Sustainable agricultural production requires an inclusive framework that concurrently considers the impacts of production methods on soil health, crop productivity, and crop nutritional quality. However, few studies have directly examined the potential associations among management impacts on soil health (SH), crop productivity, and crop quality. We evaluated these linkages in a continuous maize experiment with treatments varying in nitrogen (N) fertilizer amount and type (zero input control, inorganic N, and manure-based N treatment). We evaluated select SH indicators after six cropping years, and computed physical, chemical, biological, nutrient, and overall SH indices using the Soil Management Assessment Framework (SMAF). Crop yields, mineral nutrient concentrations (denoted with brackets), and nutrient uptake were analyzed in years six and seven. Manure application increased biological SH indicators compared to the control and inorganic N treatments and also increased available potassium (K), zinc (Zn), copper (Cu), and phosphorus (P). Overall SH indices were higher in the inorganic N and manure treatments than in the control but did not differ between the two N sources, despite the large exogenous sources of C, N, and nutrients applied via manure. The SMAF tool only directly considers P and K in terms of soil nutrients—other nutrient benefits of manure application (i.e., increases in total soil N, available Cu and Zn) were not accounted for, suggesting that the SMAF nutrient SH index should be modified to account for the impacts of management practices on nutrient availability. Crop yields were higher in treatments with higher overall SH, supporting the linkages between SH and crop productivity. Despite widely differing nutrient inputs and soil fertility levels, we found no yield differences between the two N sources. However, there were notable treatment impacts on crop quality. Grain [N] was 40% greater in the urea and manure treatments than in the control. Grain [P], [K], and [Mg], important elements in livestock nutrition, were 10% to 28% greater in the manure treatment than in the urea treatment. In addition, although a yield dilution of grain [Zn] occurred in the urea treatment, the dilution effect was mitigated in the manure treatment, likely due to increases in available Zn. Overarchingly, our results suggest that management practices that maintain or improve SH and nutrient availability also improve maize productivity and nutritional quality, which could have cascading positive impacts on animal and human nutrition.

中文翻译：

---

在连续的玉米农业生态系统中评估粪便和无机氮肥对土壤健康、作物生产力和作物质量的影响

可持续农业生产需要一个包容性框架，同时考虑生产方法对土壤健康、作物生产力和作物营养质量的影响。然而，很少有研究直接研究管理对土壤健康 (SH)、作物生产力和作物质量的影响之间的潜在关联。我们在连续玉米试验中评估了这些联系，其中处理的氮 (N) 肥料量和类型不同（零输入控制、无机 N 和基于肥料的 N 处理）。我们在六个种植年之后评估了选定的 SH 指标，并使用土壤管理评估框架 (SMAF) 计算了物理、化学、生物、养分和整体 SH 指数。作物产量、矿物质养分浓度（用括号表示）、在第六年和第七年对营养吸收进行了分析。与对照和无机氮处理相比，施肥增加了生物 SH 指标，还增加了有效钾 (K)、锌 (Zn)、铜 (Cu) 和磷 (P)。无机氮和粪肥处理的总体 SH 指数高于对照，但两种氮源之间没有差异，尽管通过粪肥施用的 C、N 和养分的大量外源性来源。SMAF 工具仅直接考虑土壤养分方面的 P 和 K——未考虑肥料施用的其他养分益处（即土壤总氮、有效铜和锌的增加），表明应修改 SMAF 养分 SH 指数考虑管理实践对养分可用性的影响。整体 SH 较高的处理的作物产量较高，支持 SH 与作物生产力之间的联系。尽管养分输入和土壤肥力水平差异很大，但我们发现两种氮源之间的产量没有差异。然而，处理对作物质量有显着影响。尿素和粪便处理中的谷物 [N] 比对照高 40%。谷物 [P]、[K] 和 [Mg] 是牲畜营养中的重要元素，粪肥处理比尿素处理高 10% 至 28%。此外，虽然在尿素处理中发生了谷物 [Zn] 的产量稀释，但在粪便处理中稀释效果减弱，这可能是由于可用锌的增加。总的来说，