[Structure characteristics of soil and canopy and their relationships in wheat field under different tillage and application of organic fertilizer.] / è€•å±‚è°ƒæŽ§ä¸Žæœ‰æœºè‚¥å¤„ç†ä¸‹éº¦ç”°åœŸå£¤å’Œå°éº¦å† å±‚ç»“æž„ç‰¹æ€§åŠå ¶ç›¸äº’å ³ç³».

With the aim to optimize the structural characteristics of wheat canopy by improving topsoil structure, we examined the effects of three different tillage treatments, deep tillage (DT), shallow tillage (ST), no-tillage (NT) alone, and with application of organic fertilizer, DTF, STF and NTF, on the soil structure and wheat canopy characteristics for five years. Under the same tillage treatment, application of organic fertilizer decreased soil bulk density, the content of soil aggregates with diameter > 5 mm, the mean mass diameter (MWD), and geometric mean diameter (GMD) values of the soil aggregates with diameter >0.25 mm. Soil porosity and the content of soil aggregates with diameters of 2-5 mm and 0.25-2 mm at 20-40 cm soil layer were increased. Compared with other treatments, NTF was better in improving soil bulk density and increased soil porosity at 0-20 cm soil layer. DTF decreased the soil bulk density and the stability of mechanical aggregate with diameter > 0.25 mm at 40-60 cm soil layer, and increased soil permeability. Application of organic fertilizer decreased leaf angle index and increased leaf area index (LAI) and the net photosynthetic rate (Pn) of the flag leaf at post-anthesis stage. The lowest angle index and the highest Pn were detected in STF and DTF treatment, respectively. Results from path analysis showed that the direct path coefficients were significant from the independent variables (soil bulk density, soil porosity, R0.25 and MWD) to the dependent variables (angle index, LAI and Pn). At 0-20 cm soil layer, the increased MWD value was beneficial to the improvement of Pn and LAI. At 20-40 cm soil layer, the increased soil bulk density would optimize the leaf angle and further improve canopy light penetration. At 40-60 cm soil layer, high soil bulk density and low porosity negatively affected the value of LAI and Pn. We concluded that deep tillage or shallow tillage with application of organic fertilizer would be beneficial for improving soil structure, increasing soil permeability, optimizing wheat canopy structure, increasing canopy light harvesting rate, leaf area index and photosynthetic rate, with positive consequences on wheat yield.