  Let $k$ be a field, let $R$ be a commutative ring, and assume the exponential
characteristic of $k$ is invertible in $R$. In this note, we prove that
isomorphisms in Voevodsky's triangulated category of motives
$\mathcal{DM}(k;R)$ are detected by motivic homology groups of base changes to
all separable finitely generated field extensions of $k$. It then follows from
previous conservativity results that these motivic homology groups detect
isomorphisms between certain spaces in the pointed motivic homotopy category
$\mathcal{H}(k)_*$.
