甘蔗脱毒原种苗田间繁育过程中氮、磷、钾营养元素的吸收及累积特征

Absorption and Accumulation Characteristics of Nitrogen,Phosphorus and Potassium in Field Propagation of Disease-free Sugarcane Original Seedlings

探讨甘蔗脱毒原种苗不同生长时期氮、磷、钾营养元素的累积需求状况,为甘蔗脱毒原种苗田间繁育栽培过程中养分管理提供参考。试验分别在2020、2021年进行,调查中糖1号甘蔗脱毒原种苗全生育期生长情况,测定其生物量及其在各生育阶段根、茎、叶中氮、磷、钾各营养元素的含量,并分析氮、磷、钾的累积量、阶段吸收量、日吸收速率。结果表明:甘蔗脱毒原种苗从种苗假植到种茎最佳收获时需6~7个月可达15茎节,在7、8月至9月下旬(茎1期至茎2期)蔗茎生长速度最快,以茎4期(10月下旬至11月下旬)干物质量累积增加最快,此阶段为生物量累积的关键阶段。在甘蔗脱毒原种苗全生育期中各元素含量及累积量从高到低依次为钾>氮>磷,在根茎叶各器官中蔗叶、蔗茎始终为氮、磷、钾含量相对较高的器官,氮、磷、钾累积量在茎伸长生长1期前主要贮存于蔗叶中,而后以蔗茎为新的主要贮存器官。甘蔗对氮、磷、钾的吸收比例在苗期和分蘖期分别为24.84%、26.18%、27.74%,在茎1~3期(7月下旬至10月下旬)分别为55.54%、58.61%、52.30%,茎4、5期(10月下旬至12月下旬)分别为19.62%、15.20%、19.96%。因此,可根据各元素的阶段吸收量进行合理施肥,进而提高甘蔗脱毒健康种苗的品质和经济效益。试验明确了甘蔗脱毒原种苗生长过程中对氮、磷、钾的需求状况,可为今后甘蔗脱毒健康种苗田间规模化繁育生产的科学合理施肥提供依据,提高脱毒原种苗田间繁育效率和养分资源利用效率。

This study was conducted to explore the cumulative demand of nitrogen,phosphorus and potassium in disease-free sugarcane original seedlings,and provide reference for the nutrient management in the process of field propa-gation of disease-free sugarcane original seedlings.The growth of the diseasefree sugarcane original seedlings of Zhongtang No.1 in 2020 and 2021 was investigated,and the biomass and contents of nitrogen,phosphorus and potassium in roots,stems and leaves at various growth stages were determined for further analysis of the accumulation,phase absorption and daily absorption rate of nitrogen,phosphorus and potassium.It took 6 to 7 months for disease-free sugarcane original seedlings to reach 15 stem nodes from temporary planting of seedlings to the best harvest of seed canes.From July,August to late September(stem 1 to 2),the growth of sugarcane stems was the fastest.The cumulative increase of dry matter was the fastest in stem 4(late October to late November),and this is the key stage of biomass accumulation.During the whole growth period of the disease-free sugarcane original seedlings,the content and accumula-tion of each element from high to low were potassium>nitrogen>phosphorus.Among the organs of roots,stems and leaves,leaves and stems always had higher nitrogen,phosphorus and potassium contents.The accumulation of nitrogen,phosphorus and potassium was mainly stored in the leaves before the stem elongation stage 1,and then mainly stored in the stems.The nutrient uptake rates of nitrogen,phosphorus and potassium at the seedling stage and tillering stage was 24.84%,26.18%and 27.74%,respectively,and it was 55.54%,58.61%and 52.30%at the stem 1 to 3(late July to late October),while 19.62%,15.20%and 19.96%during stem 4 and 5(late October to late December).Reasonable fertilization can be carried out according to the phase absorption of each element,thereby improving the quality and economic benefits of disease-free sugarcane seedlings production.The demands of nitrogen,phosphorus and potassium in the breeding process of disease-free sugarcane original seedlings were clarified,which would provide a reference for the scientific and reasonable fertilization in large-scale field propagation of disease-free sugarcane original seedlings in the future,and improving the efficiency of the propagation and nutrient utilization of disease-free original seedlings.