缓释肥对甜叶菊产量、品质及温室气体排放的影响OA

[Objective]Intensive cultivation of Stevia rebaudiana Bertoni faces dual environmental impacts due to excessive fertilizer application:compromised nitrogen use efficiency and intensified greenhouse gas emission intensity,which severely constrain the sustainable production of this crop.There is an urgent need to explore sustainable fertilizer modes.[Methods]This study set two fertilization treatments:common compound fertilizer(CF)and slow-release fertilizer(SRF),with non-fertilization(CK)as the control.The effects of different fertilization modes on plant agronomic traits,secondary metabolite biosynthesis,and carbon-nitrogen cycling were systematically analyzed under equivalent nutrient input.[Results]No statistically significant difference in plant height was observed between CF and SRF treatments(p>0.05),but both were significantly higher than CK(p<0.01).SRF showed outstanding performance in promoting biomass accumulation and yield formation,with yield increasing by 74.65%and 13.10%compared to CK and CF,respectively.Metabolomic analysis showed that SRF significantly promoted the biosynthesis of steviol glycoside.The contents of stevioside(STV)and rebaudioside A(RA)increased by 60.44%and 68.96%compared to CK,and by 7.33%and 5.40%compared to CF.In terms of environmental effects,the cumulative N2 O emissions from CF and SRF treatments were 21.94 and 17.56 times that of CK,respectively,but SRF achieved a 19.97%emission reduction compared to CF.Global warming potential(GWP)analysis showed that the CF treatment increased the system GWP by 63.45%compared to CK,while the SRF treatment reduced it by 5.60%compared to CF.Notably,the comprehensive greenhouse gas emission intensity index(GHGI)based on life cycle assessment confirmed that the SRF treatment reduced emissions by 9.35%and 10.75%compared to CK and CF,respectively,demonstrating the best environmental friendliness.[Conclusion]This study confirms that slow-release fertilizer can effectively coordinate the contradiction between"crop yield increase and carbon emissions"while ensuring yield and quality,providing a theoretical basis for the green and sustainable cultivation of Stevia rebaudiana.