Relationships between soil and foliar nutrients in young densely planted mini-plots of Pinus radiata and Cupressus lusitanica

The long-term nature of forest crop rotations makes it difficult to determine impacts of forestry on soil nutrients that might be depleted by forest growth. We used small scale, highly stocked plots to compress the length of the rotation and rapidly induce nutrient depletion. In the study, two species (Pinus radiata D. Don and Cupressus lusitanica Miller) are compared under two disturbance regimes (soil undisturbed and compacted), and two fertiliser treatments (nil and plus fertiliser), applied in factorial combination at 33 sites, covering the range of climatic and edaphic variation found in plantation forests across New Zealand. To assess our ability to rapidly highlight important soil properties, foliar nutrient concentrations were determined 20 months after planting. It was hypothesised that the densely planted plots, even at a young age, would create sufficient pressure on nutrient resources to allow development of relationships between properties used as indicies of soil nutrient availability and foliar nutrient concentrations. For both species significant relationships between foliar nutrients and 0–10 cm layer soil properties from unfertilised plots were evident for N (total and mineralisable N) and P (total, acid extractable, organic, Bray-2 and Olsen P). With the exception of Ca in C. lusitanica, foliar K, Ca and Mg were correlated with their respective soil exchangeable cation measures. The results thus confirm the utility of the experimental approach and the relevance of the measured soil properties for forest productivity.

In unfertilised plots foliar N and P concentrations in P. radiata exceeded those in C. lusitanica, the differences being eliminated by fertiliser application. Foliar N/P ratios in P. radiata also exceeded those in C. lusitanica. In contrast to N and P, foliar K, Ca and Mg concentrations were all higher in C. lusitanica, the difference being particularly marked for Ca and Mg. P. radiata contained substantially higher concentrations of the metals Zn, Mn and Al than C. lusitanica, whereas the latter contained higher B concentrations. Possible reasons for differences between species in foliar nutrient concentrations are discussed.     

Monoclonal antibodies specific to thermostable proteins in animal blood

Bovine plasma proteins are used as high-quality protein supplements in animal feed and as binders or colorants in food for human consumption. Religious observance, as well as recent fears of epidemic bovine spongiform encephalopathy, highlights the need for methods to detect bovine blood in processed food and animal feed for regulatory purposes, as the currently available methods are neither species-specific, blood-specific, nor valid for excessively heat-processed samples. This paper reports the development of monoclonal antibodies (MAbs) raised against bovine thermostable plasma proteins that display a unique species specificity pattern for plasma proteins. Immunoblotting revealed several thermostable antigenic proteins (10, 25, 40, and 60 kDa) in bovine plasma sterilized at 121 degrees C for 15 min. These MAbs can be employed individually or combined in immunoassays for analytical purposes and investigations of the chemical and biological properties of the thermostable plasma proteins identified here.     

Global genotype by environment trends in growth traits for Eucalyptus dunnii

New Forests - Eucalyptus dunnii Maiden (Dunn’s white gum) is a fast-growing tall tree with a restricted natural distribution in south-east Australia and favorable wood properties for pulp...     

PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN AGRONOM

● Virtual joint centers on N agronomy were established between UK and China. ● Key themes were improving NUE for fertilizers, utilizing livestock manures, and soil health. ● Improved management practices and technologies were identified and assessed. ● Fertilizer emissions and improved manure management are key targets for mitigation. Two virtual joint centers for nitrogen agronomy were established between the UK and China to facilitate collaborative research aimed at improving nitrogen use efficiency (NUE) in agricultural production systems and reducing losses of reactive N to the environment. Major focus areas were improving fertilizer NUE, use of livestock manures, soil health, and policy development and knowledge exchange. Improvements to fertilizer NUE included attention to application rate in the context of yield potential and economic considerations and the potential of improved practices including enhanced efficiency fertilizers, plastic film mulching and cropping design. Improved utilization of livestock manures requires knowledge of the available nutrient content, appropriate manure processing technologies and integrated nutrient management practices. Soil carbon, acidification and biodiversity were considered as important aspects of soil health. Both centers identified a range of potential actions that could be taken to improve N management, and the research conducted has highlighted the importance of developing a systems-level approach to assessing improvement in the overall efficiency of N management and avoiding unintended secondary effects from individual interventions. Within this context, the management of fertilizer emissions and livestock manure at the farm and regional scales appear to be particularly important targets for mitigation.     

