Ravindran Balasubramani, Mupambwa Hupenyu A, Silwana Sibongiseni, Mnkeni Pearson N S
Department of Agronomy, Faculty of Science and Agriculture, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.
Sam Nujoma Marine and Coastal Resources Research Centre, Sam Nujoma Campus, University of Namibia, P. O. Box 462, Henties Bay, Namibia.
Heliyon. 2017 Dec 28;3(12):e00493. doi: 10.1016/j.heliyon.2017.e00493. eCollection 2017 Dec.
Due to rapid expansion in the poultry industry, production of poultry manure has also consequently increased, resulting in unplanned disposal of this manure to the soil in some cases, with possible negative environmental consequences. In this study, 10 separate poultry manure samples were collected from different sites located in the central Eastern Cape, South Africa and characterized for chemical and phytotoxic properties. The poultry manures had an average neutral pH (range 6.94 - 7.97) whilst the electrical conductivity was highly variable from 2.45 dS/m to 12.3 dS/m between the 10 sites. The high conductivity values recorded in some of the manures indicate that caution may need to be practiced when directly applying these manure to the soil, to avoid buildup of soluble salts. All samples showed a very high concentration of total P (1963.1 mg/kg - 2644.1 mg/kg) with the plant available fraction ranging from 21.3% - 37.7% of the total P. All the heavy metals measured (Cr, Cu, Ni, Pb and Zn) were below the maximum permissible limits set by the U.S. Environmental Protection Agency. However, some of the poultry manure showed some level of phytotoxicity based on the plant bioassay, with some samples, recording a germination index less than 50% for the different crops evaluated. However, this bioassay may not be conclusive and there is need to evaluate this phytotoxicity in real world field applications as there is paucity of information on this aspect regarding poultry manure. Such filed studies can be used to evaluate alternative strategies such as planting and harvest intervals between application of these manures and planting or harvesting. It is also suggested that further biodegradation through composting or vermicomposting may be required to improve nutrient content and reduce the presence of phytotoxic compounds in some of the poultry manures before use as soil amendments.
由于家禽业的迅速扩张，家禽粪便的产量也随之增加，在某些情况下导致这些粪便未经规划就被施用于土壤，可能会对环境产生负面影响。在本研究中，从南非东开普省中部的不同地点采集了10份独立的家禽粪便样本，并对其化学和植物毒性特性进行了表征。家禽粪便的平均pH值呈中性（范围为6.94 - 7.97），而电导率在10个采样点之间变化很大，从2.45 dS/m到12.3 dS/m不等。部分粪便样本中记录到的高电导率值表明，在将这些粪便直接施用于土壤时可能需要谨慎，以避免可溶性盐的积累。所有样本的总磷浓度都非常高（1963.1 mg/kg - 2644.1 mg/kg），植物有效磷占总磷的比例在21.3% - 37.7%之间。所检测的所有重金属（铬、铜、镍、铅和锌）均低于美国环境保护局设定的最大允许限值。然而，根据植物生物测定，部分家禽粪便表现出一定程度的植物毒性，在评估的不同作物中，一些样本的发芽指数低于50%。然而，这种生物测定可能并不具有决定性，由于关于家禽粪便这方面的信息匮乏，有必要在实际田间应用中评估这种植物毒性。此类田间研究可用于评估替代策略，例如在施用这些粪便与种植或收获之间的种植和收获间隔。还建议可能需要通过堆肥或蚯蚓堆肥进行进一步的生物降解，以提高养分含量并减少部分家禽粪便中植物毒性化合物的存在，然后再用作土壤改良剂。
