HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Jemison, J. M. Articles by Fox, R. H. Search for Related Content PubMed Articles by Jemison, J. M., Jr. Articles by Fox, R. H. Agricola Articles by Jemison, J. M. Articles by Fox, R. H.

Evaluation of LEACHM: II. Simulation of Nitrate Leaching from Nitrogen-Fertilized and Manured Corn

Univ. of Maine, Coop. Ext., 104 Libby Hall, Orono, ME 04469

Jalal D. Jabro and Richard H. Fox

Dep. of Agronomy, 16 A.S.I. Bldg.

^* Corresponding author (Email: jjemison{at}umce.umext.maine.edu).

High NO₃-N concentrations in groundwater resulting from agricultural production have increased the need for mathematical models to predict the concentration and mass of NO₃-N leached from agricultural soils. Study objectives included evaluating the N version of LEACHM (LEACHMN) to predict mass of NO₃-N leached from nonmanured and manured corn (Zea mays L.), and to test two methods of model validation. Four treatments (no manure with 0 and 200 kg N ha^–1 and manure treatment with 0 and 100 kg N ha^–1) from a NO₃ leaching experiment were modeled for 1988, 1989, and 1990. Model calibration involved adjusting nitrification, denitrification, and volatilization rate constants to minimize differences between predicted and observed data. When calibrated for each year, LEACHMN produced reasonably accurate predictions of NO₃-N mass leached; however, LEACHMN tended to overestimate summer and underestimate spring leaching losses. The lack of a provision in LEACHM to allow solute diffusion out of water flow channels, and underpredicted corn N uptake early in the season probably created conditions conducive for high leaching losses early; following harvest, insufficient NO₃-N in the soil profile resulted in the model underestimating leaching in the spring. Validating LEACHMN using 1988 rate constants for the 1989 and 1990 years was unsuccessful. When 3-yr average rate constants were used, simulation accuracy improved somewhat; most accurate simulations were found if3-yr average values were close to the calibrated rate constant for that year. The model's predictive capability would probably improve if it contained a more complex corn N uptake routine and a dual-pore water flow component.

Received for publication November 22, 1991.

This article has been cited by other articles:

				J. D. Jabro, A. D. Jabro, and R. H. Fox Accuracy and Performance of Three Water Quality Models for Simulating Nitrate Nitrogen Losses under Corn. J. Environ. Qual., July 1, 2006; 35(4): 1227 - 1236. [Abstract] [Full Text] [PDF]

				H. R. S. Rozas, H. E. Echeverria, and P. A. Barbieri Nitrogen Balance as Affected by Application Time and Nitrogen Fertilizer Rate in Irrigated No-Tillage Maize Agron. J., November 1, 2004; 96(6): 1622 - 1631. [Abstract] [Full Text] [PDF]

				Y. Zhu, R. H. Fox, and J. D. Toth Leachate Collection Efficiency of Zero-tension Pan and Passive Capillary Fiberglass Wick Lysimeters Soil Sci. Soc. Am. J., January 1, 2002; 66(1): 37 - 43. [Abstract] [Full Text] [PDF]

				J.W. Roy, G.W. Parkin, and C. Wagner-Riddle Water Flow in Unsaturated Soil Below Turfgrass: Observations and LEACHM (within EXPRES) Predictions Soil Sci. Soc. Am. J., January 1, 2000; 64(1): 86 - 93. [Abstract] [Full Text]

				A. D. Johnson, M. L. Cabrera, D. V. McCracken, and D. E. Radcliffe LEACHN Simulations of Nitrogen Dynamics and Water Drainage in an Ultisol Agron. J., July 1, 1999; 91(4): 597 - 606. [Abstract] [Full Text] [PDF]