This is the kind of GMO that's generally considered fairly benign as they're only increasing the expression of genes already found in the plant, not doing weird stuff like putting fish antifreeze genes in strawberries. You still have to be careful in some cases (for example, humans have bred toxins out of many food crops by reducing expression levels over generations; the genes for toxins might still be there, i.e. potatoes, so you'd not want to trigger their expression accidentally).
As far as nitrogen use, the claim is that these plants utilize nitrogen more efficiently than wild-type, so that you'd actually have to apply less nitrogen fertilizer and thus there'd be less nitrogen runoff from fields into lakes/streams etc.
From the materials and methods:
> "For nitrogen use efficiency (NUE) measurement, rice plants were grown in three independent field blocks supplied with 0, 100, or 200 kg N/ha. The study was performed in the Experimental Station of the Institute of Crop Science, CAAS, in Beijing from May to October, 2021. The N fertilizer was applied as urea at two stages: 40% at the tillering stage and 60% at the heading stage. Each line was cultivated in randomized plots with 20 cm spacing between rows and plants, and each plot contained at least 50 plants per line."
Oddly enough, the publisher makes materials and methods freely available but not results and discussion, go figure.
As far as nitrogen use, the claim is that these plants utilize nitrogen more efficiently than wild-type, so that you'd actually have to apply less nitrogen fertilizer and thus there'd be less nitrogen runoff from fields into lakes/streams etc.
From the materials and methods:
> "For nitrogen use efficiency (NUE) measurement, rice plants were grown in three independent field blocks supplied with 0, 100, or 200 kg N/ha. The study was performed in the Experimental Station of the Institute of Crop Science, CAAS, in Beijing from May to October, 2021. The N fertilizer was applied as urea at two stages: 40% at the tillering stage and 60% at the heading stage. Each line was cultivated in randomized plots with 20 cm spacing between rows and plants, and each plot contained at least 50 plants per line."
Oddly enough, the publisher makes materials and methods freely available but not results and discussion, go figure.