华北平原免耕冬小麦生长发育特征研究

2004—2006年在河北栾城中国科学院农业生态试验站开展了不同耕作方式下冬小麦生长发育特征及其影响因素的比较研究。冬小麦基本苗数和分蘖率在不同耕作方式间差异显著, 表现为免耕<旋耕<翻耕。免耕处理冬小麦分蘖成穗率高于翻耕和免耕处理, 但基本苗数低, 2004—2005生长季比翻耕和旋耕处理分别低28.9%和29.7%, 2005—2006生长季分别低11.7%和10.0%; 免耕处理冬小麦株高、叶面积指数、地上部干物质积累和产量均低于翻耕和旋耕处理, 其中叶面积指数在2004—2005和2005—2006生长季的最高值分别为2.9和6.0, 产量比翻耕降低30.1%和27.19%、比旋耕降低15.3%和25.20%。免耕可保持耕层较高的土壤水分含量, 总体上高于翻耕和旋耕处理; 免耕处理在冬小麦苗期和返青期表现出明显的“降温效应”, 耕层土壤日均温度低于翻耕和旋耕, 冬小麦出苗和返青较翻耕和旋耕分别晚1~3 d和4~5 d。

Characteristics of Growth and Development of Winter Wheat under Zero-tillage in North China Plain

The agro-ecosystem in North China Plain is challenged by water shortage, environmental pollution with burning crop stalks and high cost. Practice of conservation tillage is very essential in North China Plain for saving water, reducing environment pollution and tillage cost, increasing the crop productivity and organic matter content of soil. With the extension of conservation techniques, zero-tillage arouses more and more attention in the area. Some investigators found yield increasing with zero-tillage, but some experiments indicated the weaker seedling and revival stage delaying of winter wheat under zero-tillage as compared with conventional tillage. The objectives of this study were to evaluate the growth and development of winter wheat under zero-tillage treatment in North China Plain and to explore the reason of the influence of zero-tillage. The experiment using the winter wheat cultivar “Kenong 9204” with three tillage treatments including conventional tillage with stubble incorporating (CT), rotary tillage with residue returning (RT), and zero-tillage with stubble direct drilling (ZT) was conducted in Luancheng Ecological Experimental Station of Chinese Academy of Sciences during 2004–2006 growth seasons. To keep similar rate of seedling emergence in all treatments, seeding rate was from 165.0 kg ha-1 (in CT and RT treatments) increased to 262.5 kg ha-1 in ZT treatment. In addition to the characteristics of growth and development of wheat, the plough layer temperature and soil water con-tent were measured. Soil temperature was measured by thermoelectric couple every day. Soil moisture was observed by TDR (plough layer soil) and neutron instrument (deeper than 20 cm) every 14 d during winter and every 7 d for the rest time. The basic seedling and tillers in three treatments ranked significantly as ZT