Evaluating a protocol for growing organic market garden cabbage using split band applications of granulated laying-hen droppings

Description

The market for Québec organic foods is growing at an average annual rate of 10%. It is, therefore, important to develop competitive production protocols, particularly with regard to fertilization, to satisfy crop nitrogen (N) requirements while avoiding undue accumulations of soil phosphorus (P). Organic producers, with their high-N-demand crops, are faced with the problem of soil P saturation. This is especially true for market gardeners, whose crops have especially high N requirements. Among the available animal fertilizers used, cattle manure and manure composts represent affordable N sources, however, they are also loaded with P. Since the N in these manures has a low fertilizing efficiency, large quantities must be applied to satisfy crop needs. Consequently, these products contribute to raising soil P levels. Granulated laying-hen droppings (GHD) could serve as an alternative source of N. They are rich in total nitrogen (35 to 40 kg N-tot/T) and easily mineralizable (C/N <8), so only half the volume is needed. This type of fertilizer has gained popularity among organic market gardeners, but it is often spread in a single broadcast application prior to planting, which results in the unnecessary fertilization of inter-rows. However, given the granular form of GHD it could be efficiently applied using band applications.

Objective(s)

This project aims to develop a GHD-based fertilizer management system using split band applications for high-N-demand crops grown in rows, e.g., summer cabbage. More specifically, we will show that by using split band applications to achieve the total dose, it is possible to…

• use less GHD than broadcast applications
• achieve equivalent or higher yields, while reducing residual post-harvest nitrate (as shown in three different areas with variable growing conditions), and
• compare the costs and revenues of the tested protocols in the context of three different crop management strategies.