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SWEEP Report #SUP1

Tillage 2000: 1985-1990
Final Report
Spring 1993

Researchers: 

    J. D. Aspinall, Ontario Ministry of Agriculture and Food, Guelph, Ont.,
    R. G. Kachanoski, Department of Land Resource Science, University of Guelph, Guelph, Ont.

Executive Summary

Evaluation Summary (Tech. Transfer Report Summaries)

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Associated SWEEP/LSP Research

 

 

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Completed: Spring, 1993

Key Words:

corn, soybeans, winter wheat, small grains, yield (machine and hand), no-till, conventional tillage, ridge till, Tillage 2000, conservation tillage, soil landscape units, benchmark, soil properties, topographic properties, crop growth characteristics, minimum tillage, percent residue cover, soil texture, eroded soils, economics, net returns

Executive Summary

Tillage 2000 was a long term (5 year), on-farm, field scale research and demonstration project which began in 1985 and was fully implemented during 1986. Twenty-three cooperators were selected in the spring of 1985 on the basis of field site suitability (soil type, topography, access, location), and the interest and capabilities of the cooperator.

The main objective of Tillage 2000 was to develop and evaluate conservation farming systems which maximized economic productivity and minimized soil degradation for specific soil types. The project was conducted on 40 farms across the province (Figure 1).

Tillage 2000 was unique to soil conservation in Ontario by virtue of its methodology and process: the project included both a research and demonstration component within an economic farm unit framework: the process was both investigative and developmental over several years. The program was designed to introduce concepts of conservation tillage systems to a larger number of producers and to provide a way to distribute known information and experience through field scale demonstration.

A viable conservation farming system must consider not only the cropping and tillage program, but also the soil resource and economic net returns. Tillage 2000 studied the relationships among these components.

Tillage 2000 was also a developmental process on each project farm. Conservation tillage systems that did not meet expectations on a project farm were modified in subsequent years to improve performance. Successful components unique to similar projects at other locations, were incorporated as well as ideas the cooperator had to improve the system.

Tillage 2000 was a cooperative effort by the Ontario Ministry of Agriculture and Food (OMAF), the Department of Land Resource Science, University of Guelph, and the Ontario Soil and Crop Improvement Association. In addition, several conservation authorities had joint agreements with OMAF to deliver the Tillage 2000 program as part of an agricultural soil and water conservation program. In southwestern Ontario Tillage 2000 was part of the federal-provincial Soil and Water Environmental Enhancement Program (SWEEP).

The project was managed by the Soil Conservation Advisors, Soil and Water Management Branch (OMAF). Project work was conducted by teams consisting of OMAF soil conservation advisors, conservation authority staff, and cooperating farmers. Data collected by the team was compiled and statistically analyzed by the Land Resource Science Department, University of Guelph.

The success of the Tillage 2000 project relied heavily upon the cooperating farmers without whom the project would not be possible. Staff and supporting program resources were funded by the following agencies: Ontario Ministry of Agriculture and Food; Joint Program Conservation Authorities; Department of Land Resource Science, University of Guelph; Ontario Soil and Crop Improvement Association; and agribusiness who provided expertise and donated products to the projects.

A paired sampling design was established on each of the field scale study sites because of the interaction between tillage and soil landscape on measured crop yield. A minimum of two field scale treatments, a conservation and conventional tillage system were established on each of the fields chosen for study. The long axis of each plot was selected so that the major soil landscape units in the field would be split (paired) by the two tillage systems. Within each major soil landscape unit, permanent paired benchmark plots (6m 6m) were established for collection of data from each tillage system.

For each treatment, information regarding field history and major aspects of field work operations were recorded. These included: crop rotation, type and use of equipment, estimated fuel consumption and time required to perform each operation, applied herbicides and pesticides, seeding rates and date, applied fertilizer, and rainfall during the growing season. Machine harvest yields were measured from a strip within each field treatment with a weigh wagon or its equivalent.

