Long-term winter wheat cropping influence on soil quality and yield stability

Abstract

In the past Century, wheat cropping has not undergone significant changes compared with row crops while the higher input of the agricultural chemistry insufficiently contributed to the yield increase. Along with this, high yielding varieties of winter wheat were continually grown. Therefore, there is a need to consider the relationship between soil quality, environmental effects and winter wheat yield stability. To access the wheat- based cropping effects, data was used from a long-term experiment (LTE) “Crop Rotation” located at the Rimski Šancevi experimental field of the Institute of Field and Vegetable Crops in Novi Sad (N 45° 19', E 19° 50'). The original experimental plots were set up in 1946/47, and modified in 1969/70. It consists of a different crop rotations and monoculture of winter wheat including different fertilization options. Long-term mouldboard tillage has influenced physical soil properties and particularly altered soil structure. As a consequence of sufficient fertilization, the considerable content of available P2O5 (24-63 mg 100g soil-1) and K2O (33-39 mg 100g soil-1) were present in the topsoil. In contrary, unfertilized plots were not sufficiently supplied with the available P but maintained available K content. Soil organic carbon (SOC) decreased because of soil inversion tillage to 65% of the original content observed at the begging of the experiment. Likewise, SOC equilibrium at the unfertilized plots was established after 25 years of the experiment running. Winter wheat monoculture was higher in the content of total N and soil organic carbon (>16 g kg-1), which could be explained with preservation of physical soil properties and available water. By analyzing the long-term yields, it was found that there is certain stability in yields at some level and relatively small annual variation. In a time span of the experiment management yield of winter wheat decreases at the 3-year rotation while wheat monoculture increase yield over time. Hence, most stabile wheat yield was observed at the 3-year rotation suggesting important role of the preceding crops and legumes (soybean) in rotation. This study could contribute to gain awareness of winter wheat role in a cropping systems of the temperate climate and to understand the relationship between wheat based cropping and soil properties.