From all what has been said, following seems to be the case:
1. Land belongs to Sarao.
2. It is agricultural land.
3. Cement will pollute. (It is immaterial as to whether that stretch of land, adjascent land etc is cultivated or not. But, it will pollute, go on polluting and go on adding to it more and more and more).
4. There would be regular movement of heavy vehicles (lorries) etc.
5. All these will definitely cause problems which can be nothing to the unit's owner, but others would not find it good to stomach it.
I would do something different from what you are attempting. I will change the idea of all these itself.
My idea may not fetch you loads of money immediately, but say over a reasonable span of 3 to 4 years, you would start seeing the difference yourself and say in 10 to 15 years, you would turn to be a God in your own right, might who saved God, nature. Are you interested? Will you be philanthrophic enough? Are you hearing the name of 'Anna Hazare'? Do you know what he did? Why don't you think of something similar to that in whichever part you are living? There are more than 3 lakh VARIETIES of grass, another 3 lakh varieties of mangroves. There are many cash crops, oil crops, medicinal crops etc etc. Many of them do not need your attention at all. They need very little investment and get you good returns too.
You have many scientific bodies, commercial agencies etc that will help you out. You could even think of leasing your area for such activities in case you have some troubles on the practical front.
There are yet other sorts of businesses too. Have you heard of Compressed Gobar Gas (CGG). It is gobar gas, but compacted using a compressor. It can be alternative to LPG, CNG etc. Experiments have been conducted and it is proven that it has hauled railway engines. It is 4 times as efficient as LPG. That means you can be helping to evolve a 'MICRO BUSINESS' in itself in your area, the first of its kind. You see 2/3 kg gas LPG cylinders for household cooking, you see 3 wheelers called autos using CNG cylinders etc. All these can be replaced in a very very green manner, all from resources that you, your friends have around in your agricultural lands. Don't you have cows in your area? That is enough. Have more fodder for them, plan a longterm business. You could be a new leader who would have set a new trend in India which will then be followed by rest of the country. Well, this CGG can be piped too, the way it happens with natural gas. If this happens then you could have electric power stations etc running on CGG. If this reaches that gigantic proposition, then you would have led a revolution. It would become a product akin to milk. Let me assure you that it would be a very very very very lucarative, satisfying business.
You could have high value/good utility grass (cow grazing) etc in combination with crops like Jatropha which needs no much water, care and are relatively disease free, attack free and you can intersperse them with some fruits or huge trees like Jamun, Mango etc too. Well, there are lots of ideas, possiblities. You would do well to talk to selfless scientists.
If you do it, you would have set a role model example that would be emulated across India. This can be done across all sorts of lands: marshy, dry, drought hit, areas with foot prints of conrete (something like the noida areas that are being returned to farmers, but farmers are not realising the value of the gold that they are getting) etc, etc. In fact, if I get an opportunity, I will present a presentation wherever it be: 'Supreme court', 'Government offices', 'Welfare organisations' etc etc.
All in all, I do not favor your cement brick project. You are you. You have to decide. I have given you a welfare oriented, longterm idea that has multiple options.