MODELING AND SIMULATION OF THE ARCHITECTURE AND DEVELOPMENT OF THE OIL-PALM (ELAEIS-GUINEENSIS JACQ) ROOT-SYSTEM .2. ESTIMATION OF ROOT PARAMETERS USING THE RACINES POSTPROCESSOR

A stochastic model of oil-palm (Elaeis guineensis Jacq.) root system a rchitecture and development has been developed. This model enabled us to create 3-D numerical models of complete root systems by simulation. The application of a postprocessor software, called ''RACINES'', to t hese 3-D numerical models, provided an estimation of some parameters o f plant root systems. The objective of this paper is to present oil-pa lm root characteristics as possible outputs of the application of this RACINES software. The outputs described in this article cover (i) spa tial distribution of roots under plantation conditions, (ii) the estim ation and distribution of total root biomass, per root type or per soi l horizon and (iii) the location and quantification of absorbent surfa ces. The computing techniques used were based on voxellization of spac e and creation of 3-D virtual sceneries exactly reproducing observed p lanting designs. By comparing the results of observations and simulati ons for spatial distribution (by trench wall density maps) and root bi omasses (by real and virtual sampling) we were able to carry out addit ional numerical validations of the model.