Fluxes of nutrient stocks and limiting nutrients in a a coffee field in Kabanyolo
Abstract
Agricultural practices have contributed to widespread soil degradation by contributing to
nutrient loss, erosion, salinity and compaction and by reducing carbon storage. Perennial
systems are expected to increase carbon and nutrient stocks in the soil and this could improve
soil fertility. A study was conducted in a coffee field at Kabanyolo to assess fluxes of soil
carbon and nutrient stocks during the period 2013 to 2023 and establish if there are currently
nutrients limiting coffee productivity. The mean stocks and standard errors (t ha-1) of Carbon,
N, and P were 2.8±0.32, 0.16±0.07 and 1.68±0.29 respectively in the coffee field as of
2023. The fluxes of nutrient stocks were -0.94 t C ha-1yr-1
, 0.002 t N ha-1yr-1 and -0.04 t P ha-
1yr-1 between 2013 and 2023. Nitrogen was the most limiting nutrient to productivity in
MUARIK coffee field with a level of 1.3±0.05% N among the coffee plants which is below
the critical value of Nitrogen in Robusta coffee. The coffee field sequestered more carbon
compared to the adjacent grass strips implying that more carbon can be stored in perennial
system. Nutrient additions are needed to improve the productivity of coffee field following a
comprehensive evaluation of all nutrient interactions