Abstract:
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]).
摘要:
这项研究探讨了使用动物排泄物对牧草营养成分的影响,关注宏观和微量元素浓度(氮;氮,磷;P,硫;S,铜;Cu,锌;锌,锰;Mn,硒;硒)从动物饲料到排泄物,土壤,和植物。使用分别施用绵羊或牛的尿液和粪便,从盆栽和田间试验中收集数据。主要研究结果表明,土壤有机碳(SOC)和排泄物的类型显着影响牧草对养分的吸收,在上面定义的七个元素之间有不同的反应。尽管与粪便相比,尿液贡献的微量营养素较少(以自然体积/质量为基础,分别),它显著提高了牧草产量和微量营养素的积累,因此,当温带农业气候地区的粘土土壤类型的土壤收到尿液时,可能会在农场一级对经济绩效和土壤肥力产生积极影响(即,在当前背景下,英格兰西南部)。相比之下,隔离中的粪便应用阻碍了硒和锰的吸收,再次有可能带来意想不到的后果,例如在粪便沉积量高的地区缺乏微量营养素。由于(b)绵羊放牧场不太可能孤立地接收尿液或粪便,我们还探索了两种排泄物类型的联合应用,这些排泄物类型对N,Cu,和锌的吸收,观察到P和S的协同或稀释效应,很大程度上取决于SOC水平。此外,排泄物类型之间的相互作用可导致对Mn和Se吸收的稀释或拮抗作用。值得注意的是,高SOC与粪便相结合可减少牧草中的Mn和Se,在某些生物情况下,对放牧反刍动物系统的关注,例如,由于在英国牧场中通常观察到的土壤硒含量不足,无法用于牲畜生长。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和排泄物营养成分的重要性。应该指出,这些发现对通过系统规模分析更广泛的可持续农业研究具有潜在的影响,由于本文报告的结果粒度阐明了可能影响的知识差距,无论是积极的还是消极的,基于模型的牛羊生产环境影响评估的解释(例如,在增加产量的情况下[有益]或需要额外的合成补充[有害])。