Nitrogen dynamics in soil management systems: II - mineralization and nitrification rates

Autor: Eduardo Garcia Cardoso, João Carlos de Moraes Sá, Clever Briedis, Ademir de Oliveira Ferreira, Paulo Rogério Borszowskei, Josiane Burkner Santos, Aline Massinham, Carla Fernanda Ferreira, Darci Siuta Júnior, Edemar José Baranek
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: Revista Brasileira de Ciência do Solo, Vol 35, Iss 5, Pp 1651-1660 (2011)
Druh dokumentu: article
ISSN: 1806-9657
0100-0683
DOI: 10.1590/S0100-06832011000500019
Popis: Nitrogen is the main limiting factor in crop productivity and thereby soil management systems may change the mineralization and nitrification rates. In an experiment on soil management systems implemented in 1988 at the experimental station Fundação ABC, Ponta Grossa, in the central South region of the State of Paraná, inorganic N dynamics were examined to find a soil management strategy with a view to a sustainable environment. The objective of this study was to calculate the net mineralization and nitrification rates of soil N and the correlation with soil pH under management systems. Randomized complete block design was used, in split plots, in three replications. The following soil management systems (SMSs) were adopted in the plots: 1) conventional tillage (CT); 2) minimum tillage (MT); 3) no-tillage with chisel plow every three years (NT CH); and 4) continuous no-tillage (CNT). To evaluate the dynamics of inorganic N, samples were collected from sub-plots at different times (11 sampling times - T1 to T11). In the CNT and NT CH, the net mineralization rates were higher in the MT and CT systems in the 0-2.5 cm soil layer, while the nitrification rate was higher in the 2.5-5 cm layer. Soon after implementing the white oat management, the mineralization and nitrification rates in all soil layers were higher in the MT and CT systems. In the period of soybean development, in the 0-2.5 and 2.5-5 cm soil layers, the mineralization and nitrification rates were higher in the CNT and NT CH than in the MT and CT systems.
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