Utility of dairy digestate as a greenhouse fertilizer

• Main Author: Manuel, Vanessa G.
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2020
• Subjects: Newfoundland
• Online Access: https://research.library.mun.ca/15064/; https://research.library.mun.ca/15064/1/thesis.pdf

Newfoundland and Labrador is currently unable to satisfy the food demand for the population of the province mainly due to climatic and geologic restrictions. Controlled environment agriculture requires consistent conditions and a cost-effective supply of inputs, principally nutrients. Dairy, as the main agricultural industry in the province, does produce significant waste-streams which contains significant nutrient concentrations. Therefore, I proposed the application of dairy digestate to soil systems under controlled greenhouse conditions to grow high value crops in Newfoundland to increase the food self-sufficiency of the province. I assessed the utility of local farm soil as a growth substrate. This study quantified the nitrogen, phosphorus and other nutrients in locally available dairy digestate, assessed nutrient budget within a soil system, and thus evaluated nutrient uptake and the quality of spent soil when dairy digestate was employed as a fertilizer to lettuce crops under controlled greenhouse conditions. It was hypothesized that dairy digestate is a suitable source of fertilizer due to its high nutrient content and that application to local soils allows greenhouse production. This study thus provides novel information pertaining to the future of agriculture and food self-sufficiency in Newfoundland, bridging the gap between the current restrictions on crop growth in Newfoundland and local options for nutrient re-use for year round agricultural production.