Abstract only

Global soil zinc (Zn) deficiencies pose a serious threat to crop production and food nutrition. Use of inorganic Zn fertilizers and synthetic chelates are avenues to alleviate deficiencies, which are however, not commonly used in smallholder farms due to high costs and inaccessibility. Approaches such as application of organic fertilizers that lead to formation of natural chelates resulting in slow but improved Zn availability, are required. A survey was conducted during the 2009/10 season to evaluate the effect of different soil fertility management practices by smallholder farmers on soil chemical properties and maize grain nutrient concentrations in Wedza and Makoni smallholder farming communities in eastern Zimbabwe. Available soil Zn from the different farmers? fields ranged from 0.5 ? 2.6 mg kg-1. In Wedza district, a combination of cattle manure at 5 t ha-1 and inorganic fertilizers produced maize grain yield of 2.3 t ha-1, sharply contrasting the non-fertilizer treatment which yielded <0.5 t ha-1. A similar trend was observed in Makoni district where organic-inorganic fertilizer combinations attained grain yields of 2.2 t ha-1 compared to 0.75 t ha-1 for the control. Up to 64% and 46% increase in grain Zn concentration was measured against the control in Wedza and Makoni respectively. Total grain Zn uptake ranged from 6.5 ? 48 g Zn ha-1, the low uptake being a function of both poor grain productivity and low concentration of <23 mg kg-1. Co-application of inorganic fertilizers with cattle manure or leaf litter, and legume-cereal rotations significantly influenced (p<0.01) Zn uptake. Maize grain P concentrations had a narrow range of 0.21 ? 0.29 mg kg-1.These results suggest that current farmer fertilization regimes may be inadequate to supply sufficient Zn to improve grain nutrition, and should therefore be supplemented by Zn- based fertilizers

Conservation Agriculture Program

English

Lucia Segura

INT2737

CIMMYT Staff Publications Collection