To establish the validity of the pairing of the benchmarks between treatments and to examine the interaction between tillage, soil landscape, and crop yield a detailed characterization of soil and topographic properties was undertaken in 1986. In addition to the one time detailed soil and topographic measurements, crop data was collected every year from each benchmark.

Measurements include: crop yield (hand harvest), moisture at harvest, crop growth characteristics (leaf number, height, growth stage dates), emergence and population counts, silk and flowering dates, surface residue cover, weed counts, soil fertility programs, pest and disease observations.

For analytical purposes, the different tillage systems were grouped into three categories; (1) Moldboard (inversion of surface residue), (2) Minimum (incorporation of but little inversion of residues), and (3) No-till (no incorporation or inversion of residues by primary tillage). The authors recognize the range in tillage systems under each of these categories. At each site, one of the tillage treatments was classified as the conservation system and the other as the conventional system.

Average surface residue cover was 10%, 29%, and 55% for the moldboard, minimum and no-till tillage systems respectively. However, values varied depending on the previous crop grown. The required minimum of 20% was barely met for the minimum tillage system following soybean or small grain crops. Approximately 50% of these had residue levels less than 20%. All of the minimum tillage sites after soybeans and small grain had surface residue covers which were less than 30%.

The highest corn yield occurred in 1987 with an average of 9153.3 kg/ha and 8727.4 kg/ha for hand and machine yields respectively. The lowest yields were experienced in 1988 which was due to the severe drought conditions prevalent in the months of June and July. The highest soybean yields were also achieved in 1987. The lowest soybean yields occurred in 1989. Disease pressures brought on by hot and humid conditions reduced small grain yields to below average yields in 1987. Record yields were harvested during the fall of 1989. The yields suggest a wide variation in climatic conditions across the 5 years of study.

Approximately one half of the grain corn conservation treatments had yields that were equal to or greater than the conventional treatments. About 40% of the conservation yields for both small grains and soybeans were greater than the conventional yields. None of the observed differences were statistically significant (0.05 probability level).

The 5 year average conservation yield indices for each crop when comparing conservation tillage with the conventional system for machine harvest and field averaged benchmark yields respectively were:

Grain Corn: 97 and 97
Soybeans: 95 and 98
Small Grains: 98 and 98

The 5 year average conservation yield indices for each crop when comparing no-till with the moldboard system for machine harvest and field averaged benchmark yields respectively were:

Grain Corn: 100 and 101
Soybeans: 98 and 94
Small Grains: 98 and 101

There was a significant interaction between soil texture and the success of conservation tillage systems. For sandy textured soils, the 5 year average machine yield was 7% higher for the conservation versus conventional systems. Machine yields in clay and to some extent in clay loam soils were lower (6%) in the conservation systems. Yields were similar in other soil textures.

Minimum tillage relative to moldboard plowing was most successful on the silt loam soils and less successful on the other textures, especially the clay soils.

The data indicated a variable success for no-till versus moldboard in the medium texture classes (loam, silt loam, clay loam). No-till had much higher yields (15%) than the moldboard in the sandy soils and much lower yields in the clay soils.

The data indicated a trend of decreasing no-till yields relative to minimum till yields with increasing clay content (decreasing sand). Similar yields were obtained for loam and silt loam texture classes. Sandy soils had significantly higher yields in no-till and significantly lower yields in clay loam and clay soils. This was similar to the moldboard versus no-till data.

Conventional and conservation final plant populations for grain corn were significantly lower than the target populations for all of the tillage comparisons. When the differences in the final 5 year average populations are compared between tillage pairs the conservation tillage populations systems were significantly less than the conventional populations. The difference between the no-till and the moldboard final populations was very pronounced. The difference (%) in populations between minimum and moldboard tillage systems had a definite trend over the 5 years of the study. The conservation system had progressively lower populations with time compared to the conventional system.

For all conservation treatments averaged over 5 years the average grain corn leaf count was approximately one-half to one leaf less than the conventional treatments. Similarly, the height of corn plants for the conservation systems were found to be about 4 to 9% less than the conventional systems.

