Favourable water and aeration conditions for growth media used in containerized tree seedling production: A review

Abstract

The importance of soil water and aeration conditions on the growth of containerized tree seedlings in conjunction with the physical properties of various growth media used are reviewed and discussed. Favourable water and aeration conditions in these different growth media are described and some implications for the Nordic production of containerized tree seedlings are considered. It is concluded that matric potentials of > — 50 kPa and oxygen diffusion rates > 70 μg m^‐2 s^‐1 in the growth medium should be achieved during the growth period. Light, low humified Sphagnum peat, which is the most commonly used growth medium in the Nordic countries, provides favourable growth conditions in the greenhouse. However, when these growth conditions are not properly managed, light peat may not favour good seedling growth. Seedling hardening and outplanting phases are critical for outplanted seedling success, but little control can be exerted over them. Thus the physical properties of growth media should be evaluated and manipulated to enhance growth and quality particularly during these phases. The physical properties of peat can be improved by the addition of suitable amendments.

Key words:

• growing medium
• nursery management
• physical properties
• seedling production
• substrate.