Daryl Domitruk

Research Manager

The themes of workshops in 1994,1995 and this year, 1996 have been "The Zero Tillage Alternative9' , "Farming for Maximum Efficiency" and "Advancing the Art" respectively. Together these themes reflect an evolving sense among no-till farmers that , although we know zero tillage is a more profitable and environmentally sound system of farming, it is again time for some forward thinking. Experience with the no till system has led us to this point. I attempted to summarize this experience at last year's workshop in Brandon. The following is an excerpt from the 1995 proceedings.

Despite their use of zero tillage technology, many producers continue to restrict their concept of crop management, including cultural practices such as crop rotation, to the practices they used as conventional farmers. However, continued adherence to the concepts that carried conventional farming limits the benefits that can be realized from zero tillage Ultimately there is an increased risk of failure. In the long run a success zero tillage operation will be one in which moisture, time, labour and capital are used efficiently. Attaining this level of efficiency in zero till will require producers to do more than simply replace tillage with herbicides.

Zero till is not - an alternative but a farming system unto itself. As with any system there are opportunities to improve and become more efficient. However, these improvements cannot be obtained solely through the use of new technology. The benefits of new technology will be short lived if the same crops are seed in the same way at the same time and treated with the same pesticide year alter year. Biological systems such as pest populations have a way of rapidly ~g to changing environmental conditions. Producres should recognize that zero tillage changes the land in many ways, and, as a result, some of the cultural practices that were used prior to zero tillage are less effective in the new agroecosystem created by zero tillage

A good place to start is to consider the link between crop pests and crop rotations. A more diverse crop rotation that includes a variety of crop types changes the times at which crops are sprayed and harvested. Greater diversity, more efficient use of the favourable moisture conditions present under zero tillage A more diversified rotation also allows a more varied herbicide program to be used which can be an effective way to prevent the development of resistant weed biotypes and, thus, avoid one of the major obstacles to efficiency in zero tillage

At present, there are few crops other than the cool season grasses such as wheat and barley, and the cool season broadleaf crops such as field pea and canola, that are adapted to conditions in the northern prairie and parkland. Analysis of the climate in this region suggests that, while we are on the fringe of the ad-on zone for warm season grasses such as corn and heat loving, cool season broadleaf crops such dry bean, they are potential crop options. Among the reasons we should encourage the development of legume crops is the rising coot of nitrogen fertilizer and the reduction of transport subsidies for grain in Canada. Similarly, corn lines with increased cold tolerance and reduced heat requirements are being produced at the Research Centre in Brandon We should strive to develop zero till methods of sowing and harvesting these crops at the same time that breeders are selecting for earlier maturity

While it may be some time before new crop types are available, there are things we can do with currently available crops to gain efficiency. Winter wheat has been developed exclusively as a zero till crop on the prairies where it is the ultimate example of a diversified seeding date and optimized development cycle.

The use of perennial forage legumes on a short term basis has great potential for reducing weed populations, providing nitrogen and improving soil structure. Once again, the rising cost nitrogen fertilizer and the removal of transport subsidies, particularly in Manitoba, suggest that diversification toward a larger animal-forage crop base is warranted.

So, we have arrived at the need for 9advancing the art' largely due to our continued battle with pests. Weeds in particular have always been with us and always will. Weeds were first reported in the Parkland by fur traders who planted gardens near the Hudson's Bay Company forts and by Red River settlers. Essentially, our problems with weeds began as soon as the native prairie was broken. The noxious weeds act Manitoba was established way back in 1883 just before massive settlement took place. The act was in response the invasion of introduced plant species such as Canada thistle, that found a home in the broken sod of the first settlers farms.

In advancing the art of no-till, it would be helpful if we had a model to refer to. Lately, the native prairie has been suggested as such a model.

You've heard Dwayne Beck talk about the native prairie in South Dakota so it is worth describing the native state of our, more northerly region. in fact, I do not come from the prairie per se. Any map will show that much of what we call the Canadian prairie region is actually a transitional zone between the northern boreal forest region and the semi arid prairie. (A majority of the area of the prairie provinces is not farmland, but is boreal forest.) This agricultural region, called the Parkland, constitutes the northern fringe of arable land in North America. it is characterized by areas of open grassland alternating with groves of trees indicating that it is more humid than the prairie to the south. The grassland component of the Parkland is classified as either mixed-grass, tall grass or fescue prairie although little of the original grasslands exist. The MZTRA farm is in an area that was once mixed grass prairie. Although trees were always a part of the plant community, few of the trees today are older than 75 years. This is particularly true in the south where the elimination of the bison and prairie fires has resulted in greater encroachment of trees onto the grasslands.

