Poljoprivreda (Dec 2010)
EXPERT MODEL OF LAND SUITABILITY ASSESSMENT FOR CROPS
Abstract
A total of 17404 soil samples (2003rd-2009th year) were analysed in the eastern Croatia. The largest number of soil samples belongs to the Osijek-Baranya county, which together with both Eastern sugar beet Factories (Osijek and Županja), conduct the soil fertility control (~4200 samples/yr.). Computer model suitability assessment for crops, supported by GIS, proved to be fast, efficient enough reliable in terms of the number of analyzed soil samples. It allows the visualization of the agricultural area and prediction of its production properties for the purposes of analysis, planning and rationalization of agricultural production. With more precise data about the soil (soil, climate and reliable Digital Soil Map of Croatia), the model could be an acceptable, not only to evaluate the suitability for growing different crops but also their need for fertilizer, necessary machinery, repairs (liming, and other measures of organic matter input). The abovementioned aims to eliminate or reduce effects of limiting factors in primary agricultural production. Assessment of the relative benefits of soil presented by computer model for the crops production and geostatistical method kriging in the Osijek-Baranya county showed: 1) Average soil suitability being 60.06 percent. 2) Kriging predicted that 51751 ha (17.16%) are of limited resources (N1) for growing crops whereas a) 86142 ha (28.57%) of land is limited suitably (S3), b) 132789 ha (44.04%) are moderately suitable (S2) and c) 30772 ha (10.28%) are of excellent fertility (S1). A large number of eastern Croatian land data showed that the computer-geostatistical model for determination of soil benefits for growing crops was automated, fast and simple to use and suitable for the implementation of GIS and automatically downloading the necessary benefit indicators from the input base (land, analytical and climate) as well as data from the digital soil maps able to: a) visualize the suitability for soil tillage, b) predict the benefits of growing crops using kriging method and c) conduct analysis for production area, planning and/or rationalization with more efficient and economical investment in primary agricultural production. Application of computer model is accurate for fertilizer crops recommendations, but caution should be taken until the model is calibrated allowing prediction within acceptable error/risk, because of relatively small number of samples and insufficient reliability of pedoclimatic data.
