Feed self-sufficiency and land conservation are important, and interrelated, aspirations because they lead to better cropping and feeding practices which, in turn, improve the production efficiency of dairy crops, animals, and farms. With the staggering complexity and demands of modern dairy farming, it is difficult for farmers to unravel the manure conundrum. This will require a community effort, where resources, knowledge, and expertise can be shared and advanced.
Using manure on crop land is a long-established practice and is of great value when there is limited access to mineral N and P fertilizers. It remains important across all farms to use manure to reduce mineral fertilizer inputs and improve soils; direct application of manure to soils remains the simplest and best way of using this troublesome resource. Manure is bulky and heavy, irregular and inconsistent, with an inconvenient nutrient composition that does not match crop needs.
Manure nutrients are also prone to losses as gases, solutes, and suspensions, and manure is a source of pathogens. Solving the manure conundrum so that it contributes value to farms, rather than merely posing a disposal issue is an incremental process with synergies, trade-offs, paradoxes and, often, costs. Integrated approaches for using manure are needed to fully exploit this resource, which is needed to help Canadian dairy farms reach their goal of ‘net zero C’.