Corn and soybean grain yield responses to soil amendments and cover crop in upland soils     

Ardeshir Adeli  John P. Brooks  John J. Read  Gary Feng  Dana Miles  Mark W. Shankle 《Journal of plant nutrition》2013,36(19):2484-2497

A field study was conducted on upland soils for six years to determine interactive effects of winter wheat (Triticum aestivum L.) cover crop, organic and inorganic soil amendments on grain yields and nutrient utilizations in a no-till corn (Zea mays)-soybean (Glycine max) rotation. Experimental design was a split-plot arrangement with four replicates. Cover crops were the main plots and fertilization treatments used as sub-plot. Fertilization treatments included an unfertilized control, poultry litter, poultry litter (PL) plus flue gas desulfurization (FGD) gypsum and inorganic N fertilizer applied every other year to corn. Corn grain yield and grain N and P uptake were greater with PL than inorganic fertilizer in 2014 and 2016. Addition of FGD gypsum to PL significantly increased corn grain yield by 15% in 2016. Cover crop increased corn and soybean grain yields in a year with less seasonal rainfall possibly by conserving soil moisture.  相似文献   

Enhancing the thermal comfort on urban level in a desert area: Case study of Dubai,United Arab Emirates     

Hanan Taleb  Dana Taleb 《Urban Forestry & Urban Greening》2014,13(2):253-260

The urbanisation of deserts in Dubai is one way in which this city can expand and explore its full potential. In this piece of research, a case study of the Dubai International Academic City was used as a basis from which to study the importance of planning and orientation of projects in open, unpopulated land. It demonstrates the various alternatives for project orientation relative to the sun and wind, its effects on temperature and wind readings and consequently on outdoor thermal comfort levels. ENVI-met was used to simulate various scenarios generated from the existing base case in both summer and winter. The orientation which best promoted and allowed for higher wind flow through the project was found to record the best outdoor predicted mean vote levels, approaching a neutral state. The findings of this research may be used for setting up regulations regarding the planning of desert areas in Dubai on the basis of early assessment of designs.  相似文献   

Effects of Scavenging on Diet Selection and Performance of Rhode Island Red and Fayoumi Breeds of Chicken Offered a Choice of Energy and Protein Feeds     

Dana N  Ogle B 《Tropical animal health and production》2002,34(5):417-429

An experiment was conducted to evaluate the effect of scavenging on diet selection and the comparative performance of Rhode Island Red and Fayoumi breeds of chicken. The breeds were compared under three feeding/management regimes: (1) a choice of ground noug cake and cracked maize, with confinement; (2) a choice of ground noug cake and cracked maize, but being allowed to scavenge for about 6 h; and (3) a commercial layer mash, with confinement. Scavenging did not change the pattern of diet selection. About 90% of the daily intake of both the confined and scavenging birds under choice feeding comprised maize. The efficiency of feed utilization and nutrient intake were also similar in these groups. The Fayoumi were more efficient in terms of feed conversion, although the egg production performance of the two breeds did not vary significantly. Scavenging hens had a significantly lower egg production than the birds under confinement offered a choice of feeds. Scavenging significantly increased the mortality in both breeds. In conclusion, scavenging affected the performance adversely and, despite the provision of a choice of feed providing a source of energy and protein, both the scavenging and confined birds on choice feeding failed to eat sufficient to meet their protein requirements.  相似文献   

Resolution of renal adenocarcinoma-induced secondary inappropriate polycythaemia after nephrectomy in two cats     

Klainbart S  Segev G  Loeb E  Melamed D  Aroch I 《Journal of Feline Medicine and Surgery》2008,10(3):264-268

Two cases of secondary, inappropriate polycythaemia caused by renal adenocarcinoma in domestic shorthair cats, are described. The cats were 9 and 12 years old and both were presented because of generalised seizures presumably due to hyperviscosity. Both cats had a markedly increased haematocrit (0.770 and 0.632 l/l) and thrombocytosis (744 x 10(9)/l and 926 x 10(9)/l). An abdominal ultrasound revealed a mass in the cranial pole of one kidney in both cats. Serum erythropoietin (EPO) concentration was within the reference interval (RI) in both cats but was inappropriately high considering the markedly increased haematocrit. The cats were initially stabilised and managed by multiple phlebotomies and intravenous fluid therapy and underwent nephrectomy of the affected kidney later on. Both the polycythaemia and thrombocytosis resolved following surgery. Postoperative serum EPO concentration, measured in one cat, decreased markedly. Histopathology of the affected kidneys confirmed a diagnosis of renal adenocarcinoma. Both cats were stable for an 8-month follow-up period; however, one cat had developed a stable chronic kidney disease (CKD), while the other was represented 8 months postoperatively due to dyspnoea, and had radiographic evidence of lung metastasis, presumably because of the spread of the original renal tumour and was euthanased. Initial stabilisation of polycythaemic cats should include multiple phlebotomies. Nephrectomy should be considered in cats with secondary, inappropriate, renal adenocarcinoma-related polycythaemia when only one kidney is affected by the tumour, and provided that the other kidney's function is satisfactory. Nephrectomy should be expected to resolve the polycythaemia and lead to normalisation of serum EPO concentration.  相似文献   

