长期定位施肥对砂姜黑土小麦根系性状和根冠比的影响

Effect of Long-Term Fertilization on Root Traits and Root-Shoot Ratio of Wheat in Lime Concretion Black Soil

为了解长期定位施肥下砂姜黑土区小麦根系的生长发育状况,研究了5种长期不同施肥模式对该区小麦根系性状和根冠比的影响。结果表明,长期单施有机肥(M)小麦的总根长、总根表面积、总根体积、总根尖数、总根分叉数、根干重皆高于长期单施化肥(NPK),其中,开花期M处理小麦的总根体积、总根尖数、总根分叉数、根干重显著高于NPK处理,根直径M与NPK处理间差异不显著。长期有机肥与化肥配施传统施氮量(MNPK)与有机肥与化肥配施高施氮量(HMNPK)处理间小麦的总根长、总根表面积、平均根直径、总根体积、总根分叉数差异皆不显著,而MNPK处理小麦的总根尖数和开花期的根干重显著高于HMNPK处理。长期有机肥与化肥配施相对于长期单施化肥和有机肥可以明显改善小麦根系性状,其中,开花期MNPK和HMNPK处理小麦的总根长、总根表面积、总根体积、总根尖数、总根分叉数显著高于NPK和M处理,而MNPK和HMNPK处理小麦的平均根直径与M处理差异不显著。长期不施肥(CK)小麦的根系性状各指标显著低于其他各施肥处理。拔节期CK处理小麦的根冠比最低,其次为HMNPK,NPK、M、MNPK处理间的根冠比差异皆不显著,开花期HMNPK处理小麦的根冠比最低,其次为MNPK。研究认为,在改善根系性状方面,长期有机肥与化肥配施的效果最优,其次为长期单施有机肥、长期单施化肥;有机肥与化肥配施下施氮量偏高并不利于根系的改善,增加施氮量会降低根冠比。

In order to provide scientific basis for improving root growth and development and yield of wheat in lime concretion black soil area,the effects of five long-term fertilization models on root traits and root-shoot ratio of wheat in this area were studied. The results indicated that the total root length, total root surface area, total root volume, total root tips, total root forks, and root dry weight of M（long-term application of single organic fertilizer） were higher than those of NPK（long-term appli- cation of single chemical fertilizer）, and the differences in total root volume, total root tips, total root forks and root dry weight between M and NPK were significant, while the difference in average root diameter between M and NPK was insignificant. The differences in total root length,total root surface area, average root diameter, total root volume, and total root forks between long-term mixed applica- tion of organic and chemical fertilizer MNPK（traditional nitrogen application rate） and HMNPK（high- er than traditional nitrogen application rate） were insignificant, while the total root tips and root dry weight at flowering stage of MNPK were significant higher than those of HMNPK. When compared to long-term application of single organic and chemical fertilizer treatments, the treatments of mixed application of organic and chemical fertilizer can obviously improve root traits of wheat,and the total root length, total root surface area, total root volume, total root tips and total root forks of MNPK and HMNPK were significantly higher than those of NPK and M,while the differences in average root di- ameter between M and MNPK, HMNPK were insignificant. The root traits of long-term no fertilizer application CK was significantly lower than those of other fertilization treatments. The root-shoot ra- tio of CK was the lowest at jointing stage, followed by HMNPK, and the differences in root-shoot ratio of NPK,M and MNPK were insignificant~ the root-shoot ratio of HMNPK was the lowest at flower- ing stage,followed by MNPK,and the root-shoot ratio of MNPK and HMNPK were lower than that of NPK and M. In terms of improving root traits, the effect of M is better than that of NPK,and the effect of MNPK is better than that of M. Increasing N application rate is not helpful to improve root traits under the conditions of MNPK. Application of mixed organic and chemical fertilizers and in- creasing N application rate decreased root-shoot ratio.