Effects of extented harvest time on yield of spring maize under different tillage and cover measures | 不同耕作覆盖措施下延收对春玉米产量的影响

chinois. 研究延收对春玉米籽粒产量、千粒质量、灌浆速率、光温资源利用及植株器官干物质运移的影响，为玉米延收增产提供依据。以玉米“金赛6850”为材料，分别设传统耕作、传统耕作+秸秆覆盖、传统耕作+地膜覆盖、免耕+秸秆覆盖、免耕+地膜覆盖5个处理延期收获（习惯收获后，每隔5 d为1个收获期），测定在不同耕作覆盖措施下延收对玉米千粒质量和产量的影响。适时延收，玉米千粒质量和产量增加显著，延收15 d，传统耕作千粒质量平均日增3.59 g，产量增加1 334.7 kg/hm2，灌浆速率为1.7 mg/(g•d)；延长收获提高了光温资源的有效利用，延收15 d，秸秆覆盖和地膜覆盖的有效积温分别增加了180.33和154.98 ℃，日照时数分别增加53.90和23.30 h，植株干物质向籽粒中运移量以传统耕作最多，达10.06 g，叶和茎秆的干物质对籽粒增重的贡献率较高。玉米适时延收具有明显的增产效果，但增产幅度因耕作和覆盖方式不同而有显著差异。

anglais. The objective of this experiment was to study the effects of extended harvest time on spring maize yield, 1 000-grain-mass, grain-filling rate, the utilization efficiency of light and temperature, and the migration of dry matters in the plant organs. The results of this study would be beneficial to increase maize yields by extending harvest time. To determine the effects of extended harvest time on 1 000-grain-mass and yield of grain under different cultivation and mulching measures, five levels of CT, CS, CP, NTS and NTP were set as extented harvest time. “Jinsai 6850” was used as the tested species, which was harvested once every 5 days after usual harvest time. Extended harvest time significantly increased maize yield and 1 000-grain-mass. With an extension of the harvest by 15 days, the average 1 000-grain-mass under conventional tillage increased by 3.59 g per day.Grain-filling rate was 1.7 mg/(g•d). The accumulated temperature higher than 10 ℃ under straw mulching and plastic film was increased by 180.33 and 154.98 ℃, respectively, and sunshine duration was increased by 53.90 and 23.30 h as well. The maximum migration of dry matter, which mainly came from the leaf and stem, was 10.06 g under the conventional tillage. Extended harvest time significantly increased spring maize yield, and the amount of increase was highly related to different tillage and coverage measures.