Effectiveness of organic fertilizer on root performance and nutrient uptake of soybean in agroforestry system

Abstract

The global population is projected to reach 9.7 billion by 2050, leading to a 70% increase in food demand, including soybean as a significant protein source. Climate change exacerbates soybean productivity with environmental stress, which can reduce yields by up to 13.5%. Pine-based agroforestry systems with organic fertilizer application offer a sustainable solution through improved soil quality and biodiversity. This study aims to evaluate the effectiveness of four types of fertilizers, namely, inorganic fertilizer, natural dye waste (Indigofera tinctoria), corn cob waste, and peanut green manure in supporting the cultivation of soybean variety Dena 1 in agroforestry systems. The research was conducted at Alas Bromo, Karanganyar, Central Java, using a randomized complete block design (RCBD) with 20 experimental units. Parameters observed included the number of leaves, plant leaf area, leaf area index, specific leaf area, root length, root dry weight, number of root nodules, root crown ratio, and nitrogen, phosphate, and potassium uptake. ANOVA and DMRT further test analyzed data. The results showed that groundnut green manure (P4) gave the best contribution, such as increasing the number of leaves (19.40 strands), specific leaf area (82.76 cm2/g), root lenght (16.64 cm), and nutrient uptake (N = 12.45 mg, K = 5.02 mg). This study concludes that peanut green manure is most effective in supporting soybean growth. Good soybean growth can support sustainable soybean productivity in pine-based agroforestry systems.