DAVID ROURKE AND ANDREW HARGRAVE CONSERVATION TILLAGE PRODUCTIVITY CENTRE

Three years of demonstration and trial work, many years of related activities and hundreds of discussions between me, myself and I as well as with many other farmers, researchers and extension specialists have caused me to ask the question "Zero till - Is it the answer?" As a research Extension person and perhaps more importantly as a farmer, should I be promoting, zero till to myself and others?

I would like to summarize some of my thoughts on this question. .First we might ask "What might zero till be the answer to?"

Is it the answer to soil erosion? With the exception of permanent pasture, zero till is without a doubt the answer to controlling soil erosion in annual cropping systems in the Prairies. While carefully managed comparative erosion studies give us nice numbers from which to prove this aspect, just look, you will see that zero till is very effective at controlling erosion.

Is it the answer to global trade wars? Even zero till can't solve this one.

Is i t the answer to a safe reliable food supply ? Even though zero till relies on the use of herbicides, in particular Roundup to replace tillage, it certainly does not mean increased risk to human health or even environmental health..Roundup has extremely low mammalian toxicity ( lower than table salt) and strict regulations of pesticide registration and us in Canada provide us all with highly acceptable risk/benefit ratios on current pesticides. Health & Welfare Canada routinely use a 100 times safety margin for residue tolerance based on a no effect level. It is reassuring to know we have an agrifood policy which allows high standards of human safety as well as the Flexibility to produce food with low input costs.

Is it the answer to environmental harmony? Food production using current and foreseeable technology uses land which competes directly with nature's creatures .Of any production system, zero till is the system which can best be harmonized with nature. Here are a few examples of how zero till interacts with the environment.

Eg.

Reduced erosion - siltation and pollution of lakes and rivers is reduced.. Standing stubble- allows for greater wildlife density on the landscape.

- additional work has been initiated to design seeding equipment which will increase benefits to ground nesting birds

and mammals without jeopardizing agronomic performance.

Lack of tillage - healthier soil, more earthworm ;, soil microbes, small birds and mammals.

Is it the answer to becoming rich without working? Wishful thinking!

Is it the answer to sustainable agriculture? {defined as farming system which provides for an economically viable business while maintaining or improving the resource base {soil). Zero till as discussed earlier is one of the best methods of maintaining or improving the resource base. The economics of zero till becomes the key to determining if it is a part of sustainable agriculture. Does zero till provide a level of net income which is comparable to other farming practices? Since Net Income = Price x Yield - Costs, how does zero till affect net income zero till of course has no effect on price but can have significant effects on yield and costs.

Over the years, a small mountain of evidence I as shown that crop yield under zero tillage can be higher when compared to conventional farming systems. Donaghy (1973), Rourke (1981), Lafond (1991), McAndews et al (1993) are just a few examples of research trial work where zero tillage has been found to have yields equal or greater to conventional farming methods. During the past 3 years, work conducted at the Conservation Tillage Productivity Centre at Minto has shown some revealing facts about the agronomics and economic performance of zero tillage. Among the many trials conducted at the Centre, the Crop Rotation X Tillage has become a focal point. The trial has consisted of 3 crop rotations:

SI:100% cereals - wheat, wheat, wheat, barley;

S2: 75% cereals - wheat, barley, wheat, mustard;S3: 50% cereals - wheat, flax, barley, mustard.

and 3 tillage systems:

conventional tillage - 2 11 tillage & I spring cultivation minimum tillage - I fall I spring cultivation zero tillage - one pass seed & fertilizer.

The results of the trials have stressed that importance of having diversified rotations to achieve the best economic advantage and has shown how zero tillage can further enhance crop performance in diversified rotations.

