Using Commercially Available Ion-Exchange Membranes to Monitor Plant-Available Nutrients in Cranberry
Davenport, J.R. and D.E. Schiffhauer . 2007. Communications in Soil Science and Plant analysis 38: 1331-1340
Abstract
Monitoring in-season nutrient availability in cranberry (Vaccinium macrocarpon Ait.) is hampered by tissue sampling being limited to a short, late-summer period, and a low-pH, high-iron (Fe) soil environment limits soil-test result interpretation. To evaluate monitoring available in-season nitrogen (N), phosphorus (P), and potassium (K), commercially available ion-exchange membranes (PRS™) were placed in plots where standard fertilizer practices were supplemented with the controlled-release fertilizer (CRF) Osmocote™ 13-13-13 at 0, 112, 224, 336 kg/ha rates. PRS™ nitrate (NO3)-N was related only to CRF and in-season fertilizer applications. Large increases in PRS™ NH4-N with increasing CRF rates suggested a synergistic effect of CRF on fertilizer NH4-N availability. PRS™ P was positively correlated with CRF P but negatively to in-season P applications, whereas PRS™ K was related to in-season fertilizer applications but not to CRF, suggesting poor plant P availability in the soil environment and relatively little K contribution from CRF, respectively. These results show promise for using PRS™ in cranberry.
Key Words
Cranberry, in-season monitoring, ion-exchange membranes, nitrogen, phosphorus potassium
