EFFECT OF THE ECOLOGICAL SYSTEM ON LETTUCE PRODUCTION GROWN UNDER DIFFERENT SOILLESS SYSTEMS

Abstract

Soilless culture is a technique for crop production without soil. Crops are grown in the nutrient solution or on a proper medium, therefore, soilless culture involves no work such tools or machines. But it needs additional costs for growing systems and chemical fertilizers. It offers earlier growth and higher yield. The main aim of this research is to study the effect of aeration on preventing the root problems by comparing the hydroponic system with aeration to the aeroponic system. The obtained results indicated that the nitrogen, phosphorus, potassium, calcium and magnesium consumption rate ranged from 22.10 to 32.63, 26.30 to 34.65, 85.80 to 120.30, 14.88 to 18.37 and 11.34 to 13.64 mg plant-1 day­-1, respectively, in hydroponic system and ranged from 25.65 to 37.35, 25.51 to 38.33, 115.70 to 127.50, 17.15 to 20.83 and10.94 to 14.90 mg plant-1 day­-1, respectively, after 50 days from transplanting in aeroponic system. The root length increased from 17.17 to 19.13 cm with increasing flow rate from 1.0 to 2.0 L h-1 in hydroponic system and increased from 17.45 to 19.56 cm with increasing flow rate from 0.5 to 1.5 L h-1 in aeroponic system. The fresh and dry mass of shoot and root were increased in aeroponic system better than those of hydroponic system. The total nutrients uptake values were higher in aeroponic system than those in hydroponic system. The average nitrogen, phosphorus, potassium, calcium and magnesium uptakes were 3.29, 1.25, 2.46, 0.43 and 0.44 %and 2.13, 0.82, 1.81, 0.32 and 0.40 % for aeroponic and hydroponic system, respectively. The average nitrate content was 155.52 and 113.73 mg plant-1 for aeroponic and hydroponic system, respectively.