Purpose

Electrical capacitance (EC) is widely used to measure root traits especially in hydroponic and wet soil environments, but its feasibility was recently questioned due to the possible leakage of electrical current before entering the root system. To investigate whether the current can travel deeper in woody roots, EC was evaluated in cotton (Gossypium hirsutum L.) grown under different soil moisture conditions (two rounds of pot experiments, one PVC tube experiment and one field experiment).

Methods

In these experiments, electrical capacitance of the root (EC_root) was recorded before and after severing roots, and immediately afterward, the roots were collected to measure root dry weight, surface area, length, and volume.

Results

The results showed that EC_root was significantly reduced after root cutting especially under dry conditions in the three experiments. The PVC tube experiment further demonstrated that root cutting did not significantly affect the changes in EC_root measured at different soil layers under dry conditions possibly suggesting that the current could flow into the deep roots under these conditions. Moreover, incorporating root tissue density and soil moisture into the prediction model can improve the predictive accuracy of EC_root. In contrast, EC_root was less affected by root cutting under wet soil conditions, indicating that it may not directly measure roots under these conditions.

Conclusions

EC_root shows the potential to directly quantify root traits under dry conditions rather than wet conditions.

中文翻译：

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电容在干燥条件下最能估计作物根系性状——棉花的案例研究 (Gossypium hirsutum L.)

目的

电容 (EC) 被广泛用于测量根系特征，尤其是在水培和潮湿土壤环境中，但由于电流在进入根系之前可能泄漏，其可行性最近受到质疑。调查当前是否可在木质根行进更深，EC在棉进行评价（陆地棉大号。）不同的土壤水分条件（两轮盆栽实验，一个PVC管试验和一个大田试验）下生长。

方法

在这些实验中，在切断根之前和之后记录根 (EC _root ) 的电容，然后立即收集根以测量根干重、表面积、长度和体积。

结果

结果表明，在三个实验中，切_根后EC_根显着减少，尤其是在干燥条件下。PVC 管实验进一步表明，在干燥条件下，根切割对不同土层测量的EC_根的变化没有显着影响，这可能表明在这些条件下电流可以流入深根。此外，将根组织密度和土壤水分纳入预测模型可以提高 EC_根的预测精度。相比之下，EC_根在潮湿土壤条件下受根切割的影响较小，表明在这些条件下它可能无法直接测量根。

结论

EC_根显示了在干燥条件而不是潮湿条件下直接量化根特性的潜力。