Infectivity and pathogenicity of Cryptosporidium andersoni to a novel host, southern multimammate mouse (Mastomys coucha)     

Kvác M  Ondrácková Z  Kvetonová D  Sak B  Vítovec J 《Veterinary parasitology》2007,143(3-4):229-233

The infectivity and pathogenicity of Cryptosporidium andersoni (bovine isolate) for neonatal and adult southern multimammate mice (Mastomys coucha) was studied using transmission experiments. C. andersoni isolate used in this study was not infective for BALB/c mice, but experimental infection proved susceptibility of neonatal and adult M. coucha to the infection. The prepatent period was 20-24 days, the patent period varied between 46 and 59 days. No signs of clinical illness or macroscopic findings were detected in infected animals. Cryptosporidium developmental stages were detected only in the glandular part of the stomach of M. coucha in histological sections stained with Wolbach's modification of Giemsa and using immunofluorecence. Histopathological changes were characterized by dilatation and epithelial metaplasia of infected gastric glands without inflammatory response in the lamina propria. Neonatal M. coucha were more susceptible to C. andersoni infection than adults. M. coucha seems to be a useful laboratory model for study of C. andersoni infection.  相似文献   

Effect of bone chars on phosphorus‐cadmium‐interactions as evaluated by three extraction procedures          下载免费PDF全文

Mohsen Morshedizad  Dana Zimmer  Peter Leinweber 《植物养料与土壤学杂志》2016,179(3):388-398

Foreseen P shortage and contamination problems have stimulated the search for renewable and contaminant‐free P‐fertilizers and amendments that immobilize Cd. We investigated the P‐dissolution and Cd‐immobilizing effect of bone char (pyrolyzed de‐fatted bone chips; BC) and bone char with added reduced S compounds (BC^plus). Five soils varying in pH and low to high Cd‐contamination were incubated with slow‐release P‐fertilizers (BC and BC^plus) and the fast P‐release diammonium phosphate (DAP), and extracted with NH₄NO₃‐, NaHCO₃‐solutions, and H₂O. The P‐concentrations obtained by the three extractants were well correlated and NH₄NO₃ well suited to simultaneously assess the P‐ and Cd‐solubility. The addition of BC increased pH in all soils whereas BC^plus and DAP lowered the pH in soils with pH > 5. Similar trends for NH₄NO₃‐P differences between treatments and control were observed for BC and BC^plus during the incubation period, although BC^plus resulted in much larger P‐concentrations. The highest Cd‐immobilization efficiency was obtained in BC‐treated soils. The addition of BC^plus and DAP decreased the Cd‐concentrations until 34 d of incubation in all soils and remained effective in Cd‐immobilizing in soils that showed a pH raise over 145 d of incubation. Thus, the results indicate that surface modification of BC may promote the P‐dissolution along with a concomitant Cd‐immobilization largely through its pH‐effect but this must be confirmed in studies under non‐equilibrium conditions.  相似文献   

Glyphosate applied at low doses can stimulate plant growth     

Velini ED  Alves E  Godoy MC  Meschede DK  Souza RT  Duke SO 《Pest management science》2008,64(4):489-496

BACKGROUND: Glyphosate blocks the shikimic acid pathway, inhibiting the production of aromatic amino acids and several secondary compounds derived from these amino acids. Non-target plants can be exposed to low doses of glyphosate by herbicide drift of spray droplets and contact with treated weeds. Previous studies have reported that low doses of glyphosate stimulate growth, although these data are very limited. The objective of this study was to determine the effects of low glyphosate doses on growth of a range of plant species. RESULTS: Growth of maize, conventional soybean, Eucalyptus grandis Hill ex Maiden, Pinus caribea L. and Commelia benghalensis L. was enhanced by 1.8-36 g glyphosate ha(-1). Growth of glyphosate-resistant soybean was unaffected by any glyphosate dose from 1.8 to 720 g AE ha(-1). The optimum doses for growth stimulation were distinct for plant species and tissue evaluated. The greatest stimulation of growth was observed for C. benghalensis and P. caribea. Shikimic acid levels in tissues of glyphosate-treated soybean and maize were measured and found to be elevated at growth-stimulating doses. CONCLUSION: Subtoxic doses of glyphosate stimulate the growth of a range of plant species, as measured in several plant organs. This hormesis effect is likely to be related to the molecular target of glyphosate, since the effect was not seen in glyphosate-resistant plants, and shikimate levels were enhanced in plants with stimulated growth.  相似文献   

