Objective: This study was conducted to investigate the effects of cultivation methods on yield, growth stage and utilization of temperature and illumination of various types of rice in different ecological regions under the rice-wheat cropping systems. It will provide a theoretical basis for scientific use and division layout of cultivation methods and its supporting variety type.

Method: With medium-maturing late japonica rice, early-maturing late japonica rice, late-maturing medium japonica rice and medium-maturing medium japonica rice (including japonica conventional rice and japonica hybrid rice) as materials, using three cultivation methods of artificial transplanting (AT), mechanical transplanting (MT) and direct seeding (DS), a comparative study of cultivation methods on yield, growth stage and utilization of temperature and illumination of rice was conducted in the following three different ecological regions: Taihu rice district in Changshu (Sunan, 31.4°N), Lixiahe rice district in Jiangyan (Suzhong, 32.3°N) and Xinghua (Suzhong, 32.6°N) and Huaibei rice district in Donghai (Subei, 34.5°N).

Result: Yield of rice with different cultivation methods was significantly different, and that of AT was the highest, while DS was the lowest. Compared with the AT, the yield of MT and DS reduced by 20-50 kg and 80-180 kg/667 m², respectively. And it demonstrated the law that the reducing extent was greater with latitude increasing. The yield of MT and DS reduced by 20-30 kg and 80-100 kg, 30-40 kg and 90-110 kg, 40-50 kg and 160-180 kg in Sunan, Suzhong and Subei, respectively. In the same region, the reducing extent of late-maturing varieties was greater than that of early-maturing varieties, and conventional rice greater than hybrid rice. The growth process of MT and DS delayed and growth stage shortened than that of AT. The shortening number of days of MT than that of AT was 11-14, and DS was 25-30, and it showed a trend of the higher the latitude the more the shortening number of days. Each growth duration would be shortened, and from sowing to jointing was the most which accounted for over 60% of the total shortening days. For the same type of varieties, the date of jointing, heading and maturity delayed, and the number of days of the growth stage increased with latitude increasing. In the same region, the shortening number of days of late-maturing varieties was more than that of early-maturing varieties. The accumulated temperature and illumination hours of MT and DS significantly reduced, and in particular, the utilization efficiency of accumulated temperature and illumination hours of DS was only 81.8% and 77.4% in Subei. The utilization efficiency of accumulated temperature and illumination hours was different because of variety types in different regions. The utilization efficiency of early-maturing late japonica rice was higher in Sunan, while that of late-maturing medium japonica rice and medium-maturing medium japonica rice in Suzhong and Subei, respectively.

Conclusion: Cultivation methods had great effects on yield, growth stage and utilization of temperature and illumination of rice. According to the large area yield target of 600 kg/667 m² in Jiangsu Province, a preliminary division for the suitable range and its supporting suitable variety types of different cultivation methods was made, in order to provide reference for the production of the large area. The preliminary division is that the AT and MT are all suitable in Sunan, Suzhong and Subei, but the DS is suitable in Sunan and sub-suitable in Suzhong while unsuitable in Subei. And each cultivation method has its supporting suitable variety types for different region, respectively.