Grazing management for more resilient mixed livestock farming systems on native grasslands of southern South America     

Pablo Modernel  Valentin Picasso  Martin Do Carmo  Walter A. H. Rossing  Marc Corbeels  Pablo Soca  Santiago Dogliotti  Pablo Tittonell 《Grass and Forage Science》2019,74(4):636-649

Droughts in southern South America affect grazing systems in many ways. They reduce biomass productivity; decrease livestock feed intake, weight and reproductive performance; increase farmers’ costs; and reduce farm income. It was hypothesized that simple grazing management variables affect the resilience of grazing systems to droughts at the paddock and farm scales. The effects of grazing management on herbage and animal production were assessed at paddock level, and how technological and structural variables relate to the production and economic performances at farm level. Results of a grazing experiment controlling herbage allowance at paddock level showed that resistance of herbage accumulation and animal live weight to drought was significantly higher for paddocks with higher pre‐drought herbage allowance than for those managed to low herbage allowance treatments. A strong positive linear relationship was found between pre‐drought herbage height and resistance of herbage accumulation rate (p < .01). In a longitudinal study of nine farms in Uruguay, resistance of cow pregnancy rate to drought was positively correlated with cow pregnancy rate (r = .72, p = .02) and farm net income (r = .78, p = .02), and negatively correlated with sheep‐to‐cattle ratio (r = ?.80, p = .01). These correlations suggest that farms with higher incomes and low proportions of sheep in the herd withstand drought better (in terms of pregnancy rate). Four common regional production strategies were identified that react differently when farmers face drought, and these results can aid farmers in those regions to design more resilient mixed livestock farming systems and can inform policymakers about effective strategies for mitigating drought impacts in the region.  相似文献   

悠然山谷中的狩猎家族     

姜雯雨 《百姓》2011,(10)

Vale Do Manantio是拥有悠久历史的知名居所;是兼具自然灵动与狩猎文化的山谷美宅;是让心灵自由放飞的灵魂归宿……来到Vale Do Manantio,与Bravo家族一起体会山谷溪流带来的野性与感动。Vale Do Manantio别墅坐落在葡萄牙南部城市阿连特茹的中心,别墅名字的涵义是淡水河谷,换言之,是拥有充足水源和盎然绿意的肥沃山谷。别墅房产经代代相传,占地面积不断扩大,  相似文献   

Evaluation of the water-quality dynamics in a eutrophic agricultural pond by using a one-box ecosystem model considering several algal groups   总被引：1，自引：1，他引：0  

Do Thuy Nguyen  Masayoshi Harada  Kazuaki Hiramatsu 《Paddy and Water Environment》2010,8(4):301-318

The Okubo pond is an agricultural pond located in the Itoshima area of Fukuoka Prefecture, Japan. It was constructed for irrigating a nearby cultivated area. A monitoring program from August 11 to November 26, 2008, suggested the risk of eutrophication in the water body. The high total nitrogen concentration (1.34 mg/l), high total phosphorus concentration (0.06 mg/l) and extreme oxygen depletion (2 mg/l on 5 November 2008) exceeded the Japanese standards for paddy irrigation water. Furthermore, luxuriant algal blooming in October indicated a hypereutrophic status according to the OECD (1982) criteria. In this study, a one-box ecosystem model was developed to obtain an insight into the seasonal variations in the algal concentrations and chemical components of the Okubo pond with the aims of protecting its aquatic ecosystem and maintaining its water quality. The model was based on a completely mixed system and included 12 water-quality indices: green algae, blue-green algae, diatoms and dinoflagellates, cryptophytes, zooplankton, particulate organic matter, dissolved organic matter, phosphate–phosphorus, ammonia–nitrogen, nitrite–nitrogen, nitrate–nitrogen, and dissolved oxygen. The monitoring data were used to verify the model simulation. Model evaluation suggested good agreement between the predicted and the observed data for the seasonal variations in the algal, nutrient, and dissolved oxygen concentrations. To determine the sensitivity of the model parameters, a sensitivity analysis was conducted leading to the conclusion that the optimal temperature, growth rate, and respiratory rate of the four algal groups, especially the ideal temperature for blue-green and green algae are the most influential factors determining the variability affecting the model inference. From the model simulation, the water temperature and nutrient concentration were considered to be the key limiting factors controlling alternative algal blooms in this period.  相似文献   

The phytotoxicity potential of olive processing waste on selected weeds and crop plants     

