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Long-term rotary tillage negatively affects the soil plow layer, and subsoiling is an effective engineering measure to improve the structure of the soil plow layer. A double cropping system with winter wheat and summer maize is commonly practiced in the North China Plain (NCP). Three different tillage treatments, viz., rotary tillage at 15 cm (RT15) as control, and subsoiling at depths 35 cm (SS35) and 40 cm (SS40) were carried out during the 2017–2019 summer maize growing seasons, before winter wheat planting. We determined these tillage treatments on chlorophyll content index (CCI), leaf area index (LAI), net photosynthetic rate (Pn), transpiration rate (Tr), and grain yield (GY) across three seasons. Subsoiling treatments significantly increased the CCI, LAI, Pn, Tr and water-use efficiency of leaves (WUEL), resulting in higher GY. Compared to the plants grown in the SS40 group, the CCI and LAI were improved during the late growth stages, kernel numbers per row and 1000-grain weight of plants in SS35 were significantly higher, thereby improving GY (by 2.87%) and WUEL (by 6.61%). These results suggest that subsoiling to a depth of 35 cm improved photosynthetic characteristics and water use efficiency of summer maize in the NCP. [ABSTRACT FROM AUTHOR]

Agricultural practices that are water-saving and high-yielding are vital to sustainable development. We investigated two planting patterns and two tillage methods in four winter wheat growing seasons in North China Plain (NCP). They're conventional tillage (CT) and no-tillage (NT) under wide-precision planting (W) and conventional planting (C). Soil water content, dry matter accumulation (DM), grain yield (GY), chlorophyll content index (CCI), photosynthetic rate (Pn), transpiration rate (Tr), and photosynthetic active radiation (PAR) interception were determined. We found W significantly increased the CCI, PAR interception, DM, and spikes number compared with C. The soil water content in 20–90 cm soil layer under NT was higher than that under CT. Both maximum water use efficiency of leaves (WUEL) and radiation use efficiency (RUE) were significantly greater under W compared with C, resulting in a higher GY. Furthermore, the Pn and spikes number were significantly higher under CT than under NT, with crop GY being higher under CT than under NT. However, the combination of NT and W showed higher WUEL and RUE that were not significantly different among treatments from NT to CT. Furthermore, the highest DM and RUE were observed in NTW treatment, with W compensating for the adverse effect of NT. [ABSTRACT FROM AUTHOR]

Summer maize (Zea mays L.) is a globally essential food crop. To find the optimal mulch for summer maize, we explored the photosynthetic characteristics and yield of maize under different mulches. Four treatments were used during the 2016–2018 summer maize growing seasons: no mulch (CK), transparent film mulch (PF), biodegradable transparent film mulch (WF), and biodegradable black film mulch (BF). Thirty days after mulching, soil temperatures decreased in the order WF>PF>BF>CK. In all growing seasons, the chlorophyll content index (CCI) of maize was highest with BF. In 2016, the CCI with BF was 17.3%, 8.2%, and 13.2% higher than that with CK. At the flowering and filling stages, the net photosynthetic rate was highest with BF and lowest with PF. Meanwhile, the leaf water-use efficiency at the filling stage was 12.7% and 15.1% higher with BF than that with CK in 2017 and 2018, respectively. The 1000-kernel weight with BF was 8.9% and 2.5% higher than that with CK in 2016 and 2017, respectively, and the GY was 14.8% and 10.2% higher. These results indicate that biodegradable black film mulching is a feasible measure to improve the photosynthetic capacity and yield of maize in the North China Plain. [ABSTRACT FROM AUTHOR]

To examine the effects of winter wheat genotypes on dry matter (DM) accumulation and grain yield (GY) under no-tillage conditions in North China Plain (NCP), a field experiment was conducted using the genotypes Tainong 18 (F) and Jimai 22 (J). Two tillage systems were tested, conventional tillage (CT) and no-tillage (NT) during the 2015/2016 and 2016/2017 winter wheat growing seasons. Genotypes and tillage systems were compared regarding DM accumulation, GY, leaf area index (LAI), photosynthetic active radiation (PAR) interception, and flag leaf fluorescence parameters. LAI, PAR interceptions, and flag leaf fluorescence parameters were significantly higher under CT than under NT conditions. This suggests that the efficiency of light harvesting by the PSII reaction center of leaves can increase due to CT. DM accumulation was significantly higher under CT than under NT. Spike DM accumulation was higher in F than in J in the heading and the filling stages. In both growing seasons, GY was significantly higher under CT than under NT, GY of NTF was significantly higher than that of NTJ, which was due to a significantly higher number of kernels per spike. This indicates that genotype F can compensate for a low GY due to NT. [ABSTRACT FROM AUTHOR]