Biogas digesters convert waste matter into a natural gas-like fuel and a nutrient-rich digestate by-product. This digestate has the potential to be used as a soil amendment to benefit crop production with or without biochar, a purported nutrient sponge. In a greenhouse study of several crop species, the effects of digestate fertilization on crop growth, photosynthetic efficiency, vegetable production and chemical nutrient levels were tested. Results indicate that increasing potency of the applied digestate fosters higher growth and fruit production rates of several studied plants but to a lesser degree than a conventional fertilizer. More potent digestate application increases antioxidant capacity, total phenolics content and ascorbic acid levels in kale compared to the control chemical fertilizer test groups but has confounding results on legume nutrient levels. Additionally, the combined application of biochar and biogas digestate added to compost and used as potting media positively impacts crop germination. This work has relevance to agrarian communities that could benefit from recycling livestock and food waste into fuel and a renewable fertilizer.

中文翻译：

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沼渣作为可再生肥料：沼渣施用对作物生长和营养成分的影响

沼气池将废物转化为类似天然气的燃料和营养丰富的消化副产品。这种沼渣有可能用作土壤改良剂，以有利于作物生产，无论是否使用生物炭，一种据称的营养海绵。在对几种作物物种的温室研究中，测试了沼渣施肥对作物生长、光合效率、蔬菜产量和化学营养水平的影响。结果表明，增加施用的消化物的效力促进了几种研究植物的更高的生长和果实产量，但程度低于常规肥料。更有效的消化应用增加抗氧化能力，与对照化学肥料试验组相比，羽衣甘蓝中的总酚类物质含量和抗坏血酸水平，但在豆类营养水平方面存在混淆结果。此外，生物炭和沼渣沼渣的组合应用添加到堆肥中并用作盆栽介质对作物发芽有积极影响。这项工作与农业社区有关，农业社区可以从将牲畜和食物垃圾回收成燃料和可再生肥料中受益。