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作 者 ：蒋耿民 李援农 周乾

期 刊 ：植物营养与肥料学报 2013年 19卷 5期 页码：1065-1072

关键词：揭膜时期；施氮量；生长；产量；水分利用效率；夏玉米；

Keywords:uncovering plastic film period, nitrogen rate, growth, yield, water use efficiency, summer maize,

摘 要 ：为了探明陕西省关中地区覆膜玉米生理生长、产量及水分利用效率同步提高的最佳揭膜时期和施氮量，制定合理的栽培措施，本试验以关中地区覆膜夏玉米为研究对象，设置3个揭膜时期（拔节抽雄期揭膜、抽雄期揭膜、全生育期覆膜）和3个施氮量（N 0、120、240 kg/hm²），研究了揭膜和氮肥互作对玉米生理生长、产量和水分利用效率的影响。结果表明，揭膜和施氮量均显著影响玉米生理生长、产量和水分利用效率，但两者的互作效应不显著。在3 个施氮水平下，与全生育期覆膜处理相比，抽雄期揭膜可通过改善根际土壤气热条件，提高根系活力，从而增加夏玉米株高、叶面积和地上部干物质量，提高了叶片净光合速率，降低了叶片丙二醛含量，获得较优的穗部性状和较高的籽粒产量及水分利用效率，而拔节抽雄期揭膜处理与全生育期覆膜处理之间无明显差异。当揭膜时期相同时，施氮处理的夏玉米生理生长、产量及水分利用效率等指标均优于不施氮处理，而高氮和低氮处理间无显著差异，但随着施氮量的增加，叶片净光合速率、籽粒产量和水分利用效率呈现减少趋势，叶片丙二醛含量呈现增加趋势。综合考虑产量、水氮高效利用、环境等综合效应，在本试验条件下，陕西关中地区覆膜玉米的适宜揭膜时期为抽雄期、适宜的施氮量为N120 kg/hm²，其籽粒产量和水分利用效率分别为11362 kg/hm²和34 kg/(hm²·mm)。

Abstract:Field experiments were carried out to verify the optimum uncovering plastic film period and nitrogen rate for higher yield, water use efficiency and better physiology, growth condition of maize in mulched fields in the Guanzhong Region, Shaanxi Province and to provide basis for the development of rational cultivation measures. Under field condition, three uncovering plastic film periods (uncovering plastic film at the jointingtasselling stage, uncovering plastic film at the tasselling stage and mulching plastic film) and three nitrogen rates (N 0, 120 and 240 kg/ha) were applied to study the interaction between uncovering plastic film period and nitrogen rate on physiology, growth, yield and water use efficiency of film mulching summer maize. The results show that uncovering plastic film period and nitrogen rate have significant effects on physiology, growth, yield and water use efficiency of summer maize, and the interactive effect between them is not significant. Through improving the gas and heat conditions around the roots, and increasing the root activity, the uncovering plastic film at the tasselling stage increases the plant height, leaf area, and dry mass accumulation and leaf photosynthetic rate, decreases the leaf MDA content, and has better ear characters, yield and water use efficiency in comparison with the mulching plastic film treatment under the three nitrogen rates. However, there are no significant differences between the uncovering plastic film at the jointingtasselling stage and the mulching plastic film treatments. With the same uncovering plastic film period, applying nitrogen fertilizer amounts of NL  (N 120 kg/ha) or NH (N 240 kg/ha) are better than that of the NZ (N 0) treatment in the physiology, growth, yield and water use efficiency of summer maize, however, there are no significant differences between the NH and NL treatments. As the increasing of nitrogen rates, the leaf photosynthetic rate, yield and water use efficiency are decreased, while the leaf MDA content is increased. In this study, taking yield, water and nitrogen use efficiencies and environment effect into consideration, the appropriate uncovering plastic film period and nitrogen rate of summer maize in mulched fields in the Guanzhong Region are uncovering plastic film at the tasselling stage and N 120 kg/ha respectively, the yield and water use efficiency of which are 11362 kg/ha and 34 kg/(ha·mm).

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