Controlled Release Fertilizer Effects on Growth and Foliar Nutrient Concentration of Container Grown Jeffrey Pine and Singleleaf Pinyon

Abstract

Abstract Two controlled release fertilizers, Sierra 17-6-12 Plus Minors controlled release nutrients and Agriform 14-4-6 container tablets, were evaluated for their effects on containerized Jeffrey pine (Pinus jeffreyi) and singleleaf pinyon (Pinus monophylla) planting stock. Seedlings produced with a conventional water soluble fertilizer, Peters 20-10-20, and unfertilized seedlings provided bases for comparison of fertilizer effects on growth and mineral nutrition. After 12 mo, mean volume of Jeffrey pine seedlings fertilized with Sierra prills exceeded that of Agriform and Peters treatments by >40% and unfertilized seedlings by 215%. Volume of singleleaf pinyon in the Sierra and Peters treatments exceeded those of the Agriform and unfertilized treatments by ≥100%. Shoot/root ratios of seedlings fertilized with Agriform tablets were significantly higher than those of the other treatments in both species. Foliar analyses for 11 plant-essential elements revealed that concentrations of most elements in fertilized seedlings were sufficient for adequate seedling nutrition. Apparent luxury consumption of one or more nutrients, particularly N, was detected in Jeffrey pine fertilized with Sierra prills and Agriform tablets. Overall, Sierra 17-6-12 proved effective for growth of Jeffrey pine and singleleaf pinyon container seedlings, while Agriform 14-4-6 was marginal for growing Jeffrey pine and unsuitable for singleleaf pinyon. West. J. Appl. For. 7(4):113-117.