Degradação do solo nos estabelecimentos rurais do nordeste brasileiro

Abstract

In the northeast of Brazil, since the colonial period, poor farming practices have contributed in some way to the current state of soil degradation in rural establishments in their respective municipalities. However, soil degradation is not only associated with inappropriate farming practices, but also with climatic conditions, especially unstable rainfall. This study sought to measure the level of soil degradation in rural establishments in municipalities in the Brazilian Northeast using an index created through the technique of factor analysis involving the variables vegetation cover per hectare, value of agricultural production per hectare, labor per hectare, average annual rainfall, average annual temperature and aridity index. Specifically, the study proposes a - to investigate possible heterogeneities in the level of soil degradation in the rural establishments of the municipalities surveyed; b - to create an index that allows the municipalities assessed to be ranked and grouped in terms of the stage of soil degradation in their specific rural establishments; c - to analyze the spatial distribution of the degree of soil degradation in the rural establishments of the municipalities analyzed; d - to identify the indicators that are most associated with the level of soil degradation in the rural establishments of the municipalities studied; e to test some indicators and identify among them those that are most associated with the potential for soil degradation in the rural establishments of the municipalities studied. The study used data collected from the 2017 Agricultural Census, the Municipal Agricultural Survey (PAM) and the National Oceanic and Atmospheric Administration (NOAA) 2022. The research used the following methodological procedures: factor analysis, cluster analysis, discriminant analysis and estimates of descriptive statistics. The results show that rural establishments in the municipalities of the Brazilian Northeast are heterogeneous in terms of both the level of agricultural production and the stage of soil degradation. With regard to the factors determining the degree of soil degradation in agricultural establishments in the northeastern municipalities, the evidence shows that climate instability, especially rainfall, is the main factor responsible. With regard to the Soil Degradation Index (SDI) estimated in the survey, most of the municipalities studied had a “Medium High” SDI in their respective rural establishments. With regard to the impact of SDI on rural agricultural establishments in the northeastern municipalities on bean, cassava and corn crops grown under rainfed conditions in the region, bean and corn crops are affected by SDI, while cassava crops are not. With regard to the influence of extremely “high” and “low” SDI on economic predominance, a large proportion of municipalities with rural establishments with extremely “high” SDI tend to migrate to non-agricultural activities, while those with extremely “low” SDI only a small proportion tend to remain in agriculture. Finally, the economic potential of municipalities in the Brazilian Northeast is associated with the level of soil degradation in their respective municipalities, i.e. lower SDI, higher economic level.