Fababeans Halve Nitrogen Needs of Next Crop

CHICAGO - Apr 12/18 - SNS -- Testing fababeans as a cover crop before sweet corn, researchers at the University of Massachusetts Amherst found it reduced the nitrogen requirement of the corn by half.

Masoud Hashemi and colleagues at the university did the test because they wanted to learn if the nitrogen from the fababean plants would meet the high nitrogen needs of the sweet corn; and whether tilling the fababeans residues into the soil or leaving them to decompose in place would provide more nitrogen for the corn.

This study showed the timing of when fababeans were planted had a dramatic effect on the biomass -- the total weight -- the plants produced before winter weather stopped growth. Seeding earlier increased biomass significantly, resulting in better yields in the following crop than was the case in fields where fababeans were sown later.

The researchers also found leaving the fababean residue on top of the crop increased yields more than tilling the residue into the soil. Researchers concluded that slowing down the decomposition of the fababean residues delayed the release of nitrogen into the soil, which benefitted growing crops.

"Fababean cover crops can add a large amount of nitrogen to the soil," Hashemi concluded. "But to make the most of its potential, especially if harvesting some fresh pods is expected, fababean has to be planted as early as possible after harvesting the summer crop. Moreover, to contribute best to the nitrogen needs of the spring crop, the residues should not be tilled into the soil and must be left on the soil surface."