<?php

$arr = array(
    array('data' => array(
        'v1' => 1,
        'v2' => 2,
        'foo' => array(62)
    )),
    array('data' => array(
        'v3' => 3,
        'v4' => 4,
        'foo' => array(52)
    ))
);

print_r(call_user_func_array('array_merge_recursive', $arr));