Field experiments were conducted to assess the performance of real time application of neem coated urea (NCU) using a customized leaf color (CLCC) chart in relation to yield and nitrogen use efficiency of direct seeded aerobic (AR) and puddled transplanted (PTR) rice in a split plot design. Six nitrogen management treatments viz-0 N, 100 kg N ha-1 as prilled urea (PU) applied conventionally, 100 kg N ha-1 as neem coated urea (NCU), applied conventionally, 100 kg N ha-1 as PU, applied on the basis of CLCC recommendation, 100 kg N ha-1 as NCU, applied on the basis of CLCC recommendation, 100 kg N ha-1 as PU and farm yard manure (FYM) in 1:1 ratio were assigned to sub plots. As compared to PU, NCU increased yield by 7.1-13.4 % and 6.8-10.0 % respectively, in AR and PTR when both applied conventionally but when it is applied on the basis of CLCC reading the yield enhancement was 21.2-22.9 % and 14.6-15.9 % respectively. Similarly, NCU resulted 6.6-8.9 and 6.2-6.5 % higher as compared to PU, which was further increased to 16.3-18.0 and 11.4-14.6 % in AR and PTR respectively when applied following CLCC reading. Application of N on the basis of leaf colour chart reading synchronized N supply with that of crop demand therefore enhanced N uptake and improved N use efficiency and yield.
Key words: Real time N application; leaf colour chart; neem coated urea; aerobic rice; N use efficiency