Sistani K R, Adeli A, McGowen S L, Tewolde H, Brink G E
USDA-ARS Animal Waste Management Research Unit, Bowling Green, KY 42104, USA.
Bioresour Technol. 2008 May;99(7):2603-11. doi: 10.1016/j.biortech.2007.04.069. Epub 2007 Jul 2.
Two studies were conducted for this research. First, a laboratory incubation to quantify broiler litter N mineralization with the following treatments: two soil moisture regimes, constant at 60% water fill pore space (WFPS) and fluctuating (60-30% WFPS), three soil types, Brooksville silty clay loam, Ruston sandy loam from Mississippi, and Catlin silt loam from Illinois. Second, a field incubation study to quantify broiler litter N mineralization using similar soils and litter application rates as the laboratory incubation. Broiler litter was applied at an equivalent rate of 350 kg total N ha(-1) for both studies except for control treatments. Subsamples were taken at different timing for both experiments for NO3-N and NH4-N determinations. In the laboratory experiment, soil moisture regimes had no significant impact on litter-derived inorganic N. Total litter-derived inorganic N across all treatments increased from 23 mg kg(-1) at time 0, to 159 mg kg(-1) at 93 d after litter application. Significant differences were observed among the soil types. Net litter-derived inorganic N was greater for Brooksville followed by Ruston and Catlin soils. For both studies and all soils, NH4-N content decreased while NO3-N content increased indicating a rapid nitrification of the mineralized litter N. Litter mineralization in the field study followed the same trend as the laboratory study but resulted in much lower net inorganic N, presumably due to environmental conditions such as precipitation and temperature, which may have resulted in more denitrification and immobilization of mineralized litter N. Litter-derived inorganic N from the field study was greater for Ruston than Brooksville. Due to no impact by soil moisture regimes, additional studies are warranted in order to develop predictive relationships to quantify broiler litter N availability.
本研究开展了两项试验。首先，进行了一项实验室培养试验，以量化肉鸡粪便氮矿化，设置了以下处理：两种土壤水分状况，即恒定在60%的水分填充孔隙空间（WFPS）和波动状态（60%-30% WFPS），三种土壤类型，分别为布鲁克斯维尔粉质粘壤土、密西西比州的拉斯顿砂壤土以及伊利诺伊州的卡特林粉质壤土。其次，开展了一项田间培养试验，使用与实验室培养试验相似的土壤和粪便施用量来量化肉鸡粪便氮矿化。除对照处理外，两项试验中肉鸡粪便的施用量均相当于总氮350 kg·ha⁻¹。在两个试验的不同时间采集子样本，用于测定硝态氮（NO₃-N）和铵态氮（NH₄-N）。在实验室试验中，土壤水分状况对粪便来源无机氮没有显著影响。所有处理中，粪便来源的总无机氮从施用粪便后0天的23 mg·kg⁻¹增加到93天的159 mg·kg⁻¹。不同土壤类型之间存在显著差异。布鲁克斯维尔土壤的粪便净来源无机氮含量最高，其次是拉斯顿土壤和卡特林土壤。对于两项试验以及所有土壤，铵态氮含量下降而硝态氮含量增加，表明矿化粪便氮发生了快速硝化作用。田间试验中的粪便矿化情况与实验室试验趋势相同，但净无机氮含量低得多，这可能是由于降水和温度等环境条件导致矿化粪便氮更多地发生了反硝化作用和固定作用。田间试验中拉斯顿土壤的粪便来源无机氮含量高于布鲁克斯维尔土壤。由于土壤水分状况没有影响，因此有必要开展更多研究以建立预测关系来量化肉鸡粪便氮的有效性。
