Performance of Site-specific and Real-time N Management Strategies in Irrigated Rice

摘要

Field experiments were conducted during kharif and rabi seasons of 2001 and 2002 with the objective of evaluating the performance of different fertilizer N management strategies including site-specific and real-time N management, on dry matter production, N uptake, yield, yield components and N use efficiency in rice. Among the different N fertilization strategies tried, both site-specific nutrient management (SSNM) with fixed N split approach i.e., 115 ± 20 kg ha~(-1) in kharif and 140 ± 20 kg N ha~(-1) in rabi as well as real-time N management viz., leaf colour chart (LCC) with critical value 4 based N management (N applied at LCC=4) (35 kg N ha~(-1) in kharif and 30 kg N ha~(-1) in rabi when the LCC value fell below 4) registered higher dry matter production, N uptake, N use efficiency and grain yield than the other treatments. The results suggest that as a simple tool, the adoption of real-time N management viz., the LCC=4 based N management is a profitable proposition of N fertilization strategy for rice.