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Maize (Zea mays L.) Growth and Grain Yield under Conventional and Site-Specific Nitrogen Management in a Dryland Farming System



Author(s)

Suzan Mashego, Brilliant Mareme Petja, Matshwene Edwin Moshia and Shadrack Batsile Dikgwatlhe

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DOI:10.17265/2161-6264/2014.08.002

Large amount of pre-plant nitrogen (N) fertilizer results in low N use efficiency due to poor synchrony between soil N supply and maize N demand, especially during N sensitive growth stages. The objectives of the study were to compare growth and yield of maize (Zea mays L.) under conventional and site-specific N management in a dryland farming system. The study, which was designed as randomized complete block design was conducted over three site-years under continuous maize cropping system in the semi-arid regions of the Limpopo Province in South Africa. Treatments of the study consisted of three N management strategies on a maize field planted to drought resistant SNK 2147 hybrid maize cultivar. Treatments were: (i) no N application (N0), (ii) site-specific N at variable rates ranging between 18 kg N/ha and 33 kg N/ha based on soil analysis results (N1) and (iii) conventional and uniform N application broadcasted during planting at 58 kg N/ha (N2). Sufficiency index as indication of N deficiency was determined using CCM-200 on maize leaves based on leaf numbers during maize vegetative growth stages V6, V10 and V14, and thereafter N was applied only when needed. The highest maize grain yield of 5.2 Mg/ha for N1 was significantly higher (P ≤ 0.05) than 3.2 Mg/ha and 4.0 Mg/ha of N0 and N2 in site-year I, respectively. Maize grain yield of 2.2 Mg/ha (N1) at site-year II was significantly higher (P ≤ 0.05) than 1.7 Mg/ha of the N0. The maize growth and yield under N2 and N1 was compared, N1 required between 43% and 69% lesser N fertilizer as compared to N2 over site-years, and resulted in higher maize height, number of leaves per plant, leaf length, and leaf area than that of conventional N management strategy. Therefore, site-specific N management strategy sustains and improves growth and yield of maize using minimal N fertilizer as compared to conventional approach in low fertility soils of semi-arid regions in dryland farming systems. In examining the results of this study, there was a consistent benefit of site-specific N management strategy on improving growth and yield of maize while saving fertilizer use in small-scale dryland maize farming system.

Africa, maize grain yield, nitrogen management, precision agriculture.