scholarly journals Soil macrofauna associated with cover crops in an Oxisol from the southwest of Piauí state, Brazil

2020 ◽  
Vol 87 ◽  
Author(s):  
Djavan Pinheiro Santos ◽  
Robélio Leandro Marchão ◽  
Ronny Sobreira Barbosa ◽  
Juvenal Pereira da Silva Junior ◽  
Everaldo Moreira da Silva ◽  
...  

ABSTRACT: The soil macrofauna is fundamental for the maintenance of soil quality. The aim of this study was to characterize the soil macrofauna under different species of cover crops, including monoculture or intercropping associated to two types of soil management in the southwest region of Piauí state. The study was carried out in an Oxisol (Latossolo Amarelo, according to Brazilian Soil Classification System) in the municipality of Bom Jesus, Piauí, distributed in 30 m2 plots. Testing and evaluation of the soil macrofauna were conducted in a 9 × 2 strip factorial design, with combinations between cover crops/consortia and soil management (with or without tillage), with four replications. Soil monoliths (0.25 × 0.25 m) were randomly sampled in each plot for macrofauna at 0‒0.1, 0.1‒0.2, and 0.2‒0.3 m depth, including surface litter. After identification and counting of soil organims, the relative density of each taxon in each depth was determined. The total abundance of soil macrofauna quantified under cover crops in the conventional and no-tillage system was 2,408 ind. m-2, distributed in 6 classes, 16 orders, and 31 families. The results of multivariate analysis show that grass species in sole cropping systems and no-tillage presents higher macrofauna density, in particular the taxonomic group Isoptera. No-tillage also provided higher richness of families, where Coleoptera adult were the second more abundant group in no-tillage and Hemiptera in conventional tillage.

2020 ◽  
Vol 12 (15) ◽  
pp. 6103
Author(s):  
Ali reza Safahani Langeroodi ◽  
Roberto Mancinelli ◽  
Emanuele Radicetti

Quinoa cultivation is well-adapted to sustainable cropping systems, even if seed yield could be severely limited due to several constraints, such as weeds. Field trials were performed in Gorgan (Iran) to quantify the effects of agro-ecological service crops (rye, CCr; winter vetch, CCw; and no cover, CC0), tillage regimes (conventional tillage, CT; and no-tillage, ZT), and herbicide rates (100% rate, H100; 75% rate, H75; and without herbicide, H0). Weed characteristics and quinoa yield were measured. Quinoa seed yield was the highest in CCw-ZT-H100. Seed yield in H100 and H75 were higher compared with H0 (2.30 vs. 1.58 t ha−1, respectively). Under conventional tillage, 46% of weed seeds were observed in the 0–10 cm soil layer and 54% in 10–20 cm soil layers, respectively, while, under no-tillage, about 63% of weed seeds were located up to 10 cm of soil. Amaranthus retroflexus L. was the most abundant species. The total weed density was the lowest in CCr-ZT-H100 and tended to be higher in CC0 (30.9 plant m−2) and under CT (29.0 plant m−2). These findings indicate that cover crops have potential for managing weeds in quinoa; however, their inclusion should be supported by chemical means to maintain high seed.


2002 ◽  
Vol 32 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Cimélio Bayer ◽  
Deborah Pinheiro Dick ◽  
Genicelli Mafra Ribeiro ◽  
Klaus Konrad Scheuermann

Land use and soil management may affect both labile and humified soil organic matter (SOM) fractions, but the magnitude of these changes is poorly known in subtropical environments. This study investigated effects of four land use and soil management systems (forest, native pasture, and conventional tillage and no-tillage in a wheat/soybean succession) on (i) total soil organic carbon (SOC) stocks (0 to 250mm depth) and on (ii) carbon (C) stocks in labile (coarse, light) and humified (mineral-associated, humic substances) SOM fractions (0 to 25mm depth), in a Hapludox soil from southern Brazil. In comparison to the adjacent forest site, conventionally tilled soil presented 36% (46.2Mg ha-1) less SOC in the 0 to 250mm depth and a widespread decrease in C stocks in all SOM fractions in the 0 to 25mm depth. The coarse (>53 mum) and light (<1kg dm-3) SOM fractions were the most affected under no-tillage, showing 393% (1.22Mg C ha-1) and 289% (0.55Mg C ha-1) increases, respectively, in relation to conventional tillage. Similar results were observed for mineral-associated SOM and humic substance C pools (34% and 38% increases, respectively) under no-tillage. Compared with labile SOM fraction results, the percentual increments on C stocks in humified fractions were smaller; but in absolute terms this C pool yielded the highest increases (3.06 and 2.95Mg C ha-1, respectively). These results showed that both labile and humified organic matter are better protected under the no-tillage system, and consequently less vulnerable to mineralization. Humified SOM stabilization process involving interactions with variable charge minerals is probably important in maintaining and restoring soil and environmental quality in tropical and subtropical regions.