Özhan Boz  Derya Öğüt  M. Nedim Doğan 《Phytoparasitica》2010,38(3):291-298

The effect of sun-dried OPW (olive processing waste) on weeds and crop plants, was investigated at the Adnan Menderes University Research and Application Farm between 2006 and 2007. Sun-dried OPW was placed in pots in doses of 9, 18, 27, 36, 45 and 54 grams per pot, which is equivalent to doses of 1, 2, 3, 4, 5 and 6 kg m⁻²; pots with no OPW served as controls. In these experiments, ten seeds each of wild oat (Avena fatua), sterile oat (Avena sterilis), blackgrass (Alopecurus myosuroides), perennial ryegrass (Lolium perenne), yellow sweetclover (Melilotus officinalis), redroot pigweed (Amaranthus retroflexus), jimsonweed (Datura stramonium), faba bean (Vicia faba), pea (Pisum sativum), and sesame (Sesamum indicum) were sown in pots; for common lambsquarters (Chenopodium album), seedlings were planted in pots. Seedlings of both weeds and crop plants were counted in order to assess the effects of sun-dried OPW on plant emergence. One plant was left per pot for observation of the effects of sun-dried OPW treatments on weed and crop plant growth. The results showed that OPW can be used to suppress the growth of all the weeds listed above, in pots containing V. faba, P. sativum and S.indicum plants and without any negative effects on crop growth.  相似文献   

Efficacy of Rinskor™ (florpyrauxifen-benzyl ester) on Herbicide Resistant Barnyardgrass (<Emphasis Type="Italic">Echinochloa crus-galli</Emphasis>) in Rice Fields of Mekong Delta,Vietnam     

Le Duy  Nguyen M. Chon  Richard K. Mann  Bobba V. N. Kumar  Mauricio A. Morell 《Journal of Crop Science and Biotechnology》2018,21(1):75-81

Barnyardgrass (Echinochloa crus-galli) seed samples were collected in rice fields in different locations at Mekong delta in Vietnam for herbicide resistance tests. The ALS-resistant and synthetic auxin-resistant E. crus-galli were confirmed at several locations in the Mekong Delta. The average LD₉₀ value of bispyribac, penoxsulam and quinclorac for assessed weed populations was 33.1, 15.1 and 550.2 g a.i.ha^?1 respectively. There were cross resistant barnyardgrass populations to bispyribac and penoxsulam, the LD₉₀ value of the two ALS inhibitors for E. crus-galli was positively correlated at R²=0.39, the cross resistant population was 33.3% of total sample. The correlation analysis was not useful to evaluate the multiple resistance between quinclorac and the two ALS inhibitors, the R² value was lower than 0.05, however, the percentage of multiple resistance weed was 36.2% of population. There was no cross resistance or multiple resistance among the 3 tested herbicides and the new synthetic auxin herbicide Rinskor?. All tested weed samples, including quinclorac-resistant populations, were effectively controlled by Rinskor?. There was no difference between control from Rinskor? in the different herbicide resistant populations. Average LD₉₀ value of Rinskor? in all tested barnyardgrass was 17.1 g a.i ha^?1.  相似文献   

Diffusion of chemicals into archaeological waterlogged hardwoods obtained from the Thang Long Imperial Citadel site,Vietnam     

Nguyen Duc Thanh  Soichiro Wakiya  Kazutaka Matsuda  Bui Duy Ngoc  Junji Sugiyama  Yohsei Kohdzuma 《Journal of Wood Science》2018,64(6):836-844

This study shows a method to easily develop suitable impregnation procedure of chemicals for preserving the archaeological waterlogged wood (WW) using diffusion constant. The steady-state diffusion coefficients of polyethylene glycol 4000 (PEG4000), trehalose, and keratin through eight archaeological waterlogged wood species were obtained from the total amounts of the chemicals diffused through the wood samples. The diffusion coefficients were strongly affected by the anatomical structures of the wood species and degree of wood deterioration. Within the same species of wood, the highest diffusion rates were measured in the longitudinal direction, followed by those in the radial and tangential directions. The longitudinal diffusion coefficients were 1.5- to 8.1-times higher than the radial diffusion coefficients, which were in turn approximately 1.1- to 5.7-times higher than the tangential diffusion coefficients. The diffusion rates were found to be inversely proportional to the molecular weight of the diffusing chemical. The diffusivity of trehalose through the waterlogged woods was found to be higher than those of keratin and PEG4000. This study provides a potential method to easily estimate chemical diffusion coefficients for dip-diffusion treatments.  相似文献   

Dothistroma spp. in Western Ukraine and Georgia          下载免费PDF全文

I. Matsiakh  H. T. Doğmuş‐Lehtijärvi  V. Kramarets  A. G. Aday Kaya  F. Oskay  R. Drenkhan  Steve Woodward 《Forest Pathology》2018,48(2)

Dothistroma needle blight (DNB) is among the most serious foliar diseases affecting Pinus spp. globally. Infected needles were collected from potential host species in four locations in western Ukraine and in four locations in eastern Georgia during spring–summer 2015 to update the knowledge on pathogen distribution in these countries. Dothistroma spp. were detected using isolation, sequencing and species‐specific priming (SSPP) PCR. Two new hosts for Dothistroma spp. were recorded in western Ukraine: D. septosporum on Pinus nigra var. australica and D. pini on P. nigra var. mollet. D. septosporum was found on 15‐year‐old P. strobus in western Ukraine. New hosts for D. septosporum were recorded in Georgia on 5‐ to 10‐year‐old naturally regenerated P. sylvestris var. hamata and on 40‐ to 50‐year‐old P. ponderosa trees. D. pini was found for the first time in Georgia on 30‐ to 40‐year‐old P. nigra trees. The work confirmed the presence of both D. septosporum and D. pini in western Ukraine and Georgia, and demonstrated new hosts for both Dothistroma species.  相似文献   

