Making organic fertilizer from cow manure mixed with green wastes and its effi ciency on the growth and yield of water spinach (Ipomoea aquatica) sprouts

Abstract

Making organic fertilizer from cow manure and green wastes helps reduce environmental pollution. Therefore, the experiment of mixing cow manure with green manure at 60:40 ratio was conducted in bag-mixers. The obtained organic fertilizer was assessed on its effectiveness by the growth and yield of water spinach via three treatments, namely (1) soil (Control); (2) soil + 5 tons per hectare compost; and (3) soil + 15 tons per hectare compost. The results after 45 incubation days showed that pH value was nearly neutral (6.84), while electrical conductivity value was low 1.82 mS/cm. Total Nitrogen, Phosphorus and potassium contents were 2.28% N, 5.06% P₂O₅, and 2.95% K₂O, respectively. Organic matter and C/N ratio were good enough at 31.57% and 13.81, respectively. The effectiveness of organic fertilizer from cow manure mixed with green manure on water spinach yield showed that the amount of 5 ton/ha was recommended because this amount attained over 90% the germination of water spinach. Plant length, fresh weight, and dry weight of water spinach were 15.2 cm, 9.24 g, and 0.64 g, respectively, significantly higher than those in the control treatment (soil) of 14.23 cm, 5.73 g, and 0.08 g, respectively.