Gruppo Ricicla, Lab. Agricoltura e Ambiente, DiSAA, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy.
DiSAA, sez. Agronomia, Università degli Studi di Milano, Via Celoria 2, 20133 Milano, Italy.
Sci Total Environ. 2016 Mar 15;547:206-214. doi: 10.1016/j.scitotenv.2015.12.156. Epub 2016 Jan 11.
Anaerobic digestion produces a biologically stable and high-value fertilizer product, the digestate, which can be used as an alternative to mineral fertilizers on crops. However, misuse of digestate can lead to annoyance for the public (odours) and to environmental problems such as nitrate leaching and ammonia emissions into the air. Full field experimental data are needed to support the use of digestate in agriculture, promoting its correct management. In this work, short-term experiments were performed to substitute mineral N fertilizers (urea) with digestate and products derived from it to the crop silage maize. Digestate and the liquid fraction of digestate were applied to soil at pre-sowing and as topdressing fertilizers in comparison with urea, both by surface application and subsurface injection during the cropping seasons 2012 and 2013. After each fertilizer application, both odours and ammonia emissions were measured, giving data about digestate and derived products' impacts. The AD products could substitute for urea without reducing crop yields, apart from the surface application of AD-derived fertilizers. Digestate and derived products, because of high biological stability acquired during the AD, had greatly reduced olfactometry impact, above all when they were injected into soils (82-88% less odours than the untreated biomass, i.e. cattle slurry). Ammonia emission data indicated, as expected, that the correct use of digestate and derived products required their injection into the soil avoiding, ammonia volatilization into the air and preserving fertilizer value. Sub-surface injection allowed ammonia emissions to be reduced by 69% and 77% compared with surface application during the 2012 and 2013 campaigns.
厌氧消化产生一种具有生物稳定性和高价值的肥料产品——消化物,可用作作物的矿物肥料替代品。然而,不当使用消化物可能会引起公众的不满(异味),并导致硝酸盐浸出和氨排放到空气中等环境问题。需要充分的田间实验数据来支持消化物在农业中的使用,促进其正确管理。在这项工作中,进行了短期实验,用消化物及其衍生产品替代了作物青贮玉米的矿物 N 肥料(尿素)。在 2012 年和 2013 年的作物季节中,与尿素相比,通过表面施用和地下注入,将消化物和消化物的液体部分在播种前和追肥时施用于土壤。每次施肥后,测量了气味和氨排放,提供了关于消化物和衍生产品影响的数据。AD 产品可以替代尿素,而不会降低作物产量,除了 AD 衍生肥料的表面施用。由于在 AD 过程中获得的高生物稳定性,消化物和衍生产品的气味影响大大降低,尤其是当它们被注入土壤中时(比未经处理的生物质,即牛粪,减少 82-88%的气味)。氨排放数据表明,如预期的那样,正确使用消化物和衍生产品需要将其注入土壤中,避免氨挥发到空气中并保留肥料价值。与表面施用相比,地下注射可使 2012 年和 2013 年期间的氨排放量分别减少 69%和 77%。