Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Modelling infiltration and geostatistical analysis of spatial variability of sorptivity and transmissivity in a flood spreading area
Get PDFKnowledge of infiltration characteristics is useful in hydrological studies of agricultural soils. Soil hydraulic parameters such as steady infiltration rate, sorptivity, and transmissivity can exhibit appreciable spatial variability. The main objectives of this study were to examine several mathematical models of infiltration and to analyze the spatial variability of observed final infiltration rate, estimated sorptivity and estimated transmissivity in flood spreading and control areas in Ilam province, Iran. The suitability of geostatistics to describe such spatial variability was assessed using data from 30 infiltration measurements sampled along three lines. The Horton model provided the most accurate simulation of infiltration considering all measurements and the Philip’s two-term model provided less accurate simulation. A comparison of the measured values and the estimated final infiltration rates showed that the Kostiakov-Lewis, Kostiakov, and SCS models could not estimate the final infiltration rate as well as Horton model. Estimated sorptivity and transmissivity parameters of the Philip’s two-term model and final infiltration rate had spatial structure, and were considered to be structural variables over the transect pattern. The Gaussian model provided the best-fit theoretical variogram for these three parameters. Variogram values ranged from 99 and 88 m for sorptivity and final infiltration rate to 686 (spherical) and 384 m (Gaussian) for transmissivity. Sorptivity, transmissivity and final infiltration attributes showed a high degree of spatial dependence, being 0.99, 0.81 and 1, respectively. Results showed that kriging could be used to predict the studied parameters in the study area
The effect of rosemary (Rosmarinus officinalis L.) essential oil on digestibility, ruminal fermentation and blood metabolites of Ghezel sheep fed barley-based diets
Get PDFThis study was conducted to evaluate the effects of rosemary essential oil (REO) on feed digestibility, ruminal fermentation and blood metabolites of Ghezel sheep. Four male sheep with average body weight 46 ± 2.0 kg were used in a 4×4 Latin square design. Treatments were control (no REO added), 100 mg d-1 of REO (low), 200 mg d-1 of REO (medium) and 400 mg d-1 of REO (high). Sheep were fed the 4 diets for 4 periods of 21 days (14 days as adaptation and 7 days for sample collection). The results showed that digestibility of dry matter, neutral-detergent fiber, acid-detergent fiber and crude protein were not affected by REO feeding (p>0.05). The concentration of ammonia-N across sampling times was lower (p<0.05) at low REO dosage compared with control. The molar proportion of acetate and butyrate across sampling times were lower at low REO dosage compared with control (p<0.05). Total volatile fatty acids (VFA) concentrations at 4 h after morning feeding were reduced (p<0.05) by adding 100 mg of REO d-1 to diet compared with the control, whereas medium REO dosage increased (p<0.05) total VFA concentrations at 4 h post feeding compared with the control. The addition of REO had no effect on total protozoa counts across sampling times (p>0.05). Supplementation with REO had no effect on plasma concentrations of glucose, triglyceride, cholesterol, total protein and albumin (p>0.05). The results of this study indicate that, although a medium dose of REO may have positive effect on rumen fermentation, a low dose of REO may have adverse effects on ruminal fermentation
Effects of different regimes of fertilization on soil organic matter under conventional tillage
Get PDFTo explore the effects of different fertilization regimes on soil organic matter (SOM) sequestration in a winter-soybean/corn rotation, a long-term field experiment was conducted in Anhui, China, from 1982 to 2011. There were six treatments, as follows: (1) no fertilizer input (CK); (2) mineral fertilizers input (NPK); (3) mineral fertilizers + 3,750 kg ha-1 wheat straw (WS/2-NPK); (4) mineral fertilizers + 7,500 kg ha-1 wheat straw (WS-NPK); (5) mineral fertilizers + 15,000 kg ha-1 composted farmyard manure (CNPK); and (6) mineral fertilizers + 30,000 kg ha-1 composted farmyard manure (DNPK). Mineral fertilizer applications combined with organic amendments improved soil physical properties. For the WS/2-NPK, WS-NPK, CNPK and DNPK treatments, the soil bulk density decreased more than 10%, while the air porosity and field water content increased more than 90% and 15%, compared with the values at the start of the experiment in 1982. Our results indicate that about two decades are needed for SOM to reach its saturation point in all treatments. The SOM sequestration rate was related to the fertilization regime. The average SOM sequestration rate in 1982-2005 was 0.27 g kg-1 yr-1 with NPK, 0.45 g kg-1 yr-1 with WS/2-NPK, 0.56 g kg-1 yr-1 with WS-NPK, 0.60 g kg-1 yr-1 with CNPK and 1.02 g kg-1 yr-1 with DNPK. Therefore, both the quantity and the quality of the organic amendment determine the SOM sequestration rate and SOM saturation level