Comparison of fecal culture and F57 real-time polymerase chain reaction for the detection of Mycobacterium avium subspecies paratuberculosis in Swiss cattle herds with a history of paratuberculosis

Background

Bovine paratuberculosis is an incurable chronic granulomatous enteritis caused by Mycobacterium avium subspecies paratuberculosis (MAP). The prevalence of MAP in the Swiss cattle population is hard to estimate, since only a few cases of clinical paratuberculosis are reported to the Swiss Federal Food Safety and Veterinary Office each year.Fecal samples from 1,339 cattle (855 animals from 12 dairy herds, 484 animals from 11 suckling cow herds, all herds with a history of sporadic paratuberculosis) were investigated by culture and real-time polymerase chain reaction (PCR) for shedding of MAP.

Results

By culture, MAP was detected in 62 of 445 fecal pools (13.9%), whereas PCR detected MAP in 9 of 445 pools (2.0%). All 186 samples of the 62 culture-positive pools were reanalyzed individually. By culture, MAP was grown from 59 individual samples (31.7%), whereas PCR detected MAP in 12 individual samples (6.5%), all of which came from animals showing symptoms of paratuberculosis during the study. Overall, MAP was detected in 10 out of 12 dairy herds (83.3%) and in 8 out of 11 suckling cow herds (72.7%).

Conclusions

There is a serious clinically inapparent MAP reservoir in the Swiss cattle population. PCR cannot replace culture to identify individual MAP shedders but is suitable to identify MAP-infected herds, given that the amount of MAP shed in feces is increasing in diseased animals or in animals in the phase of transition to clinical disease.     

Zero-inflated models for identifying disease risk factors when case detection is imperfect: Application to highly pathogenic avian influenza H5N1 in Thailand

Logistic regression models integrating disease presence/absence data are widely used to identify risk factors for a given disease. However, when data arise from imperfect surveillance systems, the interpretation of results is confusing since explanatory variables can be related either to the occurrence of the disease or to the efficiency of the surveillance system. As an alternative, we present spatial and non-spatial zero-inflated Poisson (ZIP) regressions for modelling the number of highly pathogenic avian influenza (HPAI) H5N1 outbreaks that were reported at subdistrict level in Thailand during the second epidemic wave (July 3rd 2004 to May 5th 2005). The spatial ZIP model fitted the data more effectively than its non-spatial version. This model clarified the role of the different variables: for example, results suggested that human population density was not associated with the disease occurrence but was rather associated with the number of reported outbreaks given disease occurrence. In addition, these models allowed estimating that 902 (95% CI 881–922) subdistricts suffered at least one HPAI H5N1 outbreak in Thailand although only 779 were reported to veterinary authorities, leading to a general surveillance sensitivity of 86.4% (95% CI 84.5–88.4). Finally, the outputs of the spatial ZIP model revealed the spatial distribution of the probability that a subdistrict could have been a false negative. The methodology presented here can easily be adapted to other animal health contexts.     

Perceived damage and areas of needed research for wildlife pests of California agriculture

Many wildlife species cause extensive damage to a variety of agricultural commodities in California, with estimates of damage in the hundreds of millions annually. Given the limited availability of resources to solve all human–wildlife conflicts, we should focus management efforts on issues that provide the greatest benefit to agricultural commodities in California. This survey provides quantitative data on research needs to better guide future efforts in developing more effective, practical and appropriate methods for managing these species. We found that ground squirrels, pocket gophers, birds, wild pigs, coyotes and voles were the most common agricultural wildlife pest species in California. The damage caused by these species could be quite high, but varied by agricultural commodity. For most species, common forms of damage included loss of crop production and direct death of the plant, although livestock depredation was the greatest concern for coyotes. Control methods used most frequently and those deemed most effective varied by pest species, although greater advancements in control methods were listed as a top research priority for all species. Collectively, the use of toxicants, biocontrol and trapping were the most preferred methods for control, but this varied by species. In general, integrated pest management practices were used to control wildlife pests, with a special preference for those approaches that were efficacious and quick and inexpensive to apply. This information and survey design should be useful in establishing research and management priorities for wildlife pest species in California and other similar regions.