Greenhouse is a unique structure which not only shields plants from frosts and rains, it also can be fully automated. You can control a smart greenhouse remotely from your iOS or Android device. To do so, you have to have sensors inside your greenhouse. What are the types of sensors used in greenhouses?
1. Soil moisture sensors in greenhouse
Soil moisture sensors are great to assess the efficiency of your irrigation system. Sensors report the fluctuations in soil humidity levels and help to adjust the irrigation system to water the plants according to the actual water use. That way you save water and accelerate the plant growth.
If you have a small greenhouse and water your plants with a water can, I would suggest getting a compact soil meter. All you need to do is just pop the probe into the soil about 4 inches deep. Leave it for 10 minutes and you can check the moisture level in the dial and see if your plants need to be watered more.
How much area can a soil moisture sensor cover?
It depends on the particular model, most of the time you need to take probes 3 – 4 inches deep in soil along the area where you are going to plant. That way you will estimate the average soil moisture level.
Can you leave moisture meter in soil?
No, you can’t leave moisture meter in soil as it damages the tool. You have to take it out after taking a probe and make sure to clean it before putting it back into storage box.
What should my soil moisture be?
Ideally, soil moisture should be around 40 to 79% and on some of the moisture meters it correlated to 0-10 tallies. If your soil moisture content is 0 – 39%, it is dry and 80 – 100% is overwatered soil.
2. Light Sensors
Light sensor is a great tool to assess the plant’s exposure to light. Most of the meters have the light sensor on the top of the meter and can display the following readings: Relative Light: 0-2000 lux (0-200 Low, 200-500 Low+, 500-1000 Nor, 1000-2000 High). That way you can ensure that your plants meet lighting requirements.
To assess the light intensity you need to place the meter next to the plant and orient the center of the meter top toward the light source. Record the instant reading. The instant measure is helpful to know when to use the shade cloth or when you need to change the position of the plant to receive more light. This tool is good to assess the amount of natural light plants get.
However, if you are growing plants in a greenhouse with grow light, I would suggest using a light sensor for indoor growing. This option doesn’t need batteries as it comes with lifetime silicon sensor. If you are a commercial grower, then you need a wireless light sensor like LumiGrow Light Sensors.
3. Soil pH sensors
Soil pH sensor is very easy to use and it helps to determine if you need to adjust the acidity of the soil. As you know pH scale from 0 to 14 helps to differentiate between acidity and alkalinity. An environment is neutral when pH is 7, for example, the pH of pure water is neutral. If the pH value is below 7, then the environment is acidic and value above 7 is alkaline.
Soil’s pH affects the plant grow and, for example, tomato plants prefer slightly acidic soil in the range of 6.0 to 6.8. It is applicable to the majority of plants. The alterations of soil’s pH lead to nutrient deficiencies which can result in plants’ death.
How can pH meter be used to test soil pH?
The best way to test soil pH is to use a pH meter by following these easy steps:
- Prepare the soil sample for the test, so remove little rocks etc.
- Thoroughly clean the probes with a kitchen towel or toilet paper, the probes should be clean and dry before testing.
- Make sure that the soil is not too dry, if it is, water it.
- Insert the probes into the earth about 3/4 of the probe length if the soil is thick enough. Alternatively, insert the probes 3-15 cm (1-6 inches) deep into the soil.
- Read the results on the dial after 60 seconds.
A good option is to get a 3-in-1 meter testing kit which measures soil’s moisture, pH and light. It is ideal for a small greenhouse, you can take all 3 reading in one go. You don’t need to charge it or use batteries, just take the probes and wipe it clean afterwards.
4. Humidity Sensors
Greenhouse humidity monitoring is a must. A device which measure humidity levels in the air is called hygrometer. You should aim to maintain a relative humidity of 50-70% relative humidity, although 60-80% humidity is acceptable. High humidity encourages mold in a greenhouse and pest problem. Getting a wireless hygrometer will allow you to monitor humidity levels on a daily basis so you always know when to open vents.
5. Temperature Sensors
It is extremely important to maintain ideal temperature in a greenhouse. However, it can be tricky to achieve during cold days or hot ones in summer. Needless to say appropriate temperature directly affects plant growth, so having temperature sensors in a greenhouse known as thermometer is a must.
There are tons of options on the market to choose from and most of the time you will find a sensor which check temperature and humidity at the same time. I wrote an article on the best greenhouse thermometer and hygrometer describing min and max thermometer as well as wireless monitor systems.
6. Air Quality or Carbon Dioxide Sensors
Installing air quality sensor is a must for any greenhouse grower who is using a gas or paraffin heater. Paraffin and gas heaters produce carbon dioxide (CO2) which stimulates plant growth, although you need to monitor that the levels of CO2 don’t go above or below the critical threshold.
There are some heaters that come with already built in carbon dioxide sensors but if you are using an older model I would recommend getting an air quality sensor. Alternatively, you can buy a temperature and humidity sensor which also monitors the air quality.
7. Equipment Monitoring
If you are a commercial greenhouse grower, you need to make sure that irrigation system, fans and heaters are running smoothly. Monitoring greenhouse equipment will ensure that equipment is working properly and your plants are growing in the excellent conditions.
