A preliminary study of planting northern boundary of single harvest rice in China

The planting northern boundary of single harvest rice is significant not only for crop planning but also for making countermeasures to cope with climate change in China. Single harvest rice planting northern boundary in China under natural and irrigation conditions were studied in this paper, based on the geographic information of single harvest rice from the national agrometeorological observation stations and China Meteorological Administration (CMA) as well as the dominant climate factors affecting single harvest rice planting zone distribution, together with the maximum entropy model. Furthermore, the single harvest rice planting northern boundaries from this study were compared to those from the Chinese Academy of Agricultural Sciences (CAAS) and the Cooperative Agricultural and Forest Crop Regionalization Group in China (CAFCRG). The results show that single harvest rice planting northern boundary in China could reach Mohe county, Helongjiang province under natural conditions. Daxinganling located to the west of the Mohe-Tahe-Huma central-line and the areas located to the west of the Longjing-Tailai-Duerboter-Daqing-Zhaoqing-Zhaoyuan line are not suitable to planting single harvest rice under natural conditions. The single harvest rice planting northern boundary does not exist under irrigation conditions, that is, Mohe county located at the north end of China could plant single harvest rice. And the single harvest rice planting northern boundary could extend slightly westward for the central Mohe-Tahe-Huma planting zone. The single harvest rice planting boundaries obtained from the study are more close to the practical boundaries at present and more accurate than those from CAAS and CAFCRG. This result is very helpful for the planting planning of single harvest rice in northern China.