TY - JOUR AU - Jenny, H. AU - Vlamis, J. AU - Martin, W. E. TI - Nutrient deficiencies in soils: Nitrogen and phosphorus found to be deficient in samples of soils representing many parts of the state JF - California Agriculture JO - Calif Agr Y1 - 1950/01/01 VL - 4 IS - 1 SP - 7 EP - 16 PB - University of California Agriculture and Nature Resources SN - 0008-0845 UR - http://www.ucanr.edu/sites/calagjournal/archive/?article=ca.v004n01p7 AB - Between 50% and 70% of the soils in the major farming sections of California—from Siskiyou County in the north to Imperial County in the south—are deficient in available nitrogen.