I'm Scientific twelfth grade in France, I have to create an Arduino program to manage a Irrigators plant system, but never having to program , I am unable to do so. I am here to ask for help . My system contains :
An Arduino board , a pump, a pH meter and stuff which I do not understand , I would join pictures later . I like to know if people would be able to help me because I am in a deadlock. Thank you in advance for your help, good day. 
The most effective way to get programming help on this forum is for you to make an attempt then post the code (please use code tags). I suggest starting with code that reads one sensor then prints the values to Serial Monitor.
As said, you have to start at the beginning, you cannot suddenly write all the code for a complex project.
If you have got the Arduino IDE loaded, took at the Examples folder and start off running some of the basic tasks like Blink a led, which can be modified to turn your pump on and off.
As your experience grows , so will your project.
Do post pictures of your "other Stuff" and also details/voltages of your pump and ph meter/output
You may get some ideas in Planning and Implementing a Program
Get each item working separately in short programs before you try to bring them all together.
If you want help with a particular piece of hardware post a link to its datasheet.
...R
You can take a look at the link below to read about the possibilities of using Arduino to water plants:
But as some of the others already have said - I think the keyword is small steps.
Some explanations on this subject:
Pay attention : This is a project for the French Baccalauréat exam : it will be noted and the rating count for obtaining the diploma.
On French forum our answer is clear: "We respect exams and we will not do the work in your place".
Begins by presenting a personal works and we will help you . No personal work = No help.
The French Bacalauréat has several levels:
wikipedia link in english :
In scientific discipline
Top level :
"baccalaureat general" --> to continue studies at University
S-SI -> enables access to engineering study (5 years)
Exist also E (economic) and L (literature)
Other level :
"bacalaureat technologique" :
STI2D -> generally only allows technician studies (two years) except for good students that can study engineering.
Before French high schools were using PICs but now they use more and more Arduino boards.
// http://www.instructables.com/id/WATERING-SYSTEM-INTRODUCTION/?ALLSTEPS
// https://github.com/Arduinobymyself/ArduinoWateringSystem
/*
#####################################################################################
# File: Arduino_Watering_sustem.ino
# Processor: Arduino UNO, MEGA ou Teensy++ 2.0
# Language: Wiring / C /Processing /Fritzing / Arduino IDE
#
# Objectives: Watering System - Irrigation
#
# Behavior: When the soil is dry,
#
#
#
# Author: Marcelo Moraes
# Date: 12/10/12
# place: Brazil, Sorocaba City
#
#####################################################################################
This project contains public domain code.
The modification is allowed without notice.
*/
// libraries definition
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include "RTClib.h"
// frequency musical notes
#define NOTE_C6 1047
#define NOTE_C3 131
#define NOTE_G3 196
// pins definition
int levelSensorPin = 0;
int moistureSensorPin = 1;
int audioPin = 2;
int soggyLEDPin = 3;
int moistsoilLEDPin = 4;
int drysoilLEDPin = 5;
int pumpLEDPin = 6;
int pumpPin = 7;
// variables
int levelSensorValue; // stores the level sensor values
int moistureSensorValue; // stores the moisture sensor values
int j = 0;
// system messages
const char *string_table[] =
{
" Welcome! =)",
" Tank LOW level",
" Dry soil",
" Moist soil",
" Soggy soil",
"The water pump is on",
" ArduinoByMyself",
" Watering System",
" Please wait!"
