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本文研究了传统耕作和免耕不同覆盖措施下春玉米的光合生理变化,结果表明:随着生育期的推移,各处理的叶片净光合速率(Pn)呈现先升后降的趋势,在抽雄期达到最大。传统耕作条件下,地膜+秸秆覆盖净光合速率最高,秸秆覆盖最低;免耕条件下,地膜覆盖净光合速率最高,平均为33.81μmol·m~(-2)·s~(-1),比不覆盖平均增加3.7%。不同耕作覆盖措施下叶片蒸腾速率(Tr)表现为:抽雄期>拔节期>大喇叭口期>乳熟期>苗期>成熟期。春玉米气孔导度(Gs)在苗期较低,抽雄期达到最大,传统耕作条件下,地膜+秸秆覆盖保持着较高的气孔导度,平均为260.63mol·m~(-2)·s~(-1),比不覆盖平均高46.0%;免耕条件下,地膜覆盖的气孔导度最高,秸秆覆盖最低。
In this paper, the photosynthetic changes of spring maize under different tillage and no-tillage treatments were studied. The results showed that the net photosynthetic rate (Pn) of all treatments tended to increase at first and then decrease with the growth period, to reach maximum. The net photosynthetic rate of mulching film + straw mulching was the highest under the traditional tillage conditions. The net photosynthetic rate of mulching film was the highest under the no-tillage conditions with an average of 33.81μmol · m -2 · s -1, Not cover an average increase of 3.7%. Under different tillage measures, the transpiration rate (Tr) of leaves was as follows: tasselling stage> jointing stage> big bell mouth stage> milky mature stage> seedling stage> mature stage. The stomatal conductance (Gs) of spring maize was lower at seedling stage and reached the maximum at tasseling stage. Under conventional farming conditions, mulching and straw mulching maintained high stomatal conductance with an average of 260.63mol · m -2 · s ~ (-1), which is 46.0% higher than that of non-coverage. Under no-tillage conditions, the mulching has the highest stomatal conductance and the lowest straw coverage.