I think also controlling the following would make sense: root and general plant health (are the roots sturdy, what colour are they, do they show signs of infection, do the plant have discoloration/brown patches etc.), plant growth and Wellbeing (as in is it perky and feels good or is it dropy and does not look happy), the conditions around (light, temperature, pH level,...)
When testing the impact of two different water treatments on plant and soil health, it's essential to collect a range of relevant data to thoroughly assess the effects of the treatments. Some key types of data to consider collecting include:
Plant Growth Parameters: i. Plant height: Measure the height of each plant from the soil surface to the tallest point. ii. Leaf area: Assess the total leaf area of each plant using leaf area meters or image analysis software. iii. Biomass: Weigh the above-ground and below-ground biomass of each plant to determine total plant biomass. iv. Root length: Measure the length of roots using root scanning or imaging techniques, or by manually measuring the length of individual roots. Plant Health Parameters: i. Chlorophyll content: Assess chlorophyll content using a chlorophyll meter or by analyzing leaf samples in a spectrophotometer. ii. Leaf color: Evaluate leaf color visually or using colorimeters to detect changes indicative of stress or nutrient deficiencies. iii. Photosynthesis rate: Measure photosynthesis rate using portable gas exchange systems to assess plant physiological responses.
Soil Health Parameters: i. Soil moisture: Measure soil moisture content using soil moisture sensors or gravimetric methods. ii. Soil pH: Determine soil pH using pH meters or pH test kits to assess soil acidity or alkalinity. iii. Soil nutrient levels: Analyze soil samples for nutrient concentrations (e.g., nitrogen, phosphorus, potassium) using laboratory methods such as soil extraction and chemical analysis. iv. Soil microbial activity: Assess soil microbial activity using methods such as respiration tests or enzyme activity assays to evaluate soil microbial health and activity levels.
Additional Parameters: i. Plant morphology: Record observations on plant morphology, including leaf shape, size, and overall appearance. ii. Soil texture: Determine soil texture (e.g., sandy, loamy, clayey) using soil texture analysis methods to characterize soil properties. iii. Soil compaction: Assess soil compaction using penetrometers or soil compaction meters to measure soil resistance to penetration.
By collecting data on these parameters, you can comprehensively evaluate the effects of the water treatments on plant and soil health, allowing for a thorough analysis of the treatments' impacts.
for your experimental, you may know the characteristic of the waste waters, the critical harzards in waste water is the main key data you may notice and observe it on how these harzards contain in the soil and plant.