Fertilization Practices for Bareroot Hardwood Seedlings

Large bareroot seedlings tend to be a preferred stocktype for hardwoods because they typically have larger root systems and are less expensive than seedlings grown in small containers. Fertilization can double or triple the dry mass of hardwood roots. A review of the use of fertilizers to produce bareroot hardwood seedlings revealed the total amount of nitrogen applied to seedlings depends on management objectives. The total annual rates can vary from 50 kg/ha to more than 500 kg/ha. Fertilizer regimes used to produce seedlings include a constant-rate method (i.e., each application contains similar amounts of nitrogen), a stepwise method (where initial rates are low and rates increase over the season), and formula method (where a formula is used to determine fertilizer rate). Due to a higher cost, most managers of bareroot nurseries do not use slow-release fertilizers. Some managers apply endomycorrhizal spores as insurance to prevent a phosphorus deficiency (caused by effective soil fumigation). Because micronutrient deficiencies are more likely to occur in neutral and alkaline soils, many hardwoods are grown at pH 4.5 to 5.5. Most trials in bareroot seedbeds indicate no growth benefit from K fertilization. Documented cases of Mg deficiencies in hardwood nurseries are rare and sulfur deficiencies might be overlooked in some nurseries. At nurseries with less than 1 percent organic matter, a proper fertilization regime will produce a good crop of hardwood seedlings.

Download this file:

Download this file

Details

Author(s): David B. South, Robert E. Cross

Publication: Tree Planters' Notes - Volume 63, Number 2 (2020)

Volume: 63

Number: 2