Effects of Humic Acid Application on Growth and Quality of Lettuce in Hydroponic Culture
To investigate the influence of humic acid application on growth and quality of lettuce in hydroponic culture,enact the optimal inorganic-humic acid complex nutrient solution formula,and provide theoretical basis for research in the field of humic acid in water planting,six different mass fraction of humic acid were added in the famous Yamazaki formula 15 d before harvest.The yield and quality indexes(nitrate mass fraction and vitamin C and so on) of lettuce were measured per five days after treatments.The results showed that the top fresh mass and the root fresh mass of hydroponic lettuce increased with the increase of humic acid mass fraction with 0-1.13 mg/g.The 1.13 mg/g mass fraction humic acid,which was the mass fraction of the highest volume for each aforementioned index.At the condition of above 1.13 mg/g mass fraction humic acid,each aforementioned index decreased with the humic acid mass fraction rising.The nitrate mass fraction of lettuce reduced obviously with increase of the humic acid mass fraction,however,the soluble sugar and soluble protein increased gradually and the vitamin mass fraction of lettuce increased first then decreased.Synthesizing the yield and quality factor,hydroponic lettuce would produce higher yield and improve quality when humic acid with 1.13 mg/g mass fraction were added in Yamazaki formula.
NETL
NSTL
万方数据
维普
