Effects of biofertilizer and manure application on growth rate and chlorophyll content of spinach (Amaranthus tricolor L.) under salinity stress condition

Amaranthus tricolor L. is a widely consumed and cultivated vegetable in Indonesia. Meanwhile, one of the agriculturally usable areas in the country is coastal land. However, the salinity in this land needs to be considered for proper plant growth, therefore, biofertilizer solutions are applied to enhance the growth of plants under salinity stress. This fertilizer is made from livestock urine and microbial strains. In this study, the biofertilizer was applied at a dose of 0, 10, 20, and 30 liters/ha while the stress treatment was carried out with NaCl at a concentration of 0, 2,500 5,000, 7,500, and 10,000 ppm. In addition, manure was also given as a basic fertilizer. The highest growth rate observed in the form of increase in plant height and number of leaves was found in the biofertilizer treatment of 30 and 0 liters/ha. Meanwhile, the highest mean total chlorophyll content was found in plants treated with a dose of 30 liters/ha. Based on the results, it was concluded that the application of biofertilizer affects the growth rate and chlorophyll content of spinach, but only at a certain concentration of salinity levels. © The Authors, published by EDP Sciences.