Abstract: 【Objective】To counter the problems existed in application of land equivalent ratio in intercropping, the paper has analyzed that the essence of land equivalent ratio is to estimate land use efficiency of various cropping patterns. 【Method】The method of theoretical analysis combining with experimental data was used. 【Result】On the basis of revealing the essence of land equivalent ratio, combined with living examples, the method of estimating land use efficiency of various cropping patterns, such as sequential cropping, intercropping, and crop rotation was studied. It is cleared that land equivalent ratio is an objective index of estimating land use efficiency of various cropping patterns. 【Conclusion】It was found that the land equivalent ratio of sequential cropping, intercropping, and crop rotation is 1.68, 1.38 and 1.21. Compared with single cropping, the land use efficiency under different cropping patterns is increased by 68%, 38% and 21%, respectively.

Key words: Land equivalent ratio, Sequential cropping or relay cropping, Intercrops or mixed intercropping, Crop rotation, Land use efficiency