Evaluation of two biofertilizers based on azolla filiculoides and azolla caroliniana in cabbage (brassica oleracea) production in daloa

The high cost of mineral fertilizers and their low accessibility to farmers is a limiting factor in cabbage cultivation. This crop is grown with significant amounts of chemical fertilizers that create environmental problems such as soil and ground water pollution. Yet the use of the organic amendment may be less costly and beneficial for maximizing crop yield. Azolla, a small aquatic fern used in rice cultivation in Asia, was tested in this study to improve the productivity of the cabbage (Brassica oleracea) by its use as fertilizer and compare its effects to those of compost and control. The test was conducted according to a device composed of a complete randomized block with 2 repetitions per treatment comprising 4 treatments. The establishment density of cabbage plants is at spacings of 40 cm x 40 cm at the rate of 27 plants per plank on an area of 4 m² per repetition. The treatments were compared, and evaluated by accounting the agronomic parameters: The results showed a greater growth and development of plants on plots amended with Azolla followed by compost compared to unamended plots. The highest yield has been obtained with Azolla caroliniana that produced 20.87 t / ha of cabbage. The study showed that Azolla filiculoides and Azolla caroliniana, under the conditions of this test had great potential for improving the availability of soil nutrients and could provide the needed nutrients amount for cultivation of cabbage without the use of mineral fertilizers.