Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Evaluation of technological improvements in bundling units for the collection of eucalyptus logging residues on steep terrain in Spain
Get PDFAim of the study: The objective of this study was to evaluate recent technological improvements to forest bundlers: a new cutting device with shears and a mechanism which allows the bundling pressure to be changed by the driver.Area of study: eucalyptus plantations in Northern Spain.Material and Methods: Several time studies were performed in order to compare and calculate productivity depending on the machine: John Deere bundler working with the traditional chainsaw and Monra bundler equipped with the technological improvements of shears and adjustable bundling pressure.Research highlights: Significant differences were found between cutting devices (shears and chainsaw) and between the Monra working at maximum pressure and at lower pressure. Shears were shown to be a more robust and reliable cutting device, with 1.02 cutting attempts per bundle compared to 1.55 with chain saw. The use of shears made the loading more efficient as it eliminates the need to shake the residues before feeding the bundler. A great advantage of this technological improvement is that it can be incorporated into other machines and thus improve bundling efficiency.In spite of this, working at standard bundling pressure, the productivity of the Monra bundler is only 3.2 per cent higher than that of the John Deere due to the fact that in the latter bundling is faster and it produces bundles with significantly more dry mass.For the Monra bundler, the option of producing lighter bundles further reduced productivity compared to when standard weight bundles are produced. However, it would be of interest to study the effect of the machine working at various pressures in order to optimize the work system. It is possible that working at higher pressures would have advantages in terms of increasing transport efficiency.Keywords: bundler; time study; shear; cutting device; slash collection; forest biomass
Germination ecology of the endemic Iberian daffodil Narcissus radinganorum (Amaryllidaceae). Dormancy induction by cold stratification or desiccation in late stages of embryo growth
Get PDFAim of study: We studied the germination ecology of a threatened daffodil in order to develop a protocol to produce plants ex-situ from seeds, a key tool for population reinforcement.Area of study: Experiments were carried out both outdoors and in the laboratory in Albacete (Spain).Material and methods: Embryo length, radicle and shoot emergence were analyzed to determine the level of morphophysiological dormancy (MPD). Effects on germination of cold stratification or desiccation in late stages of embryo growth were also studied.Main results: Mean embryo length in fresh seeds was 1.36 mm, needing to grow up to 2.20 mm to be able to germinate. In the laboratory, embryo growth occurred during warm stratification (28/14, 25/10ºC), and then radicle emerged when temperatures went down (15/4ºC in darkness). Phenology study in outdoors conditions revealed that embryo grew during summer-early autumn, short time after seed dispersal in nature (i.e., May); radicle emerged in autumn. The shoot however did not emerge until late winter-early spring, because it was physiologically dormant and required a cold (5ºC) period of 30 days to break dormancy. Early cold temperatures interrupted the embryo growth and induced dormancy in seeds whose embryo had grown 30% with respect to the initial length. Desiccation in seeds whose embryo had grown 30% did not induce dormancy, but did it when the embryo growth reached 70%.Research highlights: Seeds of Narcissus radinganorum have deep simple epicotyl MPD.Key words: dormancy break; radicle emergence; shoot emergence; epicotyl MPD; phenology; secondary dormancy
Comparison of stem taper equations for eight major tree species in the Spanish Plateau
Get PDFAim of study: A stem taper function and a compatible merchantable volume system are compared to evaluate which provides a better description of the stem profile for the main species in central Spain.Area of study: This research was carried out in the region of Castile-Leon, located in Central Spain.Material and Methods: A total of 6,357 trees were selected for destructive sampling. All models were fitted using a first-order continuous autoregressive error structure to address the problem of autocorrelation.Main results: In terms of accuracy, the root mean square error (RMSE) in both models ranged from 0.75 to 2.72 depending on the species analyzed, presenting values similar to those reported in other studies. Small differences in the goodness-of-fit for both procedures were also found, and the Stud model provided better accuracy for 6 of the 8 species studied, with RMSE reductions of 0.5% to 8.6%. The RMSE obtained in the cross-validation phase was on average 1.22 times higher than what was obtained in the fitting phase.Research highlights: The non-linear extra sum of squares method indicated that the stem taper differs among the five softwood species and three hardwood species. In hardwoods, the first inflection point is lower than in softwoods (at around 5%) and the second inflection point is higher (at around 85%) than those of softwoods.Keywords: taper function; volume system; Central Spain; softwoods; hardwoods
