A qualidade do solo foi avaliada após a incorporação de matéria orgânica e microrganismos eficazes (EM) em solo franco argiloso coletado em cultivos protegidos em Aranjuéz (Madrid). Os tratamentos constaram de solo (controle); solo + 50 ton./ha de esterco de animal (E50); E50 + EM (E50EM); solo + 30 ton/ha de restos de cultivos + plantas invasoras (RC30); RC30 + 30l/ha EM (RC30EM). Amostras de solo dos tratamentos foram tomadas após o tratamento, antes e após a incubação e analisadas usando os parâmetros físico-químicos e microbiológicos. Observou-se aumento significativo na produção de polissacarídeos, nas atividades enzimáticas esterases e fosfatases alcalina principalmente, nos tratamentos E50EM e RC30EM, sendo diretamente correlacionadas com a humificação da matéria orgânica, com a capacidade de campo e com a capacidade de intercâmbio catiônico. A partir desses resultados, pode se concluir que o solo tratado com microrganismos eficazes teve intensa atividade biológica, contribuindo para uma mais rápida humificação da matéria orgânica fresca e melhorando as propriedades fisico-química do solo, destacando os parâmetros microbiológicos como indicadores precoces de recuperação da qualidade do solo.

The soil quality was evaluated following the addition of organic matter and microorganisms to a clay loam soil collected in Aranjuez (Madrid) under controlled conditions of temperature and moisture, and over a period of three months. The following treatments were carried out: soil (control); soil + 50 t/ha of animal manure (E50); soil + 50 t/ha of animal manure + 30l/ha of effective microorganisms (E50EM); soil + 30 t/ha of combination of various green crop residues and weeds (RC30) and soil + 30 t/ha of combination of various green crop residues and weeds + 30l/ha of effective microorganisms (RC30EM). The soil samples were taken before and after the incubation and analysed using physical, chemical and microbiological parameters. A significant increase in the production of polysaccharides and alkaline phosphatase and esterase enzymes in the treatments E50EM and RC30EM was observed, being in direct correlation with the humification of the organic matter, with the water retention at field capacity, and with the cationic exchange capacity (CEC). It can be concluded that the incorporation of microorganisms EM potentialized the soil biological activity and improved physico-chemical soil properties, contributing to a quick humification of fresh organic matter. Those findings were proved by microbiological activities of exopolysaccharides by alcaline phosphatase and esterase enzymes, which can be used as earlier and integral soil health indicators.

One of the major interests in soil analysis is the evaluation of its chemical, physical and biological parameters, which are indicators of soil quality (the most important is the organic matter). Besides there is a great interest in the study of humic substances and on the assessment of pollutants, such as pesticides and heavy metals, in soils. Chemometrics is a powerful tool to deal with these problems and can help soil researchers to extract much more information from their data. In spite of this, the presence of these kinds of strategies in the literature has obtained projection only recently. The utilization of chemometric methods in soil analysis is evaluated in this article. The applications will be divided in four parts (with emphasis in the first two): (i) descriptive and exploratory methods based on Principal Component Analysis (PCA); (ii) multivariate calibration methods (MLR, PCR and PLS); (iii) methods such as Evolving Factor Analysis and SIMPLISMA; and (iv) artificial intelligence methods, such as Artificial Neural Networks.