Effects of soil amendments on the growth and physi-ological characteristics of Tagetes erecta
[Objective]This study investigates the effects of various soil amendments on the growth and physi-ological characteristics of Tagetes erecta in saline-alkali.[Method]Using a controlled potted experiment,we ana-lyzed four treatments:no amendment(CK),calcium superphosphate+ferrous sulfate(T1),phosphogypsum(T2),and microbial inoculants(T3).The research focused on marigold plants grown in moderately saline-alkali soil in Lan-zhou New Area.Principal component analysis and membership function analysis were employed to evaluate the effec-tiveness of the treatments.[Result]The application of calcium superphosphate+ferrous sulfate increased POD ac-tivity in marigold leaves.Phosphogypsum improved both plant height and POD activity.Microbial innoculants nota-bly enhanced stem diameter,as well asPOD and catalase(CAT)activities in leaves.Compared to the control,the dei-ffernces in POD activity were statistically significant(P<0.05).Specifically,the POD activity rankings were as fol-lows:T3>T1>CK>T2(budding stage:CK>T1>T3>T2;early flowering period:T1>T3>CK>T2).Overall,the effectiveness of four treatments in moderate saline-alkali land ranked from strongest to weakeast as:microbial innoculant>calcium superphosphate+ferrous sulfate>phosphogypsum>CK.[Conclusion]In conclusion,the microbial mycorrhizal agent emerged as the most effective soil amendment.This study offers valuable insights for the application of landscape plants in the greening of saline land.