Agronomic response of soybeans (Glycine max (L.) Merrill) to different management practices in the humid tropics

Abstract

Organic soybean (Glycine max (L.) Merrill) remains an under exploited global market niche by farmers in the tropics. Therefore, a study was conducted in two consecutive years to determine the agronomic performance of soybean under different management systems in the humid tropics. The study was carried out during the late cropping season (July–Nov.) in 2020 and 2021 on the organic research plots of the Institute of Food Security, Environmental Resources and Agricultural Research, Nigeria. The six management practices (MP) evaluated were MP1 – Control, MP2 – NoduMax, MP3 – Organic fertilizer, MP4 – NoduMax + Organic fertilizer, MP5 – Conventional, MP6 – Conventional + NoduMax in a Randomized Complete Block Design and replicated three times. Data were collected on phenology, nodulation, grain yield and yield attributes of soybeans. Number of days to full bloom (R2) and physiological maturity (R7) were significantly (p < 0.05) affected by MP in both years, except R7 in 2021. Inoculation with NoduMax (MP2) enhanced nodule number at 8 and 9 weeks after sowing (WAS) during the wetter year 2021. Number of branches and seeds per plant, seed weight per plant and grain yield were significantly (p < 0.05) affected by MP in both years. Soybean grain yield recorded under MP3 and MP4 ranged between 1,198.8–1,962.0 kg/ha in both years and compared well with the average yield values in Nigeria (926.9 kg/ha) and Africa (1,348.0 kg/ha), and significantly below the world (2,784.2 kg/ha). Therefore, MP3 and MP4 can be recommended for potential resource-constrained organic soybean farmers in the humid tropics.

Keywords

• conventional system
• management practice
• nodumax
• organic fertilizer
• soybean yield