Long-term phosphorus fertilisation increased the diversity of the total bacterial community and the phoD phosphorus mineraliser group in pasture soils   总被引：1，自引：0，他引：1  

Hao Tan  Matthieu Barret  Marlies J. Mooij  Olivia Rice  John P. Morrissey  Alan Dobson  Bryan Griffiths  Fergal O’Gara 《Biology and Fertility of Soils》2013,49(6):661-672

Fertilisers, especially nitrogen (N) and phosphorus (P) supplies, are frequently used in agricultural soil management to attain high crop yields. However, the intensive application of these chemical inputs can decrease the quality of agricultural soils and increase the probability of environmental pollution. In this study, the impact of P fertilisation on the diversity of the soil bacterial community was assessed. For this, a culture-independent approach targeting 16 rRNA and phoD genes was used on DNA extracted from pasture soils subjected to three different P fertilisation regimes for a long-term (42 years). As alkaline phosphomonoesterase (ALP) is necessary for mineralisation of organic P, an inverse relationship between the level of potential ALP activity and soil available P was expected. Indeed, a lower ALP activity was observed in soil subjected to higher chemical P fertiliser input. Analysis of the prevalence of three divergent families of ALP (PhoA, PhoD and PhoX) in metagenomic datasets revealed that PhoD is the most frequent ALP in soil samples and was selected as the most representative ALP possessed by the soil bacterial communities. Diversity of the phoD phosphorus mineraliser group, as well as the total bacterial community, was both increased in response to long-term P fertilisation. Specifically, phosphorus fertilisation decreased the relative abundance of certain taxa, including Acidobacteria and Pseudomonas fluorescens. In conclusion, this study shows that P fertilisation affects the microbial diversity of soil ecosystems, which might potentially modulate the soil biogeochemical cycle.  相似文献   

St. Augustinegrass Fertilizer Trials     

L. E. Trenholm  J. Bryan Unruh 《Journal of plant nutrition》2013,36(3):453-461

ABSTRACT

Research was conducted to verify the current fertilization recommendations for St. Augustinegrass (Stenotaphrum secundatum Walt. Kuntze) lawns. Currently, a range from 100 to 300 kg nitrogen (N) ha^{? 1} per growing season is suggested, based on factors such as location in the state, desired maintenance level, soil conditions, etc. Research was conducted at the G.C. Horn Turfgrass Field Laboratory in Gainesville, FL from 2000 to 2002, utilizing medium to high management levels and at a sod farm in Bradenton, FL from 2001 and 2002, under low management conditions. Nitrogen (N) and potassium (K) treatments were arranged in a randomized complete block design with three replications in both locations. In Gainesville, best visual quality was generally obtained with medium (MN) or high nitrogen rates (HN). In Bradenton, MN, and HN rates provided best visual quality responses in 2002 and 2003, but higher rates of N were required than in Gainesville to maintain acceptable quality. This higher N requirement could be due to the longer growing season in Bradenton or to poor turfgrass growth resulting from inadequate pest control. In the absence of biotic or abiotic stresses, the highest rates of N were not necessary to maintain an acceptable quality lawn.  相似文献   

MONOPOTASSIUM PHOSPHATE AS AN IN-SEASON FERTIGATION OPTION FOR POTATO     

Bryan G. Hopkins  Jason W. Ellsworth  Amanda K. Shiffler  Aaron G. Cook  Thomas R. Bowen 《Journal of plant nutrition》2013,36(10):1422-1434

Monopotassium phosphate (MKP) is a potential option for fertigating phosphorus (P) in potato (Solanum tuberosum L.) when petioles are low in P and high in nitrogen (N); which is a situation where using ammonium polyphosphate (APP) could potentially result in excessive N application. Fertilizer trials were conducted in 2004–2006 with 0 or 56 kg P₂O₅ ha^?1 fertigated as either APP or MKP as a supplement to the pre-plant P (112 or 224 kg P₂O₅ ha^?1) broadcast applied to all plots. Supplemental P fertigation increased petiole P concentration, US No. 1 yield, and total yield over the control not receiving any in-season P fertilizer regardless of source. In addition, MKP increased tuber specific gravity. These results support previous studies showing that fertigated P can be used to increase potato yields when petiole P concentrations are low and that MKP is a viable substitute for APP fertilizer when fertigation is necessary.  相似文献   

