This is raw data of appropriate depth for harvesting lincluding yield, shoot and root biomass, root system traits in different diameter.
The field experiments were conducted in Kaiyuan City (103o15’E, 23o42’ N, 1117m A) of Yunnan Province, in the south-west of China. The field soil soil pH was 7.5 (tested by potentiometry); The organic matter was tested by the potassium dichromate method; Soil nutrients were tested by flme atomic absorption spectrophotometry; and soil mechanical composition was tested by sedimentation method. The experiment was rainfed, and the groundwater level is approximately 2 m below the ground surface.
The climate in this region is high temperature during summer, with long winter and early spring severe drought periods. The highest values of precipitation and temperature occur in June and July.
The experiment was conducted from 2016 to 2018 on sugarcane cultivar YZ081609 (Zhao et al., 2019). The plant crop was planted on 22 April 2016 with a conventional planting density of 120,000 buds ha-1 (double buds cane setts). The planting depth (cane setts bed to soil surface) was approximately 10 cm, with about 10 ~ 15 cm of earth up before grand growth. So, after plant crop was harvested, there was a soil layer of 20 ~ 25 cm upper the original cane setts. Fertilizer N P K (20-12-18) was applied during the early elongation period of sugarcane at the rate of 1200 kg ha -1 on March 10, 2017 and 2018. Cultivation and crop management procedures were otherwise consistent with conventional cropping practices.
Based on the density of underground buds on ratoon stool and their germination potential, we divided the underground buds into 3 types.Type 1 is the terminal bud in top soil, they were lowest in amount and germinate the fastest, the roots distributed mainly in upper soil; type 2 distributed at the depth of 5 ~ 10 cm, most of them are active bud that germinate fast, and their roots distributed deeper; type 3 are mostly dormant bud distributed bellow 10 cm with the poorest germination. Accordingly, the harvesting depths (treatment) were -0 cm, -5 cm and -10 cm for T1, T2 and T3. For each harvesting, sugarcane plants were cut down by a sharp hoe manually. In order to maintain the accuracy of harvesting depth, a half side of the soil surrounding the stool were removed by the relative depth of each treatment before conducting the harvest. Plant crop was harvested on 9 March 2017, first ratoon crop was harvested on 4 March 2018 when the sucrose content reached to top (matured). The plot size was 30 m2 (5 rows wide × 6 m long). Three treatments were randomized in each of the 3 replications.
The data of each plant came from the data of the cluster dividing the millable number of the cluster
