My experience with management intensive rotational grazing in MD and MA is
that there are some days where it is not desireable to have the livestock
out on pasture... when the ground is extremly soft and pugging damage is
extreme, when the animals need to be quarantined for health reasons, when
winter weather is really extreme...
So if you have a loafing barn in place, I think this is optimal... but if
a grazier is just getting started... I think it is
possible to do without a loafing facility to minimize captial
investment...
A loafing facility gives you the perfect opportunity to accumulate
fertility and to mix high carbon bedding materials with manure... Routine
applications of scavenged waste materials such as deciduous leaves,
woodchips, straw, old hay, newspaper... to a covered loafing area can
build a microbially active manure pack that I think will "stabilize" in
place if the bedding is added in the right quantities and the pack is
allowed to sit long enough... Once the animals are back out on pasture
pigs or some other mechanical aeration could be used but keeping the
material under cover seems preferable to transporting to an outdoor
windrow...
It seems to me that the really critical aspect is how one rations the
fertility in this manure pack. I think the farm should be divided into
sections so that the rates applied are fairly high on targeted
areas... hay fields, areas in need of soil improvement... low rates
requiring lots of traffic over big areas are undesireable...
The grazing approach greatly reduces the need for manure apreading but I
think it is very valuable to have the concentrated fertility from a
loafing barn for targeted areas...
If a farmer is buying concetrates or hay or scavenging beeding materials,
much of this fertility may be deposited in his loafing facility and this
is desireable for targeted application.
I recently visited a huge dairy operation (2000 milking animals) that
started producing methane in the late 70s and the farmer told me that the
methane/electricity system is now as profitable as the milk production...
he spreads the liquid effluent using center pivot irrigation... this is in
southern PA where irrigation is not neccesary for crop production but he
went to this system to eliminate compaction of his fields to reduce the
energy cost of trucking water and to stabilize his yields at very high
levels... he only grows only forages: corn, small grains, orchard grass,
alfalfa and reed canary... an amazing system... he generally uses no
fertilizer at all...
I must conclude this message because the power is about to be shut off but
will continue these thoughts at a later date...
Joel Gruver
U of MD, Agronomy