The total gross value of Tehama County agricultural production in 2020 was $263,897,000, which represents a decrease of 12% ($36,952,200) from the previous year. Walnuts remained Tehama County’s top crop with an overall value of $72,393,600. The top five highest value agricultural crops for Tehama County in 2020 were: 1. Walnuts - $72,393,600 2.