The ridge-furrow with plastic film mulching (RF) system has been widely adopted in rain-fed crop planting due to its potential to enhance crop yield and water use efficiency. However, the impact of the RF system on maize lodging resistance, particularly when nitrogen fertilizer is applied, remains uncertain. Therefore, a two-year field experiment was carried out with two planting systems (FP: flat planting and RF) and two nitrogen application rates (N180: 180 kgN ha-1 and N300: 300 kgN ha-1) to assess the risk of lodging in maize. The results showed that compared to FP, RF resulted in a significant increase of 78.7% in lodging rate. In addition, the lodging rate increased by 22.6% with increasing nitrogen fertilizer application. The lignin content increased by 43.4%, while the stalk bending strength rose by 42.5%, under RF compared to the FP system. These improvements in the mechanical properties of maize stalks contributed to the improved lodging resistance index of RF, which was found to be approximately 21.3% higher than that of FP. In addition, high nitrogen application rates increased the risk of lodging for different planting patterns over two years. In conclusion, fertilization of spring maize with 300 kgN ha-1 under the RF system led to higher yields but increased lodging rates. The risk of lodging should be considered when planting maize under the RF system. The results of this study can provide scientific basis and technical support for the optimization of rain-fed maize cultivation measures in the Loess Plateau.

Addressing the negative impacts of lodging on crops is a global topic, but it is not clear whether and how straw and its derivatives positively affect the lodging resistance, yield, and quality of spring maize in rainfed areas. Therefore, a field experiment with three organic amendments, straw (at 9000 kg ha(-1)), cattle manure (at 7140 kg ha(-1)), and biogas residue (at 6554.52 kg ha(-1)), was set up in a typical rainfed area with film mulching. The results showed that straw and its derivatives significantly improved the mechanical properties of the third internode by improving the cellulose and lignin contents and their related synthase activities, which resulted in a significant increase in the stalk lodging-resistant index by 3.65 similar to 7.23% (P < 0.05); contributed to a deeper and longer root system that significantly improved root pulling force by 1.41 similar to 4.75%, further enhancing the positive correlation between root in the secondary zone and root lodging resistance; and improved the 1000- kernel weight, content of crude fat and crude protein by constructing a lush above-ground population, which significantly increased the grain yield by 5.95 similar to 13.22%. Among them, the performance of biogas residue fermented by both anaerobic and composting was better than that of other treatments, which provided an informative organic solution for synchronizing the spring maize lodging resistance and yield increase.