Towards understanding factors that govern fertilizer response in cassava; lessons from East Africa
2009
SB211.C3F4
Details
Title
Towards understanding factors that govern fertilizer response in cassava; lessons from East Africa
Author
Fermont, A.
Imprint
Wageningen Thesis Wageningen University Netherlands
Publication Date
2009
Description
p.87-112
Call Number
SB211.C3F4
Summary
Infonnation on fertilizer response in cassava in Africa is scarce. We conducted a series of on-farm and on-station trials in two consecutive years to quantify yield responses of cassava to miperal fertilizer in Kenya and Uganda and to evaluate factors governing the responses. Average unfertilized yields ranged from 4.2 to 25.7 t ha-I between sites and years. Mineral fertilizer use increased yields significantly, but response to fertilizer was highly variable (-0.2 to 15.3 t ha-I). Average yield response per kg applied nutrient was 37, 168 and 45 and 106, 482 and 128 kg fresh yield per kg of applied N, P and K, respectively in 2004 and 2005. Fertilizer response was governed by soil fertility, rainfall and weed management, but was not influenced by genotype, pest and disease pressure and harvest age. Relative Nand K yields were positively correlated to sac and exchangeable K, while response to fertilizer decreased on more fertile soils. Still, fertilizer response varied widely on low fertility soils (e.g. on soils with < 109 kg-I SOC, responses ranged from -8.6 to 24.4 t ha-I), indicating strong interactions between factors governing fertilizer response. Response to fertilizer was reduced if total rainfall <1500 mm or rainfall from 0 to 3 months after planting <400 mm. Fertilizer application promoted plant growth and resulted in a better soil coverage and reduced weed competition. Yields in fertilized fields were independent of weed management, unless growing conditions were unfavourable.
Book Title
Cassava and soil fertility in intensifying smallholder farming systems of East Africa
Contact Information
harvest@worldveg.org
Record Appears in
Research > Book Chapters