Examining the Effects of the Destroying Ammunition,Mines and Explosive Devices on the Presence of Heavy Metals in Soil of Open Detonation Pit; Part 2: Determination of Heavy Metal Fractions     

Neda Tešan Tomić  Slavko Smiljanić  M. Jović  M. Gligorić  D. Povrenović  A. Došić 《Water, air, and soil pollution》2018,229(9):303

As a result of the destruction of ammunition, mines, and explosive devices by the method of open detonation, the increased concentration of heavy metals is often recorded in the soil of military polygons, which is a serious ecological problem. However, in order to determine the potential risk of such locations to the environment, it is necessary to determine, in addition to the total content, the forms in which the metals are present. In this paper, a sequential extraction method was used to analyze the six fractions of five heavy metals (cadmium, lead, nickel, copper, and zinc) in the soil of the polygon for destruction of ammunition, mines, and explosive devices. Samples were collected from the place of direct detonation (so-called pits) and from the edge of the pit. The aim of this research is determination of metal speciation in order to obtain a better insight in their mobility and risk arising from this. The results showed that heavy metals are predominantly present in the residual, oxide, and organic fractions. Cd and Cu were also significantly present in the mobile fractions due to conducted activities on the polygon. To assess the potential environmental risk of soil, the risk assessment code (RAC) and individual (ICF) and global (GCF) contamination factors were used. According to the RAC, the mobility and bioavailability of the analyzed heavy metals decreases in the following order: Cd?&gt;?Cu?&gt;?Zn?&gt;?Pb?&gt;?Ni. ICF results show low to moderate risk, while GCF results show low risk in terms of heavy metal contamination in the examined area.  相似文献   

Effect of Vermicompost in Media on Growth,Yield and Fruit Quality of Cherry Tomato (Lycopersicon esculentun Mill.) Under Net House Conditions     

Ha Duy Truong  Chong Ho Wang  Tran Trung Kien 《Compost science & utilization》2018,26(1):52-58

Effects of VC application on tomato production and media properties can last for the third successive season, which was verified in this study to evaluate effects of VC application on growth, productivity and fruit quality of cherry tomato for the third season. Six treatments were designed similarly in the first and second seasons (unchanged design compared to the previous season), including: VC with rice husk ash (RHS) and coconut fiber (CF) 0% VC+ 50% RHS +50% CF (T1- control), respectively. 20%VC + 40% RHS + 40% CF(T2), 40% VC+ 30% RHS + 30% CF(T3), 60% VC + 20% RHS + 20% CF(T4), 80% VC + 10% RHS + 10% CF(T5), and 100% VC(T6). The results showed that the pH, EC, N, P, K, Ca, and Mg available in media were increased with the addition of VC. This finding revealed that the addition of VC significantly improved the physic-chemical media properties, increasing the EC and also increasing the macronutrients in the media resulting in substantial increased the yield and quality of tomato fruits. It is concluded that EC of VC was the key factor for the positive increase of the productivity and quality of tomato and the salinity (EC at 3.52 dS/m) causing restriction of water to fruits that resulted in the increase of the total soluble solids in tomato fruit and without affecting yield reduction.  相似文献   

Effects of Continuously Applied Vermicompost on Media Properties,Growth, Yield,and Fruit Quality of Two Tomato Varieties     

Ha Duy Truong  Chong Ho Wang  Tran Trung Kien 《Communications in Soil Science and Plant Analysis》2017,48(4):370-382

In the first and second seasons, growth and yield of tomato were also influenced by different vermicompost (VC) rates and reused VC. Obviously, increasing VC proportion led to the augmentation of electrical conductivity (EC), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in planting media in both seasons. However, in the first season, the nutrient absorbent ability of tomato was remarkably higher compared to those in the second season due to higher available nutrient in the media of the first season. This may influence the shoot dry weight as well as the yield of tomato in both seasons. In T4 treatment, the yield attained the highest value in the first season for both varieties with the values of 562.3 and 812.4 g/plant for small honey (V1) and graces (V2), respectively. In the second season, the N, P, K, Ca, and Mg in media significantly decreased compared to those in the first season (496.4 g/plant-V1 and 508.3 g/plant-V2). In comparison, the yields in the first season were higher those in second season by 13.2% and 59.8% for V1 and V2, respectively. However, in the second season, the maximum yield found in T5 (508.3 g/plant-V1 and 682.2 g/plant-V2) and declining by 10.6 and 19.1% compared to those in the first season for V1 and V2, respectively. This can be explained that amounts of nutrients from the media in the first season had supported the growth and development of tomato, resulting deficiency of nutrients in the media for the second season.  相似文献