Through dora agri’s nutrient solution hydroponic experiment, we research the effect of different humic acid concentration on the yield and nutrient utilization of hydroponic lettuce.
The result shows: within the range of 0-1.41 mg/g humic acid concentration, with the increase of humic acid concentration, the fresh and dry weight of lettuce above ground and below ground increased. When the humic acid concentration was 1.41 mg/g, the above indexes reached the maximum at the same time.
The concentration of humic acid was in the range of 0-1.41 mg/g, with the increase of its concentration, the water use efficiency of lettuce increased gradually, and the utilization efficiency of mineral elements gradually increased.
The effect of humic acid on the absorption of mineral elements by lettuce was not significant, and the ability of lettuce to absorb inorganic nutrients was different with different humic acid treatments.
Considering the factors of yield, water and nutrient utilization, adding 1.41 mg/g of humic acid can achieve the production effect of high yield, water saving and fertilizer saving.
1. Humic acid for lettuce yields
Effects of humic acid on the output of hydroponic lettuce
2. Humic acid on water use of lettuce
Changes of water use efficiency of lettuce treated with different humic acid concentrations
3. Humic acid on nutrient utilization of lettuce
Use efficiencies of mineral elements of hydroponic lettuce under different humic acid concentrations
Conclusions
(1) The concentration of humic acid was in the range of 0-1.41 mg/g, with the increase of its concentration, the fresh and dry weight of lettuce increased.
(2) Humic acid can improve the water use efficiency of lettuce. The water use efficiency of 1.41mg/g humic acid was the highest.
(3) The high concentration of humic acid (1.41 mg/g) can play the role of increasing nitrogen, dissolving phosphorus and promoting potassium, and can significantly improve the utilization efficiency of main mineral elements.