Remark on quasi-negative $k$-Ricci curvature

In this note, we show that if $X$ is a compact Kähler manifold with $k$-quasi-negative Ricci curvature, then $K_X$ is ample. This completes a previous result of Chu-Lee-Tam. The key ingredient is an observation that any rational curve $C$ on $X$ satisfy $K_X\cdot C>0$ based on the Gauss-Codazzi equation.