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A field experiment was conducted on a sandy loam soil during kharif season of 2012 with a view to study the relation between leaf N content, LCC and SPAD values, yield of rice. The leaf colour chart (LCC) and SPAD based N management can be used to optimize N application with crop demand or to improve existing fixed split N recommendations. We conducted a field experiment to determine the LCC and SPAD critical value for N application in irrigated rice. Treatments included 3 LCC based and 3 SPAD based N management contained the combination of three critical levels of LCC shade values (4, 4.5, 5) and three critical levels of SPAD (37, 39 and 41) values with different levels of N application were compared with recommended fertilizer dose (RFD) and soil test crop response (STCR) equation based fertilizer application. Nitrogen was applied in the form of urea as per treatment schedule and the SPAD and LCC assessed at 10 days intervals starting from 15 DAT. Result showed a considerable opportunity to increase yield, N concentration in leaf through improved N management with LCC and SPAD values. There exists a positive correlation between index leaf N, LCC and SPAD values. Since SPAD and LCC values from 45 DAT to 65 DAT had shown a significant and positive correlation with leaf N content and finally grain yield
Keywords: Leaf colour chart, Nutrients uptake, SPAD, N concentration