Conservation tillage for summer planting soybean growth dynamics and the impact of soil properties
|School||Gansu Agricultural University|
|Keywords||Loess Plateau Conservation tillage Stubble cover Soil Photosynthesis|
In this study, integrated application of biology, agronomy, physiological ecology and soil science technologies and methods, 2001 in Xifeng Loess Plateau in summer and soybeans (Glucine max CV harvest on the 12th) for the test material, the use of conservation tillage technology, under different tillage soil temperature, moisture, nutrient dynamics and summer planting soybean growth, photosynthetic physiological characteristics were studied systematically. The main results are as follows: 1. In the Loess Plateau area, straw mulch can effectively stabilize the shallow soil temperature changes, soil under no-tillage straw mulch treatment temperature variation range than conventional tillage and no-tillage were reduced by 1.64 ℃, 1.99 ℃, temperature and soil under conventional tillage mulching treatment Change compared with conventional tillage and no-tillage were reduced by 1.00 ℃, 1.33 ℃. 2. Straw mulch tillage, conventional tillage straw mulch, straw mulch does have better water retention effect, effectively reducing the evaporation of surface water, increasing soil water retention capacity to the role of straw mulch tillage is particularly evident, surface soil moisture over conventional tillage high 17.8%. 3. Tillage improves soil tilth fertility trends, summer planting soybeans after harvest 0-10cm soil layer of soil total N, organic matter content than conventional tillage increased by 5.6%, 2.3% ,10-30cm soil tillage straw to cover the performance of the Best, total N, organic matter and total P than conventional tillage increased by 10.9%, 16%, 3.8%. This conclusion is in line with the general effects of tillage. 4. Straw mulch for the summer planting soybeans provide good water and fertilizer conditions, to promote the summer planting soybean early growth had a significant effect, each growth period, covering way above ground biomass are not covered by no-tillage and conventional tillage, soybean seed yield was significantly higher Not covered in tillage and conventional tillage. Tillage compared with conventional tillage straw coverage increased 16%. Coverage under grain farming grain weight was significantly higher than other two treatment (P <0.05). 5. Growth period of summer soybean net photosynthetic rate showed a downward trend, the peak in the early growth stage. The physiological characteristics of summer soybean mainly by local sunshine hours and the impact of effective radiation characteristics. Reduced tillage straw covered soil evaporation, a significant increase in topsoil moisture, leaf net photosynthetic rate significantly increased (P <0.01). Summer planting soybean net photosynthetic rate and water use efficiency were positively correlated. Therefore, conservation tillage improves water use efficiency of summer soybean role.