We have included both the average yields from he trials as well as the economics(Tables 1, 2 and 3). It is difficult to know what prices to assign to an economic analysis with our current market variability The prices used were:

Wheat $149.95/MT ($4.07/u)Barley $ 77.13/MT ($1.68/ u)Flax $279.39/MT ($7.09/ u) Mustard $275.75/MT (.125/1 )

Costs were based on local prices: examples $@93/MT for 11-52-0 and $265/MT for46-0-0. You are encouraged to use your own numbers to determine how our yield results may fit into your operation. Of all the numbers used in our calculation machinery costs was the hardest to be sure it, would reflect the actual cost of owning, repairing, maintaining and replacing the equipment. Our figures are based on the "Farm Machinery Custom and Rental Guide 1993" published by Saskatchewan Agriculture and Food and the "Farm Planting Guide 1993 Crop estimates publication by Manitoba Agriculture. Our figures also assume commercial equipment was used and that in the zero till situation the farm may have sold off extra tillage equipment or if the equipment was fully depreciated, it remained on the farm 'just in case'.

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Table 1. Effect of crop rotation and tillage on yields.

The analysis shows clearly that zero tillage has advantages over other tillage systems both in terms of yield and profit. While the results of the trial show a much healthier picture for zero tillage, we can speculate that there will be other rotations which can be more profitable. In the future, we will replace barley with wheat and add canola and peas for mustard in this study to help achieve even greater returns. Each farm has its own consideration when planning.

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a crop rotation but under current conditions, use of a diversified rotation with zero tillage can add to the economic sustainability of the farm.

Table 3. Expenses for treated wheat production based on 1993 operations.

An added feature of the rotation x tillage study in 1993 was the inclusion of a foliar fungicide on the wheat plots. Again we found greater benefits to the addition of a fungicide when used in a well diversified rotation with zero tillage (Figure 1).

The yield response to the fungicide on Katepwa was 15 bu ac. on a zero till 50%cereal rotation versus 6 bu. ac. in a conventional till, 100% cereal rotation. The fungicide allowed us to realize the higher yield potential of the zero till production system.

The crop rotation x tillage has been a surprising study. Surprising in the magnitude of the differences, surprising in the consistency of the differences, surprising in the fact the differences started early in the rotation and surprising the differences occurred even though the last three years have tended to be average or above average for moisture availability. In the next cycle of the trial, we hope to look more closely into the reasons zero tillage has been able to excel compared to other tillage systems.

An even more surprising study has been our tillage study. The tillage study was conducted on large plots with commercial type equipment. Nine tillage systems were evaluated, each year a single crop was grown. Fertilizer was placed at seeding time an all treatments even though so treatments such as 'fall banding were included. In this trial, only the tillage effects were evaluated. Barley, flax and Biggar wheat were grown in 1991, 199! and 1993 respectively. Each year the treatment which precluded fall tillage had the higher yields and the one pass zero till tended to have the highest yield overall (Figure 2).

Again the zero till looked good despite the years being perceived as wet. However upon closer examination soil moisture availability was always higher with zero till. For example, gravimetric moisture content from 0 to 2" and 2" to 6" at seeding in 1992 was 25.8% and 25.7% on zero till compared to 20.9% and 23.7%,respectively, on conventional till. There was an additional 27.3" of moisture in zero till compared to conventional till in the top 4 ft. of soil.

Table 4 shows the economics of the tillage trial over the three years. Here again the zero tillage treatments looked extremely good, with net profit of the one pass zero till system being 4 1/4 times higher than the conventional method. While some have jokingly suggested zero till looks good because we don't know how to conventional till it is interesting to look at the plant count data taken shortly after emergence. Crop emergence was very similar, in fact, at times it was better with conventional tillage (Figure 4), suggesting that zero tillage itself was having a greater effect on the outcome than anything we may have done in managing the trial.

Table 4. Tillage comparisons and the impact on net income (3 year average).

As an addition to the 1993 tillage trial, we seeded with two different drills, a Concord air seeder with Anderson paired row openers and a double disc Haybuster 107. The objective was to determine if the soil disturbance resulting from the seeding equipment would have any effect an crop establishment, weed growth or yield. While this is only one years data, the results are dramatic (Figure 3).While there were differences in weed growth (primarily stinkweed, kochia, wild mustard and wild buckwheat) from the seeding equipment, the largest differences

were between the tillage systems. The one one pass zero tillage had the least weeds approximately 15x less than the conventional till treatments. Yield differences between the drills were minimal suggesting the differences in the disturbance at seeding was not nearly as important as fall or spring tillage.

