风沙半干旱区不同立体复合模式下大扁杏的光合特性

摘要：选择科尔沁沙地南缘3种果粮草立体复合模式（模式A：大扁杏//花生/玉米/花生//大扁杏；模式B：大扁杏//玉米//大扁杏；模式C：大扁杏//草//大扁杏），研究了3种果粮草立体复合模式下田间主要气象因子的日变化以及大扁杏的光合特性。结果表明：3种模式大扁杏所截获的光合有效辐射（PAR）为：模式C＞模式A＞模式B；模式B的空气相对湿度（RH）较大而气温（Ta）较高，田间CO2浓度也相对偏低。3种模式大扁杏叶片净光合速率（Pn）日变化均呈双峰型曲线，两个高峰值分别出现在12:00与16:00前后。3种模式的Pn日平均（8:00～18:00）分别为10.5、8.9和10.6 μmol/(m2?s)；最高值分别为17.9、15.2和18.2 μmol/(m2?s)，模式B的光合能力明显低于模式A与模式C，而蒸腾速率（E）则比另两个模式高，模式A的光合速率虽介于模式B与模式C之间，但其蒸腾速率显著低于两模式，故模式A的大扁杏WUE日平均相对较高，抗旱性较强。从经济效益分析，模式A的经济效益显著高于另两模式。因此，模式A在风沙半干旱区表现较好。

The Photosynthetic Characteristics of Prunus armeniaca Under Different Compound Modes on Semi-arid sandy Area

Three compound cultivation modes （A： Prunus armeniaca // peanut / corn / peanut // P. armeniaca; B： P. armeniaca // corn // P. armeniaca; and C： P. armeniaca // grass // P. armeniaca） in south of Horqin sandy land were chosen, to study the photosynthetic characteristics of P. armeniaca and climate factors in the three compound cultivation modes. The results showed that the capture photosynthetically active radiation （PAR） was mode C mode A mode B; the air relative humidity （RH） of mode B was better, and the temperature （T a ） of mode B was higher, and the concentration of CO 2 （C a ） in the field was lower. The diurnal variation of net photosynthetic rate （P n ） in Prunus armeniaca was double peak curve, and the high peak appeared at about 12：00 and 16：00 in the three compound cultivation modes. The daily average of P n for the three modes were 10.5, 8.9 and 10.6 μm ol/（m 2 ·s）, respectively, the highest value were 17.9, 15.2 and 18.2 μ mol/（m 2 ·s） respectively. Therefore, the photosynthetic capacity of mode B was lower than modes A and C significantly. Then of mode A was lower than that of mode C and higher than that of mode A, so the daily average of water use efficiency （WUE） of P. armeniaca in mode A was higher and the drought resistance of mode A was stronger. Economic analysis showed that the economic benefit of mode A was significantly greater than two other modes. So the mode A was better for the semi-arid sandy area.