Code for output json from Arduino. The code also listens on serial for commands to turn the pump on and off.

gistfile1.ino

#include <DHT.h>
#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP085.h>

#define DHTPIN 2
#define DHTTYPE DHT22 
DHT dht(DHTPIN, DHTTYPE);

int LDR_Pin = A0;
int MOISTURE_1_Pin = A1;
int MOISTURE_2_Pin = A2;

int pump = 10;

Adafruit_BMP085 bmp = Adafruit_BMP085(10085);

String inputString = "";
boolean stringComplete = false;  // whether the string is complete

const int pin = A0;   // Analog input pin 
unsigned long duration;
float Res0=10.0;
int photocellReading0;

void setup(){
  Serial.begin(9600);
  pinMode(pump, OUTPUT); 
  
  /* Initialise the sensor */
  if(!bmp.begin())
  {
    /* There was a problem detecting the BMP085 ... check your connections */
    Serial.print("Ooops, no BMP085 detected ... Check your wiring or I2C ADDR!");
    while(1);
  }
  
  dht.begin();

}

void loop(){

  sensors_event_t event;
  bmp.getEvent(&event);
 
  if (event.pressure) {
    
    int photocellReading0 = analogRead(LDR_Pin);
  
    float Vout0=photocellReading0 * 0.0048828125;      // calculate the voltage
    int lux0 = 500 / (Res0*((5-Vout0)/Vout0));

    Serial.print("{\"ldr\":");
    Serial.print(lux0);
    Serial.print(",");
    
    /* Display atmospheric pressue in hPa */
    Serial.print("\"pressure\":");
    Serial.print(event.pressure);
    Serial.print(",");
    float temperature2;
    bmp.getTemperature(&temperature2);
    Serial.print("\"temp1\":");
    Serial.print(temperature2);
    
    float h = dht.readHumidity();
    float t = dht.readTemperature();
    Serial.print(", \"humidity\":");
    Serial.print(h);
    Serial.print(",");
    Serial.print("\"temp2\":");
    Serial.print(t);
    
    int moisture_1 = analogRead(MOISTURE_1_Pin); 
    int moisture_2 = analogRead(MOISTURE_2_Pin); 
    
    Serial.print(",");
    Serial.print("\"waterlevel\":");
    Serial.print(moisture_1);
    
    Serial.print(",");
    Serial.print("\"moisture\":");
    Serial.print(moisture_2);
    
    Serial.println("}");
  
  }
  
  if (stringComplete) {
    inputString.replace("\n","");
    if (inputString == "on")
    {  
      digitalWrite(pump, HIGH);
    }
    if (inputString == "off")
    {
      digitalWrite(pump, LOW);
    }    
    // clear the string:
    inputString = "";
    stringComplete = false;
  }
  
  delay(3000); //just here to slow down the output for easier reading
  
}

void serialEvent() {
  while (Serial.available()) {
    // get the new byte:
    char inChar = (char)Serial.read(); 
    
    // add it to the inputString:
    inputString += inChar;
    // if the incoming character is a newline, set a flag
    // so the main loop can do something about it:
    if (inChar == '\n') {
      stringComplete = true;
      
    } 
  }
}