Minimum Tillage Offers Multiple Advantages

A trial conducted at Changins compared the impact of different tillage practices on wheat yields and soil fertility. It showed that minimum tillage provides agronomic and environmental advantages. 

Intensive soil tillage such as conventional ploughing (inversion tillage) can be associated with environmental and agronomic problems such as loss of soil organic matter and biodiversity as well as increased soil erosion. To overcome some of these problems, alternative soil tillage practices have been proposed under the term ‘conservation tillage’, ranging from no-till (direct seeding) to non-inversion tillage.

Understanding how different tillage practices affect crop productivity and soil fertility is essential for developing sustainable agriculture systems. In a trial conducted in Changins, the impact of no-till on winter wheat yields and soil fertility was investigated thirteen years after its introduction in a clay and a loam soil and compared with the impact of minimum tillage (5-8 cm deep), shallow tillage (12-15 cm deep) and conventional ploughing (20-25 cm deep).

More specifically, the researchers evaluated the following parameters: crop yield and grain quality of winter wheat, organic carbon (C) and macronutrient stocks in the 50-cm deep soil profile, soil microbial abundance and soil structural quality.

Minimum tillage appears to be a worthwhile practice

During the study period 2007–2020, the annual yield of winter wheat did not differ significantly among the four tillage treatments. However, the no-till showed the lowest relative annual yield and the largest yield variability.

The quality of winter wheat grains was affected primarily by the soil texture rather than the tillage treatment.

A significant effect of tillage on the stocks of soil organic carbon, total nitrogen and exchangeable potassium and magnesium was observed only in the topmost 10 cm, where higher values were found for the three non-inversion tillage treatments. However, when the entire 50-cm deep soil profiles were evaluated, only non-significant differences in nutrient stocks were detected between tillage treatments.

We observed a clear stratification of microbial biomass carbon along the soil profile with larger values in the topmost soil layers in the no-till and the minimum tillage.

Soil porosity was found to improve with non-inversion tillage practices.

Overall, these data indicate that even though the no-till may still be in a transitional phase in terms of crop yield, its positive effects on soil organic carbon and microbial biomass are observable after 13 years. In addition, the findings underline the fact that minimum tillage appears, at least under the local conditions, to be a very worthwhile practice providing multiple agronomic and environmental advantages.