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Coordinated uptake and utilization of water and nitrogen (N) is important for high-yield and high-efficiency cultivation of winter wheat. The relationship between soil water consumption and N uptake and utilization has not previously been widely investigated. The purpose of this study was to examine the regulatory effects of different seeding rates with wide-space sowing on water consumption and N accumulation and translocation of winter wheat. A field experiment was conducted in the southeastern part of the Loess Plateau between 2016 and 2018, in which winter wheat was sown using the wide-space method (row spacing: 22–25 cm, and seedling bandwidth: 5–8 cm) and five seeding rates: 150, 225, 300, 375, and 450 kg seeds ha−1. The results showed that soil water consumption increased significantly with an increase in the seeding rate from 150–300 kg seeds ha−1, especially from the jointing to maturity stage of wheat growth. At 300 kg seeds ha−1, N translocation from the leaf and stem + sheath to the grains was significantly enhanced, which increased grain N accumulation. The maximum tiller number, water use efficiency, N uptake efficiency, and partial factor productivity from applied N were all recorded at a seeding rate of 300 kg seeds ha−1, thus, grain yield increased significantly by 6–18%. Correlation analysis showed that N accumulation from the sowing to anthesis stage, pre-anthesis N translocation, and the grain yield of winter wheat were closely related to total soil water consumption. Overall, the findings of this study have demonstrated that wide-space sowing of winter wheat at a 300 kg seeds ha−1 seeding rate improved the water use efficiency and N uptake efficiency, which in turn increased the tiller number and grain yield.

Deep ploughing and subsoiling are important management practices used for mitigating the risk of soil compaction under long term no-tillage or reduced tillage practices. These fallow tillage methods have been widely applied in the Loess Plateau region of China to improve soil water availability and preventing soil erosion. To investigate the effect of different tillage practices for increasing the production of winter wheat (Triticum aestivum L.) and their relationship with precipitation distribution in the semiarid southeast region of the Loess Plateau, a six-year field study was conducted from 2009 to 2015, using three tillage treatments: deep ploughing (DP), subsoiling (SS), and no-tillage (NT). Our results indicated that DP and SS treatments increased soil water storage in the 0–300 cm soil layer at sowing and soil organic carbon in the 0–20 cm soil layer at maturity. In addition, DP and SS increased soil water consumption in the 0–180 cm soil layer from sowing to anthesis, and in the 120–300 cm layer from anthesis to maturity of wheat. Furthermore, the DP and SS treatments significantly increased the root length, root surface area, and the number of root tips in the 0–80 cm and aboveground dry biomass at maturity. Additionally, DP and SS treatments increased the grain yield by 31% and 26%, precipitation use efficiency by 32% and 26%, and water use efficiency by 12% and 11% respectively, as compared with those of the NT treatments. Pearson’s correlation analysis showed that soil water consumption was significantly positively correlated with precipitation from sowing to jointing and anthesis to maturity. In addition, grain yield had a significant positive correlation with precipitation during the fallow season, particularly in the SS treatment. Moreover, grain yield was significantly positively correlated with soil water consumption in the 0–180 cm soil layer from sowing to jointing, and at 60–240 cm soil depth from jointing to maturity. In conclusion, under low precipitation, DP was more favorable for winter wheat than SS, whereas, under high precipitation, SS was more beneficial than DP.

Sowing date and seeding rate are critical for productivity of winter wheat (Triticum aestivum L.). A three-year field experiment was conducted with three sowing dates (20 September (SD1), 1 October (SD2), and 10 October (SD3)) and three seeding rates (SR67.5, SR90, and SR112.5) to determine suitable sowing date and seeding rate for high wheat yield. A large seasonal variation in accumulated temperature from sowing to winter dormancy was observed among three growing seasons. Suitable sowing dates for strong seedlings before winter varied with the seasons, that was SD2 in 2012–2013, SD3 in 2013–2014, and SD2 as well as SD1 in 2014–2015. Seasonal variation in precipitation during summer fallow also had substantial effects on soil water storage, and consequently influenced grain yield through soil water consumption from winter dormancy to maturity stages. Lower consumption of soil water from winter dormancy to booting stages could make more water available for productive growth from anthesis to maturity stages, leading to higher grain yield. SD2 combined with SR90 had the lowest soil water consumption from winter dormancy to booting stages in 2012–2013 and 2014–2015; while in 2013–2014, it was close to that with SR67.5 or SR112.5. For productive growth from anthesis to maturity stages, SD2 with SR90 had the highest soil water consumption in all three seasons. The highest water consumption in the productive growth period resulted in the best grain yield in both low and high rainfall years. Ear number largely contributed to the seasonal variation in grain yield, while grain number per ear and 1 000-grain weight also contributed to grain yield, especially when soil water storage was high. Our results indicate that sowing date and seeding rate affect grain yield through seedling development before winter and also affect soil water consumption in different growth periods. By selecting the suitable sowing date (1 October) in combination with the proper seeding rate of 90 kg ha–1, the best yield was achieved. Based on these results, we recommend that the current sowing date be delayed from 22 or 23 September to 1 October.

