On page ts demise you are absolute owner of land as you do not have any siblings 

2) your wife ,daughters have no share in agricultural land 

3) once land is partitioned it would be self acquired property of your father 

1.  Assuming that the property is still in your deceased father's name and you are the only child ( no other brother/s and/ or sister/s), then the property would devolve equally to you and your two married daughters. In other words each of you would get 1/3rd share. That means your own share would be 1/3rd in the agricultural land if it were to be partitioned today.

2.  The granddaughters' share is inbuilt in their mother's main share.

1. If the mutation of property has still not yet been recorded in your name in the revenue records and still it's in your deceased father's name and is intact, then the property would become Ancestral to your 4 grandchildren.

2. If it were to be partitioned before your grandchildren's date of birth, then you being the Class-1 legal heir to your father's property would have become sole and absolute owner, but since the property is in your deceased father's name even now and not in your name so far, you would be entitled to equal share on par with other legal heirs.

The property acquired by your father through a partition deed becomes his own and absolute property.

Now upon his intestate death, his property shall devolve equally among all his legal heirs alone and not on the next generation children of his legal heirs if the said legal heirs are alive.

As you have mentioned that you are the only legal heir to your father,  upon inheritance of this property, you will become the absolute owner of the entire property.

Neither your wife nor your children or the grandchildren shall be entitled to any share in this property as a right 

Since nobody has any right in this property, you will be the absolute owner of the entire property. 

As there are no siblings, upon the demise of the owner, the agricultural land is to be solely and exclusively deemed as the self-acquired property of your father and the wife and daughters shall have no right or share therein.

- As per law, after the demise of your father intestate , his  property would be devolved upon all his legal heirs equally i.e if you are only child and mother has died then the entire property can be claimed by you only. 

- Your wife , children or grand children having no right in that land during your life time. 

You have 1/3rd share in the property if its ancestral property. if its self owned property by your father than you alone are the owner of the property.

According to Indian law, the property would be divided equally among
the surviving members of your father’s family. This would include you, your wife, your two married daughters, and your four granddaughters. Therefore, each of the family members would be entitled to an equal share of the land.

As per the Hindu Succession Act, 1956, only the Class I legal heirs of the deceased have a right to the property, so you'll be the sole owner of the property. Your wife, children and grandchildren are not class 1 legal heirs of your parents.

It will be equally divided between the legal heirs of your matter except any will is there 

Dear client,  

Based on the information provided, your share in the agriculture land would depend on the inheritance laws applicable in your state.

In most states in India, when a person dies intestate (without leaving a valid will), their assets are distributed among their legal heirs as per the personal laws applicable to them. If your father was Hindu, Buddhist, Jain or Sikh, then the Hindu Succession Act, 1956 would apply.

According to the Hindu Succession Act, in the case of intestate succession of a male dying after September 9, 2005, the following legal heirs have an equal share in the property:

The widow (your mother)
The son (you)
The daughter (your married daughters)
As per the law, the grandchildren (your four granddaughters) would not be entitled to a share in the property as they were born after your father's death.

Assuming that the property has not been partitioned since your father's death, and there are no other legal complications, each legal heir (you, your wife, and your two daughters) would have an equal share in the property i.e. 1/4th share each.

However, if the property has been partitioned since your father's death and you have been in possession of your share, then your share in the land would be the share that you inherited from your father at the time of his death.

It is advisable to consult a local lawyer to determine your exact share in the property, as the laws governing inheritance and property rights can vary depending on the state where the land is located.