A new carbohydrate retaining variety of Miscanthus increases biogas methane yields compared to M x giganteus and narrows the yield advantage of maize
A new carbohydrate retaining variety of Miscanthus increases biogas methane yields compared to M x giganteus and narrows the yield advantage of maize
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DOI：
10.1002/fes3.224
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发表时间：
2020-07-06
影响因子：
5
通讯作者：
Purdy, Sarah J.
中科院分区：
文献类型：
--
作者：
Kam, Jason;Thomas, David;Purdy, Sarah J.
厌氧消化（AD）目前严重依赖于作物原料来维持恒定的产量。主要的一年生作物是玉米，但这种做法引起了严重关切，因为种植需要高能量投入和粮食种植土地。玉米的秋收期使土壤在冬季暴露，导致侵蚀和径流进入水道。芒草在生理和形态上与玉米相似。它也对产生沼气感兴趣。作为一种多年生草，芒需要的投入少得多，可以在不适合种植粮食作物的土地上种植。它通常在冬末至早春收获。玉米比最常见的商业芒草品种（Mxg）产生更高的沼气产量，因为它具有更高的非结构性碳水化合物（NSC）浓度，有利于AD过程。我们旨在研究从高碳水化合物积累亲本类型培育的新芒草杂种（“GNT-14”）是否可以提高来自Mxg的沼气产量。在两个时间点，10月和1月的沼气产量进行了比较; NSC，纤维素和木质素浓度进行了量化;和NSC的沼气产量的贡献，通过比较完整的和洗过的样品。1月份，GNT-14的NSC浓度比Mxg高5倍，甲烷增加了28%。虽然Mxg显示与10月相比，1月份收获的生物质的甲烷产量（L/kg）有所下降，但GNT-14没有显示出这种下降。尽管GNT-14的潜在甲烷产量仅为玉米的70%，但栽培所需的能量输入（GJ ha（-1））为玉米的26%。我们的研究结果表明，GNT-14可以比玉米晚收获产生沼气，在冬季提供土壤保护。我们鼓励芒属植物的育种工作集中在NSC浓度和产量上。
Anaerobic digestion (AD) currently relies heavily on crop feedstocks to maintain a constant output. A major annual crop used is Zea mays (maize), but this practice presents significant concerns because high energy inputs and food-growing land are required for cultivation. The autumn harvest date of maize exposes soils over winter resulting in erosion and runoff into waterways. Miscanthus is physiologically and morphologically similar to maize. It is also of interest for biogas generation. As a perennial grass, Miscanthus requires far less input and can be grown on land that is unsuitable for food crops. It is typically harvested in late winter to early spring. Maize produces higher hiogas yields than the most commonly grown commercial variety of Miscanthus (Mxg), because it has a higher nonstructural carbohydrate (NSC) concentration that facilitates the AD process. We aimed to investigate whether a new Miscanthus hybrid ("GNT-14") that was bred from a high carbohydrate accumulating parental type can improve hiogas yield from Mxg. Comparisons were made on biogas yields at two time points, October and January; the NSC, cellulose, and lignin concentrations were quantified; and the contribution of the NSC to biogas yield was determined by comparing intact and washed samples. The NSC concentrations of GNT-14 were fivefold higher than Mxg in January, and a 28% increase in methane was observed. While Mxg showed a reduction in methane yields (L/kg) from biomass harvested in January compared to October, GNT-14 showed no such decline. Although the potential methane yields of GNT-14 were only 70% that of maize, the energy input (GJ ha(-1)) required for cultivation was 26% of maize. Our results demonstrated that GNT-14 could be harvested later than maize for biogas generation, offering soil protection over winter. We encourage Miscanthus breeding efforts to focus on NSC concentration as well as yield.