scholarly journals Microbiological and faunal soil attributes of coffee cultivation under different management systems in Brazil

2015 ◽  
Vol 75 (4) ◽  
pp. 894-905 ◽  
Author(s):  
D. R. Lammel ◽  
L. C. B. Azevedo ◽  
A. M. Paula ◽  
R. D. Armas ◽  
D. Baretta ◽  
...  

Abstract Brazil is the biggest coffee producer in the world and different plantation management systems have been applied to improve sustainability and soil quality. Little is known about the environmental effects of these different management systems, therefore, the goal of this study was to use soil biological parameters as indicators of changes. Soils from plantations in Southeastern Brazil with conventional (CC), organic (OC) and integrated management systems containing intercropping of Brachiaria decumbens (IB) or Arachis pintoi (IA) were sampled. Total organic carbon (TOC), microbial biomass carbon (MBC) and nitrogen (MBN), microbial activity (C-CO2), metabolic quotient (qCO2), the enzymes dehydrogenase, urease, acid phosphatase and arylsulphatase, arbuscular mycorrhizal fungi (AMF) colonization and number of spores and soil fauna were evaluated. The greatest difference between the management systems was seen in soil organic matter content. The largest quantity of TOC was found in the OC, and the smallest was found in IA. TOC content influenced soil biological parameters. The use of all combined attributes was necessary to distinguish the four systems. Each management presented distinct faunal structure, and the data obtained with the trap method was more reliable than the TSBF (Tropical Soils) method. A canonic correlation analysis showed that Isopoda was correlated with TOC and the most abundant order with OC. Isoptera was the most abundant faunal order in IA and correlated with MBC. Overall, OC had higher values for most of the biological measurements and higher populations of Oligochaeta and Isopoda, corroborating with the concept that the OC is a more sustainable system.

2021 ◽  
Vol 9 (2) ◽  
pp. 126-135
Author(s):  
Zahraeni Kumalawati ◽  
Sri Muliani ◽  
Asmawati Asmawati ◽  
Kafrawi Kafrawi ◽  
Yunus Musa

The exploration of arbuscular mycorrhiza fungi from sugarcane plantation in marginal land in South Sulawesi was carried out to find the source of inoculums showing effective infection. Soil samples were taken from four area with different characteristic of marginal land, namely land with low organic matter content, clay texture, limited irrigation, and undulating land. Mycorrhizae contained in the soil samples were then observed, and the spores obtained were used as the source of isolation by a single spore culture. The mycorrhizal spores were isolated by wet sieving and centrifugation method with 48% sucrose, which were observed under a compound microscope for spore details (100-1000x). Sugarcane root samples were taken to observe mycorrhizal infection in sugarcane root tissue by root staining method. The results of the study showed that the greatest diversity of mycorrhizal genera was found in soil samples of Jambua Block (Glomus, Gigaspora, and Sclerocistis) and AJ-5 Block area (Glomus, Acaulospora, and Sclerocistis). Single-spore isolates obtained were Glomus sp. and Acaulospora sp. Infection test result on four sugarcane varieties commonly grown in Takalar Sugar Factory showed that infectivity of mycorrhizal isolate of Acaulospora sp. was the highest (75%) and significantly different (LSD’test, p 0,05) compared to that of Glomus sp. (66%).


2019 ◽  
Vol 13 ((03) 2019) ◽  
pp. 380-385 ◽  
Author(s):  
Soraya Marx Bamberg ◽  
Silvio Junio Ramos ◽  
Marco Aurelio Carbone Carneiro ◽  
José Oswaldo Siqueira

Fertilizer application can enhance the nutritional value of plants, such effects being influenced by the presence of arbuscular mycorrhizal fungi (AMF). Nutrients × AMF interactions are well-known for variety of elements but very little has been addressed on biofortification of selenium (Se) in plants grown in tropical soils. The purpose of this study was to evaluate the effect of Se application and AMF inoculation on growth and micronutrient contents on soybean plants as forage grass. The experiments were conducted in a completely randomized factorial design with five Se doses (0.0, 0.5, 1.0, 2.0 and 3.0 mg kg-1 for soybean plants, and 0.0, 0.5, 1.0, 3.0 and 6.0 mg kg-1 for forage plants), with and without AMF inoculation in three replicates. The results showed that soil Se had only slight effect on soybean growth but it caused a two-fold increase on grain yield. However, the growth of forage grass was enhanced by Se application when AMF was present. The AMF inoculation reduced benefit for soybean growth and yield but marked positive effect on forage grass at high doses of Se. Selenium contents in both plants were increased by its application in soil, being such effect proportional to soil applied doses. Selenium application and AMF inoculation had marked effects on micronutrients contents in both soybean plants and forage grass and they may contribute to Se and micronutrient biofortification.


