LECTURES AND ESSAYS READ AT INSTITUTES. 95 



astray in our discussions if we regard manures mainly as the means used to 

 make more effective the plant-food existing in the soil. In strong, rich soils 

 the supply of plant-food may be sufficient for the wants of the crop, and the 

 addition of manure may show no increase, but in poor and exhausted lands, if 

 the physical condition is good, the most striking results are exhibited. 



The prices I have given for potassium, phosphorus, and nitrogen to make a 

 ton of clover hay, when purchased in commercial form, will afford food for 

 thought in regard to the relative economy of barn-yard and commercial 

 manures. I will again call your attention to this point when I speak of red 

 €lover. 



Why do I attach so great importance to potassium, phosphorus, and nitro- 

 gen in agriculture? For three reasons. 



I. In the absence of any one of these, no growth is possible. The Germans 

 have a maxim, "No phosphorus, no life." But the same holds true of potas- 

 sium and nitrogen. 



II. A limited supply of any of these limits correspondingly the action of all 

 the other chemicals of agriculture, however great their abundance. Even the 

 elaboration of the carbon compounds depends upon the presence and co5pera- 

 tion of these three. They are the fates that spin the thread of existence for 

 all forms of life. 



III. They are sparingly doled out by the hand of nature, and are soonest 

 exhausted by cropping. An exhausted field is one that will not produce a 

 paying crop, and such exhaustion consists in the absence of one or all of these 

 three materials in available form. 



MANURES MAY BE COMPLETE OR PARTIAL. 



A complete manure is one that furnishes all the substances which enter into 

 plant growth. The best example is barn-yard manure. Animal excrements 

 have been recognized from earliest times as powerfully promoting plant 

 growth, and increasing fruitf ulness. In the parable of the barren fig-tree the 

 remedy was to "dig about it and dung it." Dung was the only manure 

 known to the ancients, and while this word occurs twenty-two times in the 

 Bible, the word manure is not found at all. 



The value of barn-yard manure will vary with the kind of food, the variety 

 and condition of the animal, and mode of preservation. I need not consume 

 time to discuss these questions before a crowd of practical farmers. Whether 

 a farmer keeps much stock or little, the chief difficulty is to get enough of 

 this barn-yard manure. Of its value there is no question. 



One way of increasing the quantity without seriously impairing the quality 

 of barn-yard manure, I will bring to your notice. In most parts of the State 

 there are muck beds easy of access. If barn-yard manure is composted with 

 an equal volume of powdered muck by placing these materials in alternate 

 layers, and then "turning the compost," by the shovel or scraper, once in the 

 spring, a month before it goes to the field, you will have double the volume 

 of manure, scarcely inferior to well rotted barn-yard manure. Such compost- 

 ing is not a process of dilution or watering, but a substantial addition of 

 manurial matter. Muck contains nearly the same quantity of combined nitro- 

 gen (2 per cent) as well rotted manure, but this nitrogen is mostly in the inert 

 or inactive form. By composting with barn-yard manure the active fermen- 

 tation of the auimalized matter induces fermentation of the muck, and some 

 of the inert nitrogen is made active, any ammonia set free in the fermenting 

 manure will be absorbed by the muck, and loss by leaching of the soluble 



