Spatial variations in soil water storage (SWS) in 0–120 cm soil layers at 20 cm interval.

<p><b>(A)</b> SWSin2012 and <b>(B)</b> SWSin2014. Bars indicate standard errors (SE) at <i>P</i>< 0.05.</p

Yield response of spring maize to subsoiling depth and soil water deficit.

<p><b>(A)</b> Relationship between grain yield and subsoiling and <b>(B)</b> between biomass yield and subsoiling depth was fitted to a modified power function (<i>P</i>< 0.01);<b>(C)</b> relationship between grain yield and soil water deficit (SWD) and <b>(D)</b> between biomass yield and SWD was fitted to a fitted to a negative linear correlation (<i>P</i>< 0.01). AS: annual subsoiling; BS: biennial subsoiling.</p

Comprehensive assessment for different tillage treatments using water- and yield-related data standardized in a range of 0 to 1 to compare treatment effects quantitatively.

<p>Comprehensive assessment for different tillage treatments using water- and yield-related data standardized in a range of 0 to 1 to compare treatment effects quantitatively.</p

Daily and cumulative precipitation (mm) from April to September in (A) 2012 and (B) 2014, at Jiaozuo Experiment Station, China.

<p>Vertical drop lines represent daily precipitation, and curve lines stand for cumulative precipitation.</p

Soil water deficit (SWD) for each treatment, separated by growth stages.

<p><b>(A)</b> SWD in 2012, and <b>(B)</b> SWD in2014. The horizontal lines across the Fig indicate soil water deficit = 0, while the bars indicate standard errors at <i>P</i>< 0.05 (SE).</p

Seasonal schedule of crop growth stages, pre-planting irrigation and inter-row subsoiling for spring maize in the field experiment.

<p>The date in the figure was recorded when more than three quarters (>75%) of the crops developed into the particular growth stage.</p

Physical properties and taxonomic classification of the studied soils prior to the start of the experiment, at Jiaozuo experiment station, northern China.

<p>Physical properties and taxonomic classification of the studied soils prior to the start of the experiment, at Jiaozuo experiment station, northern China.</p