Chemical and mechanical conditioning for field drying of Trifolium pratense L.

First growth and regrowth of Trifolium pratense L. ’Florex’ (red clover) were used to study the effect of conditioning on the moisture content (MC = g water g−1 DM) under field conditions. Chemical conditioning using desiccant agents and mechanical conditioning with rollers were applied separately or combined. Swath MC was measured for 52 h after cutting in five trials. In all five trials, the MC of field dried, unconditioned red clover was unsuitable for baling 52 h after cutting (range: 0.25–3.8 MC). In three of the five trials, conditioning failed to lower the MC below that of unconditioned red clover because of rain, even when DM yield was moderate (2.2 t ha−1 in trial 5). Under rain-free weather, the low-rate chemical or mechanical conditioning applied alone or high-rate chemical and mechanical conditionings applied together, to moderate and high-yielding stands of red clover (2.4 and 4.2 t DM ha−1 in trials 4 and 2, respectively), reduced the MC to 0.2 or lower, and provided the practical benefit of storing hay at least a day earlier than unconditioned red clover.Key words: Clover (red), hay, desiccant, roller conditioner, field drying