Submitted to: Journal of Environmental Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2007
Publication Date: 12/1/2007
Citation: Altland, J.E., Lanthier, M. 2007. Influence of Container Mulches on Irrigation and Nutrient Management. Journal of Environmental Horticulture. 25:234-238.
Interpretive Summary: This research furthers the goal of reducing pesticide use and increasing fertilizer application efficiency in nursery crop production. Use of mulch products for weed control, in place of chemical herbicides, has been studied repeatedly throughout the past 20 years. However, the influence of these mulch products on irrigation and fertilization practices has been neglected. The goal of this research was to provide information for nursery producers on how to adapt their irrigation and fertilization practices when using mulch products instead of chemical herbicides. Research described in this manuscript documents the effect that mulch products have on water loss from nursery containers. It also documents the effect mulch products have on fertilizer application method. Overall, the mulch products evaluated did not affect the amount of water loss from nursery containers, thus irrigation practices should not change when container mulches are used. Further, it documents that plant growth and performance is reduced when fertilizers are placed above the mulch product compared to placement below the mulch product. The research will benefit nursery producers by providing specific guidance on irrigation and fertilization practices for their crops. Furthermore, it will benefit the environment by reducing herbicide and fertilizer loads released from nursery production sites. By following recommendations from this research, nursery growers will be able to more successfully use alternatives to chemical herbicides, and furthermore they will make more efficient fertilizer applications thus reducing the total amount of fertilizer needed to grow the crop.
Technical Abstract: An experiment was conducted in 2005 and repeated in 2006 to determine the influence of mulch products and controlled release fertilizer (CRF) placement on irrigation and nutrition requirements of container-grown crops. Hydrangea (Hydrangea macrophylla 'Fasan' and 'Endless Summer') were grown in 2.7 L (1 gal) containers with CRF placed above or below the mulch. Non-mulched controls were also maintained. Mulch products included geotextile discs, coco discs, plastic discs, hazelnut shells, sawdust, Biotop, and crumb rubber. Hydrangea growth, plant quality, foliar color, and foliar nutrition were measured, as well as water loss from containers. Controlled release fertilizer placed below mulch resulted in larger plants with higher quality ratings and foliar N levels compared to CRF placed above the mulch, and similar or superior size, quality and foliar N compared to non-mulched containers. After correcting for differences in plant size, there were few and minor differences in water loss from hydrangea between mulched and non-mulched containers.