固氮螺旋菌Azospirillum sp.菌劑對有機水稻秧苗及植株生育影響之研究

Abstract

本研究於一期和二期作水稻秧苗育苗過程分別接種稀釋102 倍、103 倍及104倍等液態固氮螺旋菌Azospirillum sp.菌劑，以未施用菌劑為對照處理，評估該菌劑對秧苗生育效益；及探討有機水稻每公頃施用150 kg、100 kg 及75 kg 氮素之有機質肥料，並施用稀釋102 倍菌劑對植株生育的影響。秧苗試驗結果顯示：一期作施用菌劑處理之秧苗根長皆明顯大於未施用菌劑處理；田間試驗結果顯示：一期作每公頃施用75 kg 氮素之有機質肥料及未施用有機質肥料，並施用菌劑處理之株高分別為112 cm 與104 cm，高於未施用菌劑之對照處理 (108 cm 與100 cm)。另施用菌劑處理之分蘗數與穗數亦顯略高於未施用菌劑處理的趨勢。除此，每公頃施用75 kg 氮素之有機質肥料並施用菌劑處理者之每欉稻稈乾重為57 g，高於未施用菌劑處理者 (49 g)；二期作每公頃施用150 kg 氮素之有機質肥料並施用菌劑處理之株高為98 cm，顯著高於未施用菌劑處理 (93 cm)。每100 欉稻穀乾重為3.43 kg顯著高於未施用菌劑處理 (3.15 kg)，相當於每公頃乾稻穀重為5.01 ton，比未施用菌劑處理增加9.1%。 The objective of this plan is to assess the effect of Azospirillum sp. inoculum on the rice seedling and the growth and yield of organic rice in the field. The rice seedling’s experiment was performed on the seedling trays in the first and second crop, respectively. The treatments of rice seeds were steeped in different concentrations of Azospirillum sp. inoculum (10-2, 10-3, 10-4 and control). The results of rice seedlings showed the root length of treatment with Azospirillum sp. inoculum was obviously higher than the control without inoculum in the first crop. Additionally, the rice seedlings with Azospirillum sp. inoculum diluted to 10-2 and without inoculum were chosen for the field experiments, and the results showed the height of treatment with inoculum for applying 75 kg and 0 kg of nitrogen per hectare were about 112 cm and 104 cm, respectively in the first crop that were higher than without inoculum (108 cm, 100 cm). Additionally, there was a tendency that the tiller numbers and panicle numbers treated with inoculum were also slightly higher than without inoculum. Moreover, the dry weight of rice straw per plant of treatment with inoculum and applied 75 kg of nitrogen per hectare was about 75g that was also higher than control (49 g). In the second crop, the plant height applied 150 kg of nitrogen per hectare and adding inoculum was about 98 cm that was higher than without inoculum (93 cm), and the dry grain yield of rice straw per 100 plants was about 3.43 kg that was significantly higher than control (3.15 kg). That was, the treatment applied 150 kg of nitrogen per hectare and with inoculum was about 5.01 ton that was higher than control (4.59 ton) about 9.1%.