Soybean conservation populations were not statistically significantly different from the conventional populations. The minimum tillage populations were slightly above the moldboard stands. No-till populations were essentially equal to the minimum and moldboard populations.

The growth of the soybean plants as characterized by plant height was significantly influenced by tillage system. Plant heights were significantly reduced by as much as 18% for both the minimum and no-till soybeans when compared to the moldboard system. The small grain population of the minimum tillage system when compared to the moldboard tillage system was 2% less. No-till populations were 12% lower than the moldboard and the minimum tillage systems. This difference was statistically significant for the moldboard versus no-till comparison. Differences in leaf counts were not observed for any of the tillage comparisons.

Soil texture (Ap horizon) class and tillage texture class interactions were significant (0.001 probability) in explaining the variations in yield of all crop types. Landform class was significant for corn and soybeans, but not small grains. A regression of the ratio of no-till yield/conventional tillage yield against % sand content of the Ap horizon was significant (0.05 probability). The regression indicated that for % sand contents greater than 36% the no-till yield would on average be higher than the conventional tillage system. The no-till yield for finer textured soils would on average be lower than conventional tillage systems. The interaction of tillage and texture is suggested as the reason for little overall differences in tillage system on crop yield, across all farm sites.

The difference between the highest and lowest yielding areas in a field, across all years and all sites was 40% of the mean field yield. Tillage system did not significantly affect the within field variations in yields. The lowest, highest, and range, of relative yield difference were similar in the paired tillage comparisons. The standard deviation of relative yield difference was slightly higher (0.05 probability) in the minimum compared to no-till system.

The percentage of within field variation of yield remained constant from year to year and was on average 52% and 56% (significantly different at 0.10 probability), for the conventional and conservation tillage systems respectively. Approximately 3% of the benchmarks had an average yield which was at least 30% less than the average field yield. Another 5% of the benchmarks were between 20% and 30% lower than the field average yield. A total of 15%, and 4% of the benchmarks had an average yield which was greater than 10%, and greater than 20% of the field average yield respectively. The ranking of the benchmarks with respect to relative yield was independent of the measurement year, but the year did affect the magnitude in all yield classes. The drought stress year (1988) resulted in much greater relative within field variations of crop yield.

A paired benchmark analysis on crop response on stress (low yielding) and non-stress (high yielding) benchmarks, in stress and non-stress growing conditions was carried out. It indicated that conservation tillage systems may be more buffered against adverse climatic growing conditions than conventional tillage systems. High yielding areas under conservation tillage dropped only 13.8% in yield during a stress year, compared to a 16.5% decrease in the conventional system. Low yielding areas in the conservation system decreased 24% in yield in the stress year, compared to a 31.1% decrease in the conventional system. This benchmark data supported the paired field yield data, which indicated that the ratio of conservation yield/conventional yield was the highest in 1988 the drought stress year.

There was a significant interaction of soil texture class and soil loss, on relative crop yield losses. Benchmarks were separated on the basis of % sand in the Ap horizon and yield response correlated against cesium content (an index of soil loss) in each texture class. Yield response to soil loss was predicted from these correlations. Severely eroded soils with a % sand content greater than 70% had an average predicted yield loss of 37% of the field average yield. The same severely eroded soils had a predicted yield loss of only 8.0%, 4.7%, and 0.7% for Ap horizons with 50-70%, 40-50%, and 30-40% sand content. The yield loss in all texture groupings increased during the 1988 growing season indicating soil loss was affecting available water, but more so in the sandier soils. The available water index of McBride and Mackintosh (1984) was significantly related to cesium content (soil loss) in the > 70% sand content group, but not in the other groups. The benchmarks with 20-30%, and < 20% sand content had a predicted relative yield decrease due to severe soil loss of 4.3% and 8.0% respectively. Thus, the benchmarks in the medium texture classes had much less predicted yield loss from soil loss, than benchmarks with lighter or finer soil textures. This is consistent with the higher available water holding capabilities of medium textured soils compared to other textures.