2种作图法对大豆蛋白含量性状QTL定位的比较研究     

姚丹  王丕武  闫伟 《西北农林科技大学学报(自然科学版)》2010,38(8):47-54

【目的】比较复合区间作图法(CIM)和完备区间作图法(ICIM)对大豆高蛋白含量性状QTL的定位效果,总结2种方法进行QTL作图的优缺点,为QTL作图方法的选择及分子标记辅助选择培育高蛋白含量大豆品种研究提供参考。【方法】以高油大豆品种吉农18和高蛋白大豆品种吉育47杂交后获得的F2分离群体为材料,结合2年的分子数据和表型数据,采用CIM和ICIM法对大豆蛋白含量性状进行QTL定位。【结果】利用CIM和ICIM-ADD,在连锁群12(B2+C1)和17(M)上共检测到了5个高蛋白QTL,其中ICIM-ADD检测到的QTL略多于CIM;由CIM在F2∶3家系和ICIM-ADD在F2代、F2∶3家系的检测结果可以看出,2种作图法在satt285～satt636标记区间内均检测到显著LOD,且QTL距第一个标记(satt285)的遗传距离≤5.0cM,可认为此3个QTL为同一QTL,其贡献率分别为10.87%,17.09%和17.34%,说明该QTL的稳定性较好,可在进一步的高蛋白分子辅助育种中加以利用。【结论】2种作图法各有其优缺点,在实际应用中应根据分析对象综合运用、合理选择作图方法,以最大限度地提高QTL作图的精度和效率。对研究中所定位的SSR标记,特别是稳定标记可以在今后的大豆高蛋白分子标记辅助选择育种中加以利用。  相似文献   

Effects of temperature and humidity on the survival of urediniospores of gladiolus rust (<Emphasis Type="Italic">Uromyces transversalis</Emphasis>)     

Gary L. Peterson  Dana K. Berner 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(3):509-513

Uromyces transversalis is an autoecious microcyclic rust mainly infecting Gladiolus spp. The pathogen is considered of plant quarantine importance in Europe and the USA. In 2006, the pathogen was found for the first time in the USA in several commercial nurseries in Florida and California. The US Department of Agriculture (USDA) initiated an eradication programme that recommended the immediate removal and destruction of infected plants followed by a host-free period, use of a fungicide treatment schedule, and equipment decontamination. In support of this plan, a study was conducted to determine how long urediniospores of U. transversalis would continue to germinate at temperatures of 2.8, 15.0, 18.8 and 25.0°C under controlled relative humidities (RH) of 11, 23, 43, 75, 93 and 100%. Choice of temperature and humidity parameters were mostly based on historical multi-year climate data from areas where the disease was detected in California and Florida. Analysis of variance (ANOVA) indicated no significant effect of RH on urediniospore germination but a highly significant effect of temperature. No germinating urediniospores were detected after 79 days for any treatment, but the 15°C treatment was more likely to be the result of germination independent of any low or high temperature-induced spore quiescence. Thus, lack of germination after 79 days was probably a good indicator of the lack of viable spores after this time for the 15°C treatment.  相似文献   

Impacts of climate change for coastal fishers and implications for fisheries          下载免费PDF全文

Valentina Savo  Cedar Morton  Dana Lepofsky 《Fish and Fisheries》2017,18(5):877-889

Coastal Social–Ecological Systems (SESs) are subject to several stresses, including climate change, that challenge fisheries and natural resource management. Fishers are front‐line observers of changes occurring both on the coast and in the sea and are among the first people to be affected by these changes. In this study, we perform a meta‐analysis of observations and adaptations to climate change by subsistence‐oriented coastal fishers extracted from a global review of peer‐reviewed and grey literature. Fishers' observations compiled from across the globe indicate increased temperatures and changes in weather patterns, as well as coastal erosion, sea level rise and shifts in species range and behaviours. Coastal areas offer a wide array of resources for diversifying livelihoods, but climate change is reducing these options. Specifically, climate change could reduce the resilience of fishers' communities, limiting options for diversification or forcing fishers to abandon their houses or villages.  相似文献