Abstract
Soil rotational tillage is an effective measure to overcome the problems caused by long-term of a single tillage, but the effect of the interval time of rotational tillage practices is not very well understood. Therefore, we conducted a 3-year field study in a wheat-maize cropping system to evaluate the effects of rotary tillage (RT) in rotation with plowing tillage (PT) on soil properties in northern China. Four practices were designed as follows: 3 years of RT to a depth of 10–15 cm (3RT), 3 years of PT to a depth of 30–35 cm (3PT), 1 year of PT followed by 2 years of RT (PT+2RT), and 2 years of PT followed by 1 year of RT (2PT+RT). Within 20 cm of the surface soil, the 3RT treatment significantly increased the soil quality index (SQI) by 6.0%, 8.8% and 13.1%, respectively, relative to the PT+2RT, 2PT+RT and 3PT treatments. The improvement was closely related to the significant increase in the soil organic carbon (SOC) and available nutrients concentrations in the 0–20 cm depths and the improvement of soil invertase, urease, alkaline phosphatase and catalase activities in the topsoil (0–10 cm). However, the opposite effects were observed in the subsoil (20–40 cm). Compared with the 3RT treatment, the 3PT, 2PT+RT and PT+2RT treatments decreased soil bulk density, and significantly enhanced enzyme activities, resulting in an increase in SQI of 32.6%, 24.4% and 0.7%, respectively, especially in the 3PT and 2PT+RT treatments, the difference was significant. When averaged across to all soil depths, the SQI under the 3RT and 2PT+RT treatments was much higher than that under the other treatments. The yields of wheat and maize under the 2PT+RT treatment were 15.0% and 14.3% higher than those under the 3RT treatment, respectively. The 2PT+RT treatment was the most effective tillage practice. These results suggest that RT in rotation with PT could improve soil quality in the soil profile whilst enhancing crop yield after continuous RT, and the benefits were enhanced with an interval time of one year. Therefore, the 2PT+RT treatment could act as an effective method for both soil quality and crop yield improvement in a wheat-maize cropping system under straw incorporation conditions.
Highlights
Long-term shallow tillage has formed a hard ploughing pan and increased subsoil compaction, which restrict root penetration and reduce water and nutrient uptake from deep layers, affecting drought resistance and yield improvement in most parts of northern China [1,2,3]
The experiment included four tillage treatments as follows: (i) 3 years of rotary tillage (RT) (3RT), (ii) 3 years of plowing tillage (PT) (3PT), (iii) 1 year of PT followed by 2 years of RT (PT+2RT), and (iv) 2 years of PT followed by 1 year of RT (2PT+RT)
In the 0–40 cm soil profile, the lowest bulk density (BD) was obtained in the 3PT treatment, followed by the 2PT+RT and PT+2RT treatments and there was no significant difference among the three treatments, except for at the 20–30 cm depth
Summary
Long-term shallow tillage has formed a hard ploughing pan and increased subsoil compaction, which restrict root penetration and reduce water and nutrient uptake from deep layers, affecting drought resistance and yield improvement in most parts of northern China [1,2,3]. Previous studies have shown that deep tillage (PT, subsoiling) in rotation with shallow tillage (notillage) significantly minimized soil compaction and favoured a better soil water status, which helped in crop development and increased water use efficiency [10,11]. There have been conflicting results regarding the appropriate interval time under different crop systems, soil type and climate [8,9,12,13,14]. Years of continuous application of these tillage systems have resulted in subsoil compaction, limited root growth and reduced grain yield [1,3]. Assessing the feasibility of RT in rotation with PT and determining the appropriate interval time are crucial for soil quality improvement and soil sustainable development
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
