Conservation Tillage under Variable Rainfall: Effects on Wheat Yield and Quality

In recent years, interest in conservation tillage (CT) has increased worldwide due to environmental concerns and input costs, particularly in semi-arid, rainfed systems where its effects on wheat grain yield (WGY) and quality traits (WQT) have become an important research focus. A field study was conducted from 2019 to 2021 in Ankara-Türkiye, under semi-arid rainfed conditions, using a randomized complete block design with three replications on low-organic-matter, calcareous, and slightly alkaline soils. The study investigated four tillage treatments: conventional tillage (CNV), two reduced tillage (RET) treatments (chisel, rotavator), and no-tillage (NOT). In 2020, a year with normal rainfall, CNV produced the highest WGY (1624 kg/ha), whereas in 2021, characterized by low rainfall, NOT resulted in the highest WGY (1767 kg/ha). As one of the CT methods, RET treatments yielded values between CNV and NOT in both years. The highest grain protein content (WGPC; 15.75%) was observed under NOT in 2020, while the lowest WGPC value (14.49%) was recorded under NOT in 2021. Among the other WQT, only hectoliter weight (HW) was significantly affected in the first year and was highest under NOT. In the second year, no statistically significant differences were observed in HW, thousand grain weight (TGW), or Zeleny sedimentation (ZS); however, these values were generally higher than in the first year, possibly due to differences in climatic conditions and reduced biotic stress. Under the conditions of this study, NOT showed a relative yield advantage in the drier year, suggesting its potential suitability for semi-arid environments where crop production depends on rainfall.