A Brief Discovery on the Evaluation of Rock Wool and Zeolite in a Hydroponic Drip System for The Cultivation of Lettuce (Lactuca Sativa)

Abstract

There is a growing interest in the utilization of soilless media, such as zeolite and rockwool, for cultivating vegetables in drip hydroponic systems. The motivation behind the selection of zeolite was due to its high cation exchange capacity (CEC) and ability to retain moisture. A study was conducted to determine the impact of zeolite and rockwool on the growth and leaching analysis of lettuce in a drip hydroponic system. The lettuce obtained fertilization through a nutrient solution that contains both macro and micronutrients. The solution's electrical conductivity (EC) ranged from 1.2 to 1.9 dS/m, with a pH of 5.75 and a temperature of 30-32 ºC. Based on the study on lettuce growth, an additional amount of zeolite in the rockwool system resulted in an increase of 11.48% in stem diameter, 5.13% in root weight, 25.5% in dry root weight, 20% in shoot weight, and 20.23% in dry shoot weight, as compared to rockwool only. However, there were no changes in lettuce height and leaf diameter identified. Based on the analysis of the hydroponic wastewater solution, the concentration of nitrate, nitrite, and ammonia ions decreased by 41.17%, 50%, and 75%, respectively, in the presence of zeolite in rockwool system compared to rockwool only. The presence of zeolite has a significant impact on reducing the concentration of nitrate, nitrite, and ammonia ions, however, it has a minimal effect on the growth of lettuce’s height and leaf diameter.