IMMOBILISATION OF NITROGEN IN POTTING MEDIA

KEVIN A. HANDRECK
The Nitrogen Drawdown Index (NDI) is briefly described and two examples of its relevance to fertilizer N use are presented and discussed.

When coir dust was used as a direct replacement for natural peat in soilless potting media, about 10 mg/L medium extra N per week had to be provided to satisfy the requirements of microbial activity.

Philadelphus mexicanus growing in media comprised of mixtures of peat and Pinus radiata bark with NDI75 values ranging from 1.1 to 0 (NDI150 value of 0.36), needed weekly fertilizing with solutions with N concentrations ranging from 150 to 550 mg/L for optimum growth.

HANDRECK, KEVIN A. (1993). IMMOBILISATION OF NITROGEN IN POTTING MEDIA. Acta Hortic. 342, 121-126
DOI: 10.17660/ActaHortic.1993.342.14
https://doi.org/10.17660/ActaHortic.1993.342.14

Acta Horticulturae