盐渍条件下苜蓿和羊草生长与营养吸收的比较研究

A comparison of growth and nutrient absorption in Medicago sativa and Leymus chinensis under saline condition

通过室内模拟试验 ,研究了盐分对苜蓿和羊草生长与营养吸收的影响 ,结果表明 ,盐度处理对羊草植株生长的影响低于对苜蓿的影响 ,羊草较苜蓿更为耐盐。苜蓿的蒸散量和净光合速率(NPn) ,尤其是日最大净光合速率受盐分的影响比羊草显著。随土壤含盐量的增加 ,苜蓿和羊草植株N、P含量无明显变化 ,K含量迅速降低 ,而Na含量急剧增加。苜蓿与羊草相比 ,苜蓿则有相对较低的K特定吸收率 (SAR)和高的Na特定吸收率 (SAR)。

Medicago sativa and Leymus chinensis were exposed to different content of NaCl (0,1,2,3 g/kg) in a controlled pot culture system for 30 days. Growth reduction by salt treatment was significantly greater in Medicago sativa than in Leymus chinensis and Leymus chinensis showed a higher resistance than Medicago sativa. The effect of salt stress on net photosynthesis rate (NPn) and especially on the diurnal highest net photosynthesis rate (NPn) was more distinct in Medicago sativa than in Leymus chinensis. Salinity reduced the content of K, but did not affect the content of N and P. Compared with Leymus chinensis, Medicago sativa showed a lower SAR of K, but a higher SAR of Na.