Seed production and recruitment in primary and harvested Nothofagus pumilio forests: Influence of regional climate and years after cuttings
Get PDFAim of study: Harvesting proposals (e.g. variable retention) for Nothofagus pumilio forests are based on canopy opening, to increase recruitment and enhance seedling growth, by modifying light and soil moisture. Seed production and seedling recruitment will define the success of harvesting, where remnant forest structure are the main influence factors, as well as biotic and abiotic factors. The objective was to analyse seed production, seedling recruitment and recruitment efficiency in primary and harvested forests through variable retention along the first 10 years after harvesting, as well as the influence of regional climate.Area of study: The study were conducted in a pure Nothofagus pumilio forest located in centralTierra del Fuego (54º18’ S, 67º49’ W), where harvested stands with variable retention and unmanaged forests were sampled in long-term permanent plots.Material and methods: Data of forest regeneration plots were used (n=72) (2007 a 2014), and forest structure and seed production (2006 a 2013) were also measured. Regional climate was characterised for these years from satellite images (Sea Surface Temperature) and climate re-analysis models (rainfall and temperature of land surface).Main results: Harvesting modified forest structure; however, aggregated retention maintained some characteristics of the primary unmanaged forests. These changes influenced seed production and recruitment. Seed production and recruitment were related to crown cover and the amount of seed production; however, recruitment efficiency was not affected by harvesting. The studied variables significantly changed along the years after harvesting. Seed production and recruitment were also related to regional climate factors, where it was possible to explain their variations through temperature (e.g. summer temperature) and rainfall (e.g. winter rainfall) for the different retention types in harvested forests and the primary forests.Research highlights: Variable retention harvesting generated different micro-conditions that influence seed production and recruitment. These variables were related to canopy cover. However, recruitment efficiency was not affected by harvesting. Seed production and recruitment (primary forests and harvested stands) were related to regional climate factors and their variations can be explained from variables related to temperature and rainfall.Key words: regeneration; forest management; crown cover; regional climate; modelling; Tierra del Fuego
THE YEW MATRIARCHIES OF THE SIERRA DE FRANCIA Dynamics and ecology of new known populations in the Iberian Central Mountain Range (“Sistema Central”)
No full textAim of study: Our study design presents two main objectives: 1) to create a census that details the number of yew individuals and their geographic distribution, and 2) to attempt to unravel possible reproductive relationships and their connection between true population nuclei and meta-population models.Area of study: Recently identified yew populations (Taxus baccata L.) were studied in the western sector of the Sistema Central mountain range of theIberian Peninsula, known as the Sierra de Francia. The study was carried out in five watersheds within Las Batuecas-Sierra de Francia Natural Park.Material and Methods: All yew specimens were counted and assigned to age groups. The notable differences observed in regeneration aof these communities propitiates population analysis aimed at explaining the landscape connectivity relationships between the different population nuclei and the possibility of defining the meta-population set. Ecological niche models were also created to define the main ecological characteristics of the different subpopulations studied, and to compare them.Main results: Yew in the Sierra de Francia live in an array of different Mediterranean forests, indicative of species dynamics in theIberian Peninsula. 