HELP in Sensor System Design in a Passive Solar Greenhouse!!!!

I am not so familiar with PIC. Does PIC support any kind of soil moisture sensor? Anybody can help me?

A PIC is a type of microcontroller with various input/output lines (both digital and analog); digital meaning an on/off, HIGH/LOW signal, analog meaning a varying voltage signal (usually); the PIC supports both. A simple soil moisture meter simply measures the resistance of the soil at the depth in which it is placed by reporting a varying voltage (more complex ones I imagine actually have their own built-in processor that you communicate with using some serial interface and protocol). In short, yes, it is possible to do what you are trying to do using a PIC. However, it will require programming to perform this task; you have not indicated what your level of experience is regarding programming. PICs are generally coded using assembler, C, or a version of BASIC. Do you have experience in any of these languages?

I just know some basic of C++. Now i trying to learn mikroC compiler to do the programing. Got any website or reference that you can suggest for me to refer or study?Or i still need other program to support? Actually i am trying to make a micro-controller that read data from sensor and send feedback to controller like fan and pump to maintain a fix range or temperature and humidity level of the soil.

First - if you have some familiarity with C/C++, you should be able to figure out what you need in order to work with a PIC; as far as reference websites for PIC, I don't know of any, but I am sure there are others here who do. My only experience with a PIC was a brief stint playing with a Basic Stamp 2, then I moved to the Arduino (which is based on the Atmel ATMega8/168/328 - so, AVR C/C++).