LP-EP113 เรียนเกษตรในสวน การวัดความชื้นในดินด้วยเทนซิโอมิเตอร์ (Tensiometer) และการประเมินการให้น้ำ

Tensiometer Usage Example: RainDrop Tensiometer TensioMeter Soil Moisture Meter Size: 30 cm Size: 60 cm A blue dot indicates a high soil water content. A green dot indicates a moderate soil water content. A yellow dot indicates a low soil water content. A blue dot indicates a high soil water content. This indicates that the soil surrounding the sac is fully saturated with water (the same applies to all soil types). This is the level of water pressure energy that plants can readily absorb and utilize in large quantities. However, if this persists for a long time, it indicates root suffocation. A tensiometer reading zero can occur after heavy rain or heavy irrigation. If the meter reads zero for a prolonged period (several days/weeks), it indicates soil saturation, low oxygen levels, and poor soil drainage, which increases the risk of root suffocation and plant disease. Soil Moisture Control Tensiometers can be used in general agricultural gardens. The advantage of this device is that it can measure soil moisture levels at various levels, allowing you to determine how much moisture is present, whether watering is appropriate, and, if so, how much water should be applied. RainDrop Tensiometer -1 Bar to 0 Bar (Note: 1 Bar = 100 kPa = 14.5 PSI) If the pressure is 0 Bar or the pressure energy is 0 Bar, due to saturated soil conditions, there is no force pulling water out of the sac. However, water in soil naturally exists under the attraction of soil particles, resulting in a lower pressure energy than water in contact with normal atmosphere. The pressure energy of water in normal soil is lower than zero (negative). Because water in soil is under tension, the instrument used to measure this is called "Water pressure gauges" have unit values ​​in the current system: kilopascals (kPa) or centibars (cbar). 1 Bar = 100 kPa = 14.5 PSI. If reading the scale of a RainDrop Tensiometer, the blue point indicates flooding and waterlogging. The green point indicates 0-20 kPa, which indicates abundant water and waterlogging. After watering or a recent rain, it indicates abundant water. The green point indicates approximately -30 kPa, which indicates sufficient water for plants. -30 to -50 kPa (dry) indicates porous soil surrounding the sac, which is difficult for plant roots to absorb and absorb in much smaller quantities. The plant is beginning to lack water and should begin watering. -50 kPa or more (very dry) indicates a lack of water for plants. This can be used to measure water retention during drought.