Effects of straw returning with potassium fertilizer on the stem lodging resistance, grain quality and yield of spring maize (Zea mays L.)
The effects of straw returning with potassium fertilizer on the stem lodging resistance, grain quality and yield of spring maize were investigated to provide a scientific basis for the rational utilization of Inner Mongolia spring maize straw and potassium fertilizer resources. This study utilized Xianyu 335 as the test material, and a split plot design was carried out in three ecological regions from eastern to western Inner Mongolia (Tumochuan Plain irrigation area, Hetao Plain irrigation area and Lingnan warm dry zone), with the straw returning method as the main plot and potassium fertilizer dosage as the subplot. The stem resistance index, grain quality and yield were systematically identified. Both application of potassium fertilizer and straw returning improved the resistance and yield indicators of spring maize. Straw returning increased the effectiveness of potassium fertilizer application on spring maize plant height, ear height, fresh weight of stems, brix of stems and stem puncture strength by 2.82%-5.22%, 3.11%-5.90%, 15.96%-19.78%, 4.35%-4.50% and 8.89%-14.82%, respectively. Straw returning increased the effectiveness of potassium fertilizer application on the spring maize grain protein content, spring maize grain crude fat content, maize yield and yield variation coefficient by 3.49%-6.50%, 2.09%-4.43%, 4.87%-12.50% and 5.07%-7.55%, respectively. Straw returning can be combined with reasonable application of potassium fertilizer to increase the effectiveness of potassium fertilizer and enhance lodging resistance. Along with increased maize yield, straw returning also improves grain quality and enhances yield stability, providing a theoretical basis for high-yield and stress-resistant cultivation of Inner Mongolia spring maize, which can be popularized and applied in the spring maize planting areas of Inner Mongolia.