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• Deforestation-induced rainfall changes negatively impact soybean and maize yields in Brazil. • Soybean and maize yields could have been 6.6 % and 9.9 % higher per year if rainfall patterns hadn't been altered by deforestation. • Agricultural efficiency improvements insufficient to counteract rainfall-changes effects on yields. • Study underscores the vital role of forest preservation for agricultural resilience and food security. • Forests' critical role in regulating the water cycle highlighted in the face of climate change. Whereas the global demand for food, fiber and energy is increasing, the capacity of ecosystems services to sustain agricultural production is being compromised worldwide. Brazil is a global food supplier that has benefitted from agricultural intensification in the past decades. At the same time, expansion of cropland has led to deforestation that, in turn, is increasingly affecting rainfall patterns thereby influencing crop yields. This study examines how loss in forest cover has impacted agricultural yields through change in rainfall. To do so, we use modelled data on changes in rainfall patterns due to deforestation as input to a crop model. We assess yield changes within the soybean-maize double cropping system, the country's most relevant agricultural system, in five states within the Amazon and Cerrado biomes. Findings revealed that soybean and maize yields would have been respectively 6.6 % and 9.9 % higher per year in the last decade if rainfall patterns hadn't been altered by deforestation from 1982 onwards. Although agricultural efficiency improved between 2011 and 2020, it was insufficient to offset the negative effect of altered rainfall on yields. Our paper reveals the link between deforestation and crop yields, emphasizing the need to preserve forest cover for agricultural resilience and food security. It reinforces the critical role of forests in regulating the water cycle, particularly in the face of climate change-induced warmer and drier conditions that can impact agricultural production and other human activities. [ABSTRACT FROM AUTHOR]

A series of modifications for the source code of EPIC version 0160 in order to simulate growth, yield, and nutrient uptake by the crops under the pedo-climatic conditions of the semiarid Northeastern Brazil are presented. The modifications included changes in chemical properties of the soil due to liming as manual option, changes in the estimation of soil Al saturation, effects of Na on the soil physical properties, interaction between climatic and nutrient constraints to crop growth, modifications in the estimation of labile P factor for uptake and in the calculations of the N and P stress factors which are now estimated as a function of the ratio between the daily uptake and daily demand for the potential growth.Moreover, the structure of a simple soil and plant K model designed to be incorporated into EPIC is described. The model maintains pools of exchangeable, soluble and fixed K for the mineral form in the soil; of crop residue K for the organic form and of grain, stover and root K for the crop form. The model runs on a daily time step, simulating K uptake by the crops and transformations between the different soil pools as well as several other processes like leaching, runoff, lateral subsurface flow, movement upward through soil evaporation, K recycling from crop residues and the effect of limited soil K availability on crop development. The model is sensitive to soil chemical and physical properties, crop K requirements, crop competition, tillage practices, fertilizer rate, and soil water content.In a second paper of this series, the test of the proposed modifications, including the plant and soil potassium sub-model, for simulations of crop growth, yield and nutrient uptake of a maize × cowpea intercrop in the semiarid NE of Brazil is presented. [Copyright &y& Elsevier]