The effect of nitrogen and boron fertilizer applications on Willamette red raspberry growth, and on applied and other nutrients in the plant and soil over two growing seasons

Abstract

The effects of three single, spring fertilizer treatments (complete, complete minus N and complete minus B) on raspberry plants were examined in detail over two seasons. Phosphorus, K, Ca, Mg, Na, Cu, Mn, Fe, Zn in addition to N and B were measured in various plant parts and soil samples monthly. There were no fertilizer effects on berry yield, but treatment-year primocane stem and residualyear floricane stems and laterals were smaller without N. Minus B reduced application-year lateral weights. Soil nitrate concentrations were consistently low without N showing plants used soil organic N as it was mineralized. Soil nitrate concentrations were greater with than without N during the first growing season only. Above-ground plant uptake of the 134 kg N ha-1 application was 34% over the 2 yr. Leaf tissue concentrations were too dynamic for plant N status evaluation, but floricane stem N concentrations showed promise. Hot water extract B in soil responded to B application, but varied with time of sampling. Significant soil B remained in the soil into the second year, apparently not leached as readily as nitrate. Leaf B concentrations were too variable over time for plant B status evaluation, but floricane laterals showed promise. The treatments influenced concentrations of elements other than N and B, but only above-ground P and Mn accumulations were affected significantly. Detailed plant and soil analyses were necessary to fully evaluate treatment effects on this complex-growing perennial crop. Key words: Raspberry yield, raspberry N accumulation, raspberry B accumulation, raspberry nutrient dynamics, apparent N recovery, apparent B recovery, soil nitrate test, nitrate leaching, soil extractable B, residual effects