Optimizing Tillage and Fertilization Patterns to Improve Soil Physical Properties, NUE and Economic Benefits of Wheat-Maize Crop Rotation Systems

Winter wheat and summer maize rotation is the main cropping pattern in the North China Plain (NCP). There are still problems with farmers’ production modes, including shallow tillage layers, single application of chemical fertilizer causing plow bottom layer thickening and soil pH decrease. A two-factor location experiment was conducted to investigate the effects of different tillage and fertilization patterns on the soil physical properties, soil organic carbon (SOC), nitrogen-use efficiency, and crop yield of wheat–maize rotation systems during the years 2018–2020. The different treatments were deep tillage + organic fertilizer (DTF), shallow tillage + organic fertilizer (STF), no tillage + organic fertilizer (NTF), deep tillage + nitrogen fertilizer (DT), shallow tillage + nitrogen fertilizer (ST), and no tillage + nitrogen fertilizer (NT). The results showed that STF treatment could effectively improve the physical properties of soil and, SOC content, and increase both the crop yield and revenue of farmers. In the STF treatment, soil water content was highest in the 0–20 cm layer (2018), which was 4.89–11.31% higher than that of the other treatments; additional organic fertilizer application reduced soil bulk and increased the proportion of <0.25 mm aggregates; SOC and soil total nitrogen (TN) content were highest in the 20–40 cm layer, (15.82–32.63% and 28.57–42.86%, respectively). The total yield of wheat–maize rotation for both years was the highest under STF treatment. The annual economic benefits under this treatment were 42,182.26 and 42,254.54 CNY ha−1, which were 1.02–12.94% and 2.29–9.87% higher than those of the other treatments. Therefore, the suggested planting method in the NCP is tillage of over 20 cm and additional organic fertilizer.