1969 ◽  
Vol 90 (3-4) ◽  
pp. 145-157 ◽  
Author(s):  
David Sotomayor-Ramírez ◽  
Gustavo A. Martínez

There is a need to quantitatively assess the soil fertility status of tropical soils. Descriptive summaries help describe the effectiveness of liming programs, nutritional limitation in soils and the relative risk of off-field nutrient transport. A database of 1,168 soil test results collected from 1989 to 1999 from nearly 400 cultivated farms in Puerto Rico was used. Samples were analyzed for pH, organic matter (Walkley-Black method), extractable phosphorus (P) (Olsen and Bray 1), and exchangeable bases (NH4Oac method) by a commercial laboratory. Thirty-six percent of the samples had acidity problems (pH <5.5). Twenty-three percent of the samples had low organic matter content (<20 g/kg), and 16% had high category (>40 g/kg) values. Fifty-three and 56% of the samples showed a need to fertilize with magnesium (Mg) and potassium (K), respectively, because they had values below the suggested critical levels of 2.5 cmolc/kg for soil exchangeable Mg and of 0.4 cmolc/kg for K. On the basis of current soil fertility criteria, P fertilization would be required in 69% of the samples with pH less than 7.3, but only in 28% of the samples with pH greater than or equal to 7.3. Although the soils grouped with pH >7.3 had a greater proportion of samples in the "extremely high" soil test P category, the potential environmental impact may be lessened because the climatic and topographic conditions where these soils occur favor less runoff. Follow-up studies are needed to assess the spatial variability and the temporal dynamics of the nutritional status of soils of Puerto Rico. 


Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1291 ◽  
Author(s):  
B. S. Ismail ◽  
K. Kalithasan

The mobility of metsulfuron-methyl in 5 soil series with different organic contents was determined in a greenhouse as well as under natural conditions. In these studies, the movement and biological activity of metsulfuron-methyl were determined by the bioassay method using long bean as a bioassay species. Bioactivity and movement of the herbicide down the soil profile were inversely related to the organic matter content of the soil. Phytotoxic levels of metsulfuron-methyl were restricted to the 10-cm depth of the column containing Selangor Series soil except when it received 40 mL of water daily (depth, 10–15 cm). In Munchung Series, the phytotoxic level was also mainly in the 5–10 cm layer. However, when the column received 40 mL daily or every 4 days, the residue was detected in 15–20 cm and 10–15 cm zones, respectively. The phytotoxic level moved downward to the 20–25 cm layer both in Sogomana and Holyrood Series when 40 mL of water was given daily. A phytotoxic level of metsulfuron herbicide was detected in the 20–25 cm layer when the soil column containing Serdang Series was leached with 40 mL of water every 4 days or with 20 mL daily; the phytotoxic level was detected at a depth of 25–30 cm when this soil was watered daily with 40 mL. The downward movement of metsulfuron under natural conditions showed a pattern similar to that found under simulated conditions. Phytotoxic effects of the residue could be detected in the 25–30 cm and 15–20 cm zone of Serdang and Holyrood Series, respectively, after exposure to 20 days of rainfall (total 111·9 mm). Phytotoxic residue in both Sogomana and Munchung Series soil was detected in the 10–15 cm layer, and in the 5–10 cm layer for Selangor Series soil, after exposure to 20 days of rainfall. After exposure to 40 days of rainfall (total 152·8 mm) under natural conditions, the residue could be detected in the 15–20 cm layer of Selangor Series. The phytotoxic level moved deeper in soil with low organic matter after exposure to 40 days of rainfall. Fresh weight reduction was greater in the 20–30 cm layer in Serdang Series than in the top layer.


2017 ◽  
Vol 81 (1) ◽  
pp. 111 ◽  
Author(s):  
Carlos A.M. Barboza ◽  
Tatiana Cabrini ◽  
Gustavo Mattos ◽  
Viviane Skinner ◽  
Ricardo Cardoso

Log-spiral beaches display defined physical gradients alongshore. However, the majority of studies focus on the variability of a single population of macrofauna species. We aimed to investigate the variation in species distribution and in community structure along ten transects on a log-spiral beach. Principal component analysis indicated a clear physical gradient alongshore. Redundancy analysis showed that the sheltered end was related to smaller particle sizes, higher organic matter content and high densities of polychaetes. The exposed end was characterized by coarser sand, lower organic matter content and a high presence of crustaceans. Model selection indicated that the “best fit” to explain the variability in the number of individuals included grain size and beach slope. Variability of the polychaete Scolelepis squamata was best explained by grain size, slope and sediment sorting. The best model for the cirolanid Excirolana armata only included sediment sorting. The physical gradient in sediment texture and the beach slope explained more than one-third of the variability in community structure. The physical variables were also correlated with the distribution of the individual species. We showed that the physical gradient on log-spiral coasts may be an important driver of macrofauna variability, even at mesoscales and in dissipative conditions.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Veronica Pereira Bernardes ◽  
Fernando Luis Mantelatto ◽  
Thiago Elias da Silva ◽  
Aline Nonato de Sousa ◽  
Camila Hipólito Bernardo ◽  
...  

