Effect of organic and chemical fertilizers on the growth and production of soybean (Glycine max) in dry land

Abstract

Soybean is known for its high protein content, which is the reason why it is widely used as one of the main food sources for humans and animals. In order to optimize soybean growth, farmers tend to add excessive dosage of chemical fertilizer to this crop. Furthermore, a continuous chemical fertilizer application without organic fertilizer addition may cause a rapid depletion of nutrients in the soil. This study aimed to evaluate the effectiveness of organic fertilizer treatment to reduce the amount of urea as chemical fertilizer needed in soybean cultivation. A complete randomized design was conducted using 21 treatments of organic and chemical fertilizer in triplicate with a 4x3 m plot size. Analysis of variance was carried out to compare the means of measurement data and Duncan multiple range test (DMRT 5%) was applied. The treatment 2,000 kg ha-1 compost + 50 kg ha-1 urea (O2K2A1) resulted the highest dry yield in soybean and had significant differences with urea-only treatment. A mixture of chemical and organic fertilizers had no significant result over the yield compared to the use of chemical fertilizer only. Compost application of 1,000-2,000 kg ha-1 with urea 50-100 kg ha-1 (O2K2A1 and O 2K1A2) showed an increase in seed yield of 35-38 % with a profit reaching 333-340 USD ha-1 compared to standard treatment using urea 50 kg ha -1 + SP-36 50 kg ha-1 + 50 KCl kg ha-1 (O0K0A1).