Phosphogypsum amendments and irrigation with acidulated water affect tomato nutrition in reclaimed marsh soils from SW Spain
Get PDFPhosphogypsum (PG) is a by-product of the P fertilizer industry usually valorised as amendment for acidic and sodic soils. This work was aimed to study the effects of PG on nutrient uptake by industrial tomato plants in an originally sodic soil. A completely randomized experiment was performed involving two factors: (i) acidification with nitric acid (mimics cleaning techniques in drip irrigation), and (ii) PG rate (equivalents to 0, 20, 60, and 200 Mg ha–1). The highest PG rate resulted in an increased dry matter yield, which can be ascribed at least in part to an increased water use efficiency. PG decreased K, Mg and P concentrations in shoots, and P and Cu concentrations in fruits. At the highest rate, PG increased B concentration in shoots and total B content in the aerial parts of plants when acid was applied. The highest PG rate also increased Ca concentration in fruits, which can be considered positive in view of reducing the incidence of blossom end rot. The total content of Ni and Mo in aerial parts increased with PG, probably related to a decreased adsorption of these nutrients in soils. Acid application increased the concentration of all micronutrients in shoots and the concentration of Fe, Cu and B in fruits. In conclusion, PG promoted positive effects on B, Ni, Mo, and Ca nutrition, and some negative nutritional effects through antagonisms or affecting nutrient cycling in the soils, which however did not result in decreasing yields, even at a large dose which mimics the cumulative application during 20-30 years. Acid treatments resulted in improved micronutrient nutrition of tomato plants
Short communication. Effects of purslane extract on performance, immunity responses and cecal microbial population of broiler chickens
No full textThe aim of present study was to evaluate the effect of purslane extract on performance, cecal microflora composition and immune responses of broiler chickens. One hundred and ninety two 1–day old broiler chicks (Ross 308) were allocated randomly in 4 groups with 4 replicates to receive diets supplemented with 0 (control), 100, 200 and 300 ppm of purslane extract for 42 days. Body weight gain, feed intake (FI) and feed conversion ratio were measured weekly and calculated for starter (1-21 d), grower (22-42 d) and overall periods (1-42 d). All diets were isocaloric, isonitrogenous and provided ad libitum. Antibody response against sheep red blood cell (SRBC) was measured on d-28 and d-42. At the age of 42 d, eight chicks per treatment killed aseptically for enumeration of cecal bacteria. The results of this experiment indicated that FI increased significantly with inclusion of purslane extract in grower and overall period (p≤0.05). Purslane extract did not affect coliform and Escherichia coli populations but increased Lactobacillus population of cecal content significantly (p≤0.05). There were no significant differences in primary and secondary antibody titer against SRBC and no differences among the treatments for relative weight of thymus and spleen (p>0.05). Relative weight of bursa was affected with inclusion of purslane extract in the diet. Therefore, it was concluded that purslane inclusion had a positive significant effect on cecal microflora composition, but had no effect on immune response of broiler chickens
An insight into the influence of packaging and presentation format on consumer purchasing attitudes towards cheese: a qualitative study
Get PDFUsing packaging and presentation format to appeal to consumers and to communicate product benefits directly on the shelf is a competitive advantage in the food industry. Both packaging and presentation format can attract consumers’ attention and influence their perceptions and purchasing decisions. Therefore, the objective of this study is to obtain a preliminary insight into the main attributes and factors that most affect consumers’ purchase decisions regarding presentation and packaging of cheese products. To achieve this goal, we have used the focus group technique, because of its considerable potential as a mean to collect qualitative data within consumer research. The results showed that price, product quality, packaging, origin and brand are decisive factors in the purchase decision of food products. Although packaging and presentation of food have potential influence on the consumer’s choice and purchase, packaging colour and design are the most attractive factors during the purchase process. Thus, packaging format and colour may influence consumers prior to the purchase. These stimuli can be decisive when buying cheese and may also help producers to communicate the differentiation of their products to consumers
Identification and antifungal activity of an actinomycete strain against Alternaria spp.
