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Seed oxygen consumption has been correlated to seed vigour and quality (Bradford et al., 2013). The ability of oxygen to penetrate the tissues covering the embryo or the absorption of oxygen by the enclosing tissues was pointed out as the main mechanism capable of controlling the germination (Edelstein et Welbaum, 2011). ln the same way, carbon dioxide evolution by seeds at the initial phases of germination actually represents an overall indication of metabolism and activity. The imbibition of dry seeds begins the process of respiration that can have a very different performance depending on the plant species and the viability of the seed. A colorimetric test on seed respiration was developed since 1950 (Hempton and Tekrony, 1995) and is based on the reduction of colourless solution 2,3,5-tripheniltetrazolim chloride or bromide into insoluble 2,3,5-triphenilformazan red in colour. This solution acts as an indicator for detection of reduction processes that take place in living parts of the seed. We propose a new approach where the seed is not in contact with the dye, and the respiration of single seeds is measured in a multiwell system using a spectrophotometer according to the protocol by Campbell (2003). The new protocol can be easily applied also to the screening of the taxie or stimulant effects of matrices and products directly on the seeds, using respiration as a metabolic indicator.

A laboratory incubation experiment and greenhouse studies investigated the impact of organo-mineral (OM) fertilization as an alternative practice to conventional mineral (M) fertilization on nitrogen (N) uptake and losses in perennial ryegrass (Lolium perenne) as well as on soil microbial biomass and ammonia oxidizers.While no significant difference in plant productivity and ammonia emissions between treatments could be detected, an increase in soil total N content and an average 17.9% decrease in nitrates leached were observed in OM fertilization compared with M fertilization. The microbial community responded differentially to treatments, suggesting that the organic matter fraction of the OM fertilizer might have influenced N immobilization in the microbial biomass in the short-medium term. Furthermore, nitrate contents in fertilized soils were significantly related to bacterial but not archaeal amoA gene copies, whereas in non-fertilized soils a significant relationship between soil nitrates and archaeal but not bacterial amoA copies was found.The application of OM fertilizer to soil maintained sufficient productivity and in turn increased N use efficiency and noticeably reduced N losses. Furthermore, in this experiment, ammonia-oxidizing bacteria drove nitrification when an N source was added to the soil, whereas ammonia-oxidizing archaea were responsible for ammonia oxidation in non-fertilized soil. © 2015 Society of Chemical Industry.

Impact of different fertilization practices on soil, grape and wine quality. 1. International Symposium on Grapevine Roots

Effectiveness of 3,4-dimethylpyrazole phosphate (DMPP) as nitrification inhibitor in soil as influenced by fertilizer, temperature and soil biological properties. 4.International Congress Eurosoil 2012 - Soil Science for the Benefit of Mankind and Environment

Effects of soil type on rhyzospheric and endophitic bacterial communities associated to cherry rootstock Colt (Prunusavium). 10. Symposium on Bacterial Genetics and Ecology - Coexisting on a Changing Planet (BAGECO 10)