Let M be a complete Riemannian manifold satisfying the doubling volume condition for geodesic balls and L^q scaled Poincaré inequalities on suitable remote balls for some q<2. We prove the inequality $||\Delta^{1/2}f||_p\lesssim ||\nabla f||_p$ for all p ∈ (q, 2], which generalizes previous results due to Auscher and Coulhon. Our conclusion applies, in particular, when M has a finite number of Euclidean ends. The proof strongly relies on Hardy inequalities, which are also new in this context and of independent interest.