3种改良剂对连作川党参生长及土壤生化性质的影响

Effects of three amendments on the growth of Codonopsis tangshen and soil biochemical properties in a continuous cropping system

为评价土壤改良剂对川党参连作障碍的消减作用,以有机肥、微生物肥和硅钙钾镁肥为改良材料,研究不同改良剂对连作川党参生长及土壤生化性质的影响。结果表明,有机肥、微生物肥和硅钙钾镁肥显著提升了川党参叶片SPAD值,增幅分别为41.2%、20.7%和47.4%。有机肥和硅钙钾镁肥显著增加川党参产量,增幅分别为20.2%和13.8%。有机肥和微生物肥显著提高川党参多糖百分含量,分别增加9.3个百分点和6.2个百分点。微生物肥显著增加川党参炔苷含量,增幅为18.3%。3种改良剂对川党参根际土壤生化性质影响差异较大,与对照相比,有机肥和硅钙钾镁肥处理显著提高了土壤pH,分别提高0.28个和0.14个单位;显著降低土壤交换性铝含量,降幅分别为8.7%和19.9%。微生物肥显著降低土壤有机质,降幅为12.0%。有机肥、微生物肥和硅钙钾镁肥均显著增加土壤速效钾含量,增幅分别为107.5%、23.2%和32.6%。硅钙钾镁肥显著增加细菌丰度,降低真菌丰度,细菌/真菌比例较对照处理提高5038倍。综上,3种改良剂均可提高川党参光合代谢能力,但不同改良剂对连作川党参生长及土壤生化性质的影响存在差异。有机肥和硅钙钾镁肥显著提高川党参产量,微生物肥显著提升川党参炔苷含量。综合效应分析表明,3种改良剂(施用量)对连作川党参土壤的改良效果依次为有机肥(4500 kg·hm^-2)>微生物肥(750 kg·hm^-2)>硅钙钾镁肥(750 kg·hm^-2)。

A field experiment with four treatments(control(CK),organic manure(OM),microbial fertilizer(MF),and silicon–calcium–potassium–magnesium fertilizer(SCPM))was conducted to investigate the effects of three amendments on the growth and rhizospheric soil biochemical properties of Codonopsis tangshen in a continuous cropping system to provide scientific basis and technical support for alleviating the continuous cropping obstacle of C.tangshen.Results showed that the SPAD values of the C.tangshen leaf under the OM,MF,and SCPM treatments were enhanced by 41.2%,20.7%,and 47.4%,respectively,compared with the control.The OM and SCPM treatments significantly increased C.tangshen yield by 20.2%and 13.8%,respectively.The OM and MF treatments remarkably increased the polysaccharide content by 9.3 and 6.2 percent points,and the MF treatment significantly increased the lobetyolin content by 18.3%.The three amendments had different effects on the rhizospheric soil biochemical properties of C.tangshen.After the application of OM and SCPM,the soil pH was increased by 0.28,0.14 units,and the exchangeable aluminum content of the soil was decreased by 8.7%and 19.9%,respectively,compared with the control.The MF treatment significantly decreased the soil organic matter content by 12.0%compared with the control.The available potassium content of the soil was increased by 107.5%,23.2%,and 32.6%under the OM,MF,and SCPM treatments,respectively,compared with the control.The SCPM treatment remarkably increased bacterial abundance and decreased fungal abundance of the rhizospheric soil of C.tangshen;the ratio of bacteria/fungi abundance was increased by 5038 times compared with the control.All the three amendments generally enhanced the photosynthetic capacity of C.tangshen and had different effects on plant growth and rhizospheric soil biochemical properties.The OM and SCPM treatments improved C.tangshen yield,whereas the MF treatment increased the lobetyolin content of C.tangshen.The comprehensive analysis showed that the improvement effect of the three amendments on C.tangshen growth followed the order of OM(4500 kg·hm^-2)>MF(750 kg·hm^-2)>SCPM(750 kg·hm^-2).