1Soil and Fertilizer Institute,Shandong Academy of Agricultural Sciences,Jinan 250100,Shandong,China;2Jiaozhou Agricultural Products Quality Supervision and Control Station,Jiaozhou 266300,Shandong,China;3Zaozhuang City Bureau of Garden Management,Zaozhuang 277800,Shandong,China
Abstract：Soil culture was used to study the effects of natural zeolites used as slow-released fertilizer on biomass and quality of spinach.Results showed that Z+1/2NK treatment used half of N and K in CF treatment,but the spinach yield increased obviously,compared to CF treatment.The increase rate was up to 22.31 %.Under the experimental condition,CF and Z+1/2NK treatments achieved the highest Vitamin C contents.Nitrate contents in spinach of CF and the treatments of applied zeolites were all significantly higher than that of CK,and that of Z+1/2NK was the highest and reached 1 671 mg·kg-1,but which was far lower than the limited value in safety(3 100 mg·kg-1)of nitrate and the spinach in this experiment was safe to eat.Total oxalate,soluble oxalate and insoluble oxalate concentrations in Z+1/2NK treatment were significantly reduced than other treatments applied zeolites.At the same time,the proportion of soluble oxalate/total oxalate was decreased and that of insoluble oxalate/total oxalate was increased in Z+1/2NK treatment.Thus it reduced the risk of oxalate for human health for certain extent.In one word,Z+1/2NK treatment is an optimum treatment for spinach production under this experimental condition.
