Effects of limestone application on soil physical, chemical, and biological properties and coffee yield

Abstract

Liming is essential for soil acidity in tropical regions, affecting chemical, physical, and biological soil properties with potential impacts on coffee crop productivity. This set of studies evaluated the effects of increasing lime rates (0 to 24 Mg ha-1 ), applied either on the surface or subsoiling, on fertility, structure, microbial activity, and yield in coffee-cultivated Oxisols under field conditions in Minas Gerais, Brazil. The first two studies were conducted from 2019 to 2023 on plantations at the Samambaia (Site 1) and Frade (Site 2) farms, where increasing doses of limestone were applied superficially to coffee plantations in 2018. The third study was carried out on coffee plantations located in the UFLA coffee sector. In the first study, multivariate analyses identified that doses of 3 and 6 Mg ha-1 applied superficially significantly increased soil pH values, as well as Ca, Mg, K and SO4 2- contents and soil organic matter, with an increase in productivity with the application of 6 Mg ha-1 . The second study pointed to specific effects of liming on soil structure, such as an increase in water-dispersed clay and microporosity, without significantly altering its structure in general. Coffee yield varied between sites (Sites 1 and 2), with a quadratic response and maximum yield estimated with an application of 12 Mg ha-1 on Site 1. In the third study, which compared the effect of surfaceapplied limestone doses, with or without subsoiling, it was observed that liming increased arylsulfatase activity and microbial respiration, regardless of the application method (with or without subsoiling), although it did not significantly affect microbial biomass carbon or other enzymes analyzed. Coffee tree productivity did not change significantly in the short term. In general, the results indicated that surface liming is capable of promoting important improvements in the chemical and biological properties of the soil, with localized effects on the physical structure and responses in productivity, which varies according to the environment, reinforcing the importance of specific management strategies in consolidated coffee systems. Keywords: Coffea arabica L.; microbial activity; soil fertility and structure; tropical soils.