Scientific Journals of INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria)
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Improvement of soil carbon sink by cover crops in olive orchards under semiarid conditions. Influence of the type of soil and weed
Get PDFThe olive tree is one of the most important crops in Spain, and the main one in the region of Andalusia. Most orchards are rain-fed, with high slopes where conventional tillage (CT) is the primary soil management system used. These conditions lead to high erosion and a significant transport of organic carbon (OC). Moreover, soil tillage accelerates the oxidation of the OC. Cover crops (CC) are the conservation agriculture (CA) approach for woody crops. They are grown in-between tree rows to protect the soil against water erosion and their organic residues also help to increase the soil carbon (C) sink. Soil and OC losses associated to the sediment were measured over four seasons (2003-07) using micro-plots for the collection of runoff and sediment in five experimental fields located in rain-fed olive orchards in Andalusia. Two soil management systems were followed, CC and CT. Furthermore, the changes in soil C in both systems were analyzed at a depth of 0-25 cm. CC reduced erosion by 80.5%, and also OC transport by 67.7%. In addition, Cover crops increased soil C sink by 12.3 Mg ha-1 year-1 of carbon dioxide (CO2) equivalent, with respect to CT. CC in rainfed olive orchards in a Mediterranean climate could be an environmental friendly and profitable system for reducing erosion and increasing the soil C sink. However, C fixing rate is not regular, being very high for the initial years after shifting from CT to CC and gradually decreasing over time
Visual definition of physiological maturity in sunflower (Helianthus annuus L.) is associated with receptacle quantitative color parameters
Get PDFIdentifying physiological maturity (PM) in sunflower (Helianthus annuus L.) by visual methods is subjective. The present study was conducted during two years in two short season sunflower hybrids (Macón and MG60) to determine the relationship between quantitative color parameters in the receptacle and physiological markers such as fruit dry weight (FDW) and fruit water content (FWC) from flowering to PM. Fruits from the external 25% of the capitulum radius were sampled at 3-5-day intervals from first anthesis until harvest maturity. Fruit and receptacle fresh and dry weight were calculated, and color changes of the receptacle base were followed over time using a spectrophotometer. Comparison of colorimetric coordinates a* and b*, defined by the CIELAB color space enabled quantitative correlation of color changes in the receptacle with the maturation stage of the fruits and their moisture content. In both hybrids and years, fruits attained maximum dry weight when the receptacle color turned from dark green to buttery-yellow. Strong correlations were found between FWC and a* for Macón the first (r=-0.877) and second year (r=-0.934) and for MG60, (r=-0.912 and r=-0.891) the first and second year, respectively. The same results were found for b* for Macón (r=-0.901 and r=-0.829) and for MG60 (r=-0.898 and r= -0.863) for the first and second year respectively. Maximum b* at FWC between 40 to 41% had the highest correlation with maximum fruit dry weight for both hybrids and years, and was a good indicator for identifying the attainment of PM. This work represents an original contribution and a first step towards the development of a model for predicting PM in sunflower by using colorimetric measurements
Antioxidant effects of bovine serum albumin on kinetics, microscopic and oxidative characters of cryopreserved bull spermatozoa
Get PDFThe aim of this study was to determine the effects of bovine serum albumin (BSA) as an antioxidant on post-thaw characters of bull spermatozoa such as motion variables, viability, plasma membrane integrity, morphology, lipid peroxidation, total antioxidant capacity (TAC), total thiols (TT) and the enzymes activities. Ejaculates were collected from six proven bulls and diluted with a citrate-based extender supplemented with various concentrations of BSA (0, 0.5, 1, 1.5 and 2 g/100 mL). The results showed that the semen extender supplemented with various concentrations of BSA increased (p0.05) were detected in progressive motility, sperm track straightness, beat cross frequency, curvilinear velocity and malondialdehyde production between the experimental groups. The highest concentration of BSA (2 g/100 mL) in the semen extender reduced (p<0.05) the sperm motion variables. The results indicated that the most effective concentration of BSA is 1 g/100 mL in the semen extender which is associated with an increase in the total motility, antioxidant enzymes activities, TT and TAC
Farm size and growth in field crop and dairy farms in France, Hungary and Slovenia
