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We explored the occurrence rate of small close-in planets among$\textit{Kepler}$ target stars as a function of the iron abundance and thestellar total velocity $V_\mathrm{tot}$. We estimated the occurrence rate ofthose planets by combining information from LAMOST and theCalifornia-$\textit{Kepler}$ Survey (CKS) and found that iron-poor starsexhibit an increase in the occurrence with $V_\mathrm{tot}$ from $f < 0.2$planets per star at $ V_\mathrm{tot} < 30\ \mathrm{km~s}^{-1}$ to $f \sim 1.2$at $V_\mathrm{tot} > 90\ \mathrm{km~s}^{-1}$. We suggest this planetaryprofusion may be a result of a higher abundance of $\alpha$ elements associatedwith iron-poor, high-velocity stars. Furthermore, we have identified anincrease in small planet occurrence with iron abundance, particularly for theslower stars ($V_\mathrm{tot} < 30\ \mathrm{km~s}^{-1}$), where the occurrenceincreased to $f \sim 1.1$ planets per star in the iron-rich domain. Our resultssuggest there are two regions in the$([\mathrm{Fe}/\mathrm{H}],[\alpha/\mathrm{Fe}])$ plane in which stars tend toform and maintain small planets. We argue that analysis of the effect ofoverall metal content on planet occurrence is incomplete without includinginformation on both iron and $\alpha$ element enhancement.

Small Planets in the Galactic Context: Host Star Kinematics, Iron, and $\alpha$ Element Enhancement