Edaphic fauna affects soybean productivity under no-till system

This study aimed to evaluate the relationship of edaphic fauna under a no-tillage system with different levels of soybean productivity [High (NTH), Medium (NTM) and Low (NTL)] in the west of Santa Catarina (Brazil), identifying which chemical and physical variables most affect them, and the best indicators that can be used. Native forest (NF) areas were used as a reference. A total of 207 samples of soil fauna were collected by soil monolith and pitfall trap methods over two years of evaluation in four municipalities. Based on edaphic fauna data, Shannon-Wiener (H’), Pielou (J), Dominance (D), Margalef and Fisher Alpha (α) indices were generated, in addition to the average richness and abundance. Data from NTs were submitted to analysis of variance and compared by Tukey's test (p > 0.05). The NF was used as a reference and compared with the agriculture system by Dunnett test (p > 0.05), and regressions between soybean productivity and diversity indices. The H’, Margalef, α indices, and average richness for soil fauna sampled by soil monoliths followed the productivity gradient NTH > NTM > NTL, showing a positive correlation with the increase of soybean productivity. NTH has a diversity index similar to that of NF. Soybean productivity is affected by the richness and diversity of edaphic fauna, but abundance was not sensitive in predicting treatments under no-tillage; Fisher's alpha index was more sensitive in treatment separation with soil monoliths. The environmental variables aluminum, organic matter, phosphorus, potassium and penetration resistance affect the fauna edaphic.

Soil spiders (Arachnida: Araneae) in native and reforested Araucaria forests

Spiders are part of the soil biodiversity, considered fundamental to the food chain hierarchy, directly and indirectly influencing several services in agricultural and forest ecosystems. The present study aimed to evaluate the biodiversity of soil spider families and identify which soil properties influence their presence, as well as proposing families as potential bioindicators. Native forest (NF) and reforested sites (RF) with Araucaria angustifolia (Bertol.) Kuntze were evaluated in three regions of the state São Paulo, both in the winter and summer. Fifteen soil samples were collected from each forest to evaluate the biological (spiders and microbiological), chemical and physical soil properties, in addition to properties of the litter (dry matter and C, N and S contents). For soil spiders, two sampling methods were used: pitfall traps and soil monoliths. In total, 591 individuals were collected, and distributed in 30 families, of which 306 individuals (22 families) came from pitfall traps and 285 individuals (26 families) from monoliths. Only samples obtained by the monolith method revealed seasonal differences in the mean density and richness of spiders between NF and RF. Canonical discriminant analysis showed the separation of these forests of Araucaria. Principal Component Analysis demonstrated the correlation of a number of spider families with certain soil properties (organic carbon, basal respiration, metabolic quotient, litter carbon, total porosity, bulk density and soil moisture). We identified 10 families (Anapidae, Corinnidae, Dipluridae, Hahniidae, Linyphiidae, Lycosidae, Nemesiidae, Palpimanidae, Salticidae, Scytodidae) that contributed most to separating native forest from the replanted forest, indicating the possibility of the spiders being used as bioindicators.

Edaphic fauna affects soybean productivity under no-till system

This study aimed to evaluate the relationship of edaphic fauna under a no-tillage system with different levels of soybean productivity [High (NTH), Medium (NTM) and Low (NTL)] in the west of Santa Catarina (Brazil), identifying which chemical and physical variables most affect them, and the best indicators that can be used. Native forest (NF) areas were used as a reference. A total of 207 samples of soil fauna were collected by soil monolith and pitfall trap methods over two years of evaluation in four municipalities. Based on edaphic fauna data, Shannon-Wiener (H), Pielou (J), Dominance (D), Margalef and Fisher Alpha (α) indices were generated, in addition to the average richness and abundance. Data from NTs were submitted to analysis of variance and compared by Tukey's test (p > 0.05). The NF was used as a reference and compared with the agriculture system by Dunnett test (p > 0.05), and regressions between soybean productivity and diversity indices. The H, Margalef, α indices, and average richness for soil fauna sampled by soil monoliths followed the productivity gradient NTH > NTM > NTL, showing a positive correlation with the increase of soybean productivity. NTH has a diversity index similar to that of NF. Soybean productivity is affected by the richness and diversity of edaphic fauna, but abundance was not sensitive in predicting treatments under no-tillage; Fisher's alpha index was more sensitive in treatment separation with soil monoliths. The environmental variables aluminum, organic matter, phosphorus, potassium and penetration resistance affect the fauna edaphic.(AU)

