Effect of Peat Grade, Irrigation System and Nutrition on the Production of Nursery Stock in Closed Systems

Abstract

Containerised nursery stock plants in Ireland are almost exclusively produced in peat growing media using controlled release fertilisers and are irrigated by means of overhead spraylines with the drainage water going to waste. Concern about nutrient pollution and the need to use water and nutrients more efficiently may lead in the future to regulations about capturing and re-cycling drainage water. This would particularly apply where nutrients are incorporated in the irrigation as in liquid feeding or where hard water is being acidified to neutralise bicarbonate. These experiments were started to study the performance of nursery stock plants in closed systems and to compare ebb and flood and capillary irrigation with overhead spraylines. A comparison of a liquid feeding regime as against the use of controlled release fertilisers was also included. The use of fractionated peat allows peat substrates with a wide range of physical properties to be prepared by using graded fractions or blends. It was thought desirable to include these in the experiments as there may well be interactions between irrigation systems and substrate properties