The term "nutrient unit", means the amount of nutrients that give the fertilizer replacement value of the lower of 43 kilograms of nitrogen or 55 kilograms of phosphate as nutrient as established by reference to this Protocol. This section sets out how to determine the number of nutrient units for the purposes of this Regulation and this Protocol. There are two ways to determine nutrient units depending on the requirements in the Regulation and this Protocol as set out below in sections 2.1 and 2.2.
2.1. How to determine nutrient units using the GNF management table for the purposes of regulation
When using the GNF Management Table for the purposes of the Regulation, the instructions included in the GNF Management Table must be followed to determine the nutrient units in the GNF generated at the greenhouse operations on the farm unit. Controllers must consider their past operations, GNF generation, and changes to their operations when applying the GNF Management Table.
2.2. How to calculate nutrient units using the results of GNF or test solution sampling and analysis
This section sets out how to calculate the number of nutrient units in GNF for the purposes of the Regulation when the GNF or test solution has been sampled and analyzed in accordance with this Regulation.
The number of nutrient units (NU) to be used for the purposes of the Regulation is the greater of the nitrogen NU and phosphorous NU calculated in accordance with the equations below:
- Nitrogen NU = volume of GNF generated (m3) in a calendar year * PAN (plant available nitrogen) (mg/l) /1000 /43 (kg/NU) of the GNF
- Phosphorus NU = volume of GNF generated (m3) in a calendar year * PAP (plant available phosphate) mg/l) /1000 /55 (kg/NU) of the GNF
2.2.1. Determination of the annual volume of GNF generated for the purposes of the equation in section 2.2
For the purposes of paragraph 2 of subsection 18(1), paragraph 2 of section 19, row 3 column 1 of subsection 21(3), paragraph 1 of subsection 22(2) and subsection 24(2) of the Regulation, when determining the volume of GNF for the equation in section 2.2, the term "volume of GNF generated in a calendar year" in the equation refers to the actual volume of GNF generated in that calendar year.
2.2.2. Determination of the concentration of nutrients for the purposes of the equation in section 2.2
For the purposes of the equation in section 2.2 of this Protocol and for paragraph 4 of subsection 43(2), and subsections 64(2), and 66(1) of the Regulation, the concentration of PAN, PAP and PAK (plant available potash) in GNF must be determined.
Concentrations of PAN, PAP and PAK in GNF must be determined using results from the sampling and analysis of GNF or test solution. The concentrations must be calculated in accordance with the equations below:
- PAN (mg/l) = (ammonia-N +ammonium-N) + (nitrate-N + nitrite-N) + (0.3 * (Organic-N))
- Organic-N = (Total Kjeldahl nitrogen - (ammonia + ammonium-N))
- PAP (mg/l) = total phosphorous * 2.29
- PAK (mg/l) = total potassium * 1.2