Get PDFThe aim of this article is to investigate the relationship between size and farm growth. The existing theories of the association between size and farm growth give mixed results by countries and over time. This paper pursues a twofold objective: on one hand, to test the validity of Gibrat’s Law for French, Hungarian and Slovenian specialized dairy and crop farms during the pre- and post-accession period to the European Union membership. Dairy and crops farms are prevailing in the farming structure of these countries. Using Farm Accountancy Data Network datasets makes it necessary to avoid biases due to heterogeneous structures across the farming systems. Thus we use quantile regressions to control for farm size related heterogeneity in the samples. On the other hand, the main novelty of this paper is the comparative analysis of the relationship between farm size and farm growth between transition Hungarian and Slovenian and non-transition French farming sectors, characterized by rather different farm structures. The results reject the validity of Gibrat’s Law for crop farms in Hungary and to a lesser extent in France, and for French and Slovenian dairy farms. We provide evidence that smaller farms grew faster than larger ones over the studied period 2001-2007 for France, 2001-2008 for Hungary, and 2004-2008 for Slovenia. Conversely, the results for Slovenia suggest that the rate of growth of crop farms in terms of its land is independent from its size
Response of vetch, lentil, chickpea and red pea to pre- or post-emergence applied herbicides
Get PDFBroad-leaved weeds constitute a serious problem in the production of winter legumes, but few selective herbicides controlling these weeds have been registered in Europe. Four field experiments were conducted in 2009/10 and repeated in 2010/11 in Greece to study the response of common vetch (Vicia sativa L.), lentil (Lens culinaris Medik.), chickpea (Cicer arietinum L.) and red pea (Lathyrus cicera L.) to several rates of the herbicides pendimethalin, S-metolachlor, S-metolachlor plus terbuthylazine and flumioxazin applied pre-emergence, as well as imazamox applied post-emergence. Phytotoxicity, crop height, total weight and seed yield were evaluated during the experiments. The results of this study suggest that common vetch, lentil, chickpea and red pea differed in their responses to the herbicides tested. Pendimethalin at 1.30 kg ha-1, S-metolachlor at 0.96 kg ha-1 and flumioxazine at 0.11 kg ha-1 used as pre-emergence applied herbicides provided the least phytotoxicity to legumes. Pendimethalin at 1.98 kg ha-1 and both rates of S-metolachlor plus terbuthylazine provided the greatest common lambsquarters (Chenopodium album L.) control. Imazamox at 0.03 to 0.04 kg ha-1 could also be used as early post-emergence applied herbicide in common vetch and red pea without any significant detrimental effect
Predicting the metabolizable energy content of corn for ducks: a comparison of support vector regression with other methods
Get PDFSupport vector regression (SVR) is used in this study to develop models to estimate apparent metabolizable energy (AME), AME corrected for nitrogen (AMEn), true metabolizable energy (TME), and TME corrected for nitrogen (TMEn) contents of corn fed to ducks based on its chemical composition. Performance of the SVR models was assessed by comparing their results with those of artificial neural network (ANN) and multiple linear regression (MLR) models. The input variables to estimate metabolizable energy content (MJ kg-1) of corn were crude protein, ether extract, crude fibre, and ash (g kg-1). Goodness of fit of the models was examined using R2, mean square error, and bias. Based on these indices, the predictive performance of the SVR, ANN, and MLR models was acceptable. Comparison of models indicated that performance of SVR (in terms of R2) on the full data set (0.937 for AME, 0.954 for AMEn, 0.860 for TME, and 0.937 for TMEn) was better than that of ANN (0.907 for AME, 0.922 for AMEn, 0.744 for TME, and 0.920 for TMEn) and MLR (0.887 for AME, 0.903 for AMEn, 0.704 for TME, and 0.902 for TMEn). Similar findings were observed with the calibration and testing data sets. These results suggest SVR models are a promising tool for modelling the relationship between chemical composition and metabolizable energy of feedstuffs for poultry. Although from the present results the application of SVR models seems encouraging, the use of such models in other areas of animal nutrition needs to be evaluated
Aphid populations (Hemiptera: Aphidoidea) depend of mulching in watermelon production in the Mediterranean region of Croatia
Get PDFWinged morphs of aphids were investigated under field conditions during 2008, 2010 and 2011 in the Mediterranean region of Croatia. Field experiments were conducted to record aphid diversity and compare polyethylene black mulch to straw mulch and bare soil in terms of their attractiveness to aphid species in a watermelon crop. Aphids were collected weekly using yellow water metal traps from May to July. During the study, 44 species in 31 genera were detected; 36 species in 24 genera were identified in 2008, 18 species in 15 genera were identified in 2010, and 34 species in 25 genera were identified in 2011. The overall seasonal percentage composition showed that Aphis fabae Scopoli and Myzus persicae (Sulzer) were consistently eudominant species, whereas Acyrtosiphon pisum (Harris) was consistently dominant. Cabbage aphid Brevicoryne brassicae (L.) was determined as the dominant species in 2008 and as eudominant species in 2011. Additionally, Macrosiphum rosae (L.) was twice recorded as the dominant species, whereas Aphis gossipii Glover was dominant once, and Phorodon humuli (Schrank) was eudominant once. Our study also demonstrated that mulching sporadically affected the abundance of individual species. The attractiveness of mulching for aphid species differed between the treatments. It was found that bare soil was attractive to A. pisum and M. rosae, black mulch was attractive to B. helichrysi and P. humuli, and straw mulch was attractive to four aphid species, of which two were eudominant, A. fabae and M. persicae. The presented species are mostly polyphagous, and their preference for certain mulches can be used in crop protection management
