Soil water potential sensor

1.Introduction to Soil water potential sensor

Soil water potential sensor provides long-term, maintenance-free soil potential readings at any depth and can measure soil water potential from -100kPa to 0kPa.Plant growth requires a certain amount of soil water, and the content of soil water has an important impact on plant growth and development.With the development of agriculture, the requirements for crop yield and quality are getting higher and higher, so we need to know the precise irrigation cycle of plants and give them an irrigation time point.The Soil water potential sensor can give such an irrigation point.It can clearly inform growers whether the plants are short of water, how long will they be short of water, and how often will they be irrigated, thereby improving the quality of the crops.

In modern agriculture, the role of Soil water potential sensor is very significant.When the Soil water potential sensor collects dynamic soil moisture content data of the planted crops, it then conducts more precise irrigation measures based on the growth of the crop.This not only records the soil tension change data, but also helps growers continuously supplement the soil environmental data of crop species, which is of great significance to improving crop varieties and improving crop quality and yield.

The Soil water potential sensor uses transparent PVC plastic tubes, which can clearly see the amount of water remaining in the equipment, making it convenient for adding water.It also uses a -100-0Kpa vacuum meter to facilitate users to view data clearly.The product is suitable for places where soil moisture and drought information needs to be detected.It is mostly used to monitor whether crops are water-deficient in agricultural crop cultivation, so as to better water crops.

When the PVC pipe inside the equipment is filled with water, the pressure inside the PVC pipe is 0 compared with the atmospheric pressure.After the equipment is inserted into the soil, some of the moisture inside the PVC will be sucked away by the soil, causing negative pressure to form inside the pipe.The greater the absolute value of negative pressure in a standard unit time, it proves that the stronger the soil absorbs water and the more water-deficient the soil.

2.Product features of Soil water potential sensor

1.Protection level: IP67

2.Overall machine structure: The product adopts a bottom-end monitoring structure, and the depth to be monitored by inserting the bottom of the equipment into the soil.The specific insertion depth can be customized according to on-site requirements.

3.Equipment size: The insertion depth is 60cm, and an integer multiple of 15cm can be added, up to 120cm.

4.Maximum power consumption: 0.8W (24V DC power supply)

5.Equipment material: Transparent PVC plastic pipe, which can clearly see the amount of water remaining in the equipment, making it convenient to add water.

6.Communication interface: RS485.

7.Power supply method: 5-30vdc wide voltage power supply.

8.Working environment: 0℃~+60℃.

9.Default accuracy: ±0.5kpa (25℃).

10.Range: -100kpa ~0kpa

11.Resolution: 0.1kpa

3.How to install Soil water potential sensor

1.Installation location

After the crop is sown, the equipment installation location should be selected for a relatively high and flat place to prevent rainwater from pouring back into the equipment, causing equipment short circuits or line failures.

Under comprehensive irrigation conditions, areas with less water are preferred as monitoring locations; under local irrigation conditions, areas with wet areas are selected as monitoring locations;

Select the position where the crop grows well and can represent the growth of most crops;

Understand the root distribution of the monitored crops and generally choose a location close to the crop's water-absorbing root system to determine the height of the equipment.

2.Installation method

The drilling and grouting installation method is adopted, please refer to the instruction manual for details.

3.Installation method

Prepare cold boiled water: Boil the tap water for 20 minutes, then leave it to cool and set aside.

Exhaust the clay head: Inject cool boiled water, fill it up, stand upright for 10-40 minutes (do not add a cover), and see water dripping from the surface of the clay head, then plug the silicone plug, wrap the clay head with a tissue to absorb water, so that the soil tension reaches about -40kpa.If you see bubbles rising, you can shake the equipment to exhaust as much as possible.This process is repeated 2-3 times.

Submerge the clay head into the water, wait until the soil tension returns to -10kpa, add water again and fill it up, plug the silicone plug, twist the top end cap, and set aside.

4.Things to note

Do not use oil on the clay head to avoid blocking the micropores and causing the instrument to fail.

The instrument's range is -100Kpa-0.When this limit exceeds this limit, the instrument leaks due to the rupture of the clay head tube wall, causing the instrument to lose its function.

Check regularly, add cool water to the sensor, and add it once every half a month to a month (or wait until the water level drops to the above the gas collecting pipe).Do not loosen the sensor during filling.

Before the temperature drops to 0℃, the outdoor instrument should be withdrawn to avoid freezing and cracking.

-10~0kpa, which means humidity and is too high for most crops.

-30~-10kpa, which means moist and is suitable for the growth of most crops.

-50~-30kpa, indicating that it is dry and wet-loving crops need to be irrigated.

＜-50kpa, which means dryness and most crops require irrigation.