Soybean Intercrop Enhances the Yield and Flavor Profile of Sweetcorn Grown in Alkaline Soil under Drought Condition

Declining corn yield in monoculture systems, along with soil analyses indicates increased alkalinity caused by excessive use of chemical fertilizers, which undermines the value of intercropping. A field experiment was conducted at Cebu Technological University-Barili Campus from on the driest months of the year (March to May), to evaluate the effects of different legume intercrop on the growth and development of sweetcorn (Zea mays L. Var. Macho-F1) grown in alkaline soil (pH 7.5). The experiment utilized a Randomized Complete Block Design (RCBD) with five treatments corresponding to different legume intercrop: T0 = Sweetcorn alone, T1 = Sweetcorn + Soybean (Glycine max), T2 = Sweetcorn + Rice bean (Vigna umbellata), T3 = Sweetcorn + Lima bean (Phaseolus lunatus), and T4 = Sweetcorn + String bean (Phaseolus vulgaris). The data gathered were plant height (cm) at 30 and 60 days after planting (DAP), ear height at 60 DAP (cm), ear length (cm), ear diameter (cm), weight with husk (g/ear), weight without husk (g/ear) and total soluble solids (◦Brix). Results showed no significant differences in plant height at 30 and 60 days DAP or ear height at 60 DAP. Sweetcorn intercropped with soybean produced taller corn plants (138.90±6.20 cm and 156.33±15.84 cm at 30 and 60 DAP, respectively) and highest ear height (49.23±5.72 cm at 60 DAP). No significant differences were found in ear length, ear diameter, or weight with husk. However, results demonstrated that sweetcorn intercropped with soybean consistently outperformed those intercropped with other legumes and sweetcorn monoculture. Intercropping sweetcorn with soybean resulted in the highest Total Soluble Solids value of 8.80±0.20SE (◦Brix), ear weight (126.73±28.57SE grams/ear), and computed yield (11.40±2.57 t/ha). Therefore, intercropping sweetcorn with soybean will increase its yield and improve its flavor profile, notwithstanding the supposed added income from the soybean intercrop.