Cover crops in soybean crop rotation systems: nutrient cycling and soil quality

• Ano de defesa: 2022
• Autor(a) principal: Dalla Côrt, Andressa Selestina [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Species diversity; Nutrient use; Soil microbiota; Carbon stocks; Soybean grain yield; Diversidade de espécies; Uso de nutrientes; Microbiota do solo; Estoques de carbono; Produtividade de soja
• Link de acesso: http://hdl.handle.net/11449/235338

The interactions promoted by the species diversity between crops contribute an efficient agriculture in the nutrients use, soil carbon and microbial biomass management, with cover crops in no-tillage as a fundamental factor for these processes. The objective of this work was to evaluate the potential of annual and cover crops grown in the second crop to promote nutrient cycling, improve soil chemical indicators and increase the yield of soybean sown in succession under long-term in no-tillage in the Cerrado of Mato Grosso. The treatments consisted of MC: monocropped; CS1: Crotalaria spectabilis (Roth); CS2: Pennisetum glaucum (L.) (millet); CS3: Urochloa ruziziensis (Germain & Evrard); CS4: Cajanus cajan (L.) Millsp. (pigeon pea); and MIX: all four crops intercropped (C. spectabilis+P. glaucum+U. ruziziensis+C. cajan). Intercropping cover crops (MIX) and single U. ruziziensis (CS3) increased all evaluated soil chemical attributes through nutrient cycling and SDM production under long-term NTS. MIX, U. ruziziensis (CS3), and C. cajan (CS4) were associated with increases in soybean yield after the stabilization phase of the system, i.e., in the sixth and seventh year of NTS implementation. Crotalaria spectabilis is an important cover crop to increase soybean yield by N fixation in the establishment phase of no-tillage system. Shoot nutrient accumulation and release are important indicators of the nutrient cycling process and the potential to increase soybean yield in succession under NTS. The species diversity in MIX favored soybean yield and carbon sequestration, as evidenced by improvements in resistance to soil penetration, carbon from biomass and soil microbial biomass. U. ruziziensis was important for enhancing the activity of enzymes that degrade organic residues, particularly β-glucosidase activity, in no-tillage soybean production in the Cerrado, with a positive influence on carbon increase in the system. The monocropped (MC) is not indicated for use in the Cerrado because it is not able to improve the physical and biochemical characteristics of the soil and the soybean yield.