By

H.C. Driver* and R.M. Josephson**

Prepared for "0-Tillage Conference" at

Brandon, Manitoba - January 27, 1993

* Adjunct Professor, Department of Agricultural Economics and Farm Management, University of Manitoba

** Associate Professor, Department of Agricultural Economics and Farm Management, University of Manitoba

The problem of this study is to explain how and why zero-till is economically competitive or non-competitive with conventional tillage practices. If zero-till should induce lower production costs as compared to conventional practices while maintaining or enhancing crop yields, then the goal of self-sustaining agriculture and wildlife is synergistic as opposed to antagonistic with farmer profit motives.

In the case of agriculture, zero tillage virtually eliminates soil erosion from wind and water; improves the structures and friability of soils; promotes greater populations of micro-organisms and earthworms; and traps and retain moisture. These positive affects of zero-till on soils should facilitate higher crop yields and possibly lower fertility requirements. When these affects are combined with lower tillage and labor requirements, lower costs of production are to be anticipated. However, there are also some negative affects from zero-till: 1) chemical costs may rise to control over wintering weeds, fungi and/or pests and 2) comparably higher levels of spring moisture and capacity to retain moisture along with a lower rate of increase in soil temperature on zero-till vs. conventionally tilled soil tends to delay seeding development and increase the incidence of plant diseases.

Clearly, the manifestation of these advantages and disadvantages occur over time. It is reported (Sprague and Triplett, p.421) that reduced erosion is cumulative, and that on erosion soils long term conservation tillage, of which erosion reduction is greatest with no-till, has yield advantages over conventional till. The disadvantages from disease related organisms also build up through time and adversely affect benefits. The periodic use of legumes in rotation would further improve soil structure and friability, drainage and natural fertility (Kay and Sheard) without necessarily contributing to the build-up of disease related organisms in grain and oil seed crops.

Zero-till and conventional tillage practices are dynamic systems. Successful adoption of the zero-till system on new management techniques combined with technology which facilitates fertilization and seed placement as well as weed and disease control with minimum soil disturbance. Because of this, the technology of chopping and evenly spreading straw and chaff at harvest becomes more important; likewise, post emergent sprays as compared to soil incorporated for controlling weeds; and seeding and fertilizer banding knives on cultivators and/or seeders as compared to shovels or disks. By extrapolation, the tractor horsepower and labor requirements should decrease, altering over time the portfolio of investment in productive farm assets for those who adopt the system.

It follows that potentially lower production costs and overhead investment of zero-till encourage either adoption of the system or improvisation of conventional tillage practices toward minimum till. Zero-till and improvised min-till with conventional practices might turn out to be almost equivalent in helping society achieve the goal of self-sustaining agriculture.

The specific objectives were:

1. To determine and compare annual enterprise costs and returns for 3 crops (wheat, flax and canola) raised under satisfactory rotational restrictions and two different tillage and seeding systems (conventional and zero-till).
2. To identify and evaluate production variables which explain why costs and returns might differ between the two systems.

During 1990 ten farms in the Minnedosa area participated in the study. In 1991 and 1992, seventeen cooperating farmers participated. The following guidelines were used in the registration process:

1. Each farm set aside two fields: one for zero-till and the other for conventional tillage practices.
2. The two fields were acceptable if they were essentially the same in terms of soil type, productivity and drainage characteristics.
3. Selection of which field would be designated the zero-till field or conventional till field was based on the loss of an unbiased coin where heads was used to represent zero-till.
4. Each Farmer selected a rotation over time which would provide at least two observations of each designated crop, namely, flax, wheat and canola without at the same time violating of the rotational guidelines provided by the Manitoba Department of Agriculture.

Experimental data was collected by two personal visitation surveys. Information was recorded on:

1. moisture and rainfall;
2. seed pedigree and treatment as well as seeding methods and data of seeding;
3. fertilizer blends, rates applies and methods of application;
4. weed identification and density as well as chemicals used, rates applied and methods of application;
5. presence of plant diseases, insect infestations and methods of control;
6. tractor power and type used with each tillage and seeding practice;
7. harvesting methods;
8. labor records.

Comparison of weighted average yield for each crop demonstrated that zero-till technology consistently provided higher yields than conventional in 1990. In 1991, the comparison of economic advantages were essentially reversed. Canola yields were only slightly higher for conventional till but the cost advantage for canola was an average of 65 cents per bushels. Results for canola were consistent for all five canola producing farms in 1991.

Yield and economic comparisons were not entirely consistent for wheat in 1991 but did favor conventional till. One individual wheat situation weighed heavily in this calculation on conventional wheat one-yielded zero till. Although the observation of CPS wheat were limited to three, the fact that all instances out-yielded CWRS wheat and by amounts of ten bushels per acre on conventional till and sixteen bushels per acre on zero till raises questions to be monitored and investigated in future years of this study. It appears that CPS wheat may have found the growing conditions in the Minnedosa area move favorable than other areas such as the Red River Valley area in 1991, and appeared to perform better than crops grown in the project, and at least as well zero till as with conventional till.

This analysis indicates that zero till was not as cost competitive as conventional till under the particular growing circumstances encountered in 1991. Discussion of the results between the researchers and producers raised the possibility of soil born related organisms, emerging weed patterns, and lower rate of increase in soil temperature during seeding and germination as factors that could have adversely affected zero till crops.

Results obtained from 1992 have not yet been fully analyzed. However, it appears that the unusually cool weather, lack of sunlight hours and an earl frost in the area, resulted in some later maturing zero-till acreage which affected both yield and quality of Canola crops. The somewhat different results from three years of observations suggest that additional time, observations and multidisciplinary expertise are required to fully analyze cause and effect of production factors on yields and costs and their implications for optional management of competing tillage systems.