December 27, 2010
Many Brazilian Pastures Were Killed by Extended Dry Weather
From far northern Brazil to far southern Brazil, many ranchers are wondering why their pastures have not recuperated from the dry weather even though the rains have returned. To their dismay, many ranchers are finding out that their pastures simply died from the prolonged dry season. Some areas of Brazil went over 200 days without rain (April through September), which is highly unusual. Normally, the dry season is broken up by at least several episodes of light showers, but that was not the case in 2010. Many areas of Brazil recorded their longest streak of rain free days in modern times.
Even though the rains have now returned, many pastures in Brazil still remain brown and the existing grass has not exhibited a normal regrowth.
Brazil has approximately 154 million hectares of pastures and it is estimated that 87% of those pastures are planted to one type of grass, Brachiaria. Brachiaria is native to Africa and it was introduced into Brazil because of its tolerance to wet conditions. In addition to being planted for pastures, it was also used to stabilize steep slopes along roadways. In recent years, several new Brachiaria species have been introduced into Brazil and researchers believe that some of these new Brachiaria species are the ones that were killed during the extended dry season.
A rancher in Goias reported that his pastures can normally handle 1,800 head of cattle, but in its current state of degradation, his pastures can only handle 400 head. His cattle lost a lot of weight during the dry season and now the lack of grass is making their recovery even slower than normal. Ranchers such as this are in a real dilemma. They don't want to sell their emancipated cattle because of low weights, but their pastures can't handle the existing number of cattle.
Pasture specialist have long been urging ranchers in Brazil to diversify the type of grass they plant and to do a better job at managing their pastures. The general carrying capacity of Brazil's pastures is very low due to a monocrop of grass, poor management, lack of fertilizer applications, and low native fertility. Improving all of this requires a long term commitment on the part of the rancher. The rancher's more immediate concern is to reseed their pastures and hope that the rains are adequate enough to insure that the grass gets established before the onset of the next dry season.