A comparison of two models to predict nitrogen dynamics in organic agricultural systems

Two publicly available crop/soil models were compared. These were the EU-Rotate_N model (www.warwick.ac.uk/go/eurotaten) and the NDICEA model (www.ndicea.nl). Each simulation was also compared to measured data from an organically managed site in the English Midlands. Results showed that, overall, EU-Rotate_N gave a better estimation of soil mineral nitrogen, particularly after the incorporation of a long-term fertility-building crop. This model has a lot of flexibility but is aimed at researchers and requires more work before it is ready to be used by farmers or advisors. The NDICEA model is much simpler to use with a user-friendly interface

Sort Out Your Soil: A practical guide to green manures

The booklet is a compendium of green manures species used in UK. The introduction explains the reasons why to grow green manures and the benefits they bring into the system. What follows is a guide to the choice of the species to use as green manure, with details per species (leguminous species and other species) and some comparative assessments among the species. It is focused on UK climate and farming systems but its contents can easily be used also in other temperate environments. The booklet is clear and has several photos. This tool can be used to adapt strategies for green manure to specific case

Evaluation of module-sown companion plants as a method of controlling cabbage root fly

A novel technique for controlling cabbage root fly was tested. Companion plants of either birdsfoot trefoil (Lotus corniculatus), red clover (Trifolium pratense) or yellow trefoil (Medicago lupulina) were sown into modules together with calabrese (Brassica oleracea var Italica). The presence of companion plants subsequently reduced cabbage root fly egg-laying by up to 48% and reduced root damage considerably. Companion plant species did not affect egg-laying in this trial. Although, financially, this technique compares very favourably with an alternative strategy of applying fleece, further refinement is needed to improve the survival of companion plants on a commercial field scale as they were particularly vulnerable to damage by steerage hoes, which are used commonly in organic systems

Environmental and economic modelling of organic, stockless, horticultural crop rotations

Selected results from the ongoing “EU-Rotate_N” research project are presented. This EU 5th-framework project is developing a model-based decision support system to optimise nitrogen use in horticultural crop rotations across Europe. This paper introduces the economic and the fertility-building crops sub-models, and shows data from model validation and first model runs on an organic farm in central England. Preliminary results show that the model has the potential to be a powerful support tool for farmers and advisors, making decisions on rotational plan-ning. The economic, agronomic and environmental consequences of different rotational designs can be projected and assessed in detail

MicroRNA markers for forensic body fluid identification obtained from microarray screening and quantitative RT-PCR confirmation

MicroRNAs (miRNAs) are non-protein coding molecules with important regulatory functions; many have tissue-specific expression patterns. Their very small size in principle makes them less prone to degradation processes, unlike messenger RNAs (mRNAs), which were previously proposed as molecular tools for forensic body fluid identification. To identify suitable miRNA markers for forensic body fluid identification, we first screened total RNA samples derived from saliva, semen, vaginal secretion, and venous and menstrual blood for the expression of 718 human miRNAs using a microarray platform. All body fluids could be easily distinguished from each other on the basis of complete array-based miRNA expression profiles. Results from quantitative reverse transcription PCR (RT-PCR; TaqMan) assays for microarray candidate markers confirmed strong over-expression in the targeting body fluid of several miRNAs for venous blood and several others for semen. However, no candidate markers from array experiments for other body fluids such as saliva, vaginal secretion, or menstrual blood could be confirmed by RT-PCR. Time-wise degradation of venous blood and semen stains for at least 1 year under lab conditions did not significantly affect the detection sensitivity of the identified miRNA markers. The detection limit of the TaqMan assays tested for selected venous blood and semen miRNA markers required only subpicogram amounts of total RNA per single RT-PCR test, which is considerably less than usually needed for reliable mRNA RT-PCR detection. We therefore propose the application of several stable miRNA markers for the forensic identification of blood stains and several others for semen stain identification, using commercially available TaqMan assays. Additional work remains necessary in search for suitable miRNA markers for other forensically relevant body fluids