National Chung Hsing University, Taichung City, 402, Taiwan.
Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
Sci Rep. 2024 Jul 11;14(1):16007. doi: 10.1038/s41598-024-66648-z.
This study addresses the effect of using animal excreta on the nutritional content of forages, focusing on macro- and micro-element concentrations (nitrogen; N, phosphorus; P, sulphur; S, copper; Cu, zinc; Zn, manganese; Mn, selenium; Se) from animal feed to excreta, soil, and plants. Data were collected from pot and field trials using separate applications of sheep or cattle urine and faeces. Key findings indicate that soil organic carbon (SOC) and the type of excreta significantly influences nutrient uptake by forages, with varied responses among the seven elements defined above. Although urine contributes fewer micronutrients compared to faeces (as applied at a natural volume/mass basis, respectively), it notably improves forage yield and micronutrient accumulation, thus potentially delivering positive consequences at the farm level regarding economic performance and soil fertility when swards upon clayey soil types receive said urine in temperate agro-climatic regions (i.e., South West England in the current context). In contrast, faeces application in isolation hinders Se and Mn uptake, once again potentially delivering unintended consequences such as micronutrient deficiencies in areas of high faeces deposition. As it is unlikely that (b)ovine grazing fields will receive either urine or faeces in isolation, we also explored combined applications of both excreta types which demonstrates synergistic effects on N, Cu, and Zn uptake, with either synergistic or dilution effects being observed for P and S, depending largely on SOC levels. Additionally, interactions between excreta types can result in dilution or antagonistic effects on Mn and Se uptake. Notably, high SOC combined with faeces reduces Mn and Se in forages, raising concerns for grazed ruminant systems under certain biotic situations, e.g., due to insufficient soil Se levels typically observed in UK pastures for livestock growth. These findings underscore the importance of considering SOC and excreta nutritional composition when designing forage management to optimize nutrient uptake. It should be noted that these findings have potential ramifications for broader studies of sustainable agriculture through system-scale analyses, as the granularity of results reported herein elucidate gaps in knowledge which could affect, both positively and negatively, the interpretation of model-based environmental impact assessments of cattle and sheep production (e.g., in the case of increased yields [beneficial] or the requirement of additional synthetic supplementation [detrimental]).
本研究探讨了动物粪便对饲料中宏量和微量营养元素（氮；N、磷；P、硫；S、铜；Cu、锌；Zn、锰；Mn、硒；Se）浓度的影响，重点关注动物饲料到粪便、土壤和植物中的元素浓度变化。本研究通过单独应用绵羊或牛尿液和粪便进行盆栽和田间试验收集数据。主要发现表明，土壤有机碳（SOC）和粪便类型显著影响饲料对养分的吸收，上述七种元素的响应各不相同。虽然与粪便相比，尿液提供的微量元素较少（按自然体积/质量基础应用时，分别），但它显著提高了饲料产量和微量元素积累，因此在温带农业气候地区粘土类型的草地接受尿液时，对农场层面的经济表现和土壤肥力可能会产生积极影响（即在当前情况下，即英格兰西南部）。相比之下，单独应用粪便会阻碍 Se 和 Mn 的吸收，这再次可能导致微量元素缺乏等意想不到的后果，尤其是在粪便沉积较多的地区。由于（反刍动物）放牧场不太可能单独接受尿液或粪便，我们还探索了两种粪便类型的组合应用，结果表明对 N、Cu 和 Zn 的吸收具有协同作用，而 P 和 S 则观察到协同或稀释作用，这在很大程度上取决于 SOC 水平。此外，粪便类型之间的相互作用会导致 Mn 和 Se 吸收的稀释或拮抗作用。值得注意的是，高 SOC 与粪便结合会降低饲料中的 Mn 和 Se，这引发了人们对某些生物条件下放牧反刍动物系统的担忧，例如，由于英国牧场土壤中通常缺乏牲畜生长所需的 Se。这些发现强调了在设计饲料管理以优化养分吸收时，考虑 SOC 和粪便营养成分的重要性。应该注意的是，这些发现对通过系统规模分析进行可持续农业的更广泛研究具有潜在影响，因为本文报告的结果的粒度阐明了可能对牛和羊生产的基于模型的环境影响评估的解释产生积极和消极影响的知识空白（例如，在产量增加的情况下[有益]或需要额外的合成补充[有害]）。
