ABSTRACT
Assessing soil quality under different cover crops or different management systems is essential to its conservation. This study aimed to evaluate an Oxisol cultivated with corn and cotton, after different crop successions and under no-tillage system (NTS) and conventional tillage system (CT), through the soil quality index (SQI), using an area of native Cerrado as reference. The study was carried out in the municipality of Luís Eduardo Magalhães, Western Bahia, Brazil. Soil samples with the preserved and non-preserved structure were collected in the layers of 0-0.05 m, 0.05-0.10 m, and 0.10-0.20 m to determine the macroporosity, the soil bulk density, the available water, the levels of total organic carbon, the clay dispersed in water, and the degree of flocculation. The averages of the attributes measured in the treatments and the soil quality index, which was elaborated by the method of deviations of the values of the attributes measured in the treatments concerning the reference area, followed by normalization, were compared by the Duncan test (p ≤ 0.05). The soil under CT, in all treatments, had its quality reduced when compared to the NTS. Also, the SQI used was sensitive to detect the changes caused by the management systems and assign consistent scores to the evaluated soil quality.
Key words:
soil conservation; sustainable management; crop rotation; conventional tillage; no-tillage system
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T1 - corn under conventional tillage (CT); T2 - corn under the no-tillage system (NTS) intercropped with brachiaria; T3 - corn under NTS intercropped with brachiaria in succession to soy, millet, and cotton; and T4 - corn under NTS intercropped with sunn hemp; T5 - cotton under conventional tillage (CT); T6 - cotton under CT intercropped with millet; T7 - cotton under the no-tillage system (NTS) in succession to soybean, sunn hemp, corn, and brachiaria; and T8 - cotton under NTS in succession to soy and sorghum; Lowercase letters on the error lines in the columns indicate the statistical difference among treatments by the Duncan test at p ≤ 0.05. The vertical bars represent the SQI averages obtained in the different treatments evaluated (n = 4)