Customization of DNDC Model: Simulation of Yield and Nitrogen Balance in Rice (Oryza sativa L.) in Relation to Climate Change, Soil and Management Interventions

摘要

A field study was conducted at two different locations at research farms of Department of Soil Science, Punjab Agricultural University, Ludhiana, Punjab, on sandy loam soils during kharif 2015 and 2016 to evaluate the DNDC (Denitrification-Decomposition) model. Simulation were made to assess the impact of climate change scenario, soil and management interventions on past (1986-2016) and future (2020-2050) yield, nitrogen (N) balance and use efficiency of rice, and to made projections for future yield, N balance and use efficiency of rice for different texture soils and different locations of central Punjab. Results indicate that simulated rice grain yield, N uptake, volatilization and leaching increases but agronomic and recovery efficiency decreases at higher N levels. Simulated rice grain yield, N uptake, volatilization, agronomic and recovery efficiency would decrease in future time slices but leaching would increase. Per cent reduction in yield would be more in end part of mid century, lower athigher N levels (150-180 kg N ha1) and in fine textured soils (silt loam). During time slice-4 (TS-4) (2040-2050) highest reduction in yield is expected at Patiala (54.7%) followed by Ludhiana (50.7%) then Amritsar (43.5%) but under higher N treatments(150 and 180 kg ha1) yield reduction trend would be in the order of Ludhiana> Patiala> Amritsar. Trend for per cent increase in leaching during TS-4 would be Patiala> Amritsar> Ludhiana but volatilization would be Ludhiana> Patiala> Amritsar. The study suggests that higher N levels could be good option to compensate yield reduction in future however higher N levels would lead to higher N leaching and volatilization.