Evaluation of hydroponic systems for the cultivation of Lettuce (Lactuca sativa L., var. Longifolia) and comparison with protected soil-based cultivation

Abstract

The expansion of the earth's population has led to the overuse of land and water resources, which has ultimately resulted in their scarcity. Changing climatic conditions and erratic weather behavior over the years has fueled the existing problems of land and water scarcity and continued to exact a toll on agriculture. Utilization of the latest technologies coupled with advanced methods of crop production will no doubt increase our capacity to deal with these modern challenges of the shortages of resources. Soilless or liquid culture may serve as an alternative to conventional soil-based cultivation systems. The present study was conducted to determine the suitability and viability of hydroponic cultivation as an alternative planting system to greenhouse soil-based lettuce cultivation in temperate regions of northern India. In the present study, two hydroponic techniques viz. deep water culture, and nutrient film technique were evaluated and compared to the conventional soil-based cultivation method under protected conditions. Crop performance, water consumption, and economy were the criteria chosen to assess the efficacy of planting techniques using Tukey’s multiple range test at a significance level of 0.05. Deep water culture system was found to be the most desirable concerning the duration of the crop, causing a reduction in the plant growth period by 15 days. Also, higher values of most of the photosynthetic parameters were observed in the deep water culture system, which translated into higher yield/plant for the system. The crop quality also improved under the deep water culture system, which was reflected by the higher values of quality parameters like chlorophyll, total soluble solids, protein, and crude fiber content. Both the hydroponic systems produced significantly higher yield, and nutritionally superior produce in lesser time than the soil-based system (P < 0.05). However, there was a significant reduction in the dry matter content under hydroponic conditions. Nutrient film technique resulted in significant water savings of 64% than the other two techniques. According to economic analysis indicators, both hydroponic techniques performed better than the soil-based systems, having benefit-cost ratios greater than 2. Out of the two techniques tested, deep water culture proved to be the most promising system for adoption under protected agriculture owing to its simplicity, ease of operation, higher yield, economic feasibility, and nutritionally superior produce. The results of the study established hydroponic lettuce production as an appropriate and sustainable alternative to conventional soil-based lettuce production.