Ecologists have shown that certain plant communities are favoured according to the distribution of rainfall and temperature. The amount of precipitation and heat received during the April-May-June period compared to the July-August-September period determines which species are adapted. in the Parkland of Manitoba and eastern Saskatchewan, almost 3/4 of the native plant species flower before the end of June and mature in late July and early August1'2. The remainder, the warm season species, flower in early July or later and mature from late August to early October. Of the 200 plant species that inhabit the Parkland region, 20 are warm season tall grass prairie grasses such as big bluestem. in our particular area spring temperatures are not greatly different from north to south but in the summer it is warmer in the south than in the north. Also, temperatures decrease with altitude. Warm season grass species survive in our region because the precipitation ratio is 1 or greater and they are able to produce viable seed with the amount of heat they receive. However, in the northern Parkland 60 percent of the native vegetation consisted of trees. In these northern regions and at higher elevations the late maturing warm season species were far less common.

The most outstanding attribute of the native prairie is its diversity. However, the prime function of the prairie plant community is survival. Although we intend to mimic the diversity of the prairie, we must emphasize production over survival in our crop rotations. Therefore, it is necessary to assess the risk associated with growing different crops. Risk is dependant on weather.

The following is a list of the weather expected at the MZThA farm north of Brandon 3

Average last spring frost	May25-May30
1-in 4 years last spring frost occurs on	June4 - June 9
Average first fall frost	Sept7-Septl2
1-in 4 years first fall frost occurs on	Aug3-Aug8
Average frost free period	105 days
1-in 4 years frost free period less than	95 days
Average growing degree days	1550
1-in 4 years GDD less than	1400
Average corn heat units	2300
1-in 4 years CHU less than	2200

Given this weather, the annual crops that are typically grown in this region are the following: (the list does not include forages)

Crop	Days to Maturity	Crop	Days to Maturity
Wheat	90-110	Lentil	85-100
Barley	60-90	Canary seed	95-105
Oats	85-88	Navy bean	90-100
Flax	85-100	Suntlower	120-130
Buckwheat	80-90	Potato	90-140*
Yellow Mustard	80-90	Coriander	90-100
Corn(grain)	110-120	Fababean	105-115
Canola - Argentine	92-102	Field pea	90-110
Canola - polish	73-83	Black bean	95-105

* potato requires irrigation

It is obvious that when it comes to crops, we are in cool-season country. The list seems diverse enough until you realize that corn is the only warm season species and that most of the crops are not part of a regular rotation. As we realize the important part diversity played in the native ecosystem, we may come to see a role for diverse crop rotations. There is little doubt that added diversity in seeding date, herbicide rotation, residue load and disease susceptibility will help reduce inputs and improve margins. The above list, which is not complete, should allow us to use crop rotation as an effective pest management tool.

On the MZTRA farm the basic rotation is grass-broadleaf-grass-broadleaf(sp. wheatcanola-sp.wheat-pea). Barley is often substituted for the second wheat crop. The main problem with this rotation is that these crops are all seeded and harvested at relatively the same time of the year. This is an open door for pests. Contrary to popular perception, most no-till fields do not experience dramatic shifts in weed communities. Most of the weed species that thrive under no till are identical to those that interfere with conventional crops. inevitably, however, weeds appear that are particularly adapted to undisturbed soil and narrow herbicide rotations. Weeds such as rough cinqefoil, American dragons head, stork9s bill and night flowering catchfly germinate in the crop and escape post-emergent herbicides. Fall spraying these weeds can be either ineffective or too expensive. Wild pansy, foxtail barley and yellow whitlow grass also favour no-till fields. The appearance of these weeds is a signal that simply replacing tillage with herbicides does not result in a successful no-till farm. So, if herbicides cannot fully compensate for the removal of tillage, what is the alternative? The answer to this lies in boosting the effectiveness of the herbicide program with management practices that include diverse crop sequences and diverse seeding dates.

