Young walnut grove showing intercrop of alfalfa, Portrero Avenue, near Garvey Avenue, October 20, 1930

Photograph of a young walnut grove showing an intercrop of alfalfa, at Portrero Avenue, near Garvey Avenue, on Oct. 20, 1930. A row of walnut trees stands at left, and another across it, at right, and between the rows sits a bed of alfalfa. This progression expands on both sides of the field, with alternating rows of trees and alfalfa patches.

1930年10月20日摄于Garvey大道附近Portrero大道的幼年胡桃林照片，该林内实施紫花苜蓿间作。画面左侧排布有一排胡桃树，右侧对应设置另一排胡桃树，两行林木之间种植有一片紫花苜蓿田。该种植格局沿农田两侧延伸，林木行与苜蓿地块交替分布。