Influenced of Planting Distance and Fertilization on the Production Performance of Select Manchuria Soybean (Glycine max (L.) Merrill) in Tupi, South Cotabato

Abstract

Soybean considered one of the largest food protein sources, soybeans are widely used for industrial purposes, and most soybean oil meal is used for animal feed. A series of experimental studies on the varietal adoption in some places in the Philippines, the development of a package of technology to increase yield performance was conducted. The study was conducted at Tupi, South Cotabato, from January 8 to April 7, 2025. The purpose of the study was to determine yield performance of Manchuria Select soybean relative to the planting distance and fertilization rates applied. The study carried out using Split Plot Randomized Complete Block Design (RCBD). Factor A as main plot with three (3) different planting distances while Factor B as sub-plot with fertilization composed of 4 treatments replicated 3 times. The effects of the two factors relative to the yield performance of Manchuria select soybean were not significantly different relative to plant height, number of plants harvested per plot, number of unfilled pods, number of seeds per pod, weight of 100 seeds, seed yields per plot, computed seed yield per hectare, shattering and lodging. However, the number of pods per plant and the number of filled pods were significantly influenced by both the planting distance and with no significance difference on the fertilizer applied. A significant effect on the interaction of planting distance shows that plants planted in wider spacing and full inorganic fertilization together promote the best pod development. Additionally, similar trends were observed for the number of filled pods relative to the effect in terms of planting distance and fertilizer applied.

The study concludes that Select Manchuria soybean planted in the closest spacing at A₁ (50cm x10 cm), combined with B₂ (100% Inorganic) and B4 (50% organic + 50% inorganic) fertilizers consistently produced higher yields with comparable results A₂ (40cm x10 cm). On the other hand, soybean planted on the widest spacing at A₃ (70cm x10 cm) underperformed in yield metrics despite relatively good seed weights. On the other hand, soybean planted on the widest spacing at A₃ (70cm x 10 cm) underperformed in yield metrics despite relatively good seed weights. The findings indicate that 100% inorganic fertilization at 50 cm × 10 cm spacing is the most economically viable option, offering the highest yields, net income, and ROI. While 100% organic fertilization aligns with environmentally sustainable goals, it is less profitable and more costly, especially when used exclusively. The combination treatment presents a viable compromise, with moderate costs and returns, potentially suitable for integrated sustainable farming practices. Furthermore, planting distance plays a critical role, with closer spacing significantly improving productivity and profitability.