Monday, November 13, 2006

Wide Swathing to Facilitate the Drying of Cut Forage in the Field.

Debbie J. Cherney, Cornell Univ.-Dept. Of Anl.Sci, 327 Morrison Hall, 327 Morrison Hall, Ithaca, NY 14853-4801, United States of America and Jerome Cherney, Dept.of Crop & Soil Sciences, Cornell University, Cornell University, Ithaca, NY 14853, United States of America.


Our objective was to determine if wide swathed forage would dry to a moisture content appropriate for ensiling on the same day it was mowed. The impact of crop conditioning on drying rates also was evaluated. Fields of reed canarygrass (less than 20% alfalfa), a 50:50 alfalfa-orchardgrass mixture, and alfalfa (less than 10% grass) were selected near Madrid in northern New York. Four treatments were evaluated: 1) mowing without conditioning into a wide swath (WS), 2) mowing with conditioning into a wide swath (CWS), 3) mowing with conditioning into a narrow swath (CNS), and 4) mowing with conditioning into a narrow swath, immediately followed by tedding the cut forage into a wide swath (CTNS). Mower width for all treatments was 2.8 m, using disc mowers. Swaths from WS and CWS covered approximately 90% of the mowed surface, swaths from TNS covered approximately 100% of the mowed surface. Four swaths 60 m in length were cut per plot and three replicates were sampled for yield and quality periodically through the day. Swath samples from a 0.9 x 2.4 m quadrat were collected using a hedge trimmer and chopped for subsampling. Samples taken when forage reached approximate silage moisture content were chopped and immediately ensiled in vacuum-packed bags. The CTNS treatment dried faster than WS or CWS. No differences were detected in drying rates between conditioned and unconditioned wide swaths. For pure alfalfa, pH of silage from NS (4.6) was significantly higher than from CNS (4.5), all treatments ensiled well. Total sugars were 23% higher in CTNS compared to CWS, and fiber digestibility in CTNS and WS was 36 g/kg higher than NS. Wide swath mowing to 90% or more of the cut width should consistently result in dry down to silage moisture on the same day.