Comparing only yields from tillage systems may not be appropriate when certain tillage systems have significantly lower pre-harvest production costs. The Tillage 2000 economic data from selected farms in southwestern Ontario was provided to Deloitte & Touche Management Consultants to test their proposed data management and economic analysis models. This research was funded by contract under the Socio-Economic Analysis Component of the Soil and Water Environmental Enhancement Program (SWEEP).

The objective of the economic evaluation was to determine the net economic impacts of the alternative tillage systems used in the T2000 study.

The economic data base for each cooperator was comprised of a machinery inventory, and information pertaining to the rotation, type, quantity and cost of inputs, dates and types of operations, machinery used, estimated fuel and time requirements, and machine yields.

Total costs did not include allowances for land, marketing fees, operating interest charges, and such items as the crop share of farm maintenance, electricity, phones, accounting, etc. On-farm storage or commercial storage costs were not considered. Fertilizer value and the application costs of manure applied to any of the plots were also excluded from this analysis.

Average net returns were $0.05/acre and $13.55/acre higher in the no-till corn system compared to the minimum and moldboard systems respectively. The higher profits were primarily the result of a significant decrease in the cost of field operations while maintaining equal yields.

The average net returns of no-till soybeans were $3.61/acre and $13.38/acre lower when compared to the moldboard and minimum till systems respectively. Minimum tillage returns when compared to the moldboard system were $17.18/acre less. The lower net returns for conservation tillage soybeans were primarily due to a combination of substantially higher herbicide costs and slightly decreased yields.

Winter wheat net returns were, on average, $8.94/acre higher for the minimum tillage and $12.86/acre higher for the no-till when compared to the moldboard system. An average loss of $3.96/acre occurred when the no-till was compared to the minimum tillage system. The net returns per labour hour were, on average, always higher for the minimum and no-till tillage systems for all crops except for minimum tillage soybeans when compared to the moldboard. The highest returns per labour hour were observed for no-till corn.

The Tillage 2000 project was initiated under the Local Demonstration sub-program of the Soil and Water Environmental Enhancement Program (SWEEP). The purpose of this program was to develop conservation tillage systems which reduce soil losses and improve water quality while maintaining production. Tillage 2000 demonstrated, for example, that no-till was a viable production option to producers in that there was no loss in productivity, it was economically beneficial, and there was also a measured reduction in phosphorus and soil losses and no effect on the ground water.

One of the main objectives of the SWEEP program was to reduce the phosphorus load entering Lake Erie by 200 tonnes per year. Provincial estimates of phosphorus loadings could be determined from cropping and tillage surveys in combination with the losses of phosphorus associated with the different tillage systems. The P loss data were determined on Tillage 2000 sites.

The objective of the Technology Evaluation and Development sub-program was to develop, adapt, evaluate and validate new or untested technologies related to soil productivity and phosphorus movement. Under the Tillage 2000 program tillage systems were evaluated for their effect on productivity, phosphorus losses, and their relationship to soil properties for extrapolation purposes. The possibility of within field variable management by determining if time-stable patterns of productivity were present was examined. In addition the remediation effects of conservation tillage on degraded soils was tested.

One of the components of the Socio-Economic Analysis sub-program was to research the economics of conservation tillage. A valid and comprehensive economic data base was generated by the Tillage 2000 program.

The data in the Tillage 2000 project indicate that it should be possible to implement a conservation tillage system with no loss in yield productivity or economic return, in all but the heavier textured soils. This is especially true for sandy textured soils where increases in yield are likely under conservation tillage.

 

Evaluation Summary

(From Technology Transfer Report Summaries - A. Hayes, L. Cruickshank, Co-Chairs)

The objectives of this project are:

  1. to determine the variations in crop yield response to soil landscape variability under different tillage systems;

  2. to relate variations in crop yield response to intrinsic soil properties;

  3. to determine the relative rates of soil erosion and phosphorus delivery in various landscape positions under the different tillage systems;

  4. to provide a basis for designing subsequent experiments dealing with strategies to manage farm field variability under different soil conditions and farm systems so as to enhance productivity while minimizing soil erosion and phosphorus delivery; and

  5. to investigate the causes and extent of severe shoulder slope erosion.

