Effects of microalgae Chlorella vulgaris on hydroponically grown lettuce

Chlorella vulgaris has been used as bio-fertiliser in hydroponically grown lettuce at decreasing levels of mineral fertilizers. The nutrients and aeration in the root area of lettuce have created a suitable living condition for algae. The aim of the study was whether we can reduce mineral nutrients in hydroponic production of lettuce by using the micro-algae Chlorella vulgaris without reducing the yield and crop quality. Eight treatments have been applied: 1) 100% full nutrition (control); 2) 100% full nutrition + algae; 3) 80% nutrition; 4) 80% nutrition + algae; 5) 60% nutrition; 6) 60% nutrition + algae; 7) 40% nutrition; 8) 40% nutrition + algae. Effects of Chlorella vulgaris on lettuce growth and some quality properties were investigated. The results indicated significant mineral nutrient saving in hydroponic production of lettuce. The mineral fertilizers used in the hydroponic lettuce production can be reduced up to 60% by using living Chlorella vulgaris in the nutrient solution. Chlorella vulgaris has also positively increased the quality properties of lettuce; total soluble solids (brix) and vitamin C were increased. The use of Chlorella vulgaris not only saved the mineral nutrients but also was an environmentally friendly approach.