Simulated and measured nitrogen conditions in a manured and fertilised soil

Abstract

The governing factors for soil nitrogen dynamics were identified with a simulation modelaln addition, the model was used to interpret measurements from a plot fertilisation experiment in southwest Sweden.Simulated moisture and temperature conditions were the driving variables for the simulation of soil nitrogen dynamics and leaching during a 6-year period. The results of the simulation were compared with monthly observations on two plots with grain crops, one with liquid manure and commercial fertilisers applied and one with commercial fertilisers only.Simulated temporal variations of the nitrate and ammonium storages generally agreed with observations. The dominant role of the crops as a determinant of soil nitrogen conditions was demonstrated. A higher leaching loss from the plot with application of commercial fertilisers only occurred both in simulations and measurements compared to the plot with application of both commercial fertilisers and manure. The main reason was the higher N-application in the former treatment.The effect of water flows in macropores was interpreted as a delay of simulated leaching compared to observed leaching on some occasions in summer and early autumn. No direct effect of the macropores on the yearly rates of leaching could be seen.

Modeling Nitrogen Dynamics under Maize on Ferralsols in Western Africa

“…Other research has focused on simulating organic matter transformations ( Van der Linden et al 1987;Wolf and van Keulen 1989); crop yield and N uptake (Clay et al 1985b); manure-N dynamics (Borg et al 1990); and tillage effects (Clay et al 1985a). Most of these N modeling efforts have focused on temperate areas, with very few done under African conditions in general, particularly in West Africa.…”

“…The model uses the convective-dispersion equation for solute transport, and balances N in the soil after simulating denitrification, volatilization, leaching and plant N uptake. Equations and descriptions of the processes in the model are presented in Borg et al (1990) and Hutson and Wagenet (1992).…”

A simple nitrate submodel for trickle fertigated potatoes

“…Many models have been developed which simulate specific aspects of the N cycle, such as nitrification (Smith, 1981;Rose et al, 1982;White, 1987;Engel and Reiner, 1990;Groot and Willigen, 1991) and nitrate leaching (Shaffer and Larson, 1987;Hutson and Wagenet, 1989;Baraclough, 1989a;Addiscott and Whitemore, 1987;Bergstorm and Jarvis, 1991). Some models link all the major transformations of N (Molina et al, 1989;Baraclough, 1989b;Borg et al, 1990;Godwin and Jones, 1991;Hutson and Wagenet, 1991), while others simulate most of soil transformations of N as well as its uptake by the crop (Tanji and Nour-El-Din, 1991;Smith, 1992;Zacharias and Heatwole, 1993;Izadi et al, 1996). Though a number of models (Clothier, 1984;Clothier and Sauer, 1988) exist, efforts to model nitrogen dynamics during and following trickle fertigation have been limited.…”

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

“…The major N transformation processes modeled by LEACHMN are mineralization, nitrification, denitrification, and volatilization. Equations and descriptions of these processes are presented in Borg et al (1990) and Hutson and Wagenet (1991). Slight changes in model rate constants for nitrification, denitrification, and volatilization have been shown to affect N transformations and mass leached (Hutson and Wagenet, 1991).…”