Prediction of optimal nitrogen application rate of rice based on soil test values

• Published in: European journal of agronomy Vol. 25; no. 1; pp. 71 - 73
• Main Authors: Alivelu, K., Rao, A. Subba, Sanjay, S., Singh, K.N., Raju, N.S., Madhuri, P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2006; Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; cropping sequence; economic analysis; fertilizer rates; fertilizer requirements; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; grain yield; mathematical models; nitrogen; Nitrogen fertilization; nitrogen fertilizers; Nitrogen, phosphorus, potassium fertilizations; Optimum dose; Oryza sativa; plant nutrition; QRP (quadratic response plateau model); Quadratic model; Residual analysis; rice; seasonal variation; Soil test value; soil test values; Soil-plant relationships. Soil fertility. Fertilization. Amendments; spatial variation; India; Asia; Soil test value; Residual analysis; Optimum dose; QRP (quadratic response plateau model); Quadratic model; Nitrogen fertilization; Monocotyledones; Cultivated soil; Forecast model; Cereal crop; Residual effect; Paddy soil; Oryza sativa; Application rates; Gramineae; Angiospermae; Spermatophyta; Yield; Quadratic function
• ISSN: 1161-0301; 1873-7331
• DOI: 10.1016/j.eja.2005.10.011

This study evaluated the quadratic response plateau (QRP) and quadratic models for 3–5 years, two crop sequence data set with 4, 3 and 5 nitrogen fertilizer application rates in southern, western and eastern India. The quadratic response model predicted a maximum grain yield of 2–13% larger and an optimal N fertilizer rate 2–73% larger than predicted by the quadratic response plateau model. These analyses indicate that the quadratic response plateau model is preferable to the quadratic model for predicting N fertilizer requirements of rice. Economic analyses also indicate that the benefits of using quadratic response plateau can be more than by using quadratic model. Site or season specific knowledge of crop nutrient requirements and nutrient supply from soil will be required in order to achieve maximum yields.