Comparison of three kinds of soil moisture sensor

Three kinds of soil moisture sensor
Chip : Arduino Duemilanove ATmega 328
Module : Moisture Sensor

Demo

/*******************************************************
EX_07 : Soil Moisture Sensor
2013/12/24 SteveChang, PMP (sown813@gmail.com)
********************************************************/
int MoistureSensorPin1 = A0;  // select the input pin for the potentiometer
int MoistureSensorPin2 = A1;
int MoistureSensorPin3 = A2;

int SensorValue1 = 0;  // variable to store the value coming from the sensor
int SensorValue2 = 0;
int SensorValue3 = 0;

void setup()
{
  Serial.begin(57600);  
}

void loop()
{  
  // read the value from the sensor:
  SensorValue1 = analogRead(MoistureSensorPin1);
  SensorValue2 = analogRead(MoistureSensorPin2);
  SensorValue3 = analogRead(MoistureSensorPin3);
  delay(60000);
  
  Serial.print(SensorValue1);
  Serial.print(",");
  Serial.print(SensorValue2);
  Serial.print(",");
  Serial.println(SensorValue3);
}