甘薯切块直播栽培是一项新栽培方式，它革新了传统栽培法。其增产机理是加长了甘薯生长期并充分利用了早春光热资源和地力贡献，比传统栽秧具有个体发育早、群体生长迅速的优势，其叶面积指数、蒸腾速率、叶部细胞间隙ＣＯ２浓度、净光合速率、净光合能力、光合势等生理指标均有大幅度提高，为甘薯增产增收奠定了良好的生理基础 Live cutting of sweet potato is a new cultivation method, which has revolutionized the traditional cultivation method. The mechanism of increasing yield was to lengthen the growth period of sweet potato and make full use of the contribution of light and heat resources in early spring to the contribution of soil fertility. Compared with the traditional planting seedling, it had the advantages of early development and rapid population growth. Leaf area index, transpiration rate, leaf cell intercellular CO2 concentration , Net photosynthetic rate, net photosynthetic capacity, photosynthetic potential and other physiological indicators have increased significantly for the sweet potato yield and income laid a good physiological basis