Abstract: This study evaluated the relationships between environmental factors and the spatio-temporal distribution of H. pudibundus, with the hypothesis of differential occupation in coastal areas of southeastern Brazil. The samplings took place monthly in January-December 2000 period, along nine transects from 2 to 40 m of depth, in Ubatuba region, northern coast of São Paulo. We collected 1808 individuals of H. pudibundus. The highest abundance was recorded in winter in the transects 10-25 m deep. Abundance was positively correlated with organic matter content and texture sediment (phi values). With the retreat of the South Atlantic Central Water (SACW) in autumn and winter, the sediment swirls, suspending the detritivore and filter-feeding macrofauna, increasing the food availability. Sites characterized by finer sediment offer higher food availability, besides facilitating H. pudibundus burying behavior. Due to its opportunistic predatory behavior, this species feeds on a variety of organisms, including mollusks, annelids and foraminifera, which are preys more abundant in the studied area and in sediments of finer grain size.


2017 ◽  
Vol 41 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Estêvão Vicari Mellis ◽  
José Carlos Casagrande ◽  
Marcio Roberto Soares

ABSTRACT Although nickel (Ni) has both important potential benefits and toxic effects in the environment, its behavior in tropical soils has not been well studied. Nickel adsorption-desorption in topsoil and subsoil samples of an acric Oxisol was studied at three pH values (from 3.0 to 8.0). Adsorption-desorption isotherms were elaborated from experiments with increasing Ni concentration (5 to 100 mg L-1), during 0, 4, and 12 weeks, using CaCl2 0.01 and 0.1 M as electrolytic support in order to also verify the effect of Ni-soil time contact and of ionic strength on the reaction. Experimental results of Ni adsorption fitted Langmuir model, which indicated that maximum Ni adsorption (71,440 mg kg-1) occurred at subsoil, after 12 weeks. Nickel affinity (KL) was also greater at subsoil (1.0 L kg-1). The Ni adsorption in the topsoil samples was higher, due to its lower point of zero salt effect (PZSE) and higher organic matter content. The increase in soil pH resulted in the increase of Ni adsorption. Nickel desorbed less from soil samples incubated for 4 or 12 weeks, suggesting that Ni interactions with colloidal particles increase over time. The amount of Ni desorbed increased with increasing ionic strength in both the topsoil and subsoil soil samples. Finally, adsorption-desorption hysteresis was clearly observed. Soil pH, ionic strength of soil solution and the Ni-soil contact time should be considered as criteria for selecting the areas for disposal of residues containing Ni or to compose remediation strategies for acric soils contaminated with Ni.


Pedosphere ◽  
2021 ◽  
Vol 31 (6) ◽  
pp. 903-911
Author(s):  
Carlo ANGELETTI ◽  
Elga MONACI ◽  
Beatrice GIANNETTA ◽  
Serena POLVERIGIANI ◽  
Costantino VISCHETTI

2020 ◽  
Vol 5 (1) ◽  
pp. 539-547
Author(s):  
Elizabeth Temitope Alori ◽  
Oluyemisi Bolajoko Fawole ◽  
Medinat Olaitan Akanji

AbstractA potted experiment arranged in a 5 × 3 factorial in a randomized complete block design was undertaken to investigate the occurrence of arbuscular mycorrhizal fungi (AMF) in the soil of five leguminous plants: Cajanus cajan (L.) Huth, Centrosema pascuorum Martius ex Benth, Crotalaria ochroleuca G. Don, Lablab purpureus (L.) Sweet and Mucuna pruriens (L.) DC. The effects of varying phosphorus concentrations (P0) (0 kg/ha of single superphosphate), P1 (100 kg/ha of single superphosphate) and P2 (200 kg/ha of single superphosphate) on the population of AMF spores under these legumes were also carried out. The AMF spores in soil samples were extracted at 19 weeks after planting, using the wet sieving and decanting method, and enumerated with the aid of a stereoscopic microscope. Spores of different species of genera Glomus and Gigaspora were encountered in the soils of the five leguminous plants. Spores of Glomus species predominated while the spores of Gigaspora species were found in lower numbers. The total AMF population was significantly affected by legume species (p ≤ 0.05). The total AMF spore counts were higher in the soils of Mucuna pruriens and Crotolaria ochroleuca (p ≤ 0.05). The populations of Glomus mossae in soils decreased with increasing level of applied phosphorus (p ≤ 0.05). A positive correlation was recorded between the total AMF spores, the predominant AMF spores and soil pH, while the organic matter content and the available phosphorus were negatively correlated with both the total AM spores and the predominant AMF spores.


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