谷子播期对谷子/花生间作系统生产力的影响

Effect of Sowing Date of Foxtail Millet on Crop Productivity in Foxtail Millet/Peanut Intercropping System

间作作物的播期会影响其共生期,进而影响作物生产力和种间相互作用。为探究谷子(Setaria italic L.Beauv)播期对谷子/花生(Arachis hypogaea L.)间作系统生产力的影响,以谷子金选6号和花生大花生606为试验材料,固定花生播期为5月15日,谷子从5月15日至6月9日每5天播种1期,共设置6个播期处理(S1~S6)。通过对单间作系统中作物产量、产量构成因素等指标的测定,分析不同谷子播期条件下谷子/花生间作的作物产量、系统生产力、种间竞争力的变化。结果表明,随着谷子播期的推迟,间作系统中谷子和花生的产量均表现为先升高后降低的趋势,5月25日播种时(S3)谷子产量(4.07 t·hm^(-2))和土地当量比(LER=1.24)最大,5月30日播种时(S4)花生产量(2.51 t·hm^(-2))、间作总产值(4.64万元·hm^(-2))和间作系统生产力(SP=2.93 t·hm^(-2))最大;谷子/花生间作系统的实际产量损失大于0,具有产量优势。谷子的侵占力大于0、竞争比率大于1,花生的侵占力小于0、竞争比率小于1,间作系统中的谷子是竞争优势作物,对资源的竞争能力高于花生且受谷子播期影响较大。相关性分析及通径分析发现,在间作系统中,谷子产量与穗长呈显著正相关,与穗粗、穗重、穗粒重呈正相关,且穗长对谷子产量的贡献作用最大。本研究结果对谷子/花生间作实践具有指导意义。

Sowing date of intercropped crops will influence the symbiosis period of crops,which in turn affects intercrop productivity and interspecific interaction.In order to determine the effect of sowing date of foxtail millet on crop productivity in foxtail millet/peanut intercropping system,varieties Jinxuan 6 and Da 606 were selected as experimental materials for foxtail millet and peanut,respectively.The sowing date of peanut was fixed on May 15,while six sowing date treatments of foxtail millet were applied in the period of May 15 to June 9 at the interval of 5 days.The changes of crop yield,system productivity and interspecific competitiveness of foxtail millet/peanut intercropping system under different sowing dates were analyzed by measuring crop yield and yield components in both intercropping and monoculture systems.The results showed that,with the delay of foxtail millet sowing date,the yield of foxtail millet and peanut in the intercropping system increased first and then decreased.The yield of intercropping foxtail millet(4.07 t·hm^(-2))and land equivalent ratio(LER=1.24)were the highest at the sowing date of May 25(S3).The yield of intercropping peanut(2.51 t·hm^(-2)),total output value of intercropping system(4.64 ten thousand yuan·hm^(-2))and system productivity(SP=2.93 t·hm^(-2))were the highest at the sowing date of May 30(S4).The actual yield loss of foxtail millet/peanut intercropping system was greater than 0,which indicated that the yield of intercropping was superior to monoculture.The encroachment force of foxtail millet was greater than 0 and the competition ratio was greater than 1,while the indices of peanut were at the opposite.Foxtail millet in the intercropping system had a competitive advantage,and its competition ability for resources was higher than peanut and was greatly affected by the sowing date.Correlation analysis and path analysis revealed that panicle length contributed the most to foxtail millet yield,which had significant positive correlation with panicle length,and was positively correlated with panicle width,panicle weight and panicle grain weight.The results had certain guiding significance for the practice of intercropping of foxtail millet with peanut.