The Deacon said this very quietly. He did not seem to know that he had asked one of the most important questions in the whole range of agricultural science. It is a fact that a soil may contain enough plant-food to produce a thousand large crops, and yet the crops we obtain from it may be so poor as hardly to pay the cost of cultivation. The plant-food is there, but the plants cannot get at it. It is not in an available condition; it is not soluble. A case is quoted by Prof. Johnson, where a soil was analyzed, and found to contain to the depth of one foot 4,652 lbs. of nitrogen per acre, but only 63 lbs. of this was in an available condition. And this is equally true of phosphoric acid, potash, and other elements of plant-food. No matter how much plant-food there may be in the soil, the only portion that is of any immediate value is the small amount that is annually available for the growth of crops. HOW TO GET LARGER CROPS. “I am tired of so much talk about plant-food,” said the Deacon; “what we want to know is how to make our land produce larger crops of wheat, corn, oats, barley, potatoes, clover, and grass.” This is precisely what I am trying to show. On my own farm, the three leading objects are (1) to get the land drained, (2) to make it clean and mellow, and (3) to get available nitrogen for the cereal crops. After the first two objects are accomplished, the measure of productiveness will be determined by the amount of available nitrogen in the soil. How to get available nitrogen, therefore, is my chief and ultimate object in all the operations on the farm, and it is here that science can help me. I know how to get nitrogen, but I want to get it in the cheapest way, and then to be sure that I do not waste it. There is one fact fully established by repeated experiment and general experience--that 80 lbs. of available nitrogen per acre, applied in manure, will almost invariably give us a greatly increased yield of grain crops. I should expect, on my farm, that on land which, without manure, would give me 15 bushels of wheat per acre, such a dressing of manure would give me, in a favorable season, 35 or 40 bushels per acre, with a proportional increase of straw; and, in addition to this, there would be considerable nitrogen left for the following crop of clover. Is it not worth while making an earnest effort to get this 80 lbs. of available nitrogen?