SACRAMENTO, Calif. (AP) – California is home to the nation’s largest agricultural economy, but the state auditor says it does little to ensure schools follow federal rules requiring they serve food produced in the United States. The audit released Thursday says the California Department of Education only recently began checking where school food is produced, and it says the reviews are too weak. Auditors say six school districts they checked had purchased foreign food but failed to adequately justify it. Education Department officials say the “Buy American” mandate is vague. But they agreed to implement most of the auditor’s recommended improvements. Lawmakers took an interest in school food after farmers and food processors said schools were increasingly turning to foreign suppliers.