PLANT GROWTH IN POTTING MEDIA CONTAINING WORM-WORKED DUCK WASTE
Consequently there is increasing interest in the UK into developing organic nutrient sources suitable for inclusion in peat-based media. A likely candidate for such a nutrient source is worm-worked duck waste (wwdw). This waste is particularly rich in plant nutrients compared with wastes of, for example, porcine or bovine origin and is thus suitable as a nutrient source rather than a substrate.
In this study, tomatoes (Alicante), lettuce (Webbs Wonderful) and peppers (Capsicum sp) were raised in media containing varying levels of wwdw. All species germinated well in substrates including 2-8% wwdw by volume but at higher levels of incorporation (10-20%), where conductivity and nutrient levels were high, seedling development was retarded. This was particularly pronounced with peppers.
Seedlings transferred to pots of the substrates showed optimum development in particular concentrations of wwdw. Tomatoes for example exhibited optimum growth in 8-10% wwdw by volume, while for lettuce 8% was best and for peppers 6%. At these optimum concentrations, growth of tomatoes and lettuce was superior to that in a conventional substrate containing inorganic nutrients.
Analysis of substrate nutrient status showed that rate of uptake was correlated closely with the rate of plant growth and development. Overall the study indicates that wwdw is a highly suitable nutrient source for plants raised in peat-based media.