Management of nitrogen through the use of leaf color chart (LCC) and soil plant analysis development (SPAD) or chlorophyll meter in rice under irrigated ecosystem.

A field experiment was conducted in a farmer"s field in the district of Nadia, West Bengal, India to study the management of N through leaf color chart (LCC) and soil plant analysis development (SPAD) or chlorophyll meter in rice (cv. IET-4094) during the Kharif (wet season) of 2001-2002 and 2002-2003 by taking the treatment combinations based on different levels of N at fixed schedule and through LCC and SPAD. The experimental soil (0-15 cm) had pH 7.33; organic C 0.43%; available N 408.70 kg ha(-1); available P 6.92 kg ha(-1); and available K 66.31 kg ha(-1). The results of LCC and SPAD or chlorophyll meter for the N management in rice show that values of both LCC and SPAD significantly increased with an increasing level of N. The mean values of LCC and SPAD varied from 3.19-5.31 and 27.36-39.26, respectively, in rice. The results show that the amount of N can be saved as 20-42.5 and 27.5-47.5 kg N ha(-1) through the use of LCC and SPAD in rice over the fixed-timing N treatment T7 where 150 kg N ha(-1) was applied in three (3) splits without reduction in the yield. The SPAD- and LCC-treated N plot showed higher N-use efficiency over fixed-scheduling N treatment in rice. The results further show that SPAD value of 37 and LCC value of 5 have been proved to be superior treatments over SPAD (35) and LCC (4) for the best management of N in rice in an Inceptisol.