Identifying maize yield potential and farm yield gaps in Southern Brazil

Abstract

A comprehensive understanding of the interaction between genotype and environment at the local level, coupled with the development of effective management strategies, is imperative to meet the demand for maize (Zea mays) in Santa Catarina, Brazil, and elsewhere. This study estimated maize yield potential, water-limited yield potential, and yield gaps in the state. The study also identified the key biophysical and management factors contributing to yield gaps. The nine buffer zones selected encompass 63% of the total cultivated area dedicated to maize production. To ensure the appropriate balance between the quantity of data utilized and the representativeness of the study area, the Hybrid-Maize model and the method developed by the Global Yield Gap Atlas were employed. In the 2020–2021 and 2021–2022 agricultural years, surveys were conducted in 293 fields. A comparative analysis between high and low yields, in conjunction with regression tree analyses, enables the identification of management practices that warrant investment to elevate average yields and approach values approximating 75% of water-limited yield potential. The results indicated that the yield potential of maize in Santa Catarina is 17.4 Mg ha−1, while the water-limited yield potential is 14.7 Mg ha−1. Therefore, the attainable yield gap was estimated to be 4.0 Mg ha−1. The primary management practices that constrain maize yield were identified, including the population of established plants, the rate of potassium fertilization, the sowing date, and the interval between lime applications. Improvements to these practices will enable an increase of 1.0 million Mg in the current crop area.