Inclusion of potentially toxic elements in the DRIS and CND functions to evaluate the nutritional status of Eucalyptus treated with sewage sludge

Author(s)

Paulo Henrique Silveira Cardoso

• Document type: Doctoral Thesis
• Press: Piracicaba.
• Institution: Universidade de São Paulo (USP). Centro de Energia Nuclear na Agricultura (CENA/STB)
• Defense date: 2023-03-10

Examining board members

Cassio Hamilton Abreu Junior; William Natale; Rodinei Facco Pegoraro; Mario Tommasiello Filho

• Advisor: Cassio Hamilton Abreu Junior

Abstract

The application of sewage sludge (SS) in agricultural and forestry areas has great potential for the disposal of this by-product. However, the presence of potentially toxic elements (PTEs) in its composition may prevent or limit its use in cultivated areas. The use of methods to assess the nutritional status of crops treated with SS is necessary to study the influence of PTEs on plant development. Thus, the use of tools such as the Diagnosis and Recommendation Integrated System (DRIS) and the Compositional Nutrient Diagnosis (CND) can help in the evaluation of the nutritional status of Eucalyptus treated with SS. Thus, the objective of this work was to evaluate wood productivity, nutrient and PTEs contents and to determine norms and evaluate the nutritional status of Eucalyptus, with and without the inclusion of PTEs, by the DRIS, CND-clr (centered log ratio), and CND-ilr (isometric log ratio) methods, at different ages of a Eucalyptus urograndis plantation with different SS fertilization managements. The experiment was installed in 2015 in a randomized block design, with 10 treatments and 4 replications. Treatments consisted of: i) control; ii) two treatments with two dosis of mineral fertilization; iii) and seven treatments with SS application, with or without supplementation with P and/or B. Inventories and leaf sampling to assess the nutritional status of the plants were carried out at 22, 44, 54, and 76 months after planting Eucalyptus treated with SS class B. Treatments with SS application providing 100% of the N recommendation, supplemented with 66% of the P recommendation, with or without application of B, reached productivity in an average annual increment of 34, 57, 56, and 44 m3 ha-1 per year at 22, 44, 54, and 76 months after Eucalyptus planting, respectively. These productivities were similar to those observed in treatments with application of mineral fertilizers. By modeling the DRIS functions with the PTEs, it was possible to underestimate the deficiency and overestimate the excess of the PTEs, generating nutritional balance indices, which made it possible to verify that Ba was the most limiting element due to excess. The nutritional diagnosis agreement (balanced, deficiency, and excess) with or without the inclusion of PTEs ranged from 60 to 99% of the populations by the DRIS and CND-clr methods. The inclusion of PTEs in the CND-clr norms and functions for Eucalyptus does not change the interpretation of the nutritional status of the crop. With the CND-ilr method, the high productivity and nutritionally balanced subpopulation presented, for the most part, populations of Eucalyptus treated with LE application to provide 100% of the N recommendation, with accuracy of 58 and 61% for the evaluations without and with the inclusion of PTEs at 76 months after planting, respectively. Thus, the inclusion of PTEs in the DRIS, CND-clr, and CND-irl functions can bring important information as to which element is causing more damage to the plants. The need for specific norms for each region, age and/or analysis of planting is highlighted (AU)

• FAPESP's process: 17/26375-1 - INCLUSION OF TOXIC ELEMENTS IN THE DRIS AND CND FUNCTIONS FOR THE EVALUATION OF EUCALYPTUS NUTRITIONAL STATUS
• Grantee: Paulo Henrique Silveira Cardoso
• Support Opportunities: Scholarships in Brazil - Doctorate