Dinámica del cambio técnico: el caso de las promociones de raigrás en Uruguay

Ryegrass (Lolium multiflorum) is one of the annual grasses used as winter forage, with approximately 600.000 hectares sown annually. Its ability to produce a large amount of high-quality forage in a short time makes it highly valuable. Promoting the natural reseeding of ryegrass is a common practice to regenerate the crop annually at a low cost. This involves allowing the ryegrass to seed and then stimulating and enhancing spontaneous germination from the soil seed bank.

The general objective of this study was to evaluate the promotions of ryegrass in Uruguay and to profile the producers who adopt this technology. Specifically, it aimed to determine common techniques, the advantages and limitations of the practice, and to characterize the profile of the producers.

Two methodological tools were used: i) surveys conducted with a group of 26 technical advisors and extension agents, and ii) in-depth interviews with a group of 5 technicians and a group of 5 producers. The surveys covered aspects from the working region to the management of promotions, while the interviews, conducted via Zoom, delved into technical and productive issues.

The results suggest that ryegrass promotions are an innovation developed by producers through observation and experimentation. They are more common in livestock areas than in agricultural ones. The producers who adopt them are diverse, predominantly livestock farmers who integrate cultivated pastures into natural field systems, with limited access to machinery.

The promotions are notable for their low cost and simplicity, but have weaknesses such as unproductive areas in summer, weed problems, and lack of long-term stability. Management practices vary, from completely closing the paddocks for seeding to reducing the load without completely removing grazing. It is generally recommended to maintain good summer cover and avoid grazing in summer, although this is not always followed. Weed elimination, crucial for replanting, is achieved mostly with herbicides, and to a lesser extent with intensive grazing or mechanical control. There was significant variation in the timing of this control.

Knowledge gaps were identified in the agronomic and social aspects of ryegrass promotions, suggesting the need for institutional approaches to improve the practice and mitigate its disadvantages.