Maize Response to Micro Dose Inorganic Inputs on an Acid Smallholder Farm in Kenyan Lower Midland

Abstract

The study determined nitrogen, phosphorus fertilizers and lime micro doses effects on soil chemistry and maize performance on an acid soil smallholder farm. Treatments were micro doses (50% of recommendations) of N (0 and 37.5 kg N ha-1), P (0 and 13 kg P ha-1) fertilizers and lime (0 and 2.26 tons lime ha-1). Nitrogen, Pfertilizersand lime significantly (p<0.05) increased soil N, P and pH. Agronomic N-fertilizer use efficiency were 29 and 35 kg ha-1 kg-1 N-fertilizer due to 37.5 kg N and 37.5 kg N+2.26 tons lime ha-1, respectively. Grain agronomic P-fertilizer use efficiency was 24 and 30 kg ha-1 kg-1 P-fertilizer due to 13 kg P and 13 kg P+2.26 tons lime ha-1 , respectively. N-fertilizer recovery were 47 and 50% due to 37.5 kg N and 37.5 kg N+2.26 tons lime ha-1,respectively and P-fertilizer recovery efficiency were 14 and 16% due to 13 kg P and 13 kg P+2.26 tons lime ha-1,respectively. Grain yield increments were 72, 27 and 12% due to 37.5 kg N, 13 kg P and 2.26 tons lime ha-1, respectively. Therefore, N-, P-fertilizers and lime micro doses can improve maize grain yield on acid nutrient deficient smallholder farms.