Runoff Farming for Growing Christmas Trees

Runoff farming was used to grow two species of conifers [Quetta pine ( Pinus eldarica ) and Arizona cypress ( Cupressus arizonica )] in a semiarid climate on a sandy soil treated with wax and a clay soil treated with sodium chloride salt. The treated runoff‐contributing areas were varied in length to provide a water supply estimated initially to be two, three, and four times the normal 300‐mm annual precipitation. Twenty‐five trees were planted per species per site per water‐level treatment for a total of 300 trees. Thirty‐seven percent of them (110 trees) were harvested after only three growing seasons. Eighty‐nine percent (67 trees) of the Arizona cypress on the sand‐wax site were marketable, and the remaining 43 trees were from the other three species/site locations. Large differences in tree growth existed among the four species/site locations. The best trees were the cypress grown on the sand‐wax site. Most of the cypress on the clay‐salt site were 1 to 2 years behind those at the sand‐wax site. The Quetta pines grew best on the clay‐salt site where 24% were marketable in 3 years, with most of the remaining projected to be marketable by year four. The pines grew poorly on the sand site suffering > 50% mortality on the two lower water treatments. Only the cypress on the sand‐wax site showed a significant statistical difference in tree growth as related to water level. Runoff farming shows promise of becoming a practical and practicable method for growing Christmas trees and many other crops in arid and semiarid lands where water is scarce.