May
23 To begin with, the grain sorghum was planted into last year's
residue of wheat and double-cropped soybeans. The residue levels are pretty
high as this is a no-till field. All we do is spray, plant, and harvest.
Sometimes we spray more than once for weed control, but we try and minimize
our costs of chemicals so that the cropping system is economical.
Last year this field of wheat yielded 45 bushels per acre. We then planted
soybeans following the wheat as a double crop. But with the hot and dry
summer of 2001, we didn't grow many soybeans, so this field was never
harvested. You can see some of the soybean plants still standing. And
a few of the bean seeds that did develop have sprouted this spring from
where they shattered from the pods and fell to the ground.
Field
view of recently planted grain sorghum
May 23, 2002
This
graph shows daily rainfall over the preceeding three weeks. It also indicates
runoff (the negative values in red) which we are measuring using a weir
at the edge of the field. So "effective rainfall" will be the
total rainfall minus the runoff value. If we arbirtraily use March 1 as
the start of the season, then effective precipitation is: 5.4 inches.