No matter how much fallout is present, it will decay within 2-3 weeks to safe levels. Give it a month. A month after explosion, you can even walk into Ground Zero and still expect to live a full life. Then, depending on the amount of fallout left, you either plough the field several times or replace half a feet of the top soil. If it rains, even better. And then you plant your wheat and watch it grow. In 3-6 months after an explosion you will have wheat again.
The only thing one has to be careful about is contaminating ground water. But even that's a small problem.
The amount of propaganda against nukes is downright stupid to the point where it defies logic.
The major effect of a nuke is the initial explosion, which is effective at killing people. But the aftermath is highly exaggerated.
Fallout follows the 7-10 rule. Every multiple of 7 times since an explosion, the fallout reduces by 10 times. So an area with 1000R/hr will have reduced to 1R/hr in less than 2 weeks. And this area is generally very small. Say, less than 1Km radius from Ground Zero. And fallout carried by the wind is generally dispersed and decays rapidly to the point where any that reaches the ground is largely harmless or too little to do significant damage, even noticeable damage. A large chunk of it decays while it's still harmlessly floating around.
As for cities, even after Hiroshima and Nagasaki were bombed, the unaffected areas of the cities continued functioning. Out of some 100,000 people affected by radiation, only 700 died of cancer. And only 40 babies were known to be malformed. All of this has been very well recorded. And there was no effect in farmlands around the cities. Compared to the two Japanese cities, Indian cities are massive and the major farmlands will be far away from Ground Zero.
