Short-term effect of no-tillage management on the chemical attributes and bacterial diversity in soils in an organic production system

Abstract

No-tillage (NT) has been adopted in organic agriculture as an alternative to conventional tillage (CT) for improving soil conservation. Cover crops (CC) play a vital role in this process by providing straw and releasing nutrients into the soil. Therefore, in this study, we aimed to evaluate the effects of NT and CT management on the chemical properties and bacterial diversity of soil following the cultivation of diverse CC in an organic system. The experiment was conducted using a randomized block design with subdivided plots, wherein the plots represented CT and NT, and the subplots represented the diverse CC tested, including pearl millet, sunn hemp, jack bean, seed mixes 1 and 2 (containing 100 % and 50 % of the recommended seeding rates for each crop), and spontaneous plants. The evaluations were conducted one year after the experiment was conducted. The results demonstrated that NT promoted increases in soil magnesium, phosphorus, and organic carbon contents, including increased bacterial richness. Moreover, NT resulted in a higher abundance of Bacteroidetes, GAL15, and Myxococcota. Conversely, CT favored a greater relative abundance of Actinobacteria, in addition to the members of Bacteroidetes. Regarding the influence of CC, no significant differences were observed in the diversity and structure of the bacterial communities, except for subgroup 17, which was more abundant in spontaneously grown plants. NT proved to be more effective than CT in improving soil chemical properties and bacterial diversity, implying its potential to contribute to sustainable agricultural systems.