麦茬处理方式对夏玉米光合特性的影响

采用两年三点的大田试验，研究了麦茬处理方式（平茬、立茬、除茬）对机播夏玉米光合特性及其产量的影响。结果表明，不同麦茬处理方式的夏玉米光合参数存在明显差异。夏玉米Pn、Gs表现为吐丝期最大，处理间表现为平茬〉立茬〉除茬；Tr在处理间表现为除茬〉立茬〉平茬，叶片水平上的WUE表现为为平茬〉立茬〉除茬；不同麦茬处理夏玉米的产量差异显著。

Photosynthetic characteristics of Summer Maize(Zea mays L.)with different treatments of winter wheat residues

Light is one of the important factors affecting development and production of corn (Zea mays L). Effects of different treatments of winter wheat residues (returning straw, RS; high stubble mulched, HS; zero stubble, ZS) on photosynthetic characteristics and yield of summer maize(Zea mays L.)were studied in North China by two-year experiment in three-places by field test during 2005 and 2006. The results indicated as follows: Leaf area index, yield and its components of maize varied greatly under different treatings of winter wheat residues conditions. The order of the leaf area index was RS>HS>ZS. Diurnal variation of photosynthetic rates (Pn) showed differences among winter wheat residues treatments at both jointing and silk stages.The highest value appeared in RS, the lowest value in ZS. The diurnal variation of intercellular CO2 concentration (Ci) and stomatic conductance (Gs) were also studied. Results showed that the Ci was least at noon and the Gs was very high at that time.The order of Gs under different treatment conditions was RS>HS>ZS, and their curves were single peak at both stages. The diurnal variation of transpiration rate (Tr) and water use efficiency (WUE) were also studied. Results showed that the Tr was the higest at noon. The order of Tr under different treatments conditions was ZS>HS> RS. Because of the daily changes of Pn and Tr, the order of WUE was RS>HS>ZS. Finally, yield component factors and yield were significant among all the treatments.