Fertilizer recommendations for field crops in Croatia Ph. D. Zdenko Loncaric, Faculty of Agriculture, Department of Agroecology Osijek, Republic of Croatia

Faculty of Agriculture Department of Agroecology Work objects due to achieve high yield, good quality and to preserve ecosystem: 1 A fertilization field researches 1 B soil analyses improvement (lab researches) 2 soil analyses - database 3 fertilizer recommendations

Fertilization field researches sites: 10 different locations in eastern Croatia crops: maize, wheat, sugar beet, alfalfa, pepper topics: liming, phosphorus, nitrogen, zinc, boron specific: two sites with 15 lysimeters, pot exp. aim: control of yield, quality, soil nutrient status

Soil analyses improvement 1A fertilization field researches 1B soil analyses improvement 2 soil analyses - database 3 fertilizer recommendations

Soil analyses improvement steps: 1.common and additional soil sample analyses, 2.comparison of HRN, EN and other results, 3.creating new model for result interpretations, 4.validation of existing models models: P, N, liming materials, organic fertilizer

Model Example 1: Olsen-P & AL-P

Model Example 2: Liming recommendations to target BS: Hy, CEC (blue line on the graph) to target pH: pH, Hy (red line on the graph)

Database 1A fertilization field researches 1B soil analyses improvement (lab researches) 2 soil analyses - database 3 fertilizer recommendations

Fertilizer recommendations 1A fertilization field researches 1B soil analyses improvement (lab researches) 2 soil analyses - database 3 fertilizer recommendations

Calculator Example 1: Algorithm

Producers and site data Specific nutrient demands regardnig to crop Site specific conditions related to mineralization Fertilizer assortment Fertilizer recommendation Nutrient balance MINERALIZATION

Fertilizer assortment Fertilizer recommendation Nutrient balance Data base and results Advices, directions, objections, suggestions Producers and site data Specific nutrient demands regardnig to crop Site specific conditions related to mineralization MINERALIZATION Additional analytical data SURVEYDATASURVEYDATA MODELDATAMODELDATA CEC Hy Biogenity Slope Irigation Agrotechnics Protection + liming mineralization N application balance

Example 1: Internet browser window

Example 2: Algorithm of DSS Fertilizer recommendations and economic analyses of organic field crops production

Example 2: Visual Basic application Part I – Soil suitability

Part II - Soil properties

Part III – Available Fertilizers

Part IV – Fertilizer Recommendation

Part V – Economic analyses

Thank you for your attention!