Castorbean Plant (Ricinus communis) Performance and Soil Physico-chemical Properties as Affected by Mulching and Nitrogenous Soil Ammendments in Southern Nigeria

The castor bean is currently a plant with a lot of uses and also a cash crop with high
commercialization and international demand. When cooked and fermented, is a staple food condiment
in Nigeria. Its cultivation and domestication in the humid rainforest zone of Southern Nigeria is still
low, with little information on its production. 2 separate field experiments were conducted in the Rivers
State University Teaching and Research Farm in Port Harcourt Nigeria, to evaluate the effect of
various mulch materials and various nitrogenous soil amendments on the growth and yield of castor
bean plant (Ricinus communis). Dry oil palm bunch, saw dust and dry elephant grass and black
plastic mulch were used in the mulch study. 120kgNha-1equivalent of urea, NPK 20-10-10, poultry
droppings and piggery dung were used in the nitrogenous soil amendment study. A Chinese improved
variety of castor bean plant (Zibocastor No 5) was used for both studies. pH values, organic carbon
content and total nitrogen were all significantly improved by mulching. At 6WAP, plastic mulching
increased number of leaves from 16 to 40 leaves per plant and capsule weight from 63.1 to 161.3
g/plant; when compared with unmulchedplots. The results of the nitrogenous soil amendments on the
growth and yield of castor bean plant showed that significant effect on all growth and yield parameters
measured, with the exception of percentage germination. Amending with Piggery dung gave the best
values for all parameters measured and increased yield by 397.0% over the unamended soil.