Marketing Locally Produced Organic Foods in Three Metropolitan Arkansas Farmers’ Markets: Consumer Opinions and Food Safety Concerns     

Ron Rainey  Philip G. Crandall  Corliss A. O’Bryan  Steven C. Ricke  Sean Pendleton  Steve Seideman 《Journal Of Agricultural & Food Information》2013,14(2):141-153

Consumers embrace local food systems as an alternative to the global corporate model, and nearly 75% of consumers in the United States purchase organic foods occasionally. To assess consumers’ knowledge of locally grown organic foods, surveys were administered at three metropolitan farmers’ markets in Little Rock, Hot Springs, and Texarkana, Arkansas. Consumers with Bachelor's, Associate's, or technical degrees accounted for almost half of the people surveyed. Seventy-one percent believed organic foods were safer than conventional foods. Three times as many consumers were concerned about harmful bacteria in conventional foods than in organic. The number one reason for purchasing was to support local farmers.  相似文献   

Utilization of Compost Increases Organic Carbon And Its Humin,Humic and Fulvic Acid Fractions In Calcareous Soil     

G.M. Zinati  Y.C. Li  H.H. Bryan 《Compost science & utilization》2013,21(2):156-162

Organic carbon sustainability in a gravelly calcareous soil is a great challenge under the humid conditions of south Florida. The beneficial effects of compost utilization on soil fertility prompted an investigation on (i) accumulation of total organic carbon and (ii) the soil organic carbon (SOC) in humin, humic acid (HA) and fulvic acid (FA) fractions in a gravelly calcareous soil amended with composts or inorganic fertilizer. In 1996 and 1998, compost from municipal solid waste (MSW) (100% MSW), Bedminster cocompost (75% MSW and 25% biosolids) and biosolids compost (100% biosolids) at 72, 82.7 and 15.5 Mg ha^?1, respectively, were each incorporated in soil beds and inorganic fertilizer (6-2.6-10) NPK at 2.8 Mg ha^?1. A control (no amendment) treatment was also included. Total organic carbon and various fractions of soil organic carbon were determined in two depths (0-10 and 10-22 cm) for both soil particles (< 2mm) and pebbles (> 2mm). Inorganic and organic soil amendments had decreased soil pH and increased soil electrical conductivity (EC) 19 months from initial application. Total organic carbon contents in soil particle were 4-, 3-, and 2-fold higher in MSW compost, Bedminster cocompost and biosolids compost treatments, respectively, than those in fertilizer treated or non-treated soils. MSW compost increased total organic carbon in pebbles by 4- and 3-fold in the 0-10 and 10-22 cm deep layers, respectively, more than other treatments. The soil organic carbon accumulation decreased with depth in all treatments in soil particles, but did not in pebbles. Amending soils with MSW compost significantly increased the organic carbon in humin, HA and FA fractions more than those treated with inorganic fertilizer or non-amended. MSW compost has a potential to be used as a soil amendment to increase and sustain the organic carbon in calcareous soils of south Florida.  相似文献   

Errata     

W. M. Roca  N. O. Espinoza  M. R. Roca  J. E. Bryan 《American Journal of Potato Research》1979,56(3):175-175

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Myzus persicae (Sulzer) in diffuse light and dark rustic storages and resultant PLRV transmission     

Bruce L. Parker  Robert H. Booth  James E. Bryan 《American Journal of Potato Research》1983,60(2):65-74

Population levels ofMyzus persicae (Sulzer) were studied on potato tubers in diffuse light and dark rustic storage houses in Peru. No differences in numbers of aphids/sprouted eye on potatoes infested naturally during storage in diffuse light or darkness were observed. Significantly more alate aphids were observed on tubers stored in darkness than in diffuse light storage houses. Viral transmission was occurring during the storage period. The incidence of viral transmission was not significantly influenced by storing tubers in diffuse light or dark storages. There were significantly more plants infected with virus from tubers that had not been sprayed for aphid control than from tubers that had been sprayed  相似文献   

