Crop rotation to control winter grasses

Case studies - Chamber of Agriculture Occitanie - Aglae - Georges Joya (2015) - Weed management

Field crops Cover crop management in field crops Soil cover Biodiversity Weeding in field crops Soil regeneration Weeding

Gers (department)

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Feedback from Georges Joya, as part of the Aglae project. He presents how it is possible to farm with no-till and organically.

Motivations

I started converting my farm to organic farming in 2010. Following this change, I sought to redesign my cropping system by implementing techniques other than chemical weeding for managing weeds on my plots.

At the beginning of my conversion, I practiced ploughing and applied organic fertilizers.

Over the years, I began to notice problems of erosion on my soil and an increasing number of weeds, particularly thistles and wild oats. I then considered another rotation system. I first stopped ploughing and established cover crops so that my system would be self-sufficient in nitrogen inputs. To diversify the crops in my system and broaden my economic outlets, in 2015 I decided to introduce high value-added spring crops such as lentil, flax, and chickpea. Gradually, I also stopped irrigation and consequently reduced the proportion of my summer crops in the system, notably replacing soybean with buckwheat. Today, my system is very diversified with many crops, which allows me to better manage weed infestation on my plots.

Implementation

Crop rotation: a gradual implementation

Implemented since 2015.

“I chose the crops to implement based on the following criteria:

high added value
intended for human consumption
adapted to clay-limestone soils and dryland systems.

For this, I relied on the expertise of cooperatives and other local actors who develop this type of crop.”

Benefits and points of caution

Benefits

Good economic valorization of legumes (crops under contract)
Autonomy in nitrogen thanks to the introduction of legumes
Reduction of weed pressure, particularly thistles
Allows reducing the proportion of summer crops in the rotation and thus reduces water consumption
Spreading out work over time
No additional investment other than seeds

Points of caution

No soil cover in winter because destroying a spring cover crop is difficult due to climatic conditions at that time of year on clay-limestone soil
Short window for establishing spring crops due to climatic conditions at that time of year

My advice for success

Forget the idea of having a winter cover crop returned during winter. There is too little room for maneuver for returning it, clays are difficult to work again, and it is much harder to provide the soil with good sunlight during a relatively cool and often humid period.
Establish your spring crop on dry soil
Anticipate the rotation to avoid having a cover crop to destroy before establishing a spring crop

My perspectives

Trial of sowing crimson clover combined with emmer wheat
Establish 1 to 2-year grasslands in soft wheat or cover crops

Leviers évoqués dans ce système

My results

Agro-environmental

Decrease in weed pressure
Decrease in pest pressure
Decrease in disease pressure

Social

Reduction in mechanization time
Stability regarding periods of work overload
Increase in observation time

Economic

Reduction in mechanization costs
Increase in net margin
Stability of implementation cost

Expert committee opinion

Evaluation according to the ESR analysis grid.

Redesign

Integrated protection requires a combination of all available means that force a redesign of systems to make them less dependent on phytosanitary products. This involves an approach favoring prevention and prophylaxis to place crops in the best conditions while disadvantaging bio-aggressors.