100 STATE BOARD OF AGRICULTURE. 



miles, apply them liberally to any soil, but especially if your soil is opea and 

 porous. There is little danger of an overdose, and it is not a material that 

 will wash out of the soil. 



PLASTER. 



No single manurial substance is more characteristic of American agriculture 

 than plaster. It has been applied to every kind of crop and on every kind of 

 soil. It never does harm and often shows striking benefits. It is the source 

 of sulphur for plants, and is a more available source of lime for plants than 

 the carbonate, because it is somewhat soluble in water. On grasses, such as 

 June grass, red-top, and timothy, it has little influence. Applied to grain 

 crops it increases the growth of leaf and fibre without increasing the amount 

 of grain. On luguniinous crops, especially red clover, it has a marvelous influ- 

 ence, increasing the growth of the entire plant, and increasing the amount of 

 nitrogenous material beyond what the plant would have contained not dressed 

 with plaster. The clover hay made with use of plaster is worth more, ton for 

 ton, than clover hay not plastered during growth. The two pillars of the 

 porch of the temple of Michigan agriculture are Plaster and Clover. No 

 other combination holds out richer promise of good to the farmers of the 

 peninsular State. 



Lime holds the first rank in British manuring. The peculiar climate of the 

 British Islands — cool and moist, free from climatic extremes, and with a 

 strong tendency to the accumulation of peaty matter, and tardy decomposition 

 of vegetable matter, calls for the strong disintegrating influence of lime, and 

 it is used there with a lavish hand. 



In this state the high price of lime prevents its extensive use as manure. 

 When lime costs a dollar a barrel, and ten to twenty barrels per acre are 

 required to produce its full effects, a farmer is apt to count the cost before 

 ordering the lime. Caustic lime shows the greatest benefit on mucky soils, 

 and by its use they are soonest brought into cultivable condition. Muck is 

 usually acid, and in this condition is incapable of successful cultivation. A 

 good dose of quick lime destroys the acid condition, tends to dissipate the 

 excess of vegetable matter, and soon brings the remainder into active 

 condition. Caustic lime also acts upon the compound silicates of the soil, 

 setting free a portion of their potash for the use of plants. 



The mild or carbonated lime is found most abundantly and in the cheapest 

 form in leached ashes and marl. I am often asked to give an opinion about 

 the value and use of marl. Marl is a somewhat variable mixture of the 

 carbonates of lime and magnesia, with sand and clay. It is often found at 

 the bottom of muck beds and shallow lakes, is a grayish white material, and 

 when vinegar or any acid is poured upon it, it foams up or effervesces from 

 escape of carbonic acid. You can readily determine its value by finding how 

 much is soluble in acids, since the inert materials (clay and sand) are 

 insoluble in ordinary acids. Dry a quantity of the marl, and weigh out 100 

 grains ; place this in a bowl and pour over it an ounce of muriatic acid diluted 

 with water. When all action has ceased pour off the clear liquid, wash the 

 remainder with water two or three times, dry the residue and weigh again. 

 The loss in weight will give you the per cent, of valuable materials in your 

 marl. 



Conunon salt has come into more common use for manure of late years, but 

 it deserves more attention than it has yet received. It is valuable in itself 

 because it contains two of the chemicals of agriculture, Sodium and Chlorine, 