2,450 specimens were recorded and classified into the three types of yew forest population dynamics: regressional-, naturally regenerating-, and incipient- (i.e. colonizing new territories).Research highlights: The essential role of connectivity between populations was recognized and confirmed in this study, specifically among the large female trees located at the headwaters. Based on the role of these female trees, we have created a model called “yew matriarchies”, which serves to express the relevance of large female yew trees in population dynamics.Keywords: Taxus baccata; census; connectivity; seed dispersal.New yew populations (Taxus baccata L.) have been studied in the western sector of the “Sistema Central” mountain range of the Iberian Peninsula - known as “Sierra de Francia”- in a fully Mediterranean environment forming a mosaic of climatic variants (continental Mediterranean, submediterranean, subatlantic, and even moist subtropical Mediterranean microclimates). A very complete array of different Mediterranean yew forests that manifests the species dynamics and show their historical evolution in the Iberian Peninsula.A census of the yew populations has been completed in five watersheds within the Sierra de Francia, belonging to the Duero River and Tajo River Basins, resulting in the largest group of yews known to date in the “Sistema Central”. Around 2450 specimens have been recorded and classified against three types of population dynamics that can be then typified as: regressional yew forests, naturally regenerating yew forests, and incipient yew forests that are colonizing new territories.The ecology of the different subpopulations has been characterized in terms of its relationship to other plant formations (madrone, oak, ash, alder, birch forests, etc.), of how they occupy the territory as conditioned by the geology, topography, meteorology and orientation, and the influence of other factors such as erosion dynamics or herbivore-plant dynamics such as those caused by game species and human actions.The notable differences observed in regeneration amongst said communities propitiates a population analysis aimed to explain the landscape connectivity relationships between the different population nuclei and the possibility of defining the metapopulation set so the essential role played by the large female trees located at the headwaters is confirmed. Given the regeneration and recruiting rates around such trees we have arrived to a model called “yew matriarchies”, an expression we hope carries the relevance of these female yew trees in population dynamics
An improved contour symmetry axes extraction algorithm and its application in the location of picking points of apples
Get PDFThe key problem for picking robots is to locate the picking points of fruit. A method based on the moment of inertia and symmetry of apples is proposed in this paper to locate the picking points of apples. Image pre-processing procedures, which are crucial to improving the accuracy of the location, were carried out to remove noise and smooth the edges of apples. The moment of inertia method has the disadvantage of high computational complexity, which should be solved, so convex hull was used to improve this problem. To verify the validity of this algorithm, a test was conducted using four types of apple images containing 107 apple targets. These images were single and unblocked apple images, single and blocked apple images, images containing adjacent apples, and apples in panoramas. The root mean square error values of these four types of apple images were 6.3, 15.0, 21.6 and 18.4, respectively, and the average location errors were 4.9°, 10.2°, 16.3° and 13.8°, respectively. Furthermore, the improved algorithm was effective in terms of average runtime, with 3.7 ms and 9.2 ms for single and unblocked and single and blocked apple images, respectively. For the other two types of apple images, the runtime was determined by the number of apples and blocked apples contained in the images. The results showed that the improved algorithm could extract symmetry axes and locate the picking points of apples more efficiently. In conclusion, the improved algorithm is feasible for extracting symmetry axes and locating the picking points of apples
Effect of calf sex on some productive, reproductive and health traits in Holstein cows
Get PDFRecords of Holstein cows from March 1992 to April 2008 from 194 large herds and comprising from 402,716 records for productive traits to 178,344 records of somatic cell count were used to study the effect of calf sex in different parities and calving season on the subsequent productive, reproductive and health traits in Holstein cows. T-test procedure of SAS software was used to investigate the effect of calf sex and season of calving on aforementioned traits. Cows with female calves had higher milk and fat yield, persistency of milk and fat yield and longer lactation length, while cows that gave birth to male calves had shorter calving interval and longer productive life. Also, cows with female calves had higher milk yield per day of lactation in the first two parities, but there was no difference in milk yield per day of lactation for parities ≥ 3. There was no relationship among mean somatic cell count and sex of born calf. Fall calves had the highest adjusted milk yield and milk yield per day of lactation, however, winter calves had the longest lactation lengthand productive life and the highest somatic cell count. Results from this study demonstrate that it seems necessary to consider the effect of calf sex on aforementioned traits when making decision to use sexed semen or conventional semen
