Lettuce

There are three treatments in the lettuce fertilization experiment: CK (conventional fertilization), FA - OF (humic acid - based organic compound fertilizer), and CK + FA - OF (combined application of conventional compound fertilizer and humic acid - based compound fertilizer). Base fertilizer is applied before seedling transplanting: for CK, 50 kg of conventional compound fertilizer is broadcast per mu; for FA - OF, 50 kg of humic acid - based organic compound fertilizer is broadcast per mu; for CK + FA - OF, 25 kg of conventional compound fertilizer and 25 kg of humic acid - based compound fertilizer are broadcast respectively per mu. The first topdressing is carried out 12 days after field planting: for CK, 10 kg of conventional compound fertilizer is applied by flushing per mu; for FA - OF, 10 kg of humic acid - based organic compound fertilizer is applied by flushing per mu; for CK + FA - OF, 5 kg of conventional compound fertilizer and 5 kg of humic acid - based compound fertilizer are applied by flushing respectively per mu. The second topdressing is carried out 20 days after the first topdressing, and the fertilization amount of each treatment is the same as that of the first topdressing. The third topdressing is carried out 20 days after the second topdressing, and the fertilization amount of each treatment is the same as that of the first topdressing.

Analysis of Test Results (Impacts on Lettuce Leaf Size (Corm), Color, Growth Rate, and Yield)

Figure 1: Effects of different fertilization treatments on lettuce growth

Note: Diagram A = Conventional fertilization (CK), HA-OF application, and CK + HA-OF application respectively; Diagram B = Effects of HA-OF application on different lettuce varieties at various growth stages

Compared with conventional fertilization (CK), the lettuce leaves treated with HA-OF and CK+HA-OF are significantly larger. Moreover, the lettuce leaves under the HA-OF and CK+HA-OF treatments have a darker and more intense green color. Humic acid-based organic compound fertilizer can accelerate the growth rate of lettuce and increase its yield.