Ammonia (NH₃) volatilization from broiler (Gallus gallus domesticus) litter is a microbially mediated process that can decrease bird productivity and serves as an environmental pollutant. The release of NH₃ is strongly influenced by the pH of litter. Flue-gas desulfurization gypsum (FGDG) has been suggested as a potential amendment to reduce NH₃ volatilization due to the pH buffering capacity of calcium carbonate (CaCO₃) precipitation. However, its effect on litter pH is not as pronounced as acidifying agents, such as aluminum sulfate (alum). The main objective of our study was to develop an acidified-FGDG amendment that has a more pronounced effect on litter pH and NH₃ volatilization than FGDG alone. We conducted a 33-d incubation in which litter pH, NH₃ volatilization, nitrogen mineralization, PLUP-ureC gene abundance, and CaCO₃ precipitation were measured. Treatments in the study included: broiler litter (BL), broiler litter + 20% FGDG (BL+FGDG), broiler litter + FGDG-alum mixture (BL+FGDG+A6), broiler litter + 6% alum (BL+A6), and broiler litter + 10% alum (BL+A10). Our FGDG+alum amendment decreased litter pH (0.68 pH units) and PLUP-ureC gene abundance (>1 log) compared with FGDG alone and the control (p < .05). This led to a 25% decrease in cumulative NH₃ loss after 33 d. The addition of FGDG alone did not have an effect on litter pH (p = .36) or cumulative NH₃ loss (p = .29) due to a lack of significant CaCO₃ precipitation. Treating litter with 6 and 10% alum was the most effective amendment for reducing pH and cumulative NH₃ loss.

中文翻译：

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酸化石膏混合物对肉鸡垫料产脲酶菌和氮矿化的影响

肉鸡（家鸡）垫料中氨 (NH ₃ ) 的挥发是一种微生物介导的过程，会降低家禽的生产力并成为环境污染物。NH ₃的释放受垫料pH值的强烈影响。由于碳酸钙 (CaCO ₃ ) 沉淀的 pH 缓冲能力，烟道气脱硫石膏 (FGDG) 已被建议作为减少 NH ₃挥发的潜在改良剂。然而，它对垫料 pH 值的影响不如酸化剂，如硫酸铝（明矾）那么明显。我们研究的主要目标是开发一种对垫料 pH 值和 NH ₃有更显着影响的酸化 FGDG 修正剂挥发比单独的 FGDG 高。我们进行了在该垫料pH值，NH 33-d孵育₃挥发，氮的矿化，PLUP- UREC基因丰度，和CaCO ₃沉淀进行测定。研究中的处理包括：肉鸡窝 (BL)、肉鸡窝 + 20% FGDG (BL+FGDG)、肉鸡窝 + FGDG-明矾混合物 (BL+FGDG+A6)、肉鸡窝 + 6% 明矾 (BL+A6)和肉鸡垫料 + 10% 明矾 (BL+A10)。与单独的 FGDG 和对照 ( p  < .05)相比，我们的 FGDG + 明矾改良剂降低了垫料 pH（0.68 pH 单位）和 PLUP- ureC基因丰度（>1 log ）。这导致33天后累积的 NH ₃损失减少了 25% 。单独添加 FGDG 对垫料 pH 值没有影响（ 由于缺乏明显的 CaCO ₃沉淀，p  = .36) 或累积 NH ₃损失 ( p = .29) 。用 6% 和 10% 的明矾处理垫料是降低 pH 值和累积 NH ₃损失的最有效方法。