Goyne Keith W, Jun Hee-Joong, Anderson Stephen H, Motavalli Peter P
Dep. of Soil, Environmental, and Atmospheric Sciences, University of Missouri, Columbia, MO 65211-7250, USA.
J Environ Qual. 2008 Jan 4;37(1):154-63. doi: 10.2134/jeq2007.0141. Print 2008 Jan-Feb.
Two environmental aspects associated with land application of poultry litter that have not been comprehensively evaluated are (i) the competition of dissolved organic matter (DOM) and P for soil sorption sites, and (ii) the sorption of dissolved organic nitrogen (DON) relative to inorganic nitrogen species (e.g., NO(3)(-) and NH(4)(+)) and dissolved organic carbon (DOC). The competition between DOM and P for sorption sites has often been assumed to increase the amount of P available for plant growth; however, elevating DOM concentrations may also increase P available for transport to water resources. Batch sorption experiments were conducted to (i) evaluate soil properties governing P sorption to benchmark soils of Southwestern Missouri, (ii) elucidate the impact of poultry litter-derived DOM on P sorption, and (iii) investigate DON retention relative to inorganic N species and DOC. Soils were reacted for 24 h with inorganic P (0-60 mg L(-1)) in the presence and absence of DOM (145 mg C L(-1)) using a background electrolyte solution comparable to DOM extracts (I = 10.8 mmol L(-1); pH 7.7). Soil P sorption was positively correlated with metal oxide (r(2) = 0.70) and clay content (r(2) = 0.79) and negatively correlated with Bray-1 extractable P (r(2) = 0.79). Poultry litter-derived DOM had no significant negative impact on P sorption. Dissolved organic nitrogen was preferentially removed from solution relative to (NO(3)(-)-N + NO(2)(-)-N), NH(4)(+)-N, and DOC. This research indicates that poultry litter-derived DOM is not likely to enhance inorganic P transport which contradicts the assumption that DOM released from organic wastes increases plant-available P when organic amendments and fertilizer P are co-applied. Additionally, this work demonstrates the need to further evaluate the fate and transport of DON in agroecosystem soils receiving poultry litter applications.
（i）溶解有机物（DOM）和磷对土壤吸附位点的竞争，以及（ii）溶解有机氮（DON）相对于无机氮形态（如NO₃⁻和NH₄⁺）和溶解有机碳（DOC）的吸附。DOM和磷对吸附位点的竞争通常被认为会增加植物生长可利用的磷量；然而，提高DOM浓度也可能增加磷向水资源的迁移量。进行了批量吸附实验，以（i）评估控制密苏里州西南部基准土壤对磷吸附的土壤性质，（ii）阐明家禽粪便来源的DOM对磷吸附的影响，以及（iii）研究DON相对于无机氮形态和DOC的保留情况。使用与DOM提取物相当的背景电解质溶液（I = 10.8 mmol L⁻¹；pH 7.7），在有和没有DOM（145 mg C L⁻¹）存在的情况下，使土壤与无机磷（0 - 60 mg L⁻¹）反应24小时。土壤对磷的吸附与金属氧化物含量（r² = 0.70）和粘土含量（r² = 0.79）呈正相关，与Bray-1可提取磷呈负相关（r² = 0.79）。家禽粪便来源的DOM对磷吸附没有显著负面影响。相对于（NO₃⁻-N + NO₂⁻-N）、NH₄⁺-N和DOC，溶解有机氮优先从溶液中去除。这项研究表明，家禽粪便来源的DOM不太可能增强无机磷的迁移，这与有机废物释放的DOM在有机改良剂和肥料磷共同施用时会增加植物可利用磷的假设相矛盾。此外，这项工作表明需要进一步评估在施用家禽粪便的农业生态系统土壤中DON的归宿和迁移。
