SHORT COMMUNICATION: Soil chemical changes associated with NP-fertigated and drip irrigated high-density apple orchards

Soil was sampled in 20 high-density apple (Malus domestica Borkh.) orchards which had generally been NP-fertigated using drip irrigation for the 2–5 yr since their establishment. Soil chemical changes including decreases in pH, extractable Ca, Mg, K, S and B and increases in extractable Cu, Mn and Fe were measurable, often within 2 yr. Leaf nutrient concentrations below deficiency levels were widespread for B and Zn and in a few cases, also occurred for Mg and K. Key words: Fertigation, soil chemical degradation, apple, drip irrigation