长期不同施肥模式下砂姜黑土小麦根系和光合的差异性研究

为明确长期单一施肥模式效果间的差异,研究了5种长期定位(34年)施肥模式对砂姜黑土小麦根系和光合的影响。结果表明,CK(不施肥)的根系性状表现最差,MNPK(有机肥与化肥配施等氮)与HMNPK(有机肥与化肥配施高氮)的总根长、总根表面积、总根体积和总根尖数显著高于NPK(单施化肥)和M(单施有机肥)处理,NPK与M间的总根表面积、平均根直径、总根体积差异不显著。长期有机肥与化肥配施(MNPK和HMNPK)相对于长期单施化肥(NPK)和有机肥(M)能提高小麦上3叶的长宽。在孕穗期,MNPK的光合速率、气孔导度和蒸腾速率最高,但与HMNPK差异不显著;在灌浆中期(MNPK与HMNPK发生倒伏),NPK和M处理的光合特性表现优于有机肥与化肥配施处理MNPK和HMNPK,MNPK的光合特性亦优于HMNPK(倒伏最重)。在孕穗期,有机肥与化肥配施相对于长期单施化肥和有机肥利于小麦叶绿素荧光参数的改善;灌浆中期,M处理的叶绿素荧光参数表现最优,MNPK的ΦpsⅡ、Fv/Fm、ETR、qP显著高于HMNPK。总根长、总根表面积、平均根直径、总根体积、总根尖数皆与光合高效叶片长宽及产量呈显著或极显著正相关关系;根系性状、产量与光合特性、叶绿素荧光参数Fm、ΦpsⅡ、Fv/Fm、ETR、qP呈显著或极显著正相关关系,与胞间CO_2浓度、Fo、qN呈极显著负相关关系。研究得出,有机肥与化肥配施虽有利于小麦根系及高效光合叶片长宽的改善,但有机肥与化肥配施高氮下遇特殊天气由于肥力较高易发生倒伏,造成光合速度的下降。

The Differences in Root Traits and Photosynthesis of Wheat in Lime Concretion Black Soil under Long-term Different Fertilization Patterns

In order to clarify the difference in the effects of long-term single fertilization model,we studied the effects of five kinds of long-term (34 years)located fertilization models on root traits,photosynthesis and yield of wheat in lime concretion black soil.The results showed that the root traits of CK(no fertilizer application)was the worst,the total root length,total root surface area,total root volume and total root tips of MNPK(mixed application of organic and chemical fertilizer with the same amount of nitrogen)and HMNPK(mixed application of organic and chemical fertilizer with the larger amount of nitrogen)were significant higher than that of NPK(application of single chemical fertilizer)and M(application of single organic fertilizer),in addition,the differences between NPK and M in total root surface area,average root diameter and total root volume were insignificant.When compared to long-term application of single chemical fertilizer(NPK)and organic fertilizer(M),the treatment of long-term mixed ap-plication of organic and chemical fertilizer(MNPK and HMNPK)could help to enhance the top-three leaves width and length of wheat.At booting stage,the photosynthetic rate,stomatal conductance and transpiration rate of MNPK were the highest,but there was no significant difference with HMNPK;at middle of filling stage(MNPK and HMNPK happen lodging),the photosynthetic characteristics of NPK and M were better than that of MNPK and HMNPK,and the photosynthetic characteristics of MNPK was also better than that of HMNPK(the most serious lodging).At boo-ting stage,compared to long-term application of single chemical fertilizer and organic fertilizer,the treatment of mixed application of organic and chemical fertilizer could help to improve wheat chlorophyll fluorescence parame-ters;At middle of filling stage,the chlorophyll fluorescence parameters of M was perform the best,and the ΦpsⅡ , Fv /Fm,ETR,qP of MNPK were significant higher than that of HMNPK.Total root length,total root surface area,av-erage root diameter,total root volume,total root tips were significantly or markedly significantly positively correlated to leaf length and width with high efficiency of photosynthesis and yield;Root traits,yield were significantly or markedly significantly positively correlated to photosynthetic characteristics and chlorophyll fluorescence parameters Fm,ΦpsⅡ ,Fv /Fm,ETR,qP,while markedly significantly negatively correlated to intercellular CO2 concentration, Fo,qN.The findings showed that although mixed application of organic and chemical fertilizer could help to improve root and leaf length and width with high efficiency of photosynthesis of wheat,mixed application of organic and chemical fertilizer with the larger amount of nitrogen might lead to lodging when encountered unusual weather due to higher fertility,and result in a decline of photosynthesis rate.