Weed counts in this study were taken prior post emergent spraying. All plots received the same herbicides, one could speculate that many of the zero till treatments may have not benefited from the herbicide application, but the cost of the herbicide was reflected in the economic analysis.

In a proposed future study, we will examine ways to achieve weed control in zero tillage while reducing or eliminating some herbicides in at least some crops.

Parallel results on weeds (although not as dramatic) were also noted in our pre-emergence herbicide x tillage trial . The objective of this trial was to determine if fall applied pre-emergence herbicides could be used in a reduced tillage tem to achieve weed control results similar to the conventional incorporated methods. The results of the past 2 years' trials are shown in Figures 5-8.Incorporation treatments included:

(1) no incorporation (zero till)

(2) tyne harrows following application (one pass)

(3) tyne harrows following application (two passes),(4) fall band following application,

(5) fall band plus one pass with harrows,

(6) one pass each in fall and spring tithe a wide blade cultivator and,

(7) one pass with a deep tiller and one pass with a tandem disc in fall and two passes with a tandem disc in spring.

Note the reduction in weeds in the zero till lentils untreated check compared to the weed counts in the tillage untreated check; approximately 1.5 to 2 fold reduction in green foxtail and wild oats and 15 fold in volunteer wheat.

Overall the pre-emergent herbicide x tillage trial has shown, at least under the trial conditions used, it is possible to achieve acceptable weed control using pre-emergence herbicides in a zero till situation. It is hoped that continued research by the companies involved over a wide set of conditions will result in label recommendations for this use.

From a farm perspective, the most important question to ask is:

Is zero till the answer to economic viability? For those of you who require even more evidence that zero tillage has a role to play in the economics of a healthy farm, I would like to suggest we ask the farmers. Since zero till is no longer a new concept, a number of farmers have successfully practiced zero till for a number of years. While it may not be possible to directly discern how they compare with their neighbours, the number and range of farmers who practice zero till can be used to reflect on the viability

Examples of a few Manitoba farmers who have practiced zero till over an extended time period include:

Jim McCutcheon 20 year veteran Homewood

Bob McNabb 16 year veteran Minnedosa

Robert Stevenson 10 year veteran Oak Lake79

Garth Butcher 10 year veteran Birtle

Gordon McPhee 15 year veteran Dauphin

Another example of economic viability can be found from a five year study conducted on Garth Butcher's farm at Birtle in conjunction with Owen Beever of Manitoba Agriculture. It is partially report in "Zero Tillage - A Production Manual". As in the rotation x tillage study a d the tillage study, zero tillage compared very favourably with other systems in each year of the study (Table 5)

The last question I wanted to address is

Is zero till the answer for everyone? This is a difficult question but the answer is probably no. From a survey conducted at the 1993 15th Annual Zero Till Workshop held at Brandon, it was clear that there was no monopoly on zero tilling terms of age of farmer, size of farm or soil types, however tradition and resistance to change were probably factors preventing adoption of zero tillage.

Table 5. Tillage comparison (Birtle (1986-1990)

------------- bushels / acre ------------

1986 Durum Wheat 56.0 56.0 54.0

1987 Barley 77.3 73.2 66.2

1988 Barley 77.1 69.6 63.2

1989' Canola. 11.1 8.2 6.5

1990 Durum Wheat 64.2 31.3 54.9

* 1989 was a dry year.

Average gross return/Ac $146.91 $136.60 $124.18

Average Expenses / Acre $116.46 $113.63 $110.78

Average Net Return / Ac $ 30.45 $ 22.97 $ 13.40

In a conventional till system usually the largest change to the system one has to deal with is changing the shovels on the deep tiller. In starting zero tillage, one has to learn to deal with better crop rotations, use of spring burnoff herbicides, possibly use of more sophisticated seeding equipment and better trash management.

While this is perhaps over simplifying the conventional till situations, zero tillage does require a farmer to make changes in his operation to ensure success. Some farmers have not recognized the value in taking the changes or are simply comfortable enough with what they are doing.

