黄土高原旱塬区覆盖方式对早酥梨光合特性的影响

摘要

为筛选出适宜黄土高原旱塬区梨园的土壤耕作模式.以8 a生早酥梨为试材,研究陇东黄土高原旱塬区地面覆盖对早酥梨叶片光合特性的影响.结果表明,覆草处理的净光合速率(Pn)在11:00最高,达到峰值；各处理Pn日变化均呈“双峰型”；地面覆盖显著提高水分利用效率(WUE),覆草显著高于覆膜；覆草能显著提高Gs和Ci,其Ci极显著高于CK(P＜0.01),显著高于覆膜(P＜0.05),处理间Gs和Ci变化趋势均与Pn一致；覆草后LCP显著降低,而LSP显著提高,表明对光照的适应范围较宽；覆草的Pn-max显著高于CK(高14.83％)；覆草的CO2补偿点显著低于覆膜和CK.可见,旱塬区覆草可以显著提高早酥梨叶片光合作用,有利于干物质形成,增强光能和CO2的利用能力.%In order to select soil tillage model adapting to pear in dry highland of Loess Plateau. Eight-year-old Zaosu pear were selected as experimental materials, the responses of photosynthetic characters of Zaosu pear to different covers were studied. The result showed that the diurnal variation of net photosynthetic rate exhibited dual-peak curves, which shows maximum net photosynthetic rate at 11:00 am under covering with grass. Mulching significantly increased water use efficiency (WUE), covering with grass was higher than film mulching significantly; covering with grass significantly increased Gs and Ci, and C, values were significantly higher than those CK (P