"Going green" sounds like a bad pun, but it's not, and 'going green' on the farm isn't all that difficult. Only in the past 40 years or so has the perspective of farming changed from renewing the land at every opportunity to killing everything that isn't on the list crops or forage. Basically, 'going green' on the farm, then is a return to the ancient practices that enabled farmers to feed the world for centuries before the arrogance of modern chemical farming came on the scene.
When fuel was cheap, it didn't matter if you left the pickup or the tractor running while you did something else. Today, with diesel at over $4/gallon, it definitely matters. A friend of mine told me recently that his fuel cost rose more than $28,000 in one year! And he has never been one to just leave the tractor or pickup running.
Decreasing your use of herbicides and pesticides is definitely 'greener'. Those chemicals have residues and break-down products. Back in the 1970's I was going to do a Masters in chemistry and my approach was to have been to find out what the breakdown products were of such common herbicides as 2,4-D. I came across a book the week I was to submit my thesis, which proved to my satisfaction that every interim field-breakdown product of 2,4-D was a Class 1 carcinogen.
Given that things haven't changed much in the laws of physics and chemistry in the past 1000 years, chances are they haven't changed much in the past 30 years, either.
Farm wives who use solar clothes dryers to dry their laundry in the non-freezing months are definitely 'greener' than those who use the dryer all year.
Spreading manure on the fields is one of the 'greenest' things you can do on the farm. We used to do it routinely, but it became 'unfashionable' for 25 years or so. Now it's coming back, since putting manure on fields substantially decreases the amount of chemical fertilizers needed to raise crops.
A very 'green' thing to do is to plant cover crops after harvest, or leave long stubble to help hold the soil in place, or both. Rye grass, for example, not only holds the soil after harvest, but it helps hold water from rain and snow, and when plowed under in the spring, adds nutrients to the soil, too.
If you ranch, your livestock graze pastures and spread manure for you, sort of. If your pastures aren't too big, running a drag harrow over them will spread the manure around better, which promotes more rapid breakdown of it and release of nutrient to the soil, as well as decreasing your need for vermicides (de-wormers) for your livestock.
When you have to go to town, it makes best sense to make a route for the things you have to do there, in order to save fuel and take less time.
If the farm or ranch family has a garden, doing it organically makes excellent sense. If you compost, making a compost tumbler is easy and will result in much better soil than any other method. Also, a tumbler makes compost much faster than a pile you must turn by hand for aeration.
Last, I suggest planting crops that are known to do well on your land with a minimum of artificial fertilizer and of herbicides and pesticides, and best if you companion plant in the organic farming fashion. I know these things work, because I have farmed and ranched organically all of my life, and have never failed to turn a profit in the process, even in 'bad weather' years.