"In average live-stock and dairy farming," Percy continued, "about one-fourth of the nitrogen contained in the food consumed is retained in the milk and animal growth, and you can make the computations for yourself. It should be kept in mind, moreover, that much of the manure produced on the average farm is wasted. More than half of the nitrogen is in the liquid excrement, and it is extremely difficult to prevent loss of the liquid manure. There is also large loss of nitrogen from the fermentation of manure in piles; and when you smell ammonia in the stable, see the manure pile steaming, or colored liquid soaking into the ground beneath, or flowing away in rainy weather, you may know that nitrogen is being lost. How many tons of manure can you apply to your land under such a system of farming as we have been discussing?" "Well, I've figured a good deal on manure," was the reply, "and I think with four fields producing such crops as you counted on, that I could possibly put ten or twelve tons to the acre on one field every year." "That would return from 100 to 120 pounds of nitrogen;" said Percy, "instead of the 173 pounds possible to be returned if there is no loss. There are three methods that may be used to reduce the loss of manure: One of these is to do the feeding on the fields. Another is to haul the manure from the stable every day or two and spread it on the land. The third is to allow the manure to accumulate in deep stalls for several weeks, using plenty of bedding to absorb the liquid and keep the animals clean, and then haul and spread it when convenient." "I'm afraid that last method would not do at all for the dairy farmer," said Mr. Thornton. "You see we have to keep things very clean and in sanitary condition." "Most often the cleanest and most sanitary method the average farmer has of handling the manure in dairying," said Percy, "is to keep it buried as much as possible under plenty of clean bedding; and one of the worst methods is to overhaul it every day by 'cleaning' the stable, unless you could have concrete floors throughout, and flush them well once or twice a day, thus losing a considerable part of the valuable excrement. If you allow the manure to accumulate for several weeks at a time, it is best to have sufficient room in the stable or shed so that the cows need not be tied. If allowed to run loose they will find clean places to lie down even during the night.