The actual denitrification to N 2 O and denitri- fication capacity to N 2 O after flooding of different soil samples stored for over 25 years in air-dry conditions and fresh, air dried samples were compared in our study. Zero N 2 O release was ob- served from the stored soils but the fresh soil samples had very low actual denitrification to N 2 O. NO 3 - addition significantly increased the amount of N 2 O (denitrification capacity to N 2 O) released after flooding, which depended on the length of storage and type of soils and was much higher in stored soils. Prolonged exposure of the soils to drought conditions caused a greater decrease in the Eh value compared with the fresh soil. The total cumulative release of N 2 O from the stored and fresh soils was correlated with the reduced NO 3 - and organic C content in soils enriched with NO 3 - . Some soils showed the capability of N 2 O consumption. CO 2 release depended on the length of storage and type of soils under flooding after pro- longed drought. On average, CO 2 release was higher from the stored rather than fresh soils. The organic C content in the stored soils was generally lower than in the fresh soils, probably due to the storage effect. The cumulative CO 2 release from the stored soils was well correlated with the organic C while no correlation was observed for the fresh soil samples.
Seed vigour, viability, the contents of soluble carbohydrates, total protein, albumins, and globulins, as well as seed coat structure, were analysed in yellow lupin (Lupinus luteus L.) cv. Iryd seeds stored for 20 years at -14oC, 0oC or at room temperature (approx. +20oC). Seed storage at room temperature reduced viability (to 2%) and increased seed leachate electroconductivity. Determinations of total proteins showed that protein content was significantly reduced in seeds stored at +20oC compared to the other storage regimens. Raffinose family oligosaccharides were the main soluble carbohydrates in seeds stored at 0oC and -14oC, whereas sucrose dominated in seeds stored at room temperature. Scanning electron microscopy (SEM) of seed surface and seed coat sections revealed appearance of an amorphic layer on the surface of seeds stored at room temperature (not observed in other seeds) and distinct shrinking of macrosclereid layer in seeds stored at -14oC. Macrosclereids layer in all seeds was 100 um thick and accounted for 60% of seed coat thickness. The obtained results suggest that for long term storage of lupin seeds at 0oC is the most advisable temperature if both costs of storage and seed storability are considered.
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