Effects on Wheat Root Growth and Development of Rhizosphere Environment and Stress Factors

Abstract

Plant roots directly ensuring shoot growth and development on soil surface play a significant role for obtaining high yielding and quality products in plant production. Winter wheat root has 2.2 meter depth in rhizosphere as twice as spring wheat due to early planting. Rhizosphere conditions such as available water and fertilizer, soil temperature, soil texture, soil air and other physical and chemical properties of soil and biotic factors affect root growth and development. In 50 cm depth of soil, temperature is above 0 ^°C and but where root zone is close to upper soil appears plant nutrient deficiency in early season because plant nutrient elements and water uptake are not acquired from soil. In early season, water and nitrogen are acquired due to large root system that is important for drought tolerant crops, but in late season water is acquired for grain filling. Ideal field soil should include 25 % air, 25 % water, 45 % inorganic matter and 5 % organic matter for high harvest yield. When excessive water results from decrease in oxygen and increase in CO₂ concentration, root growth and development causes to decrease in soil. However, weather condition, genotype and cultural practices allowing shoot growth also change rhizosphere environment through directly application of water and fertilizers to soil or translocation to root and assimilation of photosynthetic products. Root growth slows and ceases because photosynthetic products translocate to seed after stage of flowering. As a result, wheat growers can get high yield and quality products with adapted varieties through changing root zone environment with cultural practices before complete of flowering.