};
// objects definition
RTC_DS1307 RTC;
LiquidCrystal_I2C lcd(0x27,20,4);
void setup(){
// serial initialization
Serial.begin(9600);
// LCD initialization
lcd.init();
lcd.backlight(); // with Backlight
lcd.clear(); // clearscreen
// Wire initialization
Wire.begin();
// RTC initialization
RTC.begin();
if (!RTC.isrunning()){
// date and time adjust as the PC computer date and time
RTC.adjust(DateTime(__DATE__, __TIME__));
}
// Arduino pins initalization
pinMode(audioPin, OUTPUT);
pinMode(soggyLEDPin, OUTPUT);
pinMode(moistsoilLEDPin,OUTPUT);
pinMode(drysoilLEDPin,OUTPUT);
pinMode(pumpLEDPin,OUTPUT);
pinMode(pumpPin,OUTPUT);
// LCD initial messages
lcd.clear();
lcd.setCursor(0,0);
lcd.print(string_table[6]);
lcd.setCursor(0,1);
lcd.print(string_table[7]);
lcd.setCursor(0,3);
lcd.print(string_table[0]);
// initialization delay
delay(5000);
}
void loop(){
// RTC parameters definition
DateTime myRTC = RTC.now();
int H = myRTC.hour();
int M = myRTC.minute();
int S = myRTC.second();
// call Clock Function
//RightHour();
// reads the sensors
levelSensorValue = analogRead(levelSensorPin);
moistureSensorValue = analogRead(moistureSensorPin);
// if low water level: plays the low level alarm
if(levelSensorValue > 600){
// system messages
lcd.clear();
RightHour();
lcd.setCursor(0,3);
lcd.print(string_table[1]);
// plays the alarm sound
for(int i=0;i<2;i++){
tone(audioPin, NOTE_G3, 200);
delay(200);
tone(audioPin, NOTE_C3, 200);
delay(200);
noTone(audioPin);
}
}
// check the moisture range
if(moistureSensorValue >= 700){
// in case of dry soil:
// system messages
lcd.clear();
RightHour();
lcd.setCursor(0,3);
lcd.print(string_table[2]);
// lights up the correct LED
digitalWrite(drysoilLEDPin,HIGH);
digitalWrite(moistsoilLEDPin,LOW);
digitalWrite(soggyLEDPin,LOW);
// plays the alarm sound
tone(audioPin, NOTE_C6, 100);
delay(250);
noTone(audioPin);
}
if((moistureSensorValue < 700) && (moistureSensorValue >= 300)){
// in case of moist soil:
// system messages
lcd.clear();
RightHour();
lcd.setCursor(0,3);
lcd.print(string_table[3]);
// lights up the correct LED
digitalWrite(drysoilLEDPin,LOW);
digitalWrite(moistsoilLEDPin,HIGH);
digitalWrite(soggyLEDPin,LOW);
delay(250);
}
if(moistureSensorValue < 300){
// in case of soggy soil:
// system messages
lcd.clear();
RightHour();
lcd.setCursor(0,3);
lcd.print(string_table[4]);
// lights up the correct LED
digitalWrite(drysoilLEDPin,LOW);
digitalWrite(moistsoilLEDPin,LOW);
digitalWrite(soggyLEDPin,HIGH);
delay(100);
}
// if the soil is dry and if it is the right time: turn on the pump for 1 minute
if((H == 16) && (M == 50) && (S == 00)){
while(moistureSensorValue >= 700){
// system messages
lcd.clear();
RightHour();
lcd.setCursor(0,1);
lcd.print(string_table[8]);
lcd.setCursor(0,3);
lcd.print(string_table[5]);
// turn the pump on
digitalWrite(pumpPin,HIGH);
digitalWrite(pumpLEDPin,HIGH);
delay(10000);
// if the soil is not moist so far
// reads the moisture sensor once more
moistureSensorValue = analogRead(moistureSensorPin);
}
// turn the pump off
digitalWrite(pumpPin,LOW);
digitalWrite(pumpLEDPin,LOW);
}
}
// Real Time Clock Function
void RightHour()
{
DateTime Now = RTC.now();
String clock_date = " Date: ";
String clock_hour = " Time: ";
int _day = Now.day();
int _month = Now.month();
int _year = Now.year();
clock_date += fixZero(_day);
clock_date += "/";
clock_date += fixZero(_month);
clock_date += "/";
clock_date += _year;
int _hour = Now.hour();
int _minute = Now.minute();
int _second = Now.second();
clock_hour += fixZero(_hour);
clock_hour += ":";
clock_hour += fixZero(_minute);
clock_hour += ":";
clock_hour += fixZero(_second);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(clock_date);
lcd.setCursor(0, 1);
lcd.print(clock_hour);
delay(500);
}
String fixZero(int i)
{
String ret;
if (i < 10) ret += "0";
ret += i;
return ret;
}