This project was a cooperative effort by the Ontario Ministry of Agriculture and Food (OMAF), the Department of Land Resource Science, University of Guelph, and the Ontario Soil and Crop Improvement Association (OSCIA). The project began in 1985 with the identification of 23 farm cooperators and up to 40 farmers per year participated over the life of the project.

A paired sampling design was established on each of the field scale study sites because of the interaction between tillage and soil landscape on measured crop yield. A number of permanent paired benchmark plots (6m 6m) were established for collection of data from each tillage system. For each treatment, information regarding field history and major aspects of field work operations were recorded. A detailed characterization of soil and topographic properties was undertaken in 1986. In addition to these measurements, crop data was collected every year from each benchmark.

Average surface residue cover after planting was 10%, 29%, and 55% for the moldboard, minimum and no-till tillage systems respectively.

Soil texture (Ap horizon) class and tillage texture class interactions were significant (0.001 probability) in explaining the variations in yield of all crop types. A regression of the ratio of no-till yield/conventional tillage yield against %sand content of the Ap horizon was significant. For sand contents greater than 36% the no-till yield would on average be higher than the conventional tillage system. The no-till yield for finer textured soils would on average be lower than conventional tillage systems. The interaction of tillage and texture is suggested as the reason for little overall differences in tillage system on crop yield, across all farm sites.

Across all years, conservation corn yields averaged one percent less than the conventional yields. Soybean and small grain conservation yields were, on average, 3% less than the conventional yields. None of the observed differences were statistically significant. Grain corn conservation tillage machine yields exceeded the conventional yields 3 out of 5 years. Although the lowest yields were harvested in 1988 the average conservation yield exceeded the conventional corn yields.

For all crops minimum tillage yields were 3 and 2 percent less than moldboard yields for the machine and benchmark harvests respectively. Minimum tillage yields never exceeded moldboard yields for any of the individual crops. The machine yields show that on average no-till grain corn yields were as good as the moldboard and the minimum till yields. No-till soybean yields when compared to the moldboard yields were equal. The hand yields indicate that no-till was successful for grain corn and small grains when compared to minimum tillage.

There was a significant interaction between soil texture and the success of conservation tillage systems. For sandy textured soils, the 5 year average machine yield was 7% higher for the conservation versus conventional systems. Machine yields in clay and to some extent in clay loam soils were lower (6%) in the conservation systems. Yields were similar in other soil textures.

Minimum tillage relative to moldboard plowing was the most successful on the silt loam soils and less successful on the other textures, especially the clay soils.

The data indicated a variable success for the no-till versus moldboard in the medium texture classes (loam, silt loam, clay loam). No-till had much higher yields (15%) than the moldboard in the sandy soils and much lower yields in the clay soils.

The data indicated a trend of decreasing no-till yields relative to minimum till yields with increasing clay content (decreasing sand). Similar yields were obtained for loam and silt loam texture classes. Sandy soils had significantly higher yields in no-till; clay loam and clay soils had significantly lower yields in no-till. This was similar to the moldboard versus no-till data.

Comparisons of the differences in the final corn populations (5 year average) between tillage pairs revealed that the conservation tillage system's populations were significantly less than the conventional populations.

For all conservation treatments averaged over 5 years the average grain corn leaf count, was approximately one-half to one leaf less than the conventional treatments. Similarly, the height of corn plants for the conservation systems were found to be about 4 to 9% less than the conventional systems.

Soybean conservation populations were not statistically significantly different from the conventional populations. The minimum tillage populations were slightly above the moldboard stands. No-till populations were essentially equal to the minimum and moldboard populations. Plant heights were significantly reduced by as much as 18% for both the minimum and no-till soybeans when compared to the moldboard system.

The small grain population of the minimum tillage when compared to the moldboard tillage system was 2% less. No-till populations were 12% lower than the moldboard and the minimum tillage systems. This was statistically significant for the moldboard versus no-till comparison. Differences in leaf counts were not observed for any of the tillage comparisons.

