Global agricultural systems are predominantly concentrated in regions characterized by fertile soils, abundant precipitation, and gentle slopes. However, a significant proportion of farmland is situated in areas with poor soil quality, arid conditions, and steep slopes. In such challenging environments, particularly sandy-arid sloping farmlands, selecting native crops that are well-adapted to local conditions is critical for sustainable agricultural practices. This study categorizes local crops in arid regions into four distinct types: tall-stem monocotyledonous plants (represented by maize, Zea mays L.), short-stem monocotyledonous plants (represented by millet, Setaria italica), tap-rooted dicotyledonous plants (represented by soybean, Glycine max (L.) Merr.), and tuberous dicotyledonous plants (represented by potato, Solanum tuberosum L.). A quantitative evaluation framework was developed using five key indices: nitrogen fixation, anti-wind erosion, roots reinforcement, anti-water erosion, and water conservation. These indices were used to calculate the suitability index values for each crop type. The findings revealed that in sandy-arid sloping farmland regions, maize and millet emerged as the most suitable crops for cultivation, followed by soybean, while potato was identified as the least suitable. Maize exhibited high values across all five indices, particularly demonstrating exceptional performance in nitrogen fixation. Additionally, the study demonstrated that traditional farming practices are highly effective in sloping farmlands, since they not only promote crop growth but also mitigate soil erosion. This research offers insights into agricultural management in regions affected by drought, soil erosion, and steep terrain. The results highlight the feasibility of employing traditional farming methods to cultivate maize in such challenging environments, providing practical guidance for sustainable agricultural development.