Comparação entre o método laboratorial e o penetrômetro de Stolf na análise da densidade do solo

um estudo utilizando abordagens geoestatísticas

Resumo

The agricultural sector is a cornerstone of economic development in several countries, including Brazil, as it significantly contributes to the Gross Domestic Product and job creation. However, the pursuit of higher agricultural productivity has led to the use of heavy machinery, resulting in soil structure modification. Consequently, when desiring to cultivate a specific crop, the study of the soil's physical-chemical factors becomes crucial, yet this study is costly and may pose a financial obstacle, as not all researchers can cover the expenses, leading some to abandon their research in the absence of funding. This issue underscores the need to investigate less costly techniques with results closely approximating those obtained through laboratory analysis. This study aimed to assess the accuracy of soil density estimated by the Stolf impact penetrometer, taking laboratory density as a reference. Additionally, the research included a description of soil sampling methods, soil density determination, and basic geostatistical concepts. For this research, 78 soil samples and an equal number of impact measurements were collected in a coffee plantation in Minas Gerais, Brazil. Based on these data, exponential models were fitted, and soil density was mapped using ordinary kriging. The results revealed that the Stolf penetrometer tends to overestimate soil density, although it still exhibits a strong positive correlation (79.3%) with laboratory measurements. Therefore, it was concluded that in situations where precision is not imperative, this cost-effective approach is a viable option for soil density analysis in soil research.

Keywords: Soil density; Soil sampling; Geostatistics; Ordinary Kriging; Stolf's penetrometer.