Effects of Soil Tillage Practice on Dry Matter Production and Water Use Efficiency in Wheat

The objective of this study was to understand the effects of tillage practice on water consumption characteristics and dry matter accumulation and distribution in wheat (Triticum aestivum L.) plant under high-yielding and flexible irrigation conditions. In a fixed position experiment across 3 growing seasons from October 2007 to June 2010, only one wheat cultivar, Jimai 22, was planted in the field. In the 2007–2008 wheat season, 5 tillage treatments were designed, which were strip rotary tillage (SR), strip rotary tillage after subsoiling (SRS), rotary tillage (R), rotary tillage after subsoiling (RS), and plowing tillage (P). The same treatments were arranged in the same field plots in the 2008–2009 and 2009–2010 wheat seasons, except that SRS and RS had no subsoiling. All tillage treatments were irrigated at sowing, jointing, and anthesis stages to designed soil water content based on testing soil moisture before watering. The total water consumption was higher in SRS and RS treatments than in SR and R treatments. Treatment SRS increased the amount of soil water consumption in 0–200 cm soil layers but decreased the soil evaporation, compared to other treatments. Treatments SRS and RS gained the highest amount of dry matter accumulation, grain dry matter partitioning at maturity, and contribution to grain of dry matter assimilation after anthesis, followed by treatment P, and treatments R and SR showed the lowest levels in the above parameters, particularly SR. In the experiment across 3 years, SRS obtained the grain yields of 9409.01 kg ha⁻¹ in 2008, 9613.86 kg ha⁻¹ in 2009, and 9698.42 kg ha⁻¹ in 2010, which were equivalent to that of RS but significantly higher than other treatments. Treatments P and R also exhibited higher yield level than SR treatment. In the 2008–2009 and 2009–2010 growing years, the water use efficiencies of SRS treatment were the highest among treatments, which were 21.39 kg ha⁻¹ mm⁻¹ and 22.09 kg ha⁻¹ mm⁻¹, respectively. Treatment RS also had higher water use efficiency than SR, R, and P treatments. Therefore, SRS is recommended as the optimal tillage practice in high-yielding and water-saving production system in the Yellow-Huai-Hai River Valleys Plain.