Abstract:
The research was carried out in two locations namely: Soil Research Institute,
Kwadaso and Wenchi Agri. Research Institute, Wenchi. The experiment was
laid out in randomized complete block design (RCBD) with three replications.
Treatments in the first and second trials consisted of two factors: three levels
of fertilizer (0-15-30 N-P2O5-K2O kg ha-1,), and four cassava based cropping
systems. The behaviour of component crops in three row arrangements was
evaluated in the third trial. Root yield was significantly affected by cropping
systems at Kwadaso while fertilizer effect on root yield was observed at
Wenchi. Cassava-groundnut intercrop gave the highest root yield of 70.2 t/ha
at Kwadaso. The highest root yield (34.6 t/ha) at Wenchi was reported in plots
treated with 15 N-P2O5-K2O k/g. The study showed higher increased in
organic carbon by 39 -97% at Kwadaso and Wenchi. Total soil nitrogen
decreased by 16.7%, available phosphorus by 70.8% and exchangeable
potassium by 20% at Kwadaso. Increase in soil total nitrogen was reported at
Wenchi. Exchangeable potassium decreased by 30% under cassava-soybean
+15 N-P2O5-K2O kg/ha. Cassava showed higher values of aggressivity (1.8),
relative crowding coefficient (57.4) and competitive ratio (21.4) in cassavacowpea
2:1, cassava-soybean 1:1, and cassava-cowpea 2:1 intercropping
system while cowpea and groundnut showed higher values of 0.5 and 0.6 for
aggressivity. In the study, intercropping system gave higher land equivalent
ratio (LER). Furthermore, cassava was more productive in terms of
competitive ratio when it was in association with cowpea, soybean and
groundnut.
