In recent years, rice planting area in China has been stablized at about 33 million ha with yield exceeding 5.7t/ha. The multiple cropping index of rice field (grain-rape) has reached 202.4%, of which rice cropping index is 138.1%. Rice field cropping systems are basically characterized by rice-based multiple rotational cropping systems although there is a great variation in different regions regarding detailed cropping patterns.
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