Meat quality of veal: Discriminatory ability of weaning status
Get PDFThe physicochemical and fatty acid compositions of meat from 81 calves were measured in order to prove whether the extension of suckling period could distinguish “Normal” from “Suprema” class calves. Three groups of animals were investigated depending on their weaning status: NW (animals were milk-fed until seven months), W1 and W2 (animals which were weaned at different ages and reared either in family farms or in feedlot, respectively). There was no difference among animals in relation to the main components (moisture, protein and ash). Significant differences (p<0.05) were found regarding intramuscular fat; the contents were higher in animals weaned at early ages. Color and texture parameters were significantly affected by weaning status. The intramuscular fatty acid composition in the three types of animals showed that saturated fatty acids were the predominant ones in the three groups with values ranging between 48.71% and 49.52% of total methyl esters. Significant differences (p<0.001) were found depending on weaning status in linolenic acid and in the n-6/n-3 ratio, obtaining the highest values in NW animals. Factor analysis method using principal component was applied to the data. The data matrix constructed was subjected to a canonical discriminant analysis in order to classify the NW, W1 and W2 groups. These results showed that 96.6% for the NW group, and 66.7% and 82.4% for W1 and W2 groups respectively, were correctly classified
A new mechanised cultural practice to reduce Ceratitis capitata Wied. populations in area-wide IPM
Get PDFThe Mediterranean fruit fly (or medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), affects most of the fruit species grown in temperate and tropical climate regions, causing significant economic damage. One of the classical cultural strategies against this pest is to gather and bury the remaining fruit after harvest, but this is economically unfeasible today. Wood shredders already available in current Spanish groves can be used to grind or crush fruits laying on the soil as an alternative to this practice and to the use of pesticides in area-wide integrated pest management (IPM). With the purpose of evaluating this alternative, the initial step of this study was to perform laboratory tests to assess the efficacy of crushing and grinding as a method for controlling medflies. The results showed that grinding was 78% effective against larval stages, while crushing resulted in a 17% efficacy, leading us to choose the first alternative. As a second step, the operational parameters (type of cutting tool, shaft rotation speed and tractor speed) of the wood shredders were adjusted to efficiently carry out this practice under field conditions. Finally, the effect of the mechanised grinding of fallen fruit on C. capitata populations was evaluated for two consecutive years in commercial citrus orchards. The results showed a significant 27-46% reduction in C. capitata populations the following spring, thus demonstrating that the newly proposed mechanised alternative can be included in the current area-wide IPM of the pest in Spain
Short communication. Biological fixation of nitrogen and N balance in soybean crops in the pampas region
Get PDFBiological nitrogen fixation (BNF) is of key importance in the N balance of soybean (Glycine max) crops. A number of authors have suggested that a negative balance may occur under high yield conditions. Few studies have measured the contribution of BNF to soil N in the pampas region. The aims of the present study were to compare three BNF determination methods – two isotopic methods using sorghum or a non-nodulating soybean isoline as a reference crop, and one involving the calculation of the difference in N content between the nodulating and non-nodulating soybean isolines – and to estimate the N balance in soybean crops raised under conventional tillage and no tillage practices. The study was performed in 2004-2005; a complete randomised block design was used with three replicates (plot dimensions 3 × 7 m). The different methodologies estimated BNF to account for 45-58% of total plant N, equivalent to 94 to 123 kg N ha-1. Depending on the methodology for estimating the BNF the soil N balance varied between –7 and 22 kg N ha-1. With an average grain yield of 1,618 kg ha-1 and a BNF accounting for approximately 50% of total plant N (i.e.,115 kg N ha-1), the soil N balance was slightly positive (14 kg ha-1) and independent of the tillage practice. The tillage systems had no effect (P < 0.05) on the mass or number of nodules, shoot biomass production at the R1 or R6 growth stages, the N content, BNF, or grain yield. Since the present results were obtained using non-commercial soybean isolines, further research is required to determine the soil N balance when high yielding soybean crops are raised