马铃薯／燕麦间作对马铃薯光合特性与产量的影响

摘要

在宁夏南部山区，通过田间小区试验，以单作马铃薯为对照，研究了4种马铃薯燕麦间作行数比[2∶2（P2 O2）、2∶4（P2 O4）、4∶2（P4 O2）、4∶4（P4 O4）]对马铃薯光合特性与产量的影响。结果表明，开花期，间作马铃薯的叶面积指数（LAI）、比叶重（SLW）显著下降，随着第1茬燕麦的收获，间作马铃薯能获得更多的光照和更广阔的生长空间，良好的通风透光条件使 SLW 有一定程度的回升；成熟期间作 LAI 高于单作。整个生育期 P4 O4处理的 LAI 和叶绿素总含量（Chla＋Chlb）显著高于其他间作处理。在开花期，与单作相比，间作马铃薯叶片的净光合速率（P n ）、气孔导度（Gs ）、蒸腾速率（T r ）显著降低，胞间 CO2浓度（C i ）显著提高；成熟期，光合指标的变化趋势与开花期相反。与单作相比，间作马铃薯由于增加了单株块茎重、单株商品薯重，减少了小薯个数，而使产量显著增加，P4 O4产量最高。马铃薯／燕麦间作具有一定的间作优势，各间作处理经济产量土地当量比（LER）均大于1，其中 P4 O2的土地当量比最大，为1．22；其次为 P4 O4处理。在马铃薯／燕麦间作生产中适当增加马铃薯行数或减少燕麦行数有利于增加间作优势，在生产中宜采用马铃薯与燕麦间作行数比为4∶2、4∶4的间作模式。%Intercropping systems with four different potato-oat row ratios (2 ∶2,P2 O2 ;2 ∶4,P2 O4 ;4 ∶2, P4 O2 ;4∶4,P4 O4 )were tested to determine effects on the photosynthetic characteristics and yield of potato. During the flowering period,potato leaf area index (LAI)and leaf weight ratio (SLW)decreased significantly. After the first crops of oats are harvested,potatoes receive more light and growth space;thus SLW recovered to a degree.When the crops were mature,the LAI of potato in intercropping systems was higher than that in monoculture.Compared with other intercropping ratios,the LAI and total chlorophyll content under P4 O4 treatment were significantly higher during the entire growth period.During the flowering period,net photo-synthetic rate (P n ),stomatal conductance (G s )and transpiration rate (T r )of potato in intercropping systems significantly reduced compared to those in monoculture,while intercellular CO2 concentration (C i )significantly increased.However,the photosynthesis indexes decreased at maturation point.Compared to monoculture,in-tercropped potato returned significant increases in production,possibly due to increased tuber yield and market-able yield per plant,as well as reduced numbers of small potato.The highest yield was obtained under P4 O4 treatment.Intercropping with oats also returned land equivalent ratios (LER)greater than 1.LER was highest (1.22)under the P4 O2 treatment,followed by the P4 O4 treatment.The results suggest that potato/oat row ra-tios of 4∶2 or 4∶4 perform better than other ratios in this intercropping system.