不同耕作方式对复播大豆光合特性、干物质生产及经济效益的影响

Effects of different tillage methods on photosynthetic characteristics,dry matter production and economic benefit of double cropping soybean

2013-2014年设置复播大豆田间试验,调查滴灌条件下麦后不同耕作方式复播大豆的生理指标及主要农艺性状,以探究适合北疆滴灌条件下麦后复播大豆的高产耕作方式.结果表明:麦后实施不同土壤耕作方式复播大豆在测定期间的群体叶面积指数(LAI)、叶绿素含量(SPAD)、叶片净光合速率(P_n)、蒸腾速率(T_r)和气孔导度(g_s)均表现出翻耕覆膜(TP)>翻耕(T)>旋耕(RT)>免耕(NT),而胞间CO_2浓度(C_i)呈现相反的结果.其中,TP处理两年LAI、SPAD、P_n、T_r、g_s的均值分别比NT处理高55.0%、9.1%、41.8%、37.5%和56.4%,而C_i下降22.1%,且均达显著差异水平,说明TP处理增强了大豆的光合效率,提高叶片同化CO_2的能力,这是其较NT处理大豆增产的主要光合生理机制.TP处理显著提高了植株干物质积累量,其单株荚数、单株粒数、百粒重分别较NT处理提高50.3%、48.1%、11.8%,增产达20.8%,差异显著.因此,本试验条件下,北疆麦后复播大豆宜采用翻耕后地膜覆盖结合膜下滴灌技术的耕作方式.

In order to explore suitable mode of high yield cultivation of double cropping soybean after wheat under drip irrigation in northern Xinjiang,field trials were set in 2013-2014 to investigate physiological indices and agronomic traits of double cropping soybean under different tillage methods under drip irrigation.The results showed that leaf area index（LAI）,chlorophyll content（SPAD）,leaf net photosynthetic rate（Pn）,transpiration rate（Tr） and stomatal conductance（gs） during the determination period under different tillage methods were in the order of tillage plus film covering（TP） tillage（T） rotary tillage（RT） no-tillage（NT）,and the concentration of intercellular CO2（Ci） was the opposite.LAI,SPAD,Pn,Tr and gs of TP were higher than that with NT by 55.0%,9.1%,41.8%,37.5%and 56.4%,respectively,and Ci was decreased by22.1%.TP enhanced the photosynthetic efficiency of soybean and improved the ability of CO2 assimilation,consequently leading to the increase of soybean yield under TP compared to NT.The plant dry matter accumulation of TP treatment was improved greatly,with the pod number and seeds number per plant,100-seed mass and yield of quadric sowing soybean being increased by 50.3%,48.1%,11.8%and 20.8%compared with that under NT,and the differences were significant.Therefore,the plastic film mulching combined with tillage under drip irrigation technology was suitable for double cropping soybean after wheat in northern Xinjiang under this experimental condition.