Soil spiders (Arachnida: Araneae) in native and reforested Araucaria forests

Spiders are part of the soil biodiversity, considered fundamental to the food chain hierarchy, directly and indirectly influencing several services in agricultural and forest ecosystems. The present study aimed to evaluate the biodiversity of soil spider families and identify which soil properties influence their presence, as well as proposing families as potential bioindicators. Native forest (NF) and reforested sites (RF) with Araucaria angustifolia (Bertol.) Kuntze were evaluated in three regions of the state São Paulo, both in the winter and summer. Fifteen soil samples were collected from each forest to evaluate the biological (spiders and microbiological), chemical and physical soil properties, in addition to properties of the litter (dry matter and C, N and S contents). For soil spiders, two sampling methods were used: pitfall traps and soil monoliths. In total, 591 individuals were collected, and distributed in 30 families, of which 306 individuals (22 families) came from pitfall traps and 285 individuals (26 families) from monoliths. Only samples obtained by the monolith method revealed seasonal differences in the mean density and richness of spiders between NF and RF. Canonical discriminant analysis showed the separation of these forests of Araucaria. Principal Component Analysis demonstrated the correlation of a number of spider families with certain soil properties (organic carbon, basal respiration, metabolic quotient, litter carbon, total porosity, bulk density and soil moisture). We identified 10 families (Anapidae, Corinnidae, Dipluridae, Hahniidae, Linyphiidae, Lycosidae, Nemesiidae, Palpimanidae, Salticidae, Scytodidae) that contributed most to separating native forest from the replanted forest, indicating the possibility of the spiders being used as bioindicators.(AU)

Cinnamomum zeylanicum essential oil reduces infestation by Alphitobius diaperinus in poultry litter

Background: Even though insecticides are managed and the period of sanitary emptiness in poultry is respected, the elimination of Alphitobius diaperinus may not be successful. The use of essential oils of plant origin presents as a good alternative in the substitution of insecticides with synthetic molecules, since they are easy to obtain, with rapid degradation and without risk of residues for non-target organisms. The main objective of the present study was to examine whether Cinnamomum zeylanicum oil reduces Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) infestations under experimental conditions, without causing toxicity to broilers chicks exposed to treated litter.Materials, Methods & Results: The experimental design was completely randomized, with four replications per treatment. The treatments were as follows: solvent control using the diluent Dimethyl Sulfoxide 5% (oil diluent); chemical control using 5 g/m² cypermethrin; one spray of C. zeylanicum 5% oil; and two sprays of C. zeylanicum 5% oil. Each experimental unit was infested with 150 lesser mealworm adults. At 15 days of the broiler chick’s life, blood was collected for biochemical analysis (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, albumin, globulin, triglycerides and uric acid), and liver fragments were isolated for histopathological analysis. Using TupeTrap devices, we counted lesser mealworm 40 days after treatment. The treatments did not alter biochemical variables, and did not cause histopathological lesions in liver. The treatments with C. zeylanicum 5% oil with one and two sprays efficiently reduced lesser mealworm infestation compared with solvent control. Cypermethrin treatment had no effect. Discussion: Many of the commercial products present low effectiveness in the control of A. diaperinus, since the target organisms develop resistance to the product.[...]

Cinnamomum zeylanicum essential oil reduces infestation by Alphitobius diaperinus in poultry litter

Background: Even though insecticides are managed and the period of sanitary emptiness in poultry is respected, the elimination of Alphitobius diaperinus may not be successful. The use of essential oils of plant origin presents as a good alternative in the substitution of insecticides with synthetic molecules, since they are easy to obtain, with rapid degradation and without risk of residues for non-target organisms. The main objective of the present study was to examine whether Cinnamomum zeylanicum oil reduces Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) infestations under experimental conditions, without causing toxicity to broilers chicks exposed to treated litter.Materials, Methods & Results: The experimental design was completely randomized, with four replications per treatment. The treatments were as follows: solvent control using the diluent Dimethyl Sulfoxide 5% (oil diluent); chemical control using 5 g/m² cypermethrin; one spray of C. zeylanicum 5% oil; and two sprays of C. zeylanicum 5% oil. Each experimental unit was infested with 150 lesser mealworm adults. At 15 days of the broiler chicks life, blood was collected for biochemical analysis (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, albumin, globulin, triglycerides and uric acid), and liver fragments were isolated for histopathological analysis. Using TupeTrap devices, we counted lesser mealworm 40 days after treatment. The treatments did not alter biochemical variables, and did not cause histopathological lesions in liver. The treatments with C. zeylanicum 5% oil with one and two sprays efficiently reduced lesser mealworm infestation compared with solvent control. Cypermethrin treatment had no effect. Discussion: Many of the commercial products present low effectiveness in the control of A. diaperinus, since the target organisms develop resistance to the product.[...](AU)