  Positive pion and kaon production from Au+Au reactions have been measured as
a function of beam energy over the range 2.0-10.7~AGeV. Both the kaon and the
pion production cross-sections at mid-rapidity are observed to increase
steadily with beam kinetic energy. The ratio of K$^+$ to $\pi^+$ mid-rapidity
yields increases from 0.0271$\pm0.0015\pm0.0014$ at 2.0~AGeV to
0.202$\pm0.005\pm0.010$ at 10.7~AGeV and is larger than the K$^+$/$\pi^+$ ratio
from p+p reactions over the same beam energy region. There is no indication of
an onset of any new production mechanism in heavy-ion reactions in this energy
range beyond rescattering of hadrons.
