Soil Fertility Assessment and Management Prioritization of Permanent Grasslands Using Agrochemical Indicators: A Case Study from Western Romania

Abstract

Permanent grasslands represent agricultural ecosystems with an essential role in fodder production, biodiversity conservation and soil quality maintenance. The aim of this study was to assess the agrochemical status of permanent grasslands in Fârdea ATU (Timiș county) and to substantiate a differentiated management system based on soil fertility indicators. The analysis included 72 plots with a total area of ​​772.06 ha. The main agrochemical indicators were determined: soil reaction (pH), mobile phosphorus (P-AL), mobile potassium (K-AL), humus content (H), and nitrogen index (NI). Descriptive statistics, correlation analyses and synthetic indicators of soil quality were used to interpret the data. The area-weighted average values ​​indicated a weakly acidic soil reaction (pH = 6.31), a medium level of phosphorus supply (26.54 ppm), a good potassium supply (218.82 ppm), as well as a favorable humus content (3.23%) and nitrogen index (2.74). Approximately 27.2% of the analyzed area has pH values ​​below 6.0, and 26.1% of the area falls into phosphorus deficient classes, highlighting the need for differentiated interventions. Correlation analysis revealed a very strong relationship between humus content and nitrogen index (r = 0.96), confirming the role of organic matter in ensuring soil nitrogen reserves. The results obtained demonstrate that agrochemical zoning and site-specific management can contribute to optimizing fertilization and increasing the sustainability of permanent grasslands.