Soil physical properties and soil organic carbon content in northeast Brazil: long-term tillage systems effects

Abstract

Concerns about the negative effects of agriculture on soil physical quality and soil organic carbon (SOC) pools have spurred on the adoption of conservation tillage systems in tropical regions. This study aimed to evaluate the long-term impacts (16 th year) of conventional (CT), minimum (MT) and no-tillage (NT) practices and different cover crops (sunn hemp and a bean/ millet sequence) on soil physical properties and SOC content of a corn cultivated Ultisol in the northeast of Brazil. Soil bulk density (Bd), soil penetration resistance (SPR), soil aggregation, and total aggregate-associated carbon (C) (4-2 mm) were evaluated. Tillage practices exerted strong control on soil physical properties and total aggregate-C content but were influenced by cover crop species. Minimum tillage presented the lowest Bd, irrespective of cover crop, while NT with bean/millet sequence resulted in the lowest SPR. However, as regards soil aggregation and total aggregate-C, the results indicated that there were no differences between MT and NT, with both systems presenting greater mean weight diameter (MWD) and total aggregate-C content than CT. Total aggregate-C content in the 0.00-0.05 m soil layer in conservation tillage was increased by the adoption of a bean/millet sequence. Increased mechanical disturbance through CT practices was harmful to Bd, soil aggregation and SOC accrual. Overall, more conservative tillage practices and the proper choice of cover crops might yield greater soil quality. Low intensity of soil disturbances due to the adoption of MT favors soil aggregation and the accrual of SOC in weakly structured soils through increases in contact between organic and mineral particles while not causing significant destruction of soil aggregates.

Effects of Tillage Systems and Cropping Patterns on Soil Physical Properties in Mozambique

“…However, no clear trends were observed between different cropping patterns. Similarly, Oliveira et al [37] found no significant difference between beans and millet intercropping effects on Db.…”

Predictive physico-chemical model for soil quality index in a long-term green manure farming system at tropical conditions, North-eastern Brazil

“…In fact, the green manure practice has the ability to change both soil physical and chemical soil properties due to the high biomass production on soil surface (e.g., at this point the green manure plants act as cover crops protecting soil surface from erosion) and their biomass incorporation into soil pro le (e.g., here promoting rhizodeposition, nutrient cycling), thus resulting in a healthy soil environment from the subsequent annual plant species (Pacheco et al 2017;Hirte et al 2018;Çerçioğlu et al 2019;Oliveira et al 2020;Hu and Chabbi, 2021;Liu et al 2021;Mortensen et al 2021). Our results highlight the importance of considering the green manure practice as an alternative way to input organic resources (Haruna et al 2020).…”

Legume Cover Crops as One of the Elements of Strategic Weed Management and Soil Quality Improvement. A Review

“…Residues of CC plants, including legume CCs, improve soil structure by influencing soil strength, porosity and hydraulic properties. They also increase the diffusion capacity of soil air, as well as the formation of soil aggregates (basic units of soil structure) [217][218][219] (Table 3). [222] no legume CCs mixture of S. cereale L., P.…”