations range from fallow-wheat to continuous wheat, with and without inorganic fertilizer, livestock manure, legume green manure, or alfalfa hay. The crop rotation and replenishment of nitrogen (N) impacted soil quality as measured by soil organic carbon (SOC), light fraction carbon (LFC), light fraction nitrogen (LFN), and mineralizable carbon (C) and N. Rotations that replenished N with alfalfa, N fertilizer, and green or livestock manure had higher SOC and grain yield.
Citation: Smith, E.G., Janzen, H.H., Ellert, B.H., and Nakonechny, D.J. 2012. Rotation 120 - Lethbridge, Alberta. Prairie Soils and Crops 5:155-164. [http://www.prairiesoilsandcrops.ca]
Alberta - Long-Term Field Bioassay of Soil Quality
Author(s): Janzen, H.H., Olson, B.M., Zvomuya, F., Larney, F.J. and Ellert, B.H.
Summary: A field bioassay of soil quality was established in 1990 at the Lethbridge Research Centre to study how measured differences in soil quality affect yield. At each of two sites, 36 diverse soils were deposited onto subsurface soil, and spring wheat was grown, with and without added nitrogen, to measure yield responses. The experiment shows that plants really do 'notice' differences in soil quality, as evident from large and persistent yield differences among plots.
Citation: Janzen, H.H., Olson, B.M., Zvomuya, F., Larney, F.J. and Ellert, B.H. 2012. Long-Term Field Bioassay of Soil Quality. Prairie Soils and Crops 5:165-168. [http://www.prairiesoilsandcrops.ca]