Get PDFAlternaria alternata (Fries) Keissler is a phytopathogenic fungus responsible for tobacco brown spot disease. This study aims to evaluate the antifungal activity of strain 163 against A. alternata and clarify its taxonomic status. The evaluation of the antifungal activity of strain 163 and its bacteria-free filtrate of fermentation broth was done through measuring the diameters of inhibition zones, and testing the antimicrobial spectrum and the inhibition effect on mycelial growth in vitro. The biocontrol activity of the bacteria-free filtrate in vivo was evaluated by using detached tobacco leaves method and assaying the inhibition rate to disease incidence in growth chamber. A polyphasic approach was taken in the identification of strain 163. The bacterial strain 163 showed inhibitory effect in vitro against A. alternata. The bacteria-free filtrate of the strain 163 fermentation broth showed a 56.7% inhibition rate in a detached leaf assay. In growth chamber conditions, it showed greater biocontrol activity when applied before plants being inoculated with A. alternata than after, the inhibition rate being 46.05%. Investigations into the morphological, cultural, physiological and biochemical properties of strain 163 found it to be most similar to Streptomyces microflavus. Its classification into cell wall type I and sugar type C further confirmed its Streptomyces characteristics. Construction of a phylogenetic tree based on 16S rDNA verified that strain 163 was most closely related to Streptomyces microflavus. From polyphasic taxonomical analysis, strain 163 was found to be identical to S. microflavus
The effects of agricultural trade openness on food price transmission in Latin American countries
Get PDFTrade of agricultural commodities has grown significantly in most Latin American countries (LAC) over the last two decades. However, after the international food price surges in 2006-08 and 2011-12 concerns about food access of the poor arose. Within a panel framework containing six LAC (Argentina, Brazil, Chile, Colombia, Mexico and Peru), we used a single equation error correction model to identify possible cointegrating relationships between the food consumer price index (CPI) and a set of trade related and domestic variables. The main focus of the study was to examine how different levels of trade openness impact international food price transmission to domestic markets. Our results confirm that deeper market integration increases global price transmission elasticities. In other words, more agricultural trade openness proves to elevate food CPIs during global price spikes. Thus, for poor consumers world price shocks can be deteriorating in the short-run and domestic food prices will slowly converge to a higher long-run equilibrium. Especially in increasingly integrated economies, effective policies to buffer food price shocks should be put in place, but must be carefully planned with the required budget readily available. We also found that exchange rate appreciations can buffer price shocks to a certain extent and that monetary policies seem to be an appropriate means for stabilizing food prices to safeguard food access of the poor population
Efficacy of a Spanish modified live virus vaccine against homologous porcine reproductive and respiratory syndrome virus infection
Get PDFThe objective of this study was to determine the protective properties of the Spanish MLV vaccine Amervac-PRRS® against porcine reproductive and respiratory syndrome virus (PRRSV) infection with the homologous wild-type strain5710. The experimental design comprised eighteen 3-week old pigs randomly divided into three groups. Animals fromgroup A received one dose of MLV vaccine Amervac-PRRS on days –42 and –21. Animals from groups B and C served as infected and uninfected controls, respectively. On day 0, pigs from groups A and B were intranasally challenged with homologous strain 5710 and 18 days after challenge all pigs were euthanized. The results reported in this study show that, although the titre of neutralizing antibodies elicited by vaccination was modest, MLV vaccine Amervac-PRRS® provided protection against homologous PRRSV infection and drastically reduced post-challenge viremia and completely block PRRSV dissemination to peripheral tissues
From the juvenile to the adult vegetative phase in olive seedlings: the transition along the stem axis
Get PDFSexual reproduction in olive is carried out for purposes such as breeding. The seedlings evolve from the juvenile to the adult stage, and until now, only the discrete developmental phases have been investigated in detail. However, the transition process has been poorly studied in fruit trees, especially in olive. In this paper, juvenile to adult transition has been explored in 30 olive seedlings coming from the Table Olive Breeding Program of the University of Sevilla, Spain. Despite of the great variability found in the olive leaf morphological parameters, mean values increased linearly from the bottom (juvenile) to the top (adult tissue) of the seedling. An upward lineal decrease in the rooting ability was also observed for the set of seedlings evaluated. No significant differences were found for the maximum net photosynthesis (PNmax) or maximum stomatal conductance (gsmax), although the lowest values were measured at <0.5 m. For all of the analysed parameters, the transitional tissue showed intermediate values. These results show for the first time in olive that the transition along the seedling stem axis follows a clear lineal tendency with a stepwise loss of juvenile characters being the shift from juvenile to adult phase in olive not an abrupt change but a gradual process. The usefulness of a fibre optic probe with a reduced sampling surface coupled to near-infrared spectroscopy (NIRS) was evaluated. NIR analysis has been confirmed to be a useful tool to discriminate the juvenile and adult leaves, but not the transition ones