Effects Of Mechanical Harvesting On Ratoon Sugarcane Growth And Physical And Chemical Properties Of Soil

In this experiment, five sugarcane varieties Funongl5, Liucheng03/182, Ganzhel8, Yuetang00/236, Taitang668were used as tested materials, and carried on the agricultural experimental base in Shuhe Village which belong to Luoxu town in Wuming county of Nanning. The experiment was conducted with the traditional manual harvesting and mechanical harvesting of sugarcane, to explore the effects of mechanical harvesting on ratoon sugarcane growth and physical and chemical properties of soil by determined physiological and biochemical indexes of drought resistance, agronomic traits, yield traits, cane yield and quality indicators, the main physicochemical properties of soil indicators under different varieties of sugarcaneecane-leaf returning and row spacing. The main results were as followed:1. Under the conditions of different varieties, the sugarcane leaves nitrate reductase activity and chlorophyll content of mechanical harvesting decreased, but the soluble protein content and root activity did not change significantly. Mechanical harvesting mainly affected0-10cm plow layer lead to soil bulk density increased, soil porosity and water content reduced, but after the cultivator in the end of May until June it was basically fully recovered. The available N content in the soil of mechanical harvesting decreased, the available P and K content increased, organic matter content did not change significantly. The impact of mechanical harvesting on the number of sprouting were different because of different varieties, the elongation speed, stem length, stem diameter and single-stem weight of sugarcane varieties Funong15, Liucheng03/182, Ganzhe18under mechanical harvesting were better than manual processing. Compared with the manual processing, the effective number of stems on Funong15and Liucheng03/182by mechanical harvesting was significantly reduced except Ganzhe18. The differences of sugarcane yield and sugar content between machine processing and manual processing of three varieties were no significant differences. The studies showed that the influence of mechanical harvesting on ratoon sugarcane growth is not obvious under the conditions of different varieties.2. Under the conditions of sugarcane-leaf returning field, the differences of leaves’nitrate reductase activity and soluble protein content of Yuetang00/236which gained by machine processing and manual processing were no significant difference, but the chlorophyll content and root activity increased by machine processing. The available N content and pH in the soil of mechanical harvesting decreased, but the content of available P, available K and soil organic matter had great degree increase, therefore the number of sprouting, cane elongation speed, stem length, stem diameter, and sugers and yield of sugarcane by machine processing were better than the manual processing which showed the effect of mechanical crushed on sugarcane-leaf returning field to improve soil environment was more effective than that artificial cut to accept the sugarcane leaves field directly.3. Under the conditions of different line spacing, the content of proline increased but the MDA content declined in leaves of Taitang668by machine processing, the influence of mechanical treatment on the membrane permeability increased with row spacing increasing. Overall, the mechanical harvest helped enhance the drought resistance capacity of ratoon sugarcane while this role differed from different row spacing, and the drought resistance index performed better by1.2m row spacing under machine processing. The effects of mechanical harvesting on the number of sprouting were different by different line spacing and the small row spacing received the big influence elongated speed of sugarcane stem increased or decreased by different line spacing under mechanical harvesting, but in the whole mechanical harvesting had the promoter action to the sugarcane stem elongation. The stem length, stem diameter, single stem weight and number of productive tiller of sugarcane by1.2m and1.3m line spacing through mechanical harvesting were better than that of manual processing, the differences of sugarcane yield and sugar content between machine processing and manual processing of four different line spacing were no significant differences.Thus it could be seen, the wheels of the RCC in the mechanical harvesting process caused soil compaction, soil physical and chemical properties had certain changes which had some negative impact on sugarcane shoot and root growth, however, the negative impact of the RCC could be eliminated after the open ridge of loose pocket and cultivator earth. The impact of mechanical harvesting on yield and sugar content of ratoon sugarcane was not obvious. Under the experimental conditions, the1.2m line spacing and machine income combined with the crushed leaves returning the field which could extremely reduce the impact of the wheels rolling by mechanical harvesting of ratoon sugarcane growth, to achieve high and stable yield in ratoon sugarcane.