This study investigated how repeated applications of different types of anaerobic digestates and undigested cattle slurry affected the growth responses and nutritional aspects of ryegrass swards ( Lolium perenne L.) and soil nutrient concentrations, in a two-season field trial. The treatments included four different types of anaerobic digestate, undigested cattle slurry, nitrogen control (N-control) with calcium ammonium nitrate (CAN) and a no fertiliser control, distributed in a randomised block design with three replicates. The different types of biofertilisers drove a comparable average forage daily growth rate varying between 65 and 79 kg ha −1 day −1 ( p > 0.05). Crude protein and neutral or acid detergent fibre of the forage were not influenced by any type of biofertiliser ( p > 0.05). Most of the anaerobic digestates led to increases in the level of soil available P and K ( p < 0.05). Despite the detectable influence of the levels of NPK in the biofertilisers on the plant growth responses, different anaerobic digestates when applied using the same dry matter amounts can drive comparable forage grass growth responses with low influence over the nutritional quality of the ryegrass forage. Repeated applications of anaerobic digestates can help to increase or reduce the losses of the soil available P and K. The application of anaerobic digestate, cattle slurry and calcium ammonium nitrate led to increases in the N content of the soil; however, there were no differences between them, despite their considerable differences in terms of N inputs. This might be linked to the volatility and losses of the readily available N from the biofertilisers applied.

中文翻译：

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厌氧消化物生物施肥：对黑麦草和土壤养分生产性状的影响

本研究在为期两季的田间试验中调查了重复施用不同类型的厌氧消化物和未消化的牛浆如何影响黑麦草 (Lolium perenne L.) 的生长反应和营养方面以及土壤养分浓度。处理包括四种不同类型的厌氧消化物、未消化的牛粪、含硝酸铵钙 (CAN) 的氮控制（N 控制）和无肥料控制，分布在随机区组设计中，三个重复。不同类型的生物肥料推动了可比较的平均草料日增长率在 65 和 79 kg ha -1 day -1 之间变化（p > 0.05）。草料的粗蛋白质和中性或酸性洗涤纤维不受任何类型生物肥料的影响（p > 0.05）。大多数厌氧消化物导致土壤有效磷和钾水平增加（p < 0.05）。尽管生物肥料中 NPK 的水平对植物生长反应有可检测的影响，但当使用相同的干物质量施用不同的厌氧消化物时，可以驱动类似的饲草生长反应，而对黑麦草的营养质量影响很小。厌氧消化液的重复施用有助于增加或减少土壤有效磷和钾的损失。厌氧消化液、牛粪和硝酸铵钙的施用导致土壤氮含量增加；然而，尽管它们在 N 输入方面存在相当大的差异，但它们之间没有差异。