播种机械与秸杆覆盖对玉米衰老生理及产量的影响

Effect of Sowing Machine and Straw Mulching on Leaf Senescence Physiology and Yield of Maize(Zea mays L.)

针对黄土高原区农田如何高效利用自然降水的保护性耕作技术集成问题,采用田间试验在黄土高原半湿润易旱区研究了不同播种机械与秸杆覆盖对玉米花后叶片衰老生理及产量的影响.播种机械包括大拖拉机(东方红-75/802型,功率为58.8kW)和小拖拉机(泰山-12型;功率为11kW),覆盖处理包括秸秆覆盖0.9kg/m2与不覆盖.结果表明,大拖拉机播种玉米及秸秆覆盖,可减缓玉米开花后穗位叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性降低及叶绿素的降解,叶片丙二醛(MDA)含量低,可延缓叶片衰老.采用大拖拉机与秸秆覆盖能降低土壤容重,增加土壤水分入渗能力,保蓄土壤水分.大拖拉机播种玉米及秸秆覆盖,比不覆盖增产14.75%,比小拖拉机播种增产10.90%.研究表明采用大拖拉机播种与秸杆覆盖结合是延缓玉米叶片衰老,提高玉米产量的一种有效措施.

Drought（water deficit）is the major constraint factor for maize （Zea mays L. ）productivity in the semi-humid area of the Loess Plateau. Conservation tillage has been considered as a water-saving technique in this area. The effects of different sowing machine, mulched and non- mulched treatments on maize leaf senescence physiology and yield were conducted in Yangling, Shaanxi Province, China, in order to provide a technological basis for conservation tillage to use rainfall efficiently in farmland in Loess plateau. The split-plot design consisted of sowing machine treatments in the main plots with straw mulching at a rate of 0.9kg/m2 and non- mulching as subplots. Sowing machine included large tractor（Dongfanghong-75/802） and small tractor（ Taishan-12 ）. The results showed that activity decreased of superoxide dismutase （SOD） ,peroxidase（POD）, catalase （CAT）and degradation of chlorophyll in maize leaf were mitigated by the small tractor and non-mulched, large tractor and straw mulching. The content of malondialdehyde （MDA）was also reduced. These resulted in delay of senescence of maize leaf and made leaf physiological function stronger in later growing period. Methods of large tractor and straw mulching could increasing soil infiltration capacity and soil water content. Maize yield of large tractor and straw mulching were significantly higher than that of non-mulching, and the increasing rate was 14.75%. Compare with small tractor, the yield of large tractor treatment increased by 10.90%. These data indicated that combining large tractor and straw mulching is a better practice for maize production in semi-humid area of Loess Plateau.