FOR BETTER CROPS 75 



throui,'-h the decay of too much veg-etable matter, there is acid- 

 ity in these black soils. In many other cases tliere is some 

 ditllculty in establishini^ bacterial energy, and tlie reason for 

 this is unknown. However, the remedy has l)een found to be 

 applications of barnyard manure, which works like magic on 

 tliese black prairie soils, and when coupled with the under- 

 draining, where it is needed, alfalfa is found to grow with 

 remarkable vigor and profit on the black corn soils of Iowa and 

 Illinois. The reader, if he dwells in this land, should consult 

 the bulletins of the Iowa and Illinois experiment stations for 

 help to make his alfalfa surely grow. 



Soils on which it is Difficult to Grow Alfalfa — It is more 

 difficult to grow alfalfa on some soils than on others, and on 

 some of them it is not wise to make the attempt. First, any 

 soil that is not more than two and one-half feet above the water 

 line is too shallow for continual alfalfa growth. It needs a 

 depth of at least three feet to water, and if the distance is even 

 grsater all the better. In laying tile underdrains for a founda- 

 tion to an alfalfa field, seek, then, to get the level of the water 

 line down at least three or four feet. 



On peaty soils with little clay or sound earth within them, it 

 is not often that alfalfa will thrive. There are some exceptions 

 to this rule, though they are not well understood. 



On nearly barren sands it is doubtful if it is worth while 

 trying to establish alfalfa fields. They must be continually fed 

 in order to produce this forage, so rich in mineral elements, and 

 it must be remembered that these mineral elements must come 

 from the soil. 



Clays— While the most luxuriant growth of alfalfa is usually 

 from a porous soil, a loam or gravelly alluvium, yet clays drained 

 and stored with vegetable matter are producing some of the 

 best growths of alfalfa in the United States. This is especially 

 true of strong, tough limestone clays that, when in their natural 

 state, hold w^ater "like a jug," but when underdrained and well 

