Crop growth models are usually split into two opposite groups: complex comp
rehensive and simplified applied. The objective of this paper is to show ho
w the different models ran be used together to form an integrated crop mode
ling system. The software engineering methods that are employed include the
needs of potential users in the system requirements. As a specific example
, the process of development and implementation of an integrated crop simul
ation system, DIASPORA (DIAlog Simulator and PredictOr for Research in Agri
culture), is described. The DIASPORA system is primarily designed to make m
ore effective use of the field treatment data collected at the Lithuanian I
nstitute of Agriculture (LIA) and to allow a multitasking application of cr
op growth and development models. To achieve these tasks, a simulation envi
ronment has been developed that includes the complex simulation model, mode
l database, multilingual user interface, and the set of simplified models f
or particular applications. Three local research stations of the LIA-Traku
Voke (south-eastern Lithuania), Dotnuva (central Lithuania), and Vezhaichai
(western Lithuania)-serve as sources of experimental information, and ther
efore, as sites for further implementation of the system. The models of cer
eal crops implemented within the system have also been verified using exper
imental data sets from several regions in Russia; Gornyj Lozen in Bulgaria;
and Morris, MN, USA.