Reuse of rapeseed by-products from biodiesel production
Get PDFThe objective of this paper is to investigate usability of rapeseed cake from biodiesel fuel production as an energy source. For this research, rapeseed was grown at the research site of the Faculty of Agriculture in Zagreb, Croatia. The investigated rapeseed cake, residue from cold pressing, was divided in two groups of samples. The first group was a mix of three varieties (Bristol, Express and Navajo), while the other group consisted of three hybrids (Artus, Baldur, Titan). The utilization of rapeseed cake for energy via two routes was evaluated; namely, utilization of rapeseed cake as (1) solid biofuel (pellets) with addition of 3% of glycerol, and (2) as substrate in anaerobic digestion (AD). In investigation of cake as solid fuel, proximate (moisture content, ash content, fixed carbon and volatile matter), ultimate (content of carbon, sulphur, hydrogen, oxygen and nitrogen) and physical and calometry analyses (abrasion, diameter, length, density, higher and lower heating value were carried out. As for its use in AD, production of biogas during 40 days was monitored with a view of assessing the use of digested residue as fertilizer in agricultural production. Both groups of digested residues were analysed (pH, electroconductivity, moisture content, ash content, content of nitrogen and carbon, C/N ratio, content of P2O5, K2O, Ca, Mg, Na). The analysis indicated that the investigated raw material is usable as solid and gas biofuel, and digested residue as fertilizer in ecological agriculture. The two groups of samples analysed here did not show significant differences
Short communication. Phenological growth stages of saffron plant (Crocus sativus L.) according to the BBCH Scale
Get PDFPhenological studies are important for understanding the influence of climate dynamics on vegetative growth, flowering and fruiting on plants and can be used in many scientific subjects, such as Agronomy, Botany and Plant Biology, but also Climatology as a result of the current global interest in climate change monitoring. The purpose of the detailed specific culture descriptions of the principal growth stages in plants is to provide an instrument for standardization of data recording. To date, there was no coding method to describe developmental stages on saffron plant (Crocus sativus L.). Because of the increasing world-wide interest on this crop, a novel growth development code based on the BBCH extended scale is proposed in this paper. Six principal growth stages were set up, starting from sprouting, cataphylls and flowers appearance, plant appearance and development, replacement corms development, plant senescence and corm dormancy. Each principal growth stage is subdivided into secondary growth stages. Descriptive keys with illustrations are included to make effective use of the system
Colostrum production of Alentejano and Large-White × Landrace sows: consumption, passive immunity and mortality of piglets
Get PDFColostrum production and composition of 45 Alentejano (AL) and 45 crossed (Large–White × Landrace, LL) sows together with consumption and passive immunization of piglets, were evaluated. Piglets were weighed at birth, 24h, and 21 and 28 days of age. Colostrum was collected, chemically analysed and immunoglobulin G (IgG) determined. On piglets, serum IgG concentrations were determined at 2d and 28d of age. Alentejano piglets consumed 19% less colostrum than LL piglets (267 vs 328 g; p<0.001), but when adjusted for birth weight, the difference between genotypes was not significant (p=0.891). Alentejano sows produced less colostrum (1985±139 g vs 3761±139 g, p<0.001) than LL sows, even after adjustment for litter birth weight. IgG concentrations were higher in AL colostrum at 12 h and 36 h after the onset of farrowing. They were higher in AL than in LL piglets (p=0.025) and higher at 2d than at 28d of age (p<0.001). Mortality rate of piglets until d21 post–farrowing was higher in AL genotype (27% vs 16.1%, p<0.001). In both genotypes main factors influencing piglet mortality were birth weight and colostrum intake (g/kg birth weight). Higher mortality in AL than in LL genotype was attributable to the higher proportion (28.7% vs 11.6%, p<0.001) of light piglets. It is concluded that for similar birth weight, both AL and LL piglets have a similar ability to ingest colostrum and that AL sows are less able to produce colostrum than LL sows. IgG concentrations of colostrum and of piglets serum were higher in AL than in LL genotype