Assessment and Application of EPIC in Simulating Upland Rice Productivity, Soil Water, and Nitrogen Dynamics under Different Nitrogen Applications and Planting Windows

Tajamul Hussain, Hero T. Gollany, David J. Mulla, Zhao Ben, Muhammad Tahir, Syed Tahir Ata-Ul-Karim, Ke Liu, Saliha Maqbool, Nurda Hussain, Saowapa Duangpan

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4 Scopus citations


A suitable nitrogen (N) application rate (NAR) and ideal planting period could improve upland rice productivity, enhance the soil water utilization, and reduce N losses. This study was conducted for the assessment and application of the EPIC model to simulate upland rice productivity, soil water, and N dynamics under different NARs and planting windows (PWs). The nitrogen treatments were 30 (N30), 60 (N60), and 90 (N90) kg N ha−1 with a control (no N applied −N0). Planting was performed as early (PW1), moderately delayed (PW2), and delayed (PW3) between September and December of each growing season. The NAR and PW impacted upland rice productivity and the EPIC model predicted grain yield, aboveground biomass, and harvest index for all NARs in all PWs with a normalized good–excellent root mean square error (RMSEn) of 7.4–9.4%, 9.9–12.2%, and 2.3–12.4% and d-index range of 0.90–0.98, 0.87–0.94, and 0.89–0.91 for the grain yield, aboveground biomass, and harvest index, respectively. For grain and total plant N uptake, RMSEn ranged fair to excellent with values ranging from 10.3 to 22.8% and from 6.9 to 28.1%, and a d-index of 0.87–0.97 and 0.73–0.99, respectively. Evapotranspiration was slightly underestimated for all NARs at all PWs in both seasons with excellent RMSEn ranging from 2.0 to 3.1% and a d-index ranging from 0.65 to 0.97. A comparison of N and water balance components indicated that PW was the major factor impacting N and water losses as compared to NAR. There was a good agreement between simulated and observed soil water contents, and the model was able to estimate fluctuations in soil water contents. An adjustment in the planting window would be necessary for improved upland rice productivity, enhanced N, and soil water utilization to reduce N and soil water losses. Our results indicated that a well-calibrated EPIC model has the potential to identify suitable N and seasonal planting management options.

Original languageEnglish (US)
Article number2379
Issue number9
StatePublished - Sep 2023

Bibliographical note

Funding Information:
The authors would like to acknowledge the Prince of Songkla University and Ministry of Higher Education, Science, Research, and Innovation for providing the funds under the Reinventing University Project (Grant Number REV65032). Any mention of trade names or commercial products in this publication does not imply recommendation or endorsement by the U.S. Department of Agriculture–Agricultural Research Service. The USDA is an equal opportunity provider and employer.

Publisher Copyright:
© 2023 by the authors.


  • evapotranspiration
  • N mineralization
  • nitrate leaching
  • runoff
  • volatilization
  • yield


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