DRIS Cacao - Integrated System for Diagnosis and Recommendation of Fertilization for Cacao Trees

FertilizaCacau – Integrated System for Diagnosis and Recommendation of Fertilization for Cacao Trees The FertilizaCacau spreadsheet is an operational decision-support tool for nutritional diagnosis and recommendation of liming and fertilization in cacao plantations (Theobroma cacao L.), developed by Paulo Guilherme Salvador Wadt (Embrapa Rondônia), based on the DRIS/CND method and on the Potential Response to Fertilization criterion (Wadt, 2005). Purpose It operationalizes the complete workflow: data entry → interpretation (DRIS/CND classes and indices) → recommendation (liming/fertilization) → conversion into commercial fertilizer sources → costs and records. Spreadsheet structure The spreadsheet is organized into 5 functional sheets interconnected by formulas: DadosBásicos (Basic Data) – input of farm data, technical manager, crop information, foliar and soil fertility laboratory reports. DiagnoseFoliar (Foliar Diagnosis) – calculation of DRIS/CND indices (Jones, 1981; log-transformed ratios), Nutritional Balance Index (IBNm), and nutritional status classification using the Potential Response to Fertilization criterion. Recomendacao (Recommendation) – generation of N, P₂O₅, K₂O, lime, gypsum, and micronutrient (B, Zn, Fe, Mn, Cu) rates, with splitting schedules and conversion into commercial sources (urea, single superphosphate, KCl, etc.). Lista (List) – auxiliary interpretation tables (pH, carbon, K, P, Ca+Mg, Al, CEC) and nutrient contents of fertilizers. TabelaModular (Modular Table) – core of the balanced modular fertilization method: calculation of the export factor, fertility and nutritional factors, and composition of compound NPK formulations per application. Embedded method Diagnosis: Integrated Diagnosis and Recommendation System (DRIS) and Compositional Nutrient Diagnosis (CND), with preliminary norms for Rondônia. Interpretation criterion: Potential Response to Fertilization (Wadt, 2005), which classifies each nutrient as High Deficiency, Deficient, Balanced, Excess, and High Excess. Recommendation: balanced modular fertilization, adjusted by target yield (kg ha⁻¹), soil–plant system availability (fertility and history), foliar diagnosis (DRIS/CND), planting density (plants ha⁻¹), propagation type (seedling/clonal), irrigation, and crop age. Outputs: rates in kg ha⁻¹ and g plant⁻¹, splitting schedules (one, two, three, bimonthly, quarterly), compound formulations, and simple sources. Validation and database According to the TED 1AAGTH Technical Report (SEI Process 21000.007928/2021-28), the spreadsheet was calibrated and validated with: 199 foliar analysis reports; 253 soil analyses; standardized foliar sampling procedures (~40 leaves per production unit); inter-laboratory evaluation with agreement ranging from 56% to 99% depending on nutrient and criterion; assisted field validation with SENAR-RO technicians, under the CEPLAC–SENAR-RO Cooperation Agreement. Target audience and use Agricultural extension and technical assistance (ATER/ATEG) professionals; Researchers in plant nutrition and soil fertility; Public policy managers for Amazonian cacao farming. Notice: The spreadsheet should be used only with the guidance of the responsible technical professional, as indicated in the Recomendacao sheet itself. Limitations and perspectives The CND norms are preliminary and specific to the soil and climate conditions of Rondônia. The spreadsheet is a transitional instrument; migration to an online system is recommended, with governance agreed upon among partner institutions for parameter updates, data quality control, version management, and continuous training. The deposited version is password-free (semsenha) for transparency and reuse, but operational use must respect technical validation. How to cite WADT, P. G. S. FertilizaCacau – Integrated System for Diagnosis and Recommendation of Fertilization for Cacao Trees. Version 20240223. Spreadsheet. 2024. Funding: CNPq (Grant 307808/2020-3). Funding National Council for Scientific and Technological Development (CNPq) – Grant 307808/2020-3. Keywords: cacao tree; DRIS; CND; nutritional diagnosis; fertilization recommendation; soil fertility; Amazon; Rondônia. Language: Portuguese (Brazil).