The Effect of Humic Acid Concentration on Alkalinity and Soil Elements Release, Germination and Growth Index in Lawn

Development of sustainable land scape requires the identification of appropriate strategies. In this research, humic acid is used as an alkalinity reducer and increasing nutrient availability in the soil and improving lawn growth.

  The study run as completely randomized block design (CRBD) with 30 plot for cold region and tropical lawn with five concentrations of humic acid (0, 3, 6, 9 and 15mg /liter) with three replicates for each concentration at a ten day intervals. Then, physical and chemical properties (nutrients, salinity and alkalinity of soil in these plots were investigated.

Results showed that with increased application of humic acid, the release of nutrients such as N,P,K, Ca, Mn, S, Fe, Zn, Cu, Mg, B and Mo increase in soil. Spearman correlation coefficient between two variables of acid concentration and nutrients content was 0.949. Given that this value is positive, it can therefore be said that these two variables have a direct relationship with each other. The results of studying lawn seed germination percentage in petri dish with five concentrations indicated that germination percentage decreased with increasing humic acid concentration. In this research, lawn root and length and weight of stem increased with increasing humic acid concentration.

Application of humic acid reduces the alkalinity and release nutrients in the soil and improves the condition of lawn in terms of nutrient uptake, growth rate, vegetation and resistance to environmental conditions.