Effect of Nitrogen Application Methods on Crop Yield and Grain Filling Characteristics of Maize in Maize-Soybean Relay Strip Intercropping System Yield Component and Dry Matter Accumulation in Wheat Varieties with 9000 kg ha−1 Yield Potential in Sichuan Basin Effects of long-term no-tillage with straw mulch on photosyntheticcharacteristics of flag leaues and dry matter accumulation and translocation of winter wheat in dryland Effects of Drought Stress on Physiological Characteristics and Dry Matter Production in Maize Silking Stage