Department of Biological Systems Engineering, University of Wisconsin-Madison, 460 Henry Mall, Madison, WI 53706, USA.
Sensors (Basel). 2022 Mar 22;22(7):2438. doi: 10.3390/s22072438.
Livestock manure is typically applied to fertilize crops, however the accurate determination of manure nutrient composition through a reliable method is important to optimize manure application rates that maximize crop yields and prevent environmental contamination. Existing laboratory methods can be time consuming, expensive, and generally the results are not provided prior to manure application. In this study, the evaluation of a low-field nuclear magnetic resonance (NMR) sensor designated for manure nutrient prediction was assessed. Twenty dairy manure samples were analyzed for total solid (TS), total nitrogen (TN), ammoniacal nitrogen (NH4-N), and total phosphorus (TP) in a certified laboratory and in parallel using the NMR analyzer. The linear regression of NMR prediction versus lab measurements for TS had an R2 value of 0.86 for samples with TS < 8%, and values of 0.94 and 0.98 for TN and NH4-N, respectively, indicating good correlations between NMR prediction and lab measurements. The TP prediction of NMR for all samples agreed with the lab analysis with R2 greater than 0.87. The intra- and inter-sample variations of TP measured by NMR were significantly larger than other parameters suggesting less robustness in TP prediction. The results of this study indicate low-field NMR is a rapid method that has a potential to be utilized as an alternative to laboratory analysis of manure nutrients, however, further investigation is needed before wide application for on farm analysis.
牲畜粪便通常用于给农作物施肥，然而，通过可靠的方法准确测定粪便养分组成对于优化粪便施用量以最大限度地提高作物产量和防止环境污染非常重要。现有的实验室方法可能既耗时又昂贵，而且通常在粪便施用之前不会提供结果。在本研究中，评估了一种专门用于预测粪便养分的低场核磁共振（NMR）传感器。在经过认证的实验室中对 20 个奶牛粪便样本进行总固体（TS）、总氮（TN）、氨氮（NH4-N）和总磷（TP）的分析，同时使用 NMR 分析仪平行进行分析。对于 TS < 8%的样本，NMR 预测与实验室测量的 TS 线性回归的 R2 值为 0.86，TN 和 NH4-N 的 R2 值分别为 0.94 和 0.98，表明 NMR 预测与实验室测量之间具有良好的相关性。对于所有样本，NMR 对 TP 的预测与实验室分析结果一致，R2 值大于 0.87。NMR 测量的 TP 的内样和间样变异明显大于其他参数，表明 TP 预测的稳健性较低。本研究结果表明，低场 NMR 是一种快速方法，具有作为替代实验室分析粪便养分的潜力，然而，在广泛应用于农场分析之前，还需要进一步的研究。