It may seem that a 100 day growing season offers little opportunity for altering a crop rotation. in this country the time between planting, spraying and harvest is just about the time it takes to regain your breath. But the element of time is the most useful ecological factor available for creating a systems approach to farming. For example, at the Indian Head Experimental Farm seeding dates are varied from year-to-year in a cereal-oilseed-cereal-pulse rotation. The timing of the spring Roundup application corresponds to the seeding date. Late spring applications control a larger number of weeds and make it possible to reduce in-crop herbicides. Early seeding gives the crop an edge on weeds and provides an opportunity to skip the preseeding Roundup application. Success with this method depends on restricting soil disturbance at seeding so weeds are not encouraged to emerge in the crop.

There are other ways of varying the timing of seeding and spraying. The ultimate example is winter wheat. This crop provides competition against early emerging weeds and leaves more time for fall herbicide applications. New varieties with better quality and disease resistance are on the way guaranteeing winter wheat a spot in well managed no-till rotations. The cereal year of the rotation can also be occupied by corn. The problem is that there are few hybrids on the market that mature with 2300 CHU's. As an alternative, we are investigating dwarf corn. This crop reaches physiological maturity with 2000 CHU's and, unlike hybrids, can also be put in the bin at 16% moisture right from the field. Dwarf corn is grown like wheat so it does not require special row crop equipment. At the MZTRA farm we are developing the agronomic package for this crop. Dwarf corn is being developed by the Brandon research centre of Agriculture and Agri-Food Canada. It remains to be seen if plant breeding can improve the potential for this crop in the Parkland. There is certainly room for varying seeding dates in the legume year of the rotation. We have a choice of legumes that represent early, middle or late seeding dates. Faba bean are seeded in late April and peas are seeded in early to mid May. Dry beans are being grown in the legume year as a late seeded crop. Of course beans can't be grown everywhere due to their requirement for heat. Most navy varieties will be ready to harvest in 95 days if they are planted in the last week of May. Although not a legume, buckwheat, another late seeded crop, can also be grown in the legume year or in place of canola in the oilseed year. Fall frost is the enemy of buckwheat. However, if buckwheat is planted on June 1 a crop should come off 85 days later. A late Roundup application just before seeding will control a lot of weeds in either beans or buckwheat. Beans still require post-emergent weed control but some farmers have grown buckwheat without it. In a good cropping system the bean or buckwheat fields will be planted to a cereal early the following year. Because these are very low residue crops early planting is usually possible.

One of the more novel ideas being evaluated is fall dormant seeding. Canola has received most of the attention since, unlike winter wheat, winter canola cannot be grown on the prairies. However, the objective of dormant seeding is the same as winter wheat; to escape pests through early development. Normal spring-type canola is sown into frozen or semi-frozen soil in late autumn. Nothing happens until spring when the soil warms to at least 60C, the critical temperature for the biochemical processes that control germination in canola At the zero tillage research farm the top 1/2 " of our black clayloam was at 1 10C on May 5, a full 20 days before we were able to sow our regular canola In 1995 our dormant sown canola was equal to our best spring sown hybrid under the hot dry conditions we experienced in southwestern Manitoba. Ken Kirkland at Agriculture and Agri-Food Canada's experimental farm at Scott, Sask. has the most experience with dormant sowing. Ken's crop emerged at the end of April this year and provided a two week gain in maturity, but no yield advantage, over canola seeded in mid-May. Taking advantage of that great ecological factor, timing, the dormant seeded plots escaped the bertha armyworm. This undoubtedly increased profit. According to Ken it is too early to declare dormant seeding a viable method.

Some of the work being conducted on no-till beans at the MZTRA farm is summarized below.

l. Looman, J. 1983. Distribution of plant species and vegetation types in relation to climate. Vegetatio 54:17-25.

2. Criddle, N. 1927. A calendar of flowers. Can. Field-Naturalist 41:48-45.

3. Ash, G.B.H, Shaykewich, C.F. and R.L. Raddatz. 1992. Agricultural Climate of the Eastern Canadian Prairies. Environment Canada, University of Manitoba and Manitoba Agriculture.