Abstract: Maize were studied in this research to test the diurnal variation of photosynthetic performance, inclu- ding net photosynthetic rate, stomatal conductance, transpiration rate and intercellular CO₂ concentration under con- servation tillage technology and conventional tillage technology, to compare the differences of photosynthetic charac- ters of maize under different tillage types. The results showed that the maximum value of net photosynthetic rate of maize under different tillage types occurred 11:00 as well as stomatal conductance of maize under different tillage types, the maximum value of net photosynthetic rate were 30. 61, 27. 30 μmol /(m²·s) respectively, the maximum value of stomatal conductance were 0. 20,0. 19 mmol /(m²·s) respectively; the diurnal variation of transpiration effi- ciency of maize under protective tillage was a bimodal curve, and the maximum value of transpiration rate of maize under technology of conservation tillage and conventional tillage occurred 15: 00 and 11: 00, the specific value of that were 5. 81,6. 05 mmol /(m²· s) . respectively; the diurnal variation of transpiration efficiency of maize under tra- ditional tillage was only a single peak, and the maximum value of transpiration rate of maize under traditional tillage occurred 11:00, the specific value was 4. 82 mmol /(m²· s), and there were no significant change between the two type tillage at other sampling points. Diurnal variation of intercellular CO₂ concentration showed decrease firstly and then increase. Net photosynthetic rate of maize under conservation tillage technology higher than conventional tillage technology. Given this, from the view of the photosynthetic efficiency, conservation tillage technology systems can re- place the traditional tillage type in south Tumochuan Plain in Inner Mongolia.

Key words: Photosynthesis, Diurnal variations, Maize, Conservation tillage technology

CLC Number: 

• S513.01