Ma. Zobisch et al., NUTRIENT LOSSES FROM CROPLAND IN THE CENTRAL HIGHLANDS OF KENYA DUE TO SURFACE RUNOFF AND SOIL-EROSION, Soil & tillage research, 33(2), 1995, pp. 109-116
Soil loss, runoff and nutrient losses were measured on runoff plots du
ring the rainy season from November 1992 to January 1993. Crops grown
were maize (Zea mays L.), beans (Phaseolus, vulgaris L.) and an interc
rop of maize and beans. The control treatment was bare fallow. The tot
al loss of C, N, P, K and plant-available P and K in the eroded soil a
s well as P and K dissolved in the surface runoff water were not depen
dent on the nutrient concentration of the eroded soil and water, but r
ather on the total amount of runoff and eroded soil. Compared to bare
fallow, P (and K) losses under maize were reduced to 24.2% (28.3%), un
der beans to 15.3% (15.4%) and under intercrop to 9.3% (10.7%).