Spanish Journal of Agricultural Research
Not a member yet
2067 research outputs found
Sort by
Influence of aerobic treated manure application on the chemical and microbiological properties of soil
No full textAim of study: This study evaluated the effect of the application of liquid aerobic treated manure (continuous liquid composting, CLC) on physical, chemical and biological soil properties, with the objective of monitoring changes induced by soil management with CLC as a biofertilizer.Area of study: Colonia, Uruguay (lat. 34,338164 S, long. 57,222630 W).Material and methods: Soil’s chemical properties, including nitrogen mineralization potential (NMP) and 15 microbiological properties (microbial biomass carbon, MBC; mesophylic aerobic bacteria; actinobacteria; filamentus fungi; fluorescein diacetate hydrolysis; dehydrogenase; with NMP; acid and alkaline phosphatase; cellulolose degraders; P-solubilizing bacteria; nitrifying; denitrifying and free-living N-fixing microorganisms; glomalin; and soil-pathogenicity index, SPI) were evaluated in two sites with similar cropping history, with one and three years of respective CLC application.Main results: CLC application had significant effects on soil microbial biomass (p<0.05), soil enzyme (p<0.1) and functional groups activity (p<0.05). SPI decreased in both sites with CLC application. No significant variations were detected for the chemical variables, with the exception of NMP, which was significantly high (p<0.05) in soil treated with CLC at both sites.Research highlights: The improved biological soil properties analyzed (MBC, soil enzyme activities and SPI, together with NMP) emerged as reasonable indicators to assess and monitor the effects of CLC application
Effect of irrigation water quality on soil properties and infrared spectroscopic signatures
No full textAim of study: To study the effect of irrigation with medium-to-low-quality water on an olive farm that seems to be causing salinity and/or sodicity problems in soils, and the ability of infrared spectroscopy to detect this problem.Area of study: The study was conducted in an olive (Olea europaea L.) grove located in Guarromán (Jaen, Spain), on the boundary of the Sierra Morena Mountains and the Guadalquivir Depression.Material and methods: The olive farm is cultivated over two soil typologies, a calcareous area (carbonated) dominated by Regosols and a siliceous area with Leptosols. Typical soil physical and chemical parameters were determined, as well as near and mid infrared spectra were collected for analysis.Main results: Soil physical properties were affected by irrigation, with low infiltration rates and symptoms of structural degradation. Chemical properties were also altered, showing high pH, low amounts of organic carbon and N, and high sodium concentrations. These effects were stronger in the samples directly affected by the irrigation bulb, with the siliceous soils more affected than carbonated, probably due to the positive effect of the higher amounts of calcium in the latter. Using infrared spectroscopy, it was possible to discriminate the samples of this farm affected by sodicity from similar soil samples in Jaen province not affected.Research highlights: the use of medium-to-low quality irrigation water affected soil physical and chemical properties. Infrared spectroscopy could be useful for quick assessment of soil quality and soil degradation from salinity and sodicity
Reproductive performance of captive Senegalese sole, Solea senegalensis, according to the origin (wild or cultured) and gender
No full textAim of study: The reproductive performance over a five year period in three different sole broodstocks: wild males with cultured females (WM), cultured males with wild females (CM), and a control of cultured males and females (C).Area of study: Cantabria, Northern Spain.Material and methods: The parental contribution was evaluated through the allocation of hatched larvae and a behavioural study was performed using underwater video recordings.Main results: Fertilized natural spawns were only obtained from group WM showing a significantly higher mean annual volume of floating eggs compared with groups CM and C. Over the entire 5-yr a higher number of spawns, total and floating volumes of eggs were obtained compared with groups CM and C. The analysis of four polymorphic microsatellites enabled the identification of the individuals involved in the fertile spawns by parental assignment. The percentage of individuals contributing to spawns ranged between 56.3% and 75% showing fidelity patterns. However between 46.2% and 68.6% of the contribution to production was a result of the crossing of three single couples. According to the behaviour analysis, group WM presented the highest peak of activity at 20:00 h and a higher activity profile during the night, moreover, the courtship behaviours “swim follow” and “swim followed”, were only recorded in group WM.Research highlights: The study has importance for aquaculture as it demonstrated how broodstocks with wild males and cultured females had adequate egg production for a commercial operation to supply eggs and implement single sex breeding programs
Foliage applications of jasmonic acid modulate the antioxidant defense under water deficit growth in sugar beet
No full textAims of study: Water deficit (WD) is becoming an alarming problem in many regions of the world. Jasmonic acid (JA) is considered an important intracellular plant growth regulator. The aim of the current research was to investigate the important role of JA in mitigating the negative effects of WD on plant growth.Area of study: Sugar beet production systems of two locations in Chaharmahal-Bakhtiari province, Iran.Material and methods: A field trial was conducted to assess the foliar applications of JA (0, 5 µM and 10 µM) and WD (50%, 75%, 100% plant water requirements) effects on physiological yield components of sugar beet (Beta vulgaris L.) plants.Main results: WD significantly (p<0.05) increased catalase, ascorbate and peroxidase activities, and malondialdehyde, hydrogen peroxide and white sugar content (WSC); however, it caused a reduction in white sugar yield and root yield (RY). JA foliage applications further enhanced the enzymes activity in WD treated plants resulting in higher WSC, potassium concentrations, white sugar and final RY. Interestingly the effects of JA applications were more pronounced under severe WD (50%) compared to mild (75%) or well-watered plants (100%). JA (10 µM) foliage applications increased the RY and white sugar production by 21% and 24% under severe WD.Research highlights: JA can ameliorate the adverse effects of WD and increase the WD tolerance of sugar beet crop by upregulating the antioxidant enzyme activities to withstand adverse environmental conditions
Does pollen diversity influence honey bee colony health?
