Molecular Soil Biology 2024, Vol.15, No.5, 216-226 http://bioscipublisher.com/index.php/msb 219 microbial diversity, which in turn promotes higher soybean yields (Wei et al., 2023). Effective nutrient management strategies, including the use of organic amendments like farmyard manure (FYM) and micronutrients, can maintain soil fertility and support sustainable soybean production (Chaturvedi et al., 2012). 3.4 Challenges of over-fertilization Over-fertilization poses significant challenges to soil health and the environment. Excessive application of nitrogen fertilizers can lead to nutrient imbalances, reduced plant growth, and lower yields, particularly in the absence of drought conditions (Basal and Szabó, 2020). High rates of fertilization can also result in nutrient leaching, soil acidification, and contamination of water bodies, leading to environmental degradation (Santachiara et al., 2019). Additionally, overuse of fertilizers can disrupt soil microbial communities, reducing soil fertility and affecting long-term agricultural sustainability (Wei et al., 2023). Therefore, it is essential to adopt balanced fertilization practices and integrate organic and inorganic nutrient sources to mitigate the adverse effects of over-fertilization (Chaturvedi et al., 2012). 4 Soil Types and Soybean Growth 4.1 Overview of soil types in agricultural systems Soybean cultivation is influenced by various soil types, including sandy, clay, and loamy soils. Sandy soils, characterized by large particles and low water retention, are often found in regions with high drainage capacity but may require frequent irrigation (Jahan et al., 2020; Suriadi et al., 2021). Clay soils, with fine particles and high water retention, can support soybean growth but may pose challenges in terms of drainage and root penetration (Hati et al., 2006; Çalişkan et al., 2008). Loamy soils, a balanced mixture of sand, silt, and clay, are considered ideal for soybean cultivation due to their optimal water retention and nutrient availability properties (Lasisi and Aluko, 2009; Arora et al., 2011). 4.2 Soil physical properties and their influence on water and nutrient retention Soil texture significantly impacts water retention and nutrient availability. Sandy soils, due to their coarse texture, have low water retention and nutrient-holding capacity, necessitating frequent irrigation and fertilization (Jahan et al., 2020; Suriadi et al., 2021). Clay soils, with their fine texture, retain water and nutrients well but can become waterlogged, affecting root growth and nutrient uptake (Hati et al., 2006; Çalişkan et al., 2008). Loamy soils offer a balanced texture that provides adequate water retention and nutrient availability, supporting optimal soybean growth (Lasisi and Aluko, 2009; Arora et al., 2011). The addition of organic amendments like biochar can improve water retention and nutrient availability in both sandy and clay soils (Jahan et al., 2020). 4.3 Soil chemistry and its impact on soybean nutrition Soil chemistry, including pH, organic matter content, and cation exchange capacity (CEC), plays a crucial role in soybean nutrition. Optimal soil pH for soybean growth ranges from 6.0 to 7.0, as extreme pH levels can hinder nutrient availability and uptake (Çalişkan et al., 2008). Organic matter enhances soil structure, water retention, and nutrient supply, promoting better root development and nutrient absorption (Hati et al., 2006). High CEC in soils, particularly in loamy and clay soils, improves the soil's ability to retain essential nutrients like potassium, calcium, and magnesium, which are vital for soybean growth (Lasisi and Aluko, 2009; Arora et al., 2011). 4.4 Case studies from different agro-ecological zones Several case studies highlight the impact of soil types, irrigation, and fertilization on soybean growth. In tropical sandy loam soils, conventional tillage methods significantly improved soybean growth and yield compared to no-tillage methods (Lasisi and Aluko, 2009). In Lombok, optimal irrigation schedules varied across soil types, with sandy loam soils requiring more frequent irrigation to achieve the highest yields (Suriadi et al., 2021) (Figure 2; Table 1). The use of biochar amendments in sandy loam and clay loam soils under moisture deficit conditions improved soybean physiological and yield attributes (Jahan et al., 2020). In Western São Paulo, Brazil, cover crops and nitrogen management in sandy soils previously under degraded pastures significantly increased soybean yield (Cordeiro et al., 2021). In Mediterranean-type soils, the combination of nitrogen and iron fertilization improved soybean growth and yield, particularly in soils with high pH and bicarbonate levels (Çalişkan et al.,
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