How to merge listing query to display property and land

Using the WordPress  pre_get_posts filter you can alter the default post type archive page to include another listing custom post type.

function my_property_land_merged_query($query) {
	// Do nothing if is dashboard/admin or doing search
	if ( is_admin() || epl_is_search() )

	// Show property and lang post types on the main /property/ page
	if ( $query->is_main_query() && is_post_type_archive( 'property' ) ) {
		$query->set('post_type', array( 'property', 'land' ) );
add_action( 'pre_get_posts', 'my_property_land_merged_query' , 20  );

Alternatively you can use the [listing] shortcode and specify two listing types with the post_type="property,land" options.