氮素形态与吡虫啉对甘蔗根系和地上部生长的影响

本研究通过水培的方式,探究不同形态氮素以及不同形态氮素和新烟碱类杀虫剂吡虫啉（IMI）处理对甘蔗生长、根系伤流强度和根系形态的影响。研究结果显示：与缺氮（CK）相比,添加铵态氮（A）、硝态氮（N）或铵态硝态氮（AN）能够显著提高甘蔗植株的株高和茎径（P<0.05）,其中株高增高了大约3倍,茎径增粗2~3倍,与硝态氮相比,铵态氮能促进甘蔗茎径变粗、鲜重增加以及侧根和不定根的形成;硝态氮为氮源可促进甘蔗根系的纵向生长;铵态氮和硝态氮共存时甘蔗根系总长、根表面积、根系体积以及伤流液强度大于单一氮源处理。添加吡虫啉促进了缺氮条件下甘蔗的生长;与对应的氮素处理组相比,吡虫啉和氮素共处理组甘蔗的鲜重均增加,其中A+IMI处理比A处理增加17.69%,N+IMI处理比N处理增加46.19%,AN+IMI处理比AN处理增加29.43%,在硝态氮存在时差异达到显著水平（P<0.05）;此外,吡虫啉和硝态氮共存显著提高了甘蔗根系总长、根表面积和伤流液强度（P<0.05）。结果表明铵态氮和吡虫啉共施对甘蔗整体的生长最为有利,吡虫啉和硝态氮共施可促进甘蔗鲜重增加以及根系的生长。本研究为甘蔗氮肥施用以及吡虫啉和氮肥在甘蔗中的共施提供重要的理论依据,同时,为“药肥一体化”技术在甘蔗上的应用提供借鉴。

Effects of Nitrogen and Imidacloprid on Growth and Root System of Sugarcane

Hydroponic experiment was conducted to explore the effects of different forms of nitrogen and the treatment with imidacloprid on sugarcane growth, root injury intensity, and root morphology. The treatment with different nitrogen forms, ammonium nitrogen (A), nitrate nitrogen (N) or ammonium nitrate nitrogen (AN), could significantly increase the plant height and stem diameter of sugarcane (P<0.05) when compared with nitrogen deficiency (CK), plant height increased by 3 times and stem diameter increased by 2-3 times. Compared with nitrate nitrogen treatment, ammonium nitrogen treatment could promote stem diameter, fresh weight and the formation of lateral and adventitious roots of sugarcane. In addition, the treatment with nitrate nitrogen could promote the longitudinal growth of sugarcane roots. When the treatment with ammonium nitrogen and nitrate nitrogen, the total length, root surface area, root volume, and fluid strength of sugarcane were greater than those of the single nitrogen source. Under nitrogen-deficient condition, the addition of imidacloprid could promote the growth of sugarcane. The fresh weight of sugarcane improved in the co-treated imidacloprid and nitrogen treatment groups when compared with the corresponding treatment (without imidacloprid added). The fresh weight of sugarcane treated with ammonium nitrogen and imidacloprid increased by 17.69% compared with the treatment with ammonium nitrogen alone. The fresh weight of sugarcane treated with nitrate nitrogen and imidacloprid increased by 46.19% compared with the treatment with ammonium nitrogen alone. The fresh weight of sugarcane treated with ammonia nitrogen, nitrate nitrogen and imidacloprid increased by 29.43% compared with the treatment of ammonia nitrogen and nitrate nitrogen. In addition, the difference reached a significant level when nitrate nitrogen was present in the treatment (P<0.05). The total root length, root surface area, and effluent strength of sugarcane increased significantly (P<0.05) with the treatment of imidacloprid and nitrate nitrogen. It is concluded that co-application of ammonium nitrogen and imidacloprid is most beneficial to the overall growth of sugarcane, co-application of imidacloprid and nitrate nitrogen increased the fresh weight of sugarcane and root growth. This study would provide an important theoretical basis for the application of nitrogen fertilizer in sugarcane fields and the co-application of imidacloprid and nitrogen fertilizer in sugarcane.