Soil Systems ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 50 ◽  
Author(s):  
Patricia Dörr de Quadros ◽  
Adam R. Martin ◽  
Kateryna Zhalnina ◽  
Raquel Dias ◽  
Adriana Giongo ◽  
...  

There are multiple mechanisms by which enhanced diversity of plant communities improves soil structure and function. One critical pathway mediating this relationship is through changes to soil prokaryotic communities. Here, nine different cropping systems were studied to evaluate how legume and grass cover crops influence soil fertility and microbial communities in a maize-based no tillage system. The soil’s bacterial and archaeal communities were sequenced (Illumina GAIIx, 12 replicates for treatment) and correlated with eight different soil features. The microbial community composition differed widely between planting treatments, with three primary “community types” emerging in multivariate space: (1) A community type associated with bare soil linked with low P, low pH, and high aluminum [Al]; (2) a community type associated with Lablab beans linked with high soil N, total organic carbon and other base cation concentrations, and high pH; and (3) a community type of all other non-lablab planting arrangements linked with higher soil P (relative to bare soil), but lower soil fertility (N and base cations). Lablab-based arrangements also expressed the highest microbial richness and alpha diversity. The inclusion of Lablab in maize-based cropping systems represents a potential alternative to reduce the use of chemical fertilizers and increase the chemical and biological quality in agricultural soils under the no-tillage system.


2017 ◽  
Vol 47 (1) ◽  
pp. 72-79
Author(s):  
Lamara Freitas Brito ◽  
João Carlos Cardoso Galvão ◽  
Jeferson Giehl ◽  
Silvane de Almeida Campos ◽  
Steliane Pereira Coelho

ABSTRACT The no-tillage farming has become a popular practice in Brazil, but problems with weed control and plant nutrition persist under organic production systems. This study aimed at evaluating the agronomic traits and yield of maize, after using different off-season cover crops under two organic no-tillage systems. A randomized block design, with a 7 x 2 factorial scheme, being 7 treatments (weeds; black oat monoculture; sunflower; white lupin intercropped with black oat in rows; white lupin intercropped with black oat by broadcasting; white lupin monoculture; and no cover crop) and 2 cropping systems (maize alone and intercropped with jack bean), and four replications was used. The agronomic traits evaluated were plant height, first-ear insertion height, stem diameter, prolificacy, 1,000 grain weight, grain yield and nitrogen released at 60 days of mulch decomposition. White lupin straw in monoculture and intercropped with black oat release a higher amount of N during the decomposition process and, consequently, these treatments increase maize yield. Intercropping with jack bean within the same row as maize reduces its yield potential under an organic no-tillage system.


Bragantia ◽  
2011 ◽  
Vol 70 (4) ◽  
pp. 899-907 ◽  
Author(s):  
Enderson Petrônio de Brito Ferreira ◽  
Adriane Wendland ◽  
Agostinho Dirceu Didonet

Aiming to evaluate the effects of soil management and cover crops on microbial indicators of soil quality, an experiment was carried out under field conditions in which common bean and corn were cropped under no-tillage (NT) and conventional tillage (CT) after sunnhemp, velvet bean, pigeon pea, jack bean, sorghum and fallow (weeds). The basal soil respiration (BSR), C and N of the microbial biomass (Cmic and Nmic), metabolic quotient (qCO2), total enzymatic activity (TEA), β-glycosidase (β-GA) activity and acid phosphatase activity (APA) were evaluated in samples collected in 0-0.10 m depth. Cmic, qCO2, TEA, β-GA and APA were more sensitive in determining the effects caused by tillage and cover crops. Although the cover crops had not provided a remarkably influence on the studied indicators, in general, the highest values of Cmic, Nmic, BSR, TEA, β-GA and APA and the lowest values of qCO2 were observed under NT compared to CT. Cmic and TEA values were 35% and 13% higher under NT when compared to CT, respectively. In addition, NT showed values closer to those found under "Cerrado" area for the studied parameters, indicating a greater sustainability under this soil management system compared to CT management.


2012 ◽  
Vol 32 (4) ◽  
pp. 784-793 ◽  
Author(s):  
Daniel F. de Carvalho ◽  
Marcio E. de Lima ◽  
Alexsandra D. de Oliveira ◽  
Hermes S. da Rocha ◽  
José G. M. Guerra

Under organic management in Seropédica-RJ, Brazil, using a weighing lysimeter, the crop coefficients (kc), the maximum evapotranspiration and the productivity of eggplant cultivation under two cropping systems (no tillage with straw plus soil with conventional preparation) were determined. A whole randomized layout with two treatments (no tillage and conventional) and five replicates during 134 days of cultivation were adopted. There were no significant differences in the eggplant cultivation in the two cropping systems, with a maximum commercial productivity obtained from 47.42 Mg ha-1 for the no-tillage system, and 47.91 Mg ha-1 for the conventional tillage. The accumulated ETc was 285.15 and 323.44 mm for the no-tillage and conventional, respectively. The crop coefficients value for the phases: 1 - transplanting, flowering, 2 - flowering-fruiting, 3 - fruit- first harvesting, 4- first harvesting of the final crop cycle was 0.83, 0.77, 0.90 and 0.97 in no-tillage system for the respective phases and for the conventional one 0.81, 1.14, 1.17 and 1.05 for the same steps described above.


