The analysis of factors in which the superfluous applied potassium suppresses photosynthetic rate of the leaves and sugar production of sugarcane.

本研究阐明了甘蔗根系吸收土壤中积累的多余钾和高钾导致叶片光合速率下降的因素。在此过程中，阐明了光合速率随着束鞘细胞NADP-ME和Rubisco活性的降低而降低，这是通过降低镁的吸收来抑制的。除上述结果外，还研究了蔗渣炭对甘蔗含糖量和产量的影响，并探讨了蔗渣炭对钾肥可持续农业的影响。研究了甘蔗渣炭中钾的丰富含量，考察了不同钾输入量对甘蔗生长和品质的影响。甘蔗渣木炭的使用是为了成为每1公斤土壤10、30、50克。施用改良的Hoagland溶液培养基，每周1次（每罐500 ml），适当洒施。种植后第5个月，测定甘蔗茎长、茎重、抽汁元素和含糖量。结果表明，甘蔗渣炭中所含的钾被甘蔗吸收。由于蔗渣炭处理对甘蔗吸钾量的改变并没有对甘蔗的生长和品质产生影响，因此蔗渣炭被认为是钾肥的替代品。因此，蔗渣炭可以通过改善土壤物理性质来减少甘蔗的肥料。

In this study, the factor that the root of sugarcane absorbed the superfluous potassium which accumulates in the soil and that the decreased photosynthetic rate of leaf due to the higher potassium content was clarified. As the process, it was clarified that the photosynthetic rate was decreased with the lowering of NADP-ME and Rubisco activities of bundle sheath cell through the lowering of magnesium of which the absorption was suppressed for rivalry like.In addition to the above-mentioned result, the effect of the bagasse charcoal on sugar content and yield of sugarcane was investigated, and the possibility of sustainable agriculture in concerned with the potassium was also examined. The potassium was abundantly included for the bagasse charcoal, and the effect of the difference of the input on growth and quality of the sugarcane was examined. The bagasse charcoal was used in order to become 10, 30, 50 g per 1 Kg soil. The fertilization gave modified Hoagland Solution culture medium once a week (500 ml per pot), and the sprinkling was properly carried out. Fifth month after planting, the stem length, stem weight, elemental component in juice extraction and sugar content of cane were measured. As the result, it was confirmed mat the potassium which is included for the bagasse charcoal was absorbed to the sugarcane. The bagasse charcoal was regarded as becoming the substitution of the potassium fertilizer, because the change of potassium uptake quantity by the bagasse charcoal treatment did not give growth and effect in the quality of the sugarcane. Therefore, it was clarified that the reduction of the fertilizer of sugarcane could be expected with the improvement on the soil physical property through the bagasse charcoal.