Repeated cultivation of crops in a certain sequence on a fixed land is called crop rotation.
crop-rotation intensity=(No of crops grown in rotation/No of years in rotation)x100
Rice- pea rotation for one year, C.R.I=
(jowar+cowpea) – (Berseem+oats) C.R.I=
here jowar and cowpea are intercrops hence counted as one.similarly for berseem and oats.Former group of crops is grown in Kharif and the later one is grown in Rabi season. Hence here year of rotation is 1.