In 2019 Delphy started a planting-hole application trial in Viburnum Tinus at Tree nursery Marcel Michels located in Hilvarenbeek. Delphy is a leading internationally operating organization for research and advice in the tree nursery sector. Planting-hole applications with controlled release fertilizers are increasingly used in ornamental tree nurseries.
Partly caused by simple application through mechanization. (planting hole machinery on GPS). Increasing number of tree nurseries have invested in mechanization to reduce labour costs.
Positive experiences in plant quality are just as decisive for the success of this application. Controlled release of nutrition direct in the rootzone is the reason for this success.
In this trial a distinction is made between controlled released fertilizers and soil stimulants & substrates. In the trial setup of 2019-2020 these objects have been tested separately from each other.
In this report we will focus exclusively on the results of the controlled released fertilizers as planting-hole fertilizer and a non-planting-hole application with mineral-organic fertilizers Object D.
Year before trial is planted
50 tons cattle farmyard manure