2018 ◽  
Vol 36 (0) ◽  
Author(s):  
C.T. FORTE ◽  
L. GALON ◽  
A.N. BEUTLER ◽  
F.W. REICHERT JR. ◽  
A.D. MENEGAT ◽  
...  

ABSTRACT: Phytosociological studies are groups of methods that aim at the identification, composition and distribution of plant species in a community. The objective of this study was to identify and quantify the main weeds found in beans, maize and soybean cultivated in no-tillage and conventional systems. The experimental design was a randomized block one, with four replications. Experiments were conducted during three consecutive years, with summer crop (bean, maize and soybean) treatments, no-tillage system (NTS) composed by the covers, black oat, vetch and forage radish, in addition to their intercrop. In the conventional planting system (CTS), the area was left fallow in the off-season. The shoot dry matter of the covers was evaluated in each crop. The evaluated variables were: frequency, density, abundance, dry matter and the importance value index of the species in the area. Eighteen species of weeds and 12 families were identified, with Asteraceae and Poaceae families showing the highest number of individuals. The shoot dry matter production presented a difference among the covers; the cover black oat alone and intercrop with radish and vetch stood out, with the highest averages in the 3 years of the experiments. Cropping systems and different cover crops within the no-tillage system interfered in the number of encontered species. The emergence of Euphorbia heterophylla was favored, while the emergence of Lolium multiflorum was inhibited. E. heterophylla was the most encountered in the NTS areas, and its germination was negatively influenced by soil mobilization. The intercrop of black oat and vetch provided maximum weed control in soybean.


2012 ◽  
Vol 47 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Adriano Stephan Nascente ◽  
Carlos Alexandre Costa Crusciol

The objective of this work was to evaluate the effect of cover crops and timing of pre-emergence herbicide applications on soybean yield under no-tillage system. The experiment consisted of four cover crops (Panicum maximum, Urochloa ruziziensis, U. brizantha, and pearl millet) and fallow, in addition to four herbicide timings (30, 20, 10, and 0 days before soybean sowing), under no-tillage system (NTS), and of two control treatments under conventional tillage system (CTS). The experimental design was a completely randomized block, in a split-plot arrangement, with three replicates. Soybean under fallow, P. maximum, U. ruziziensis, U. brizantha, and pearl millet in the NTS and soybean under U. brizantha in the CTS did not differ significantly regarding yield. Soybean under fallow in the CTS significantly reduced yield when compared to the other treatments. The amount of straw on soil surface did not significantly affect soybean yield. Chemical management of P. maximum and U. brizantha near the soybean sowing date causes significant damage in soybean yield. However, herbicide timing in fallow, U. ruziziensis, and pearl millet does not affect soybean yield.


Author(s):  
Marla O. Fagundes ◽  
Diony A. Reis ◽  
Roberto B. Portella ◽  
Fabiano J. Perina ◽  
Julio C. Bogiani

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.


2020 ◽  
Vol 12 (4) ◽  
pp. 194
Author(s):  
Venâncio Rodrigues e Silva ◽  
José Luiz Rodrigues Torres ◽  
Danyllo Denner de Almeida Costa ◽  
Bruna de Souza Silveira ◽  
Dinamar Márcia da Silva Vieira ◽  
...  

The period of implantation of the no-tillage system (NTS) is a fundamental factor to the dimension of the changes that occur to the soil&#39;s physical, chemical and biological attributes. Thus, the objective of this study was to evaluate the soil changes to the physical attributes and correlate the results to the soil organic matter in areas of different long-term soil management. The study was set as a completely randomised design, in a 4 &times; 4 factorial scheme, with four management systems [5 years NTS (NTS5); 17 years NTS (NTS17); conventional tillage system for 20 years (CTS20); native area (NA)], and four soil depths (0-0.05, 0.05-0.1, 0.1-0.2, 0.2-0.4 m), with five repetitions. Soil mechanical resistance to root penetration (RP), bulk density (SD), volumetric moisture (VM), macro (Ma), microporosity (Mi) and total porosity (TP), and the aggregation parameters were evaluated. The CTS20, NTS5 and NTS17 presented superior SD in the most superficial soil layers, which was not yet causing resistance to root development. The SD was the only physical attribute that correlated significantly with all the other soil attributes evaluated, indicating the importance of such attribute to evaluate soil quality to crops. The soil physical attributes found in the Cerrado native area followed the sequence of similarities: no-tillage system with 17 years (most similar), with five years and the conventional tillage system (less similar). The changes caused by the anthropic activity in the soil&#39;s physical attributes are more pronounced and perceptible in soil depths up to 0.2 m.


Sign in / Sign up

Export Citation Format

Share Document