Theory question 105
Farming Systems(a)(i) Define crop rotation. (ii) Design a four-year crop rotation system using yam, cassava, maize and groundnut
(b) State four reasons why weeds are difficult to control.
(c) Mention two effects of diseases on crop production.
Show the model answer
(a)(i) Crop rotation is the growing of different crops in a planned order on the same piece of land over a number of seasons
(ii) Example (four plots, crops move each year): Year 1 – yam (heavy feeder after fallow); Year 2 – maize; Year 3 – groundnut (legume restores nitrogen); Year 4 – cassava (tolerant of poorer soil); then back to yam. Other orders acceptable if a heavy feeder follows the legume or fallow and crops of the same family do not follow each other
(b) Any four: produce many seeds; seeds stay dormant in soil for years; spread by rhizomes, stolons and tubers; seeds dispersed easily; grow fast; resistant to herbicides; some look like crops; deep roots
(c) Any two: reduce yield; lower quality and market value; kill plants; increase cost of production; reduce viability of seeds
Show the rotation as a table of plots and years.