Effect of Soil Reaction (Soil pH) on the Rhizosphere Soil, Growth and Yield Performance of Root and Tuber Crops (RTCs) Production: A Review.

Root and tuber crops play a crucial role in global food security, providing a significant source of nutrition and income for millions of people. The rhizosphere, the zone of soil surrounding the plant roots, is a dynamic environment that strongly influences crop growth and development. One critical factor that affects the rhizosphere's functionality is soil reaction, commonly represented by pH levels. This research reviewed the effects of soil pH on the rhizosphere soil, growth, and yield performance of root and tuber crops production. To achieve this, a review of soil pH levels of root and tuber crops was carried out focusing on the key roots and tuber crops such as cassava, sweet potato, potato, yam, and cocoyam etc. Their different soil pH level was observed and noted. It was observed that soil reaction significantly influenced the rhizosphere's physicochemical properties, including nutrient availability, microbial activity, and soil structure. Altered pH levels affected the uptake of essential nutrients, which consequently impacted plant growth and development. Higher or lower pH levels disrupted the balance of nutrients, leading to reduced root and tuber crop yields. Furthermore, soil pH also influenced the rhizosphere's microbial community composition and diversity. Acidic or alkaline conditions affected beneficial microbial populations, such as mycorrhizal fungi and nitrogen-fixing bacteria, leading to potential nutrient deficiencies and reduced plant vigour. In conclusion, maintaining an optimal soil pH in the rhizosphere and soil management practices are essential for maximizing the growth and yield performance of root and tuber crops. Keywords: Soil pH, Rhizosphere soil, Cassava, Sweet Potato, Potato, Yam, Cocoyam