Manitoba Zero Tillage Research Association

Two Rotation Systems

Barry Fraser Farm & Extension Program Manager

Crop rotations have developed over time as one of the most effective methods to manage many crop production problems. Crop rotations together with reduced tillage and especially no tillage can noticeably increase soil productivity while reducing input cost.

The Manitoba Zero Tillage Research Association (MZTRA) farm located 11 miles north of Brandon has embarked on two-rotation systems that replicated within a zero tillage system. One system is an annual crop system and the other is a livestock system. There are two replicates of the systems the west half of the farm is the annual crop system and the east is the livestock system. Replicate one is the south half of the farm while replicate two in the north half. There are two fields of about 35 acres in each system. The first year (2001) the farm was all sowed to canola for uniformity then it was split into the systems (2002). The map showing the farm with this year crops and the splits is on the next page.

The chart below shows the rotations in each system.

Some of the crops in the rotation systems will help the crop in the following year. Nitrogen fixing crops supply some of that nutrient for the crops to follow. Flax is a beneficial crop because of the herbicide options available for excellent grasses weed and good broadleaf weed control.

The annual crop rotation system was designed to try and manage the different pest cycle and to decrease input cost. These systems require more intense management skills.

Diseases over winter and survive on the crop residue. Crop residue has a slower rate of decomposition on zero till operations. With this in mind crop rotation can break the reproductive cycle of the diseases by preventing the reproduction of these organisms.

Allowing a certain amount of time between crops of same kind will allow a break in the cycle reduces the amount of diseases present and results in less disease in the future. With less disease organisms in the residue there will less chance of disease in the crop that is grown and can reduce the expensive cost of spraying crops.

Weeds can also be a challenge in developing a crop rotation program. With different crop there are particular weed problems associated with these crops. With crop rotation one can change the weeds environment, which can help keep the weed problem in check by disrupting their life cycle.

This year in the Winter Wheat crop we did not have to spray for weed control. The weed count was low and the winter wheat was well ahead of the weeds.

When talking about crops rotations there should also be a great consideration given to herbicide rotation. This will help control some herbicide resistance from developing in the weed populations.

Our goal with this crop rotation program is to reduce energy use and input cost to the producers. By reducing the amount nitrogen fertilizer. Lowering our dependence on pesticides. This can help reduce the energy it takes to produce these products by reducing our use of them. Another goal was try to develop a system that works in all years, whether normal, excessively wet, or extremely dry. With these goals we must insure that this is all economically sound and maintains a profit to help keep agriculture sustainable in Manitoba.

The livestock rotation system has an alfalfa component. The alfalfa will be sowed for a 3-year period. These fields of alfalfa are to split into different systems. The one system will produce hay and the other will be into cattle grazing system. These different systems will be compared to one another on economic bases.

The two cuts of hay will be sold as standing hay at the day’s price. The hay will be measure for the amount of production per unit and total number.

The whole livestock system has been fenced. The fields that will be used for grazing are to have fresh water piped in from the yard. The grazing fields will have temporary fences to make smaller paddocks for rotational grazing. The plan is to get about 400 Lbs. of beef per acre. The cattle will be grazed for about 110 days.

This rotation is not steadfast there might have to be compromises along the away. Sometimes the market benefits or weed or disease problems may change the rotation but keep in mind the risks. Challenges will be to devise a rotation that maximizes benefits and have the lowest risk possible.

There is lots of research that is going on at the research farm conducted by outside interest. One project that we are investigating is whether by removing the chaff from the field has any effect on weed population and disease carryover. As this project is only just started this fall there is no data to share with you at this time.