508 STATE BOARD OF AGRICULTURE. 



Limestone or marl may be added immediately before seeding or to 

 growing crops without injurj', but if caustic lime is used, it should be 

 applied and incorporated with the soil at least ten days or two weeks 

 before seeding, in order that its caustic properties may be dissipated 

 before the seeds germinate, thus avoiding injury to the j'oung plants. 



Alfalfa may be top-dressed with the carbonate carrying compounds 

 and where the alfalfa renovator or spring-tooth harrow is used tht 

 lime may be mixed with the soil to some extent. As a rule if the land 

 is limed previous to this crop it will endure as long as the alfalfa is 

 permitted to occupy the land. Reports are on record which show that 

 permanent meadows and pastures growing on soils deficient in lime may 

 be profitably top-dressed with this substance. 



It is readily seen that one may apply lime under widely different 

 conditions. Thus, there are opportunities for the consideration of this 

 operation in relation to other farm work^ condition of weather and the 

 land. 



Lime must be applied repeatedly to the soil. It has been shown by 

 determining the amount of lime carried by river water, well water, and 

 drainage water from tile, and large containers, filled with soil and placed 

 in the ground, that as a general rule much more of this substance is 

 washed out of the soil than is removed by crops. Although the amount 

 so lost has been' shown to vary rather widely it is probable that 800 

 pounds per acre annually, closely approximates the losses under average 

 conditions. At any rate it is now looked upon as being sound practice 

 to lime the soil at least once in each four or five-year rotations. Further 

 experience may show that small frequent applications of lime are most 

 profitable on some soils. 



Lime and Manure. Under some conditions lime and manure may be 

 applied to the soil at the same time. Where the lime is in the form of 

 the carbonate, namely, as marl, ground limestone, air slaked, sugar 

 factory lime or that obtained from the manufacture of acetone, it may 

 be mixed with the manure in the heap or stable or applied to the soil 

 ^'ith it. In the light of our present knowledge the oxide and the 

 hydrated lime should not come in contact with the manure and should 

 precede its application to the soil ten days or two weeks. 



SUMMARY. 



Lime is needed by many soils to increase their crop-producing power. 

 When applied to soils that are deficient in it lime may alter the struc- 

 ture, neutralize acids and other injurious substances, satisfy the sili- 

 cates, in some cases make available mineral plant food elements, in- 

 crease the rate of decay of vegetable matter, make manures and fer- 

 tilizers more efflcient and supply lime needed in the formation of plant 

 food. 



The principal forms of lime used in Michigan's agriculture are ground 

 limestone, hydrated lime and marl. 



There are two inexhaustible sources of lime in Michigan, the limestone 

 deposits and marl beds. The utilization of many of the marl beds 

 await the perfection of suitable mechanical apparatus for the removal 

 of the marl. 



