Need your suggestions to address few issues facing in our farm

Dear all,
  need your suggestion on below issues we are facing in our farm .
My father takes care of our farm in northern Maharashtra .
In last 4 years we are able to get water permission from river, electricity, water pump and water pipeline in farm .

We got a caretaker who looks after farm on profit sharing basic .
Initially couple of year we had soyabean and groundnut .
Last year we planted lemon trees in 2 acres and doing inter-cropping with cotton, groundnut etc .

Initial years we did not faced much issues with pest and no pesticides/chemical fertilizers were used (crops were soybean/groundnut) .

But when I visited during December it was disheartening to see pest everywhere, cotton, onions, lemon plants, even small plots of beans, brinjal etc.

Our caretaker started using pesticides and it was pesticides been sprayed everywhere.
We have below issues and need your help to address them .

Live Fencing :
We were planning for a sagargota fencing (since farm area is almost 18 acres) but not much action taken till now .
3 years ago we tried to put sagargota seeds on one side of the farm during rainy season, it did not worked .
Roadblock : Not sure if we need to come up with small nursery, grow a few month old sagargota plants and then replant during rainy season of june/july .
Note:we are facing menace of neelgay and wild pigs at farm so fencing is must.

Cowdung as manure:
We are willing to have cow at farm so that cow dung can be used and chemical fertilisers can be reduced . Also can think of organic pesticide where cow urine is usefull .
Roadblock :
No farm house or shed as of now . Also caretaker might not be interested to take care of cow unless he is benefitted in some way.

Need to get away from chemical pesticides :
Roadblock : Caretaker says its very easy to get pesticide bottle and spray, difficult to make organic/herbal pesticides .

Since our farm is next to riverbed with throughout year water, it had a good ecosystem, so I thought we will have less problems with pest .

I will be really grateful if you can guide me how and in which order I need to address these issues.

Thanks & Regards,

See my comments inline.

Padmanabhan Ganesan

brain wash your caretaker every time you meet him but slowly(I have done and doing it even now) My labors were reluctant to use jeevamritha but now They are convinced.

Padmanabhanji, Sriji,
    thanks for your valuable suggestions .
Best regards,