Method for Rapid Labeling of Waste Sludge from a Food Factory with ¹⁵N-Glycine and Evaluation of N Use Using Komatsuna (Brassica rapa Var. perviridis)

Figure 2

The nurse reactor for preparing the ¹⁵N-SF-PM. Waste sludge of 170 kg that came from a bean curd factory was mixed with 30 kg of shredded newspaper and placed in a box reactor (60 cm l × 60 cm b × 120 cm h). The composting reaction starts by aeration with warmed air at around 35°C, and 3∼5 days after the start of aeration when the temperature reached around 40∼50°C, the sandwiched ¹⁵N-WS-PM was placed horizontally at the area marked with a black bar at 10 cm below the top of the WS-PM. Right after the insertion of the sandwich, the aeration was restarted (for details, see Section 2.2).