seal  Purdue News

July 2, 2003

Agronomist: Double cropping twice as nice for forage producers

WEST LAFAYETTE, Ind. – Producing two crops in a single crop year isn't exclusive to grain farming. Forage producers can turn a double play themselves, said a Purdue University Cooperative Extension Service agronomist.

To many farmers, "double cropping" means planting soybeans on the same land that just produced winter wheat. Like grains, forages afford double-crop opportunities if managed properly, said Keith Johnson, Extension forage specialist.

"In the area of livestock production there are crops that fit into some double-crop uses," Johnson said. "We could be more effective if, after a wheat grain harvest, we followed that up with some summer annual grasses or forage turnips. Also, a summer annual grass like pearl millet for forage purposes following a July 10 grain harvest will, in most years, prove to be an economic consideration for producers that need that type of forage for ruminant livestock."

Another double-crop option is seeding a winter-annual small grain or annual ryegrass following late summer corn silage or early autumn soybean harvests, Johnson said.

Corn residues grazed immediately after corn harvest present a double-crop opportunity producers often overlook.

"We underutilize corn residues," Johnson said. "One thing that has kept people from using them is the fear of soil compaction, which can occur if we don't manage properly. But research done here at Purdue tells us we can get a $20 savings in hay value by grazing corn residues for a 45-day period. You start taking that savings times the number of cows that you have over the course of a career of 30 or 40 years, and you end up with a lot of extra money in your pocket."

Livestock producers considering double-crop forage should carefully investigate their animals' nutritional needs, potential crop combinations and other factors before making a decision.

"One of the questions that has to be asked is, 'Does this crop match the need of the animal that I'm feeding?'" Johnson said. "That's very important, because a lactating dairy cow needs high-quality feed. You don't want to be feeding it a maturing small grain for optimum milk production. You're probably looking at feeding a high-digestibility sorghum-sudangrass, supplemented properly with corn grain or forage turnips, which are very high in net energy."

Double cropping also helps reduce potential autotoxicity associated with continuous alfalfa. "We need to think about breaking the cycle of alfalfa following alfalfa," Johnson said. "It makes sense, because the last economic hay harvest typically happens in late May. That gives us the rest of the season to do something with that crop."

A growing number of producers are discovering double-crop forage systems, but many more could take advantage, Johnson said. Some producers also could benefit from rethinking their emphasis on annual crops.

"Double-crop opportunities are there for livestock producers from Posey County on up to Steuben County," he said.

"There are farmers in the state of Indiana who are utilizing annual crops more as their base program, when they ought to be looking at perennials being the base program and letting these double-crop options be more supplementary. You've got to remember annual crops mean annual seed expense, annual planting and annual frustration with Mother Nature to get it planted. Sometimes she's forgiving, and a lot of years she's not."

Additional forage advice is available on the Purdue Forage Information Web page.

Writer: Steve Leer, (765) 494-8415,

Source: Keith Johnson, (765) 494-4800,

Related Web site:

Purdue University Department of Agronomy

Ag Communications: (765) 494-2722; Beth Forbes,;

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