Forage legumes can save livestock producers some of the costs of adding nitrogen fertilizer to pastures, says Ray Smith, a Texas AgriLife Research scientist (pictured).

But there is a lot of "hype" surrounding forage legumes such as crimson or arrowleaf clover and their nitrogen-fixing capabilities, adds the legume breeder, based in Overton.

“They're not a get-out-of-jail card. They're not a silver bullet. But they do offer some valuable alternatives to high-cost nitrogen,” says Smith. He has long advocated using clover and ryegrass winter pastures to offset winter feeding costs and supply N for warm-season grasses.

With enough moisture, forage legumes are an economically sound investment for cow-calf and stocker operations, he says. Now, with N at 80 cents/lb, they’re not just an option but a necessity for East Texas forage-based cattle operations to remain profitable.

“A healthy stand of arrowleaf or crimson clover overseeded on warm-season perennial grass pasture in East Texas will provide a nitrogen input of up to 100 lbs/acre/year,” Smith says. “However, this is only accomplished through a grazing system with the recycling of animal waste. You've got to be thinking in terms of animal grazing.”

Although legumes do fix N, many myths persist about the practice, Smith says. One such fallacy: that growing clover with ryegrass will provide enough nitrogen for the ryegrass.

“Wrong!” Smith says. “Clover will not directly provide nitrogen for the ryegrass in a ryegrass-clover mixture. It will provide nitrogen to the warm-season grass (that comes later) through recycling.”

Also, the amount of nitrogen fixed by legumes depends on the amount of N already in the soil. It’s common to plant a clover-ryegrass mix to extend the winter grazing period, but ryegrass needs N before the clover can provide it. The problem can be solved by applying 50-60 lbs/acre of N in late December or January rather than at planting in October, Smith says.

“This will increase the ryegrass growth and allow the mix to efficiently fix and use nitrogen.”

Another myth, Smith says, is that clovers can cause animal health problems. The only such problem associated with clovers grown in East Texas has to do with bloat. But it can be easily managed by not turning hungry cattle into lush pastures, feeding hay with winter pastures and putting out anti-bloat blocks.

Producers face bigger issues, including increasing seed, fertilizer, fuel and other production costs, Smith says. The attraction of growing more lucrative crops, such as wheat, is another factor, he adds.

Fall seed costs for clover will range from $14/acre for white clover to $22/acre for Apache arrowleaf clover to $44/acre for crimson clover. More seed-cost information can be found at the AggieClover site.