湖南省龙山县是一个地处湘、鄂、川三省交界处,海拔从200多米延伸至1700米以上的少数民族聚居的山区县。全县有稻田面积25万亩,由于山高水冷,水稻单产最高的也只700来斤。龙山县种子公司为了改变山区低产面貌,从1984年起,每年都安排上万元资金进行杂交稻新组合引种试验。他们先 Longshan County, Hunan Province is located in the junction of Hunan, Hubei and Sichuan provinces, extending from 200 meters above sea level to more than 1700 meters above sea level inhabited by the mountainous counties. The county has an area of ​​250,000 acres of paddy fields, due to the high mountains and cold water, the highest yield of rice is only 700 pounds. Longshan County seed companies in order to change the appearance of low-yield mountain, from 1984 onwards, arranged tens of thousands of yuan each year for new combinations of rice introduction test. They first