Essel B, Abaidoo RC, Opoku A, Ewusi-Mensah N. Economically Optimal Rate for Nutrient Application to Maize in the Semi-deciduous Forest Zone of Ghana.
J Soil Sci Plant Nutr 2020;
20:1703-1713. [PMID:
33191974 PMCID:
PMC7655581 DOI:
10.1007/s42729-020-00240-y]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
Low inherent nitrogen (N), phosphorus (P), and potassium (K) contents of smallholder farms limit maize grain yield. Maize grain yield response to N, P, and K mineral fertilizer application and economically optimal rates for nitrogen (EORN), phosphorus (EORP), and potassium (EORK) were evaluated on a Ferric Acrisol within the semi-deciduous forest zone of Ghana. The nutrient rates evaluated were N (0, 30, 60, 90, and 120 kg N ha-1), P (0, 30, 60, and 90 kg ha-1 P2O5), and K (0, 30, 60 and 90 kg ha-1 K2O). The treatments were arranged in a randomized complete block with three replications using an incomplete factorial design. Nutrient responses were determined using asymptotic quadratic-plus plateau functions. The best nitrogen rate for all P and K levels was 60 kg ha-1, which gave grain yield of 5 t ha-1 . Nitrogen uptake, N agronomic and N recovery efficiencies peaked at 60 kg N ha-1 while N partial factor productivity declined with increasing N application rate. Cost to grain price ratios (CP) were 1.29, 1.65, and 1.65 for N, P, and K, respectively. The EORN was 61 kg ha-1, 32% less than the recommended 90 kg N ha-1 for maize production in the semi-deciduous forest zone of Ghana. Nitrogen application had the lowest CP ratio, making its application economically profitable than P and K. The findings suggest that the application of N at 61 kg N ha-1 to maize is economically profitable than at higher application rates. However, further studies should be conducted on farmers' fields to validate the results obtained.
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