234 STATE BOAED OF AGRICULTUKE. 



not fair crops, but large, crops, and for this he wants a supply of nitrates or 

 some other active form of nitrogen. Your horse may be in fair condition and 

 do a fair amount of work when fed on hay alone ; but how much more he can 

 accomplisli with a liberal dose of oats ! The "oats'' a farmer needs to feed to 

 his fields are nitrates! 



How shall the farmer get these nitrates? He may buy them, but they cost 

 money, and a good deal of it. It is a safe rule in farming, never buy what you 

 can make for yourself at far less expense. Nitrates are naturally formed when 

 moist and Avarm earth, containing lime, and charged Avith decaying organic 

 matter containing nitrogen, is freely exposed to the air. This is the way that 

 the artificial nitre beds are made in Avhich most of the nitre of commerce is 

 manufactured. But if any of these conditions are wanting, — if the soil is too 

 dry or too wet, ir it is not properly opened to the access of air, if no lime or 

 alkaline substance is present, and if there is no decaying organic matter, very 

 little if any nitrates are formed. Under the proper conditious, this formation 

 of nitrates will take place in any soil, whether we call it a nitre bed or a culti- 

 vated field. Indeed, a well cultivated field is a nitre bed on a large scale, and 

 many operations of farming are simply means of promoting nitrification. For 

 this, in part, at least, you drain, plough, harrow, cultivate, and hoe your land ; 

 and aside from destroying weeds and putting in seed, the whole of these opera- 

 tions are simply means of affording the conditions of nitrification. You liave 

 all noticed tliat frequent stirring of your soil does something more than to 

 destroy weeds. The increased growth under such circumstances is an indirect 

 result of nitrification in the soil. 



European chemists have given mucli attention to this subject, and the 

 researches of Boussiugault and Bretschneider have shown that a large amount 

 of nitrates are formed in fertile soils. The experiments of Bretschneider are 

 especially valuable, because lie examined this matter in the soil of a cultivated 

 field, and thus gives us an insight into this matter under agricultural conditions. 

 He found that the quantity of nitric acid in an acre of soil taken to the depth 

 of 12 inches was 56 lbs. at the end of April ; June 12 it had increased to 281 

 lbs. in one ]}\oi, and 270 lbs. in another ; June 30th to 328 lbs. and 442 lbs. ; 

 July 22d it had decreased to IIG lbs. and 89 lbs. ; Aug. 13th to 53 lbs. and G 

 lbs. ; and Sept. 9th, none. 



The noticeable features of these investigations are the small amount of nitrates 

 in the soil at the end of April, the large amount at tlie end of June, and their 

 disappearance in September. "What had become of these nitrates? Undoubt- 

 edly they were washed out by the rains, and had disappeared in the drainage 

 water, for the soil has no power to hold in an insoluble form the nitrates. The 

 amount of nitrates carried by the rivers into the sea every year is enormous. 

 The Rhine is said to daily carry to the sea nitrates equivalent to more than 220 

 tons of saltpetre ; the Nile every day pours 1,100 tons of nitrates into the Med- 

 iterranean Sea, and our Mississippi jorob ably pours 2,000 tons of nitrates into 

 the Gulf of Mexico every twenty-four hours. The nitrates formed in one year 

 are not stored up to any appreciable extent for the next year's use, and spring 

 opens upon the year's work with the treasury empty of nitrates: they form 

 slowly in early spring, but rapidly in hot summer weather. But it is in early 

 spring growth that these nitrates are es2:)ecially needed to give our crops a good 

 send-off. If your corn, your oats, etc., enter June with a good, pushing growth, 

 you feel little anxiety about their future development. How to give our crops 

 this early and vigorous start is a very important question in the management of 



