Agroclimatic Zoning to Optimize Crop Suitability under Soil, Water and Terrain Constraints in Tropical Conditions of Brazil

Abstract

Agroclimatic zoning is widely used to support crop planning in tropical environments, yet the relative importance of climate, soil and terrain in determining agricultural suitability remains poorly quantified at local scales. It supports the formulation of territorial planning policies for different crops at the state and municipal levels. The objective of this work was to evaluate crop suitability across major production systems using an integrated agroclimatic zoning in northeastern Brazil. Climate indicators, including the Water Requirement Satisfaction Index (WRSI), were derived from long-term datasets, while soil and terrain variables were assessed through field surveys and geospatial analysis. Despite relatively stable climatic conditions, crop suitability is primarily constrained by soil physical limitations, water deficit and slope. Only 42.06% of the evaluated area was classified as suitable for agricultural use, with strong variation among crop groups. Perennial crops and pasture systems exhibited greater adaptability, whereas annual crops and sugarcane were more restricted due to higher sensitivity to water deficit and terrain limitations. Agroclimatic zoning maps related to annual crops, permanent crops, sugarcane, planted pasture, and forestry are presented. Given that only 42.06% of the municipal territory is classified as suitable for agricultural use, the strategic selection of crops based on this zoning becomes a valuable tool for mitigating agricultural production risks and minimizing environmental impacts. The findings showed that soil and topography can override climatic suitability in subhumid tropical systems, emphasizing the need to integrate conservation-oriented management practices to enhance water retention and reduce erosion risks. The proposed framework supports crop selection, land-use planning and risk management in water-limited tropical environments.