Containerized Jeffrey Pine Growth and Nutrient Uptake in Response to Mycorrhizal Inoculation and Controlled Release Fertilization

Abstract

Abstract Ectomycorrhizal inoculation with basidiospores of Pisolithus tinctorius and fertilization with two controlled release nutrient formulations, High N 24-4-7 and Sierra 16-6-10 Plus Minors, were evaluated for their effects on containerized Jeffrey pine (Pinus jeffreyi) seedlings. Noninoculated and nonfertilized seedlings and a water soluble fertilizer treatment using Peters 20-10-20 provided for comparisons of mycorrhizal and nutrient amendment effects on growth and mineral nutrition. At 6 months, inoculated seedlings had greater root dry weight while fertilization increased shoot dimensions and weight, with the response to controlled release nutrients exceeding that to water soluble fertilizer. After 12 months, inoculation increased mycorrhizal formation, and inoculated seedlings had greater shoot volume as well as root volume, dry weight, and total length. Controlled release fertilization also promoted greater shoot growth than water soluble nutrients at the final measurement, while root system development was comparable overall among fertilized seedlings regardless of nutrient formulation. Foliar analysis revealed that concentrations of most macro- and micronutrients were sufficient for adequate seedling nutrition in all treatments. However, inoculated seedlings exhibited greater uptake of P, Ca, Mg, S, Fe, Mn, and Zn. Fertilization generally increased foliar concentrations of all of the above elements except Mg and Fe, but also increased N uptake. Overall, these results suggest that inoculation with P. tinctorius and controlled release fertilization with High N 24-4-7 and Sierra 16-6-10 facilitate production of Jeffrey pine container stock suitable for outplanting on harsh sites. West. J. Appl. For. 12(2):33-40.