"Our results showed that zucchini yield was influenced positively by the vetch residue management strategy, although the response was significantly different between years," the scientists said. "The vetch cover crop increased marketable zucchini yield in the first year by 46.6% compared with the fallow treatment, indicating that this fertility-building crop could reduce off-farm nitrogen (N) fertilizer input for subsequent crops. Averaging over 2 years of the experiment, marketable zucchini yield increased by 15.2% and 38% with the roller-crimper mulch and green manure plow-down, respectively, compared with the fallow treatment, although differences were significant only in the first year."
The application of organic fertilizers in vetch management plots increased marketable zucchini yield by 21.8% in the first year compared with the unfertilized control. "This result is particularly relevant, because organic fertilizers were applied at about 50% of the normal application rate for zucchini after taking into account biological N fixation attributable to the vetch," the scientists noted. "The greatest yield response was obtained in the green manure treatment, probably as a result of high aboveground biomass production that, when incorporated into soil, progressively mineralized and increased the available N content," said the study's lead author Francesco Montemurro.
Montemurro also noted that the findings indicated that both cover crop and application of organic fertilizers and amendments in zucchini organic farming are constrained by environmental cond
|Contact: Mike W. Neff|
American Society for Horticultural Science