Contribuições do sistema de integração lavoura-pecuária sobre os atributos químicos, frações da matéria orgânica e índice de manejo de carbono em latossolo vermelho

Abstract

Sustainable management should consider the soil a resource to be preserved, working to improve their conditions and the satisfactory development of production systems employed. The objective of this work was to evaluate the chemical attributes, total organic carbon, physical fractions, carbon stocks, chemical and oxidizable fractions and the carbon management index in different configurations of integrated systems of agricultural production (SIPA) when compared among themselves and between production hay and native forest areas in a Red Latosol in the western region of Paraná. Nine soil management systems were evaluated, six of which were cultivated in the winter with different densities of black oats, 40 kg and 60 kg ha-1, and grazing frequencies, 0, 1 and 2, with soybean succession in summer (A40, 40ILP1, 40ILP2, A60, 60ILP1, 60ILP2), one in the winter period occurred natural reseeding ryegrass and forage turnip (RNAN) and soybean succession in summer and two management systems as witnesses, being one of hay production of Tifton 85 hay (Haying) and native forest fragment (Forest). In each area samples representative of the layers of 0.000.05, 0.05-0.10 and 0.10-0.20 m, where the chemical attributes were determined: hydrogen potential chemical properties (pH), phosphorus (P), potential acidity (H+Al) potassium (K), calcium (Ca), magnesium (Mg), sum of bases (SB), cation exchange capacity (CEC), base saturation (V), total organic carbon (TOC), carbon stock, fractions chemical (fulvic acids - FA, humic acids - HA and humic - HUM), oxidizable (F1, F2, F3 and F4) and physical grain size (particulate organic carbon - POC and associated with mining - AMOC) SOM and carbon management index (CMI), it is compared the managements together by Tukey and managements by the witnesses by Dunnett. Regarding the chemical characteristics were observed differences in managements areas witnesses, indicating maintenance of the contents of nutrients to the soil. Regarding TOC, the grazing management did not differ from the control areas. For the physical granulometric fractions all the managements contributed to the addition of residues to the POC when compared to the control areas, whereas for the AMOC it was not possible to observe improvements of the managements. Were observed maintaining the carbon content of the humic substances, particularly in depth, and of the oxidizable fractions F1, F3 and F4 when compared the areas witnesses. With respect to carbon management index (CMI) are management areas did not differ from witnesses, demonstrating that they provided maintenance on soil carbon content. The different configurations of SIPA, especially in 60ILP1 and 60ILP2, contributed to the maintenance and, or, in some cases, increase, among the chemical attributes, total organic carbon, physical fractions, carbon, chemical fractions, oxidizable and carbon management index when compared to other managements and the witnesses.