Development of an automated gridded crop growth simulation support system for distributed computing with virtual machines

Abstract

The spatial distribution of crop yield has been assessed under current and future climate conditions using gridded crop growth simulations. This task usually requires considerable efforts to prepare input data and post-process the outputs. In the present study, the Gridded cRop grOWth simuLation suppoRt System (GROWLERS) was developed to automate repetitive and tedious tasks using multiple PCs. In particular, the system was designed to aid researchers who have minimum knowledge on computer programming, network, and cluster management. An object oriented programming language, C+ +, was used to design and implement the GROWLERS, which would increase flexibility of a system while simplifying complexity including supports for different types of gridded data. Functionality of the GROWLERS includes preparation of weather input files, launch of crop growth model, and creation of gridded output files. Tools for the GROWLERS were installed on virtual machines connected through local network, which allows for building of a cluster computer without dedicated workstations. In a case study, 5.8 x 10(7) simulations using the ORYZA2000 model were performed to examine spatial distribution of the optimum sowing date for rice under current climate conditions in Korea. The subsets of these simulations were allocated to groups of virtual machines hosted within five custom built personal computers of which the central processing unit was manufactured about 10 years ago. Weather input data were prepared automatically using the GROWLERS. A set of scripts were also prepared using the GROWLERS, which allowed to reduce the wall clock time by 88% using 16 processor cores for worker nodes. These results suggest that the GROWLERS would minimize researcher's time involved in preparation and operation of a large number of crop growth simulations. Still, the support for nested simulations using multi-scale datasets would be needed to improve the GROWLERS, which merits further development as a next step.