[Effects of short-term deep vertically rotary tillage on topsoil structure of lime concretion black soil and wheat growth in Huang-Huai-Hai Plain, China]. / 短期深旋松对黄淮海沙姜黑土耕层结构及小麦生长的影响.

Annual rotary tillage can often create a compacted plough pan and shallow arable layer which hampers the high crop yield in Huang-Huai-Hai region. A brand new farming method named Vertically Rotary Tillage was introduced to solve this problem. One short-term field experiment was conducted to explore the effect of deep vertically rotary tillage on soil physical properties and photosynthetic characteristics at flowering stage of winter wheat. Two tillage treatments were designed including subsoiling tillage with 20 cm depth (SS20, CK) and deep vertically rotary tillage with 30 cm depth (DVR30). The result showed that compared with SS20 treatment, DVR30 treatment could thoroughly break the plow pan and loose the arable layer. The soil bulk density at 10-20 cm and 20-30 cm layers under DVR30 treatment was decreased by 9.5% and 11.2% respectively than that under SS20 treatment. Meanwhile, the penetration resistance at 20-30 cm layer under DVR30 treatment was also decreased by 42.3% than that under SS20 treatment. Moreover, water infiltration under DVR30 treatment and the soil water storage in the deep soil layers was then increased. The mass water content of soil increased significantly with the increase of soil depth. There was significant difference of mass water content of 30-40 cm 40-50 cm between SS20 and DVR30. The mass water content 30-40 cm and 40-50 cm layers under DVR30 treatment was increased by 16.9% and 10.6% compared with SS20 treatment, respectively. Furthermore, DVR30 treatment promoted the improvement of the photosynthetic capacity of wheat which could contribute to the dry matter accumulation of winter wheat. The net photosynthesis rate and SPAD at flowering stage of winter wheat leaves under DVR30 treatment were increased by 1.3% and 15.5% respectively than that under SS20 treatment, thereby the above and underground dry matter accumulation of winter wheat under DVR30 was increased significantly. Due to all the superiority of DVR30 treatment over SS20 treatment showed above, the winter wheat yield under DVR30 treatment was increased by 12.4% than that under SS20. It was concluded that deep vertically rotary tillage could provide a new and effective way to break up the compacted plough pan, build a reasonable soil structure and increase crop yield.