Gruppo Ricicla labs., DiSAA, Università degli Studi di Milano, Via Celoria 2, 20133 Milan, Italy.
Acqua & Sole Srl, Via Giulio Natta, 27010 Vellezzo Bellini (PV), Italy.
Sci Total Environ. 2021 Aug 15;782:146882. doi: 10.1016/j.scitotenv.2021.146882. Epub 2021 Apr 5.
The use of digestate in agriculture represents an opportunity for reducing the use of synthetic fertilizers while promoting nutrient and organic matter recycling, i.e. contributing to a circular economy. However, some environmental impacts could result from digestate use, with particular reference to N emissions, which can contribute to particulate matter formation in the atmosphere. So, correct digestate spreading methods need to be tested to reduce ammonia emission and, possibly, also to avoid annoyance to the inhabitants. In this work a digestate from organic wastes was used as a fertilizer by its injection at 15 cm, in comparison with a synthetic one (urea) for three consecutive years in open fields, measuring ammonia and odours emission. On average, the ammonia emission from digestate was of 25.6 ± 9.4 kg N Ha (11.6% ± 4 of Total Ammonia Nitrogen - TAN - dosed), while urea emitted 24.8 ± 8.3 kg N Ha (13.4% ± 4.5 of TAN dosed). The injected digestate also emitted less odour than urea (601 ± 531 and 1767 ± 2221 OU m h, respectively), being ammonia coming from urea hydrolysis responsible for odour productions. The different N fertilizers did not lead to differences in crop yields, i.e. 18.5 ± 2.9 Mg grain Ha and 17.4 ± 1.2 Mg grain Ha for digestate and urea respectively.
在农业中使用消化液代表了一种减少合成肥料使用的机会，同时促进养分和有机物的循环利用，即有助于循环经济。然而，消化液的使用可能会带来一些环境影响，特别是氮排放，这会导致大气中颗粒物的形成。因此，需要测试正确的消化液施撒方法，以减少氨气排放，并可能避免对居民造成滋扰。在这项工作中，将有机废物的消化液作为肥料，连续三年以 15 厘米的深度注入田间，与合成肥料（尿素）进行比较，测量氨气和气味排放。平均而言，消化液的氨气排放量为 25.6 ± 9.4 kg N Ha（总氨氮（TAN）施用量的 11.6% ± 4），而尿素的排放量为 24.8 ± 8.3 kg N Ha（TAN 施用量的 13.4% ± 4.5）。注入的消化液释放的气味也比尿素少（分别为 601 ± 531 和 1767 ± 2221 OU m h），尿素水解产生的氨气是产生气味的原因。不同的氮肥并没有导致作物产量的差异，即消化液和尿素分别为 18.5 ± 2.9 Mg 籽粒 Ha 和 17.4 ± 1.2 Mg 籽粒 Ha。
