Background and aims

Soil acidification can negatively affect agricultural production by reducing uptake of essential nutrients and increasing aluminium toxicity in crops. This study investigated whether hyperspectral imaging could accurately measure wheat response to soil acidification and subsequent remediation via liming.

Methods

A high-throughput, automated greenhouse and hyperspectral imaging facility was used to evaluate differences between hyperspectral data of wheat plants in either acidic soil or soil that had been limed. Using RGB imaging and growth rate prediction, plant growth was measured to assess if it increased with lime application. The study also used partial least squares regression analysis (PLSR) to assess whether hyperspectral imaging could predict plant tissue nutrient concentration and indicate nutrient deficiencies and toxicities associated with soil acidity.

Results

Spectral differences were observed between plants in acidic and non-acidic soil around the end of tillering and beginning of stem elongation. The red edge spectral region contributed significantly to this difference and, when used in vegetation indices, confirmed increases in plant growth following lime application, observed via high throughput phenotypic analysis. PLSR analysis was ineffective in predicting nutrient concentration of plant tissue in this context, likely due to low concentrations of nutrients associated with acidification, limited sample size, and small variation in nutrient concentrations.

Conclusions

Findings suggest that hyperspectral imaging could prove useful in the detection of soil acidification effects on wheat crops under contained controlled environmental conditions, and may, with further in-field testing, enable improved spatial mapping of paddocks to help remediate this significant agricultural issue.

中文翻译：

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使用高光谱成像评估小麦对土壤酸化和石灰的反应

 背景和目标

土壤酸化会减少对必需养分的吸收并增加作物中铝的毒性，从而对农业生产产生负面影响。本研究调查了高光谱成像是否可以准确测量小麦对土壤酸化和随后通过石灰进行修复的反应。

 方法

使用高通量、自动化温室和高光谱成像设施来评估酸性土壤或石灰土壤中小麦植株的高光谱数据之间的差异。使用 RGB 成像和生长速率预测，测量植物生长以评估它是否随着石灰的施用而增加。该研究还使用偏最小二乘回归分析 （PLSR） 来评估高光谱成像是否可以预测植物组织养分浓度并指示与土壤酸度相关的养分缺乏和毒性。

 结果

在分蘖结束和茎伸长开始时，在酸性和非酸性土壤中观察到植物之间的光谱差异。红边光谱区域对这种差异有显著贡献，当用于植被指数时，证实了施用石灰后植物生长的增加，通过高通量表型分析观察到。在这种情况下，PLSR 分析在预测植物组织的营养物质浓度方面无效，这可能是由于与酸化相关的营养物质浓度低、样本量有限以及营养物质浓度变化小。

 结论

研究结果表明，高光谱成像可用于检测在封闭受控环境条件下土壤酸化对小麦作物的影响，并且通过进一步的现场测试，可以改进围场的空间测绘，以帮助解决这一重大农业问题。