The question in the future for many farmers will not be "Does zero till work?" but "How do we get the most out of the system?" To address at least some of the questions which are being asked or will be asked, a number of projects were

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initiated at the Conservation Tillage Productivity Centre over the last 3 years. These included:

a) Fertilizer options for Zero till,

b) Fertilizer and seeding in one pass,

c) Fine tuning burnoff herbicide mixtures and rates,

d) Perennial weed control in zero tillage,

e) Crop establishment and geometry for optimum yields,

f) Use of pre-emergent herbicides in zero till situations.

In the future we hope to address the following questions:

a) Why does zero tillage give us higher yields,

b) Do root or foliar diseases differ between zero till and conventional till,

c) Can we enhance the cultural weed control advantages of a zero till system to reduce herbicide use in some crops crops with the view of reducing costs and / or likelihood of developing herbicide resistance,

d) What strategies will prove effective to prevent seeding delay in wet years,

e) Can we develop systems which use equipment with more precise fertilizer placement and lower draft and lower cost/foot than existing machines.

ZERO TILL - IS IT THE ANSWER?

I believe zero till can be an important component of a healthy farm if the manager wants to exploit the benefits, but it will require changes. At least some minor changes in equipment are required, depending on where you are coming from. You need a chaff and straw spreader, reliable seeding equipment and it is very useful to have a shield on a suitably sized sprayer. You will get the most benefits out of zero -tillage if you follow a diversified crop rotation (economics, diseases, crop cultivar will need to be considered to devise the most practical and profitable rotation for your farm). You will need to be able to identify and develop weed strategies for their control. You will want to practice good field & equipment sanitation and preventative weed control strategies such as mowing around field borders to prevent wide spread of bromegrass across the field.

There are lots of tricks to the trade but would suggest anyone who makes a concentrated effort to learn about zero tillage can be successful.

Zero tillage is a challenging opportunity.

For further information on zero tillage, we suggest:

a) attending the annual Manitoba-North Dakota Zero Tillage Workshop

b) attend summer tours, eg. CTPC summer tour & Annual Man. N.D. Zero till tour

c) get a copy of Zero Tillage - A Production Manual or Direct Seeding Manual SSCA

d) Look for the CTPC highlights report, available from Manitoba Agriculture, at

the Zero Till Workshop or from the CTPC

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e) Talk to experienced farmers, research and extension specialists

f) Read - there are lots of articles on zero till in many popular magazines &papers as well as the Manitoba-North Dakota Zero Tillage Farmers' Association newsletter.

The future looks bright for zero tillage. As we examine the new technology presently being developed, we see the following trends:

1) development of crops resistant to wide spectrum post emergent herbicides such as Roundup & Harvest,

2) development of additional herbicides which will help compliment weed control in zero tillage; eg. Pursuit in peas,

3) development of seeding equipment which allows greater precision of seed and fertilizer placement in direct seeding situations,

4) lower cost of key herbicides such as glyphosate. With the patent off of Roundup we can expect to see some new source of glyphosate,

5) more extensive use of pre harvest weed control,

6) possible use of pre-emergent herbicides zero till situations.

New solutions are being found to many of our old stumbling blocks Go ahead - exploit zero tillage.

This is not a Catch 22 - we can stop soil degradation and improve net incomes.

Zero tillage will be the answer for many prairie farmers.References:

Donaghy 1973. Zero tillage crop production in Manitoba. Ph.D. thesis, University of Manitoba, Winnipeg.

Lafond G. 1991. The performance of zero ti1 at Indian Head. 13th Annual Proceedings of the Manitoba - North Dakota Conservation Tillage Workshop.

McAndrews O.W., K. Handford, R.P. Zentner, M. Gorda and J. Doner. 1993. Agronomic and Economic considerations in various barley reduction systems in east central Alberta. 15th Annual Proceedings of the Manitoba - North Dakota Conservation Tillage Workshop.

Rourke D.R.S. 1981. The effects of crop residue management on zero till crop production in Manitoba. MSc. thesis. University of Manitoba.