Understanding the role of clipping biomass in nutrient budgets of turfgrass systems is critical to improving N use efficiency (NUE). The objective of this study was to evaluate the effect of mowing frequency on clipping tissue characteristics, N mineralization (NMin, %), and NH₃ volatilization (AV, %) from decomposing ‘TifTuf’ bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy] clippings applied to the soil surface. Turfgrass clippings were collected from two research facilities in Athens, GA, at 3-, 7-, 10-, and 14-d mowing intervals (MIs). A subsample of clippings from each plot was ground and analyzed using near-infrared spectroscopy to determine tissue characteristics. Soil from each location was packed into polyvinyl chloride cylinders, treated with grass clippings on the surface or left unamended, and incubated for 90 d. Cumulative evolved NH₃ was trapped, and inorganic N was extracted from each cylinder and analyzed colorimetrically after 90 d. Rates of NMin varied significantly across treatments and locations, making it difficult to generate informed recommendations for reducing N fertilization based on MI. Although dry yield (g m^–2) and tissue characteristics (carbohydrates, cellulose, and lignin) were found to be significant parameters in predicting NMin, no clear relationship was established between MI and tissue characteristics in this study. More frequent mowing (3-d MI) appeared to support more vigorous turfgrass growth through greater net clipping yield and may also decrease AV as a function of smaller clipping yield for unique mowing events. Mowing more than one time per week may be more N-use efficient and promote healthier turfgrass systems overall.

中文翻译：

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割草间隔对草坪剪草组织特性和土壤氮动态的影响

了解修剪生物量在草坪系统养分预算中的作用对于提高氮利用效率 (NUE) 至关重要。本研究的目的是评估割草频率对剪草组织特征、N 矿化 (NMin, %) 和分解 'TifTuf' 狗牙根 [ Cynodon dactylon (L.) Pers. 的N 矿化 (NMin, %) 和 NH ₃挥发 (AV, %) 的影响。×德兰士瓦狗牙根Burtt Davy] 剪报应用于土壤表面。从佐治亚州雅典的两个研究机构以 3 天、7 天、10 天和 14 天的割草间隔 (MI) 收集草坪草屑。每个地块的剪报子样本被研磨并使用近红外光谱分析以确定组织特征。将每个地点的土壤装入聚氯乙烯圆柱体中，在表面用草屑处理或保持原状，培养90 d。 收集累积逸出的 NH ₃，从每个圆柱体中提取无机 N 并在 90 天后进行比色分析。NMin 的比率因处理和位置而异，因此难以根据 MI 生成减少施氮的明智建议。虽然干产量 (gm ^–2) 和组织特征（碳水化合物、纤维素和木质素）是预测 NMin 的重要参数，本研究中未在 MI 和组织特征之间建立明确的关系。更频繁的割草 (3-d MI) 似乎通过更大的净修剪产量支持更旺盛的草坪生长，并且还可能降低 AV 作为独特割草事件的较小修剪产量的函数。每周修剪一次以上可能更有效地利用氮，并促进整体草坪系统更健康。