Study of spatial relationships among some soil physico-chemical propertiesof a field in central Italy using multivariate geostatistics

Soil variability within fields results from complex geological and pedologi cal processes, therefore soil variables are expected to be correlated in a scale dependent way. An accurate soil characterization, taking into account soil and spatial variability, will allow the farmer to follow crop managem ent practices fitted with the real soil situation. The study of the scale-d ependent correlation structure of some variables was investigated by means of Factorial Kriging Analysis (FKA) developed by Matheron. This analysis co nsists: modeling of the coregionalization, analysing the correlation struct ure between the variables, estimating and mapping the regionalized factors. The present study was conducted in a 4-ha field located in central Italy. Soil samples were collected at 0-10 and 10-30 cm depth and were then analys ed for pH, (cation exchange capacity) CEC, total N, Olsen P, exchangeable K , and Na. The analytical results were submitted to different kinds of analy sis: classical statistical and geostatistical analysis which showed that pl ant macro- and micro-nutrients coming from fertilization had led to short-r ange variation, especially in Na, N, and CEC. The effects of these were sup erimposed on long-range processes, producing systematic patterns in soil fe rtility. (C) 2000 Elsevier Science B.V. All rights reserved.