Interplanting of Three Lupine Cultivars with Orange Trees at Three Lupine Planting Densities in Sandy Soil

Background and Objective: Interplanting legumes with orchards is a popular practice on newly reclaimed soils. A field trial was conducted at the newly reclaimed soils of East of Suez Canal Horticulture Research Station, Agricultural Research Center (ARC), North Sinai Governorate, Egypt. The study aimed to identify the optimal plant density for three lupine cultivars when interplanted with orange trees in sandy soil to enhance crop productivity, land use efficiency and profitability. Materials and Methods: The 18 treatments were formed by combining three lupine cultivars (Giza 1, Giza 2 and Giza 3) with three planting densities (50.0, 62.5 and 75.0% of the recommended sole lupine density) under interplanting and sole plantings. The treatments were arranged in a strip split-plot design with three replicates. The two cropping systems were assigned in the vertical strips, the three lupine plant densities were assigned in the horizontal strips and the three lupine cultivars were distributed in the sub-plots. Results: Interplanting negatively affected the seed yield and yield components of lupine compared with sole plantings. However, the seed yield/fad increased with increased lupine plant density. The Giza 3 showed higher productivity than the other two cultivars. The productivity of orange trees increased when the plant density was 75.0% of the recommended sole lupine. Additionally, there was an increase in the productivity of orange trees with Giza 3 compared to the other two cultivars. Conclusion: Interplanting 6 ridges of Giza 3 with orange trees achieved high productivity of both crops, efficient land usage and profitability under sandy soil conditions.