View source for Process for testing biodigester effluent fertilizer quality in lab with IRRI

==Methods==
For each test site, we will collect one sample from the untreated waste waiting in the registro and one sample of fresh biol that comes out when applying pressure on the biodigester bag.   We will place the samples on ice, and get the bacteria tests incubating within 6 hours of collection.  After initial testing of the fresh biol we will leave it unrefrigerated in order to analyze the changes and degradation of biol, over a period of months.  Since different growers use the biol at different times we will test how well the biol stores over time in liquid form.  While avocado tree growers may not use the biol for 4 to 6 months until the trees are flowering, others may only wait a month or less before applying it on their corn crops, thus we will test after 1, 2, 4, and 6 months.  (Davenport) Also since some farms are located far from the animals and biodigester we will test how the biol changes after dehydration and rehydration as done for transporting biosolids. (Crush, 2006) We will be testing for pH, temperature of the biol, temperature outside, nitrate, total ammonia (NH3 + NH4), phosphorous, potassium, magnesium, and calcium.  These represent major indicators for stimulation of plant growth or an indicator of the stability of the nutrients in the biol (especially in relation to ammonia and ammonium levels).  We will coordinate our lab research with standardized site visit questionnaires for families asking: what types of animals are used and what are they fed, if biogas is being produced and how much, if they use the biol for fertilizer and for which types of crops, how long they wait before using the biol, and other observations including their satisfaction with the biodigester.  This will help us understand how biogas production relates to fertilizer quality, how different animals and feeds affect the fertilizer quality, and how farmers are already using the fertilizer and their satisfaction with it.