抽象的な

Placement of Nutrients in Soil: A Review

K Radhika, S Hemalatha, S Maragatham, and S Praveena Kathrine

Placement of nutrients and fertilizer rates are important factors to be considered to produce maximum yield of crops. Particularly deep placement of nutrients might be beneficial to crop growth. Increased early growth has been observed with deeper P placement as well as by deep band placement of K when compared to broadcast application. The method of N, P and K placement has typically been found effective over broadcasting on the top of the soil, and it is also influenced by the amount of water used for irrigation. Normally fertilizers are broadcasted. Many a time, straight fertilizers are used as the source of nutrients. In order to manage the losses with these highly soluble fertilizers split application is recommended, particularly for urea. However, the entire quantity of P and K is applied basally at the time of sowing. Due to variations in their solubility and kinetics, the added nutrients are found to be available to plants at varying rates in different soils. In order to achieve the expected yields a comprehensive technology is required that can demonstrate an efficient use of added nutrients and irrigation water. Other than crop improvement aspects, this would be possible by switching over to nutrient management that employs methods like deep placement of fertilizer nutrients. Deep placement if can be done with simple tools and incidentally aim in the reduction in labour requirement then farmers can prefer to adopt easily. The literature pertaining to methods of fertilizer application on nutrient availability, response of maize and other crops to applied nutrients and nutrient use efficiency are reviewed.