钾硅肥配施对胡麻茎秆碳水化合物及抗倒性的影响

Effects of combined application of potassium and silicon fertilizer on carbohydrate and lodging resistance of oil flax stem

为明确钾硅肥施用对胡麻茎秆碳水化合物主要成分含量及抗倒伏特性的影响,探讨钾硅肥运筹调控胡麻茎秆抗倒伏能力的机制,选用裂区试验设计进行了研究,以两个品种为主处理,三个K_(2)O钾肥用量(K0:不施钾;K1:52.5 kg/hm^(2);K2:105 kg/hm^(2))为副处理,两个SiO2硅肥用量(Si0:不施硅;Si1:90 kg/hm^(2))为副副处理。结果表明,胡麻茎秆的抗倒伏性能主要取决于碳水化合物总量及其中非结构性碳水化合物所占的比例;碳水化合物总量及其中非结构性碳水化合物的占比、可溶性糖及淀粉含量,均与抗折力、抗倒伏指数显著正相关。施钾后茎秆纤维素、木质素、可溶性糖、淀粉、碳水化合物总量及非结构性碳水化合物占比分别增加了11.74%~32.27%、12.18%~68.78%、12.48%~33.59%、23.96%~121.65%、8.95%~35.09%和17.48%~20.29%,抗倒伏指数提高了19.80%~86.37%,提升效果随钾肥用量的增加而增加。施硅对纤维素、木质素和碳水化合物总量的提升效果显著。茎秆中结构性碳水化合物组分的含量均不受钾硅互作的影响,而非结构性碳水化合物组分的含量与之相反,高钾水平不施硅时提升最显著。K2Si0、K1Si1比K0Si0,可溶性糖含量分别增加38.08%~46.15%和21.60%~40.83%,淀粉含量分别增加56.13%~176.54%和50.00%~61.41%,碳水化合物总量分别增加44.18%~53.40%和34.08%~36.73%。高供钾下不施硅、低供钾下配施硅肥,可提升非结构碳水化合物的比重,增强抗倒伏能力。施钾后籽粒产量显著提高,而硅肥对产量无显著的主效。单施钾肥的抗倒和增产效果显著,而硅肥的主效较小;钾硅配施的抗倒正交互作用只有在低供钾条件下才能表现出来。

The aim of this study was to understand the effects of potassium(K)and silicon(Si)fertilizers on main carbohydrate components content and lodging resistance characteristics of oil flax stalks,and to explore the regulatory mechanism of these two fertilizers on lodging resistance of flax stalks.Split plot design was used,with two varieties as main treatment,three potassium fertilizer dosage(K0:no potassium;K1:52.5 kg K2O/hm^(2);K2:105 kg K2O/hm^(2))as split-treatment,two silicon fertilizer dosage(Si0:no silicon;Si1:90 kg SiO2/hm^(2))as sub-split treatment.The results showed that lodging resistance capability of oil flax stem mainly depended on both total carbohydrate(TC)content and proportion of non-structural carbohydrate(NSC).TC content,NSC proportion,the content of soluble sugar and starch were all significantly and positively correlated with breaking resistance and lodging resistance index.Potassium increased the content of stalk cellulose,lignin,soluble sugar,starch,TC and NSC percentage by 11.74-32.27%,12.18-68.78%,12.48-33.59%,23.96-121.65%,8.95-35.09%and 17.48-20.29%respectively,and increased lodging resistance index by 19.80-86.37%.Meanwhile,higher potassium had better increase effects.Silicon promoted cellulose,lignin and TC contents significantly.Content of structural carbohydrate(SC)was not affected by K-Si interaction.But NSC content was affected.NSC increased under higher K level without Si.Compared with K0Si0,K2Si0 and K1Si1 increased soluble sugar content by 38.08-46.15%and 21.60-40.83%respectively,and starch content by 56.13-176.54%and 50.00-61.41%respectively,and TC by 44.18-53.40%and 34.08-36.73%respectively.Higher K without Si,or lower K accompanied by Si could both improve the proportion of NSC and then enhanced lodging resistance.K application significantly increased grain yield,while Si fertilizer had no significant main effect on yield.Applying K alone had a significant effect on lodging resistance and yield increase.Com‐bined positive interaction of K and Si to lodging resistance could be manifested only under low K condition.