Biofertilizing Effect of Chlorella sorokiniana Suspensions on Wheat Growth

Abstract

The potential of microalgae as a biofertilizer in agriculture is increasingly recognized. We studied the effect of applications of Chlorella on growth of wheat in terms of its phytostimulating capacity and its potential for substituting chemical fertilizers. Four biofertilizer treatments were used in this experiment: (i) Biomass of Chlorella sorokiniana harvested by centrifugation from cultures in the exponential growth phase and re-suspended in spent growth medium (Solution 1); (ii) filtered BG11 medium used for algae culture after the algae biomass was harvested (Solution 2); (iii) harvested algae that were re-suspended in fresh BG11 medium (Solution 3); and (iv) fresh BG11 medium (Control). Seeds of Triticum aestivum were germinated in pots containing a growing substrate (peat vermiculite 1:1 (v/v) mixture) and grown for 15 days with applications of the four treatments solutions. In general, plant length was increased by 30% with Solution 2; total dry biomass of aboveground and belowground parts were improved by 22% and 51%, respectively, in treatments with filtrate of Chlorella sorokiniana (Solution 2), as compared to the control, indicating that nutrients and extracellular substances excreted by algae in the filtrate were pertinent to the beneficial effects on plant growth.