To identify more carbon (C)-friendly agricultural technology, we studied the coupling impact of film mulching during summer fallow and sowing method on carbon footprint (CF) of dryland winter wheat (Triticum aestivum L.) on the Loess Plateau. From 2011 to 2014, a two-factor split block design was conducted with the following treatments: water-permeable film mulching in the summer fallow season (FM) or no mulching in the summer fallow season (FM0) with either conventional drill sowing (DS) or drill sowing beside a common film (DSF). The greenhouse gases (GHG) emissions associated with agricultural inputs were 7013.3, 5908.3, 5298.5, and 4193.5 kg CO2-eq·ha−1·yr−1 for FM × DSF, FM0 × DSF, FM × DS, and FM0 × DS treatments, respectively, which contributed >80% of total GHG emissions during the winter wheat production. Fertilizer, especially P2O5 fertilizer, was the largest contributor to GHG emissions from agricultural inputs. The CF of dryland winter wheat was 1.14 to 3.60 kg CO2-eq kg−1, which was the lowest under the FM × DS treatment while the largest under the FM × DSF treatment. Film mulching during summer fallow with drill sowing (FM × DS) could be a C-friendly technology for winter wheat production on the Loess Plateau.

Soil physical properties are a greatly important part of the soil and indicator of soil quality, which can directly affect soil nutrient turnover and crop yields in dryland. This study was carried out with three tillage practices during the summer fallow season since 2011, including no tillage (NT), plow tillage (PT), and subsoiling (ST) in dryland winter wheat fields of the Loess Plateau. Results showed that soil tillage during the summer fallow had a small effect on soil bulk density (ρ b) in the 0–50-cm soil profile before sowing and after harvesting of winter wheat. Soil ρ b under NT at a depth of 20–30 cm was significantly greater than those under PT in both seasons. Both soil gravimetric water content (θ g) and volumetric moisture content (θ v) after harvesting increased by 28.8–78.6% and 37.5–87.3%, respectively, compared with those before sowing. Adoption of PT significantly increased soil θ g and θ v in the entire 0–50-cm profile before sowing compared with NT and ST (P

Dryland winter wheat in the Loess Plateau is facing a yield reduction due to a shortage of soil moisture and delayed sowing time. The field experiment was conducted at Loess Plateau in Shanxi, China from 2012 to 2015, to study the effect of subsoiling and conventional tillage and different sowing dates on the soil water storage, Nitrogen (N) accumulation, and remobilization and yield of winter wheat. The results showed that subsoiling significantly improved the soil water storage (0&ndash, 300 cm soil depth) and increased the contribution of N translocation to grain N and grain yield (17&ndash, 36%). Delaying sowing time had reduced the soil water storage at sowing and winter accumulated growing degree days by about 180 &deg, C. The contribution of N translocation to grain yield was maximum in glume + spike followed by in leaves and minimum by stem + sheath. Moreover, there was a positive relationship between the N accumulation and translocation and the soil moisture in the 20&ndash, 300 cm range. Subsoiling during the fallow period and the medium sowing date was beneficial for improving the soil water storage and increased the N translocation to grain, thereby increasing the yield of wheat, especially in a dry year.

Sustainability of winter wheat yield under dryland conditions depends on improving soil water stored during fallow and its efficient use. A 3-year field experiment was conducted in Loess Plateau to access the effect of tillage and N (nitrogen) rates on soil water, N distribution and water- and nitrogen-use efficiency of winter wheat. Deep tillage (DT, 25–30 cm depth) and no-tillage (NT) were operated during fallow season, whereas four N rates (0, 90, 150 and 210 kg ha−1) were applied before sowing. Rates of N and variable rainfall during summer fallow period led to the difference of soil water storage. Soil water storage at anthesis and maturity was decreased with increasing N rate especially in the year with high precipitation (2014–2015). DT has increased the soil water storage at sowing, N content, numbers of spike, grain number, 1,000 grain weight, grain yield, and water and N use efficiency as compared to NT. Grain yield was significantly and positively related to soil water consumption at sowing to anthesis and anthesis to maturity, total plant N, and water-use efficiency. Our study implies that optimum N rate and deep tillage during the fallow season could improve dryland wheat production by balancing the water consumption and biomass production.