Organomineral fertilizer based on wood ash in bean cultivation in acidic tropical soil

Abstract

Purpose: Organomineral fertilizer using wood ash, an agro-industrial waste, as an organic material has potential in agriculture as an alternative fertilizer. The objective was to evaluate the effects of the use of organomineral fertilizers from wood ash in comparison with conventional mineral fertilization in the cultivation of cowpea in acid tropical soil. Method: The experimental design used was randomized blocks, in a 4x3 factorial scheme, corresponding to three levels of base saturation (no liming - 0%, V = 30% and V = 60%), and four fertilization treatments: mineral, wood ash, organomineral and granulated organomineral, with four replications. The soil used was Oxisol. To produce organomineral fertilizer – wood ash and mineral fertilizers were used as organic raw material. The fertilizer granulated organomineral used the same composition as the organomineral. The test crop used was cowpea. Results: The highest soil pH values of 6.8 and 6.2 were observed at 30 days after emergence in wood ash and organomineral fertilizers, respectively. The organomineral fertilizer provided the highest shoot dry mass (23.0 g/pot) when no lime was applied, when compared to the other fertilizers. The highest grain yield of cowpea was observed in wood ash and organomineral, in the absence of liming. The nodulation capacity of cowpea plants was reduced when lime was applied (V = 30% and 60%) and fertilized with wood ash and organomineral. Conclusion: The transformation of wood ash into organomineral fertilizer proved to be a promising step in converting a solid waste into a commercially viable agricultural fertilizer. Research Highlights • Eucalyptus sp. ash has positive agronomic effects for cowpeas; • The effects of ash and organominerals on soil pH are observed in the short term; • The non-granulated organomineral provides greater productivity for cowpeas; • Ash and organominerals reduce bean nodules as the dose of lime increases; • Organomineral is an alternative fertilizer for growing cowpeas

Keywords

• Alternative fertilizer
• Nodulation
• Solid residue
• Vigna unguiculata