Kernza intermediate wheatgrass (Thinopyrum intermedium) is the first commercially developed perennial grain crop in North America, with multiple environmental and economic benefits. One of the major challenges for adoption of this dual-use forage and grain crop is the decline in grain yield in subsequent harvest years. Post-harvest management practices (e.g., chopping, burning, chemical, and mechanical thinning) could reduce the intraspecific competition for light and maintain Kernza grain yields over time. We aimed to identify management practices that improve light penetration and propose a conceptual model to explain the mechanisms contributing to Kernza grain yield. We applied 10 management practices after the first Kernza grain harvest in a randomized complete block design experiment with three replications, at two different locations in Wisconsin, USA. Light penetration increased when post-harvest management practices were applied. Mechanical or chemical thinning had relatively lower lodging and increased yield components per row, but not per area due to a reduction in the number of productive rows. Threshed grain yield per area in the second year of Kernza was similar among the treatments despite the differences in vegetative biomass generated. Further research is needed to optimize management practices to maintain Kernza grain yield over time.

中文翻译：

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收获后管理实践对光穿透力和克恩萨州中层小麦草产量构成要素的影响

克尔扎中间小麦草（中间Thin属））是北美第一种商业开发的多年生谷物，具有多种环境和经济效益。采用这种两用饲料和谷物作物的主要挑战之一是随后的收成年谷物产量下降。收获后的管理实践（例如切碎，燃烧，化学和机械稀化）可以减少种内对光的竞争，并随着时间的推移保持克恩萨州谷物的单产。我们旨在确定可提高光线穿透率的管理实践，并提出一个概念模型来解释促成克恩萨谷物产量的机制。在美国威斯康星州的两个不同地点进行的一次完整的随机区组设计实验中，我们进行了第一次Kernza谷物收获后的10种管理实践，该实验进行了三次重复。采用采后管理方法，透光率会提高。机械减薄或化学减薄具有相对较低的倒伏并且每行而不是每面积增加产量成分，这是由于生产行数的减少。尽管产生的营养生物量存在差异，但在各处理之间，克恩扎州第二年的脱粒谷物产量相似。需要进一步研究以优化管理方法，以保持Kernza谷物的长期产量。