I am sorry for your situation. The answer to your question is no, the child would not have a direct right to your property.
There are two rights that the child has, only once paternity has been established either through your official admission or through the courts:
-> the right to material support from you; and
-> the right to inherit you.
The right to material support is only granted in circumstances where the child needs it, and requests it (through the mother) through the courts. After 18 years of age, the circumstances change, and this right does not normally exist (there can be an obligation of support even at a higher age, but then it depends on real hardship).
In an extreme circumstance, if child support is ordered by the courts and you do not pay, your farm may be taken and sold to pay for the arrears. But this would be an extreme circumstance, and normally the entire issue would revolve around monthly payments, adapted to the child's needs and your means.
I hope this has answered your question and look forward to your rating, which is essential to my activity.
Dr I L Vlad