The soil gravimetric water content was 7.9% when the wheat
seeds were sown. The 15
flumes were divided into
five groups. Each
group of three
flumes received a specific water amount (30, 40, 50,
60 or 70 mm) that was applied as a spray during the experimental
period. Following wheat-seedling emergence, about 10 days after
sowing, each water treatment was applied in six equal parts over
the whole
flume on six occasions during the experimental period.
The wheat-seedling growth period was between 40 and 44 days for
different water levels because each rainfall simulation had to be
conducted on separate, consecutive days. The last application of
sprayed water was carried out six days before the rainfall
simulation experiment. The
flumes were left outdoors, but were
covered with a clear plastic sheet when it rained to prevent the
addition of rainwater. However, water losses due to evapo-
transpiration were permitted to occur as part of the induced
relationship between cover and soil moisture.