Fertilização microorganismos e biodiversidade : os estudos edáficos no desenvolvimento agronômico do Cerrado

Abstract

The Cerrado has its controversial name since the beginning of its characterization, treated by some authors as tropical savannah, others Biogeographic system and others as a biome, so also named by the Ministry of the Environment. What is certain is that the Cerrado is a complex phytogeographic domain, composed of savanna, rural and forest phytophysiognomy. Occupying the central region of Brazil, this biome has undergone extreme transformation in recent years, anchored by government projects such as the National Development Plans (PND), passes from inhospitable land, considered infertile or of low fertility by the high degree of aluminum in the soil, and becomes a region of many investments in soil research with the emphasis on the creation in the 1970s of the Brazilian Agricultural Research Company (EMBRAPA), as a result of investments, the Cerrado soil region in the 1980s and 1990s became a major producer of commodities and the largest star of Brazilian agribusiness. The aim of this research is to describe the phytophysionomic aspects of the Cerrado Biome, discussing its position as a tropical savannah and linking it with soil fertilization themes and microorganisms with emphasis on mycorrhizas. The work consists of four chapters: the first chapter provides a description of the characteristics of the phytophysiognomies of the Cerrado, description of its soils, occupation of the region, and the use as a tropical savannah as a space for the advancement of the agricultural frontier in the country; the second chapter is a scientometrics on soil fertilization in the Cerrado and its agricultural use, with information that corroborates the history of research conducted in the biome, such as the increase in research in the 1980s and the most relevant topics. Another result that the second chapter brings is about the journals where these studies were published, highlighting the largest proportional amount of publications, which was the journal Pesquisa Agropecuária Brasileira, which belongs to EMBRAPA. The third chapter refers to the bibliographic research on the history of studies related to the role of microorganisms in the maintenance of soil quality of the Cerrado, with emphasis on Mycorrhidae and its action facilitating the aggregation of soil particles and the absorption of compounds such as phosphorus and nitrogen. The fourth chapter discusses soil biology and the influence of fungal and bacterial communities in the recovery of spaces that have suffered from environmental stress factors such as water deficiency and forest fires. The chapter also discusses the influence of forest fires and seasonal variations on the dynamics of total microorganisms in soil of five Cerrado phytophysiognomies.