Instrumental and sensory quality characteristics of blueberry fruit from twelve cultivars   总被引：1，自引：0，他引：1  

Robert Saftner  James Polashock  Mark Ehlenfeldt  Bryan Vinyard 《Postharvest Biology and Technology》2008,49(1):19-26

We compared the instrumental and sensory quality characteristics of blueberry fruit from ten highbush (Vaccinium corymbosum L.) cultivars, Chanticleer, Weymouth, Hannah's Choice, Duke, Bluecrop, Coville, Berkeley, Bluegold, Elliott and Lateblue and two rabbiteye (Vaccinium virgatum Aiton) cultivars, Coastal and Montgomery, grown in New Jersey. Cultivars varied in sensory intensity and acceptability scores. Highbush cultivars, Coville and Hannah's Choice, scored highest among the cultivars in sensory scores for intensity of blue color, juiciness, sweetness and blueberry-like flavor and for acceptability of appearance, color, fruit size, sweet/tart balance, flavor and overall eating quality. In contrast, rabbiteye cultivars, Coastal and Montgomery, and the highbush cultivars, Elliott and Weymouth, scored lowest among the cultivars in sensory scores for intensity of bursting energy, skin toughness, texture during chewing, juiciness, and blueberry-like flavor and for acceptability of appearance, color, fruit size, flavor and overall eating quality. Analytical quality characteristics of surface color, size, compression firmness, soluble solids content (SSC), pH, titratable acidity (TA), SSC/TA ratio, and aromatic volatile concentration also varied among cultivars, but no instrumental measurement adequately predicted consumer acceptability scores. The overall eating quality of blueberry fruit was best correlated with flavor scores followed by sensory scores for intensity of juiciness, bursting energy and sweetness and for acceptability of appearance.  相似文献   

Advances in Functional Genomics and Genetic Modification of Potato     

Howard Davies  Glenn J. Bryan  Mark Taylor 《Potato Research》2008,51(3-4):283-299

The challenges facing potato breeding have actually changed very little over the years with resistance to pests and pathogens remaining high on the agenda together with improvements in storability, reduction in blemishes, and novelty and consistency in cooking/processing qualities. The need to expand the range of targets for potato improvement is being driven by requirements for reduced agrochemical usage and by predictions of the effects of changing climates. Thus fertiliser and water use efficiency are moving up the political agenda. Genetic variation present in germplasm collections needs to be harnessed to provide the genes and alleles required. This paper provides examples of the functional genomics tools and approaches being developed and deployed to provide new options for advancing the breeding of next generation crops. Whilst genetic modification (GM) approaches remain contentious in Europe, this paper will also provide some recent examples of the range of potential impacts that GM approaches could make. It will also consider the value of so-called intragenic or cisgenic approaches to potato genetic engineering.  相似文献   

Binding characteristics of swine erythrocyte insulin receptors     

G Dieberg  G S Bryan  J L Sartin  J C Williams  T J Prince  R J Kemppainen 《American journal of veterinary research》1985,46(9):1929-1933

Crossbred gilts (controls; n = 7) had 8.8 +/- 1.1% (mean +/- SEM) maximum binding of [125I]insulin to insulin receptors on erythrocytes. The number of insulin-binding sites per cell was 137 +/- 19, with a binding affinity ranging from 7.4 X 10(7)M-1 to 11.2 X 10(7)M-1 and mean of 8.8 X 10(7)M-1. Pregnant sows (n = 5) had a significant increase (P less than 0.01) in maximum binding due to an increase in number of receptor sites per cell. Lactating sows fed a high-fiber diet (n = 3) and a low-fiber diet (n = 4) did not develop a significant difference in maximum binding of insulin. Sows fed the low-fiber diet had a significantly higher number of binding sites and a significantly lower binding affinity than did sows fed a high-fiber diet. Receptor-binding affinity was lower in the low-fiber diet group than in cycling gilts, whereas data from sows fed the high-fiber diet did not differ from data for cycling gilts. Data from this study indicated that insulin receptors of swine erythrocytes have binding characteristics similar to those in other species. Pregnancy and diet will alter insulin receptor binding in swine.  相似文献