No full textAim of study: Colony losses of the western honey bee Apis mellifera have increased alarmingly in recent years. These losses have been attributed to nutritional deficiency, environmental conditions, viral infection and the global presence of the ectoparasite mite Varroa destructor. Ensuring pollen availability may improve colony health, so the present study aimed to examine whether the diversity of pollen collected by the colony as well as landscape characteristics of apiaries influence colony health.Area of study: Tenerife Island (Canary Islands, Spain).Material and methods: Colonies at eight apiaries were sampled in late summer to determine colony strength, presence of varroa and load of DWV. Pollen was collected during six months and analyzed. Landscape of each apiary was spatially analyzed.Main results: Pollen diversity did not correlate significantly with colony strength or the load of DWV, but it positively correlated with varroa levels. In contrast, DWV load correlated with varroa infestation, and both variables negatively correlated with colony strength. Weak colonies were located in landscapes with areas less suitable for bee nutrition.Research highlights: These results suggest that DWV and varroa infection as well as landscape characteristics influence colony survival, while pollen diversity on its own does not seem to have direct relationship. Our findings highlight the usefulness of DWV and varroa as predictors of colony losses, and they suggest the need to carefully assess honey bee apiary location in order to ensure adequate nutritional resources
Rosmarinus officinalis essential oil as an effective antifungal and herbicidal agent
No full textIn order to reduce the use of chemical pesticides, great interest has been focused on environment-friendly biological control agents and botanicals that preserve biodiversity. In this context, our study aimed to assess the antifungal and herbicidal activities of Rosmarinus officinalis essential oil (EO) to find an alternative to synthetic pesticides. The chemical composition of R. officinalis essential oil was determined by gaz chromatography-mass spectrometry analysis (GC-MS). Results showed that R. officinallis EO was rich in monoterpenes and the major constituents were 1,8-cineole (54.6%), camphor (12.27%) and α-pinene (7.09%). However, under laboratory conditions, two tests were carried out. The first one consisted on the study of EO antifungal activity using ELISA microplates and the second one consisted on evaluating the effect of EO on seedling growth of weeds. It was confirmed that this EO significantly inhibits spore germination of Fusarium oxysporum, Fusarium culmorum, Penicillium italicum and at 6 mM, the percentage of inhibition reached 100% on Fusarium oxysporum. Indeed, EO slows down seedling growth of Trifolium incarnatum, Silybum marianum, and Phalaris minor. In fact, EO at 5 mM completely inhibits seed germination. On the other hand, another experiment was carried out to evaluate the herbicidal activity by spraying EO on weeds. This showed that a novel herbicide formulation was set up for the first time to improve the activity of R. officinalis EO on post-emergence. Overall, R. officinalis EO can be suggested as a potential eco-friendly pesticide and suitable source of natural compounds potentially usable as natural pesticides
Evaluation of poultry manure and goat cheese whey anaerobic co-digestion
No full textHen droppings (HD) and Goat Cheese Whey (GCW) are two difficult substrates to be treated by anaerobic digestion due to their characteristics; however, their co-digestion offers the possibility of successfully treating these substrates together. The goal of this study was to evaluate the anaerobic co-digestion of HD and GCW at laboratory scale in order to determine biogas potential and possible operational problems before extrapolating results to a full-scale biogas plant. The potential methane production of HD, GCW and a mixture of both substrates was studied in batch mode, whereas the co-digestion of the mixture of HD and GCW was also studied in semi-continuous mode in a continuously stirred tank reactor. Results showed that the addition of GCW to HD increased methane production compared to HD alone; however, GCW alone showed the highest methane potential. In semi-continuous mode, the mixture of GCW and HD showed high biogas and methane yields (582.0±29.5 Lbiogas kg VS-1 and 381.2±19.0 LCH4 kg VS-1, respectively), although intense foaming incidents occurred. The composition of both substrates is complementary for their co-digestion and it improved the energy yield of the process. However, the economic viability of a biogas plant of 30 kWe, designed for treating HD and GCW, would be economically feasible only with subsidies for the investment and in the low range of investment costs for small scale biogas plants
