Comparison of organic fertilisers: impact on climate, yield and soil life скачать в хорошем качестве

Comparison of organic fertilisers: impact on climate, yield and soil life

The project Recycle4Bio has been conducted by FiBL and Agroscope since 2018. In this video, Else Bünemann-König and Lucilla Agostini from FiBL present the first results of a field trial (2018-2024) in which the effect of various organic fertilisers on climate, yields and soil biology was investigated. Organic farming relies on the supply of nutrients from organic fertilisers. Traditionally, farmyard manure from animal husbandry is used, either as manure or slurry. However, a large proportion of this farmyard manure is now used in combination with other biomass in biogas plants to produce renewable energy. The nutrients are then returned to the fields in the form of digested slurry or manure and liquid or solid digestate. Recycle4Bio now wants to answer the question of how the anaerobic digestion of organic fertilisers affects yields, the climate and, in the long term, soil fertility. In terms of yields, the liquid organic fertilisers were almost able achieve the levels of mineral fertiliser, which served as a control treatment. The solid organic fertilisers lead to very low yields in the first few years of application. However, over time, the soil fertility in these treatments increased and so did yields. The climate impact of the fertilisers is quantified by the emissions of nitrous oxide and methane. The data from 2023 shows that nitrous oxide emissions from cattle slurry are similar to those of the minerally fertilised control. The nitrous oxide emissions from the digested slurry and the liquid digestate tended to be lower than those from cattle slurry. There were significant differences in methane emissions immediately after application. Methane emissions from cattle slurry were higher than from digestated slurry and liquid digestate. After application, as soon as the soil has absorbed the liquid organic fertilisers, no more methane emissions occur. The agricultural soil then becomes a methane sink in all treatments. Organic fertilisers always have an impact on soil fertility. In this experiment, the liquid organic fertilisers kept fertility constant, while the solid organic fertilisers built up humus. The overall evaluation of the seven-year field trial is currently being made. The results are expected in 2025.