Nutrient deposition in the pampas and its impact on crop production

Abstract

Nutrient deposition from the atmosphere can be an important input in agroecosystems. The quantity and distribution patterns are related to meteorological phenomena such as rainfall and winds. This work examines the annual deposition rates and spatial patterns of nutrients in the Pampas (Argentina) to evaluate their potential agronomic impact. A review compiling data from 16 sites across the country showed mean annual deposition rates of 6.2 kg N ha−1, 0.2 kg P ha−1, 3.4 kg S ha−1, 2.9 kg K ha−1, 5.1 kg Ca ha−1, and 1.1 kg Mg ha−1. Nitrogen, sulfur, and potassium deposition correlated positively with rainfall amounts, while chlorine and sodium increased with proximity to the ocean. Local deposition values for nitrogen were generally lower than global model estimates of 10?20 kg N ha−1 year−1 for this region. In contrast, deposition of bases like calcium and magnesium exceeded typical ranges reported globally. The atmospheric contribution represents a significant fraction of crop nutrient requirements, averaging 9% for N, 25% for K, up to 47% for Ca and Mg, and as high as 70% for micronutrients like copper. While actual impacts depend on bioavailability and synchronization with crop demand, this work highlights atmospheric deposition as an appreciable nutrient source to be integrated into comprehensive nutrient management strategies for sustaining productive Argentinian agroecosystems.