水保所知识产出(1956---)知识库

【目的】通过电导率（EC）准确反应水肥一体化条件下磷酸氢二铵和氯化钾不同配比值的肥液质量浓度。【方
法】测定了一定质量浓度范围（2~10 g/L）和温度范围（20~45 ℃）内不同磷酸氢二铵和氯化钾配比混合肥液的 EC
值，并基于灰色关联分析（GRA）法研究了质量浓度  f 、温度 T 和配比值 rv 对磷酸氢二铵、氯化钾混合溶液电导率
的影响。【结果】磷酸氢二铵、氯化钾混合肥液电导率（EC）随质量浓度  f 和温度 T 的升高而增大，随配比值 rv 的
增大而减小；3 个因素对混合液 EC 影响的大小顺序为：质量浓度  f >温度 T>配比值 rv；基于拟合优度评价指标对比
3 次样条插值和 3 次 B 样条插值后的数据分别优选混合溶液质量浓度-EC、温度-EC、配比值-EC 单因素曲线模型，
构建了以磷酸氢二铵、氯化钾混合肥液 EC、温度 T、配比值 rv 为自变量的质量浓度预测模型。【结论】该模型预测
精度为 97.53%，满足实际使用要求，可用于水肥一体化灌溉过程中的肥液浓度的实时监测。

【Background】 Integrating fertilization and irrigation is a potential agricultural management technology
and its success depends on accurately real-time monitoring the change in fertilizers concentration. The existing
electric conductivity (EC) method is only able to detect concentration of single fertilizer, and developing simple and
cheap device to accurately real-time monitor concentration of mixed fertilizers solution is hence needed.【Objective】
The purpose of this paper is to study the feasibility and accuracy of an electric conductivity method to real-time
monitor the concentrations of diammonium hydrogen phosphate and potassium chloride at in their mixed solution.
【Method】We first measured the EC of the mixture of diammonium phosphate and potassium chloride at different
concentrations ranging from 2 g/L to 10 g/L and different temperatures ranging from 20 ℃ to 45 ℃, and then
analyzed the change in EC with temperature, concentration and ratios of the two fertilizers using the grey correlation
analysis (GRA).【Result】The EC of the mixed solution increased with its concentration and temperature and
decreased as the ratio (n) of diammonium hydrogen phosphate to potassium chloride increased. It was also found
that the factors affecting the EC of the mixed solution was ranked in the descending order of concentration >
temperature > n. Based on goodness of the fitting, the evaluation index of the GRA was compared with the measured
data after cubic spline interpolation and cubic B-spline interpolation, from which we obtained pairwise models for
concentration-EC, temperature-EC and n-EC relationships, respectively. These enabled us to derive a model to
predict the concentration of each fertilizer in their mixed solution based on EC, temperature, and the ratio n.
【Conclusion】Testing against measured data showed that the model accuracy was 97.53%, meeting the requirement
in practical application. The method can thus be used for real-time monitoring concentration of mixed fertilizers
solution in integrated irrigation and fertilization.