Sorghum Response to Fertilizer and Nitrogen Use Efficiency in Uganda
Date
2012
Authors
Kaizzi, C. Kayuki
Byalebeka, John
Semaluluo, Onesmus
Alou, Isaac
Zimwanguyizza, Williams
Nansamba, Angella
Musinguzi, Patrick
Ebanyat, Peter
Hyuha, Theodore
Wortmann, S. Charles
Journal Title
Journal ISSN
Volume Title
Publisher
American Society of Agronomy
Abstract
Sorghum [Sorghum bicolor (L.) Moench] is important for smallholder production in semiarid parts of Uganda. Grain yields are
low because of low soil fertility. Little fertilizer is used. Yield response to N, P, and K application, economically optimal rates for
N, P, and K (EONR, EOPR, and EOKR, respectively), and N use effi ciency (NUE) were evaluated at 11 site-seasons. Mean sorghum
yield with no N applied (N0) was 0.69 Mg ha–1 and was consistently increased by a mean of 230% with N application. Mean
EONRs were 34 to 18 kg ha–1 N with fertilizer use cost to grain price ratios (CPs) of 10 to 30, respectively. Mean EOPRs were 11
to 2 kg ha–1 P with CPs of 10 to 50, respectively. Sorghum did not respond to K application. Net economic returns were greater
for N than P application. Mean aboveground biomass N with 0 and 90 kg ha–1 N applied was 31.3 and 75.9 kg ha–1, respectively.
Grain N concentration, N harvest index, and internal NUE at the EONR were 1.67%, 53.2%, and 31.8 kg kg–1, respectively, and
higher than for N0. Mean recovery effi ciency, partial factor productivity, and agronomic effi ciency declined with increased N rate
and were 135%, 79 kg kg–1, and 52 kg kg–1, respectively, at the EONR. Th e profi t potential of fertilizer N use is high for smallholder
sorghum production in Uganda. Policy interventions to reduce fertilizer cost and improve grain marketing effi ciency will
enable smallholders to increase fertilizer use for substantial increases in sorghum production.
Description
Keywords
Sorghum Response to Fertilizer and Nitrogen Use, Sorghum growing in Uganda
Citation
Kaizzi, K.C., Byalebeka, J., Semalulu, O., Alou, I., Zimwanguyizza, W., Nansamba, A., Musinguzi, P., Ebanyat, P., Hyuha, T. and Wortmann, C.S., 2012. Sorghum response to fertilizer and nitrogen use efficiency in Uganda. Agronomy journal, 104(1), pp.83-90.