Comparison of different classical and molecular methods for identifying self-incompatibility in two olive cultivars
No full textAim of study: To determine compatibility relationships and select suitable pollinizers for two olive (Olea europaea L.) cultivars (‘Amygdalolia’ and ‘Konservalia’).Area of study: The Kazeroun Olive Research Station, Fars, Iran.Material and methods: Emasculated flowers from ‘Amygdalolia’ and ‘Konservalia’ cultivars were treated with self-pollination, open-pollination, and cross-pollination with pollen from cultivars such as ‘Dacal’, ‘Amygdalolia’,‘Konservalia’, ‘Koroniki’, and ‘Manzanilla’. Controlled pollination, pollen tube growth, and molecular analysis were employed.Main results: Controlled pollination, pollen tube growth, and molecular analysis showed that cross-pollination was beneficial for ‘Amygdalolia’ compared to self-pollination. The results showed that this cultivar is self-incompatible, and its best pollinator is the ‘Dacal’ cultivar. Experiment results indicated that ‘Konservalia’ behaves as a self-compatible cultivar. The highest fruit percentage and higher pollen tube growth rates were found in self-pollination treatments. Molecular attempts to isolate candidates for sporophytic self-incompatibility (SSI) led the researchers to analyze the expression of SRK and SLG genes.Research highlights: The results indicated an antagonist transcriptional expression pattern in the flowers of ‘Amygdalolia’, classified as a self-incompatible cultivar, and ‘Konservalia’, classified as a self-compatible cultivar, for the SRK and SLG genes
A sinusoidal equation as alternative to conventional growth functions to describe the evolution of growth in quail
No full textAim of study: The aim of the present study was to introduce a sinusoidal equation into poultry science by applying it to temporal growth data from quail.Material and methods: To examine the performance of the sinusoidal equation in describing the growth patterns of quail, four conventional growth functions (Gompertz, logistic, López and Richards) were used as reference in this study. Comparison of models was carried out by analysing model behaviour when fitting the curves using nonlinear regression and assessing statistical performance. Maximum log-likelihood estimation, mean squared error, Akaike and Bayesian information criteria were used to evaluate the general goodness-of-fit of each model to the different data profiles.Main results: The selected sinusoidal equation precisely describes the growth dynamics of quail. Comparison of the growth functions in terms of the goodness-of-fit criteria revealed that the sinusoidal equation was one of the most appropriate functions to describe the age-related changes of bodyweight in quail.Research highlights: To the best of our knowledge there are no studies available on the use of sinusoidal equations to describe the evolution of growth in quail. The sinusoidal equation used in this study represents a suitable alternative to conventional growth functions to describe the growth curves for a range of strains/lines of male and female Japanese quail
Evaluation and cluster analysis of inflammatory reactions of dairy cattle mastitis pathogens in milk samples submitted for microbiological examination
No full textAim of study: We have classified into homogenous groups a wide spectrum of mammary pathogens according to their frequency of isolation in clinical mastitis and their somatic cell counts in non-clinical mastitis.Area of study: The study was conducted in Galicia (NW Spain)Material and methods: 163,741 dairy cattle quarter milk samples were analyzed. We identified mastitis pathogens to the species level and performed a cluster analysis to classify these microorganisms by their median of Linear Score (mLS), percentage of isolation in clinical mastitis samples (%ICS) and percentage of isolation in samples with somatic cell counts under 100,000 cells/mL (%ISU100).Main results: Forty-three different species were isolated. Cluster analysis identified 4 groups of pathogens; mLS and %ICS progressively increased from Group I to Group IV and %ISU100 decreased. However, several pathogens included in groups II and III showed %ISU100 values higher than 2% and 3%. Minor pathogens were mainly clustered in Group I (e.g., Corynebacterium spp. and most of Staphylococcus spp.), while known major pathogens were included in Groups II, III y IV. Species of the same family, genus or microbiological group like Enterobacteriaceae or Enterococcus spp. were frequently separated into different groups, thus showing heterogeneity among the members of these groups.Research highlights: Results obtained here may aid in assessing the pathogenicity of sporadic pathogens in relation to more well-known pathogens and suggest that the traditional classification between minor and major pathogens is an oversimplification of the reality, especially for the latter category