Effect of Humic Acid on the Growth, Yield, Nutrient Composition, Photosynthetic Pigment and Total Sugar Contents of Peas (Pisum Sativum L)

A pot experiment was conducted to evaluate the effects of humic acid (HA) applied as soil and foliar at 15, 30 and 45 ppm on the growth, biochemical content, nutrient concentrations and yield of peas. Soil as well as foliar application of HA increased the plant growth and grain yield of peas; however magnitude of increase was higher in soil application than foliar. Highest plant growth and grain yield was achieved with soil application of 15 ppm HA followed by 30 ppm and foliar application of 45 ppm HA respectively. Percentage increase in dry grain yield due to 15 ppm was 37%, with 30 ppm was 29% and foliar application of 45 ppm was 25%. Nutrient concentrations (P, K, Fe, Zn, Mn and Cu) were increased with soil and foliar application of HA. The concentrations of nutrients were relatively higher in shelf than grain. Maximum concentration of P, K and Fe was obtained with the soil application of HA at 15 ppm. Humic acid applied at 15, 30 as soil as well as foliar application at 45 ppm significantly increased chlorophyll, carotenoid and total sugar content. Our results indicate that soil application of HA at 15 and 30 ppm, while foliar application at 45 ppm can increase growth, nutrients concentration, chlorophyll content and yield of Peas in calcareous soil conditions.