Impact of tillage, seeding rate and seeding depth on soil moisture and dryland spring wheat yield in Western Siberia

Dryland crop production in the Western Siberian grain belt is an important contribution to Russia's growing importance as a global wheat supplier. After the break-up of the Soviet Union significant changes in agricultural structures with recent intensification on cropland took place. Together with climate change predictions of drier and warmer growing conditions, this leads to upcoming challenges for water-limited crop production in the south of the Asian part of the Eurasian grain belt. A full-factorial field trial was conducted on a farmer's field to test adaptations of tillage (usual conventional tillage ‘CT’ vs. no-till ‘NT’), seeding depth (usual deep 6.5cm vs. shallow 4.5cm) and seeding rate (usual high 600grainsm−2 vs. reduced 450grainsm−2) for potential to increase water use efficiency and grain yield in spring wheat. Results from two above-average wet and cold growing seasons showed significant better soil water storage of NT (+40%) and no adverse effect on spring wheat grain yield and grain quality for the study site in the south of Western Siberia. Variations in seeding rate of the regional variety were compensated by different manifestation of the individual yield components: high seeding rates resulted in more reproductive ears per m2 whilst reduced seeding rates produced more grains per ear. The traditional deep seed placement was found to be beneficial for NT but shallow placement was advantageous with CT. The highest yields of 3.19 and 3.82tha−1 were observed in 2014 with NT, deep seed placement and high seeding and in 2015 with NT, deep seed placement and reduced seeding rate, respectively. The on-farm field trial results revealed, that NT can be successfully used in dryland cropping under current agro-climatic conditions of Western Siberia and is a promising perspective under climate change predictions.