Combined use of millet glume-derived compost and mineral fertilizer enhances soil microbial biomass and pearl millet yields in a low-input millet cropping system in Niger

ABSTRACT

A two-year field experiment was conducted in Niger to explore the effects of integrated use of millet glume-derived compost (MGD-Compost) and NP fertilizer on soil microbial biomass carbon (C_mic), nitrogen (N_mic) and millet yields. Three compost rates (3000 kg ha⁻¹, 1500 kg ha⁻¹ and 0 kg ha⁻¹) and three NP fertilizer rates (100%, 50% and 0% of recommended NP fertilizer) were arranged in a factorial experiment organized in a randomized complete block design with three replications. Combined application of compost and NP fertilizer induced a synergistic effect on C_mic and N_mic. Compost application increased millet grain yield from 59% to 91% compared to control. Combined application of compost and NP fertilizer increased millet grain yields from 57% to 70% in 2013 and from 36% to 82% in 2014 compared to sole application of mineral fertilizer. Agronomic efficiency (AE) of nitrogen values increased by 3.7 and 2.3 times than those of sole NP fertilizer application in 2013 and 2014, respectively. Phosphorus AE was 1.6 times higher than that of the sole application of NP fertilizer. These findings indicate that integrated application of MGD-Compost and NP fertilizer enhances soil microbial biomass content and increases millet grain yield in a low-input cropping system.

KEYWORDS:

• Low-input
• productivity
• composting
• millet
• nutrient use efficiency (NUE)

Acknowledgments

The first author wishes to thank Alliance for Green Revolution in Africa (AGRA) for funding the study under the Soil Health Program at Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. We express our gratitude to the reviewers for the very thorough review which address all aspects of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.