After the strong cold waves that occurred in June and July 2021, when negative temperatures were reached in many parts of the Center-South of the country, pastures suffered severe damage from frost. Visually, it is easy to see its effects, as the landscape has become “yellowish” and very vulnerable to the occurrence of fires.
The drier climate in winter, as occurs in much of the region affected by the cold, naturally results in a drop in pasture production and quality at this time of year, harming animal performance. In regions where frost occurs, in addition to losses due to drought, there are also severe losses as a result of extreme cold.
What strategy could be used to mitigate the effects of frost on pastures? This is a relevant question for many regions in the Center-South of Brazil, as they experience, with some frequency, problems arising from frost events.
One of the strategies is to have the areas cultivated with new pasture, which is viable in the crop-livestock integration system (ILP), when after the soybean harvest, brachiaria is implemented in sequence. This way, there is always an area with new pasture during the autumn-winter and this has a greater capacity to tolerate the cold compared to old pastures.
In Embrapa research carried out at the Technological Reference Unit (URT), in Naviraí-MS, in a partnership with the Cooperativa Agrícola Sul-Mato-Grossense (Copasul) and the ILPF Network, several production systems are being evaluated. In the frosts that occurred in 2021, the temperature reached negative values, with a minimum of -1,2 °C. Even so, the new pasture, with three months in the ILP area, still remained with 40% to 50% green mass. However, areas with old pasture, two years old or more, were much more affected, maintaining a maximum of 10% of green mass.
The inclusion of the forestry component in the production system also minimizes the negative effect of low temperatures on both animals and pasture.
In Naviraí, MS, Embrapa Agropecuária Oeste identified that protection was practically 100% when the pasture was new and cultivated within the ILPF. This protective effect is due to the microclimatic changes that are provided in the production area by the forestry component, which creates a kind of “thermal pocket” that keeps the air warmer in the environment.
In this experimental area, which has been monitored since 2015, whenever frost events occurred, temperatures within the ILPF environment were 1 °C to 3 °C higher than in open-air cultivated pastures. This was enough to keep the new pasture free from the evils of frost. Even the old pasture benefited when cultivated among the trees in the ILPF, remaining with 50% of the green mass.
Therefore, in regions considered susceptible to frost, the use of the ILPF system can be an alternative to protect pasture and ensure, at least in part of the area, an option to guarantee better quality forage for livestock.
Receive the latest agriculture news by email
Receive the latest agriculture news by email
