THE INTEGRAL OF MIXED SCALAR CURVATURE ALONG A LEAF OF FOLIATION Vladimir Rovenskii 1991 Math. Subject Classification: 53C12. Key words: Foliation, distribution, mixed curvature, Riccati equation. Abstract: By using the method of matrix Riccati ODE, we study Riemannian manifolds with foliations (distributions), whose mixed Ricci or scalar curvature is nonnegative and the norms of integrability tensors are bounded above. We obtain the integral formula for mixed scalar curvature along the complete leaf, rigidity of totally geodesic distribution, splitting of foliation with "large" dimension.