A paired benchmark analysis on crop response on stress (low yielding) and non-stress (high yielding) benchmarks, in stress and non-stress growing conditions was carried out. It indicated that conservation tillage systems may be more buffered against adverse climatic growing conditions than conventional tillage systems. The field yield data also indicated that the ratio of conservation yield/ conventional yield was highest in 1988 the drought stress year.

There was a significant interaction of soil texture class and soil loss, on relative crop yield losses. Severely eroded soils with a % sand content greater than 70% had an average predicted yield loss of 37% of the field average yield. Severely eroded soils with 50-70% and <20% sand content had an average predicted yield loss of 8% of the field average yield. The benchmarks in the medium textured classes had much less predicted yield loss from soil loss, than the benchmarks with lighter or finer soil textures. This is consistent with the higher available water holding capabilities of medium textured soil compared to other textures.

Comparing only yields from tillage systems may not be appropriate when certain tillage systems have significantly lower pre-harvest production costs.

The data in the Tillage 2000 project indicate that it should be possible to implement a conservation tillage system with no loss in yield productivity or economic return, in all but the heavier textured soils. This is especially true for sandy textured soils were increases in yield are likely under conservation tillage.

The net returns per labour hour were, on average, always higher for the minimum and no-till tillage systems for all crops except for minimum tillage soybeans when compared to the moldboard. The highest returns per labour hour were observed for no-till corn. See SWEEP Report #11 "An Economic Evaluation of Tillage 2000 Demonstration Plot Data (1986-1989)" for more information.

Comments:

This is an excellent report. All of the objectives were met either in this report or in the parts of the project which were funded by the Technology Evaluation and Development section of SWEEP. This project is the only one of its kind to successfully conduct research on field scale plots on farms in Ontario.

The direct involvement of the farmer (planting, harvesting, etc. with his own equipment) and extension staff (OMAF and others) provided the following benefits:

  • the farmers and extension staff involved gained experience with conservation tillage systems

  • the extension staff involved were able to provide expertise to the farmers involved

  • the extension staff and the farmers involved were able to communicate the results of the project to the farm community as they became available

  • tillage plots were established in several communities across the province giving other farmers the opportunity to see conservation tillage systems first hand

  • farmers put more faith in machine harvested yields from field size plots

  • it demonstrated that a field scale research design would work and it gained farmer and researcher credibility

  • it provided the first field scale research data for conservation systems in Ontario

Associated SWEEP/LSP Research:

  • SWEEP Report #1 - Tillage 2000 and Its Effect on Awareness of Conservation Tillage

  • SWEEP Report #10 - An Economic Evaluation of Tillage 2000 Demonstration Plot Data (1986-1988)

  • SWEEP Report #11 - An Economic Evaluation of Tillage 2000 Demonstration Plot Data (1986-1989)

  • SWEEP Report #32 - Optimal Herbicide Use in Conservation Tillage Systems

  • SWEEP Report #38 - Management of Farm Field Variability. I. Quantification of Soil Loss in Complex Topography. II. Soil Erosion Process on Shoulder Slope Landscape Positions.

  • SWEEP Report #40 - Management of Mulch Tillage Systems on Clay Soils

  • SWEEP Report #41 - Evaluation of Row Crop Planter Modifications for Corn Production within Conservation Tillage Systems

  • SWEEP Report #45 - Management of Farm Field Variability. III. Effect of Tillage Systems on Soil and Phosphorus Loss

  • SWEEP Report #46 - Management of Farm Field Variability. IV. Crop Yield, Tillage System and Soil Landform Relationships

  • OMAF - Tillage 2000 Progress Reports

Future Research: ( ) indicates reviewers suggestion for priority, A - high, C - low.

(A) More research needs to be done to improve conservation tillage yields on the clay and clay loam soils.

 

 

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Created: 05-28-1996
Last Revised: Thursday, May 19, 2011 08:56:07 PM