Abstract:

To explore the effects of different no-tillage years and re-tillage times on soil bulk density and rice growth in paddy fields, the research includes no-tillage for 1 to 10 years of paddy field and re-tillage once, re-tillage twice and re-tillage 3 times after no-tillage for 3 to 6 years of paddy field. The results showed that the soil bulk density of no-tillage soil was always higher than that of conventional tillage soil at surface soil and sublayer soil, with the increase of no-tillage time, soil bulk density increased. The soil bulk density significantly increased after 3-year no-tillage compared to that of conventional tillage (P<0.05). With the increase of re-tillage time, soil bulk density gradually decreased. In the paddy fields with no-tillage for 1 to 5 years, the highest seedlings, effective panicles and yield of rice under no-tillage cultivation were higher than that of conventional tillage cultivation. The tillering ability and yield of rice treated with 6-year no-tillage were relatively flat and stable and that of rice treated after 7-year no-tillage decreased significantly. The tillering ability and yield of rice in paddy fields under the re-tillage treatment were always lower than that of the corresponding no-tillage treatment, and the gap gradually widened with the increase of re-tillage times. The tillering ability and yield of rice treated with no-tillage for 7 years were the same as that treated with the corresponding re-tillage once after no-tillage for 6 years. In summary, 6-year no-tillage treatment is the best measure for paddy production in the study area, when the continuous no-tillage of paddy fields exceeds the optimum years, it is necessary to re-tillage the paddy fields once.

Key words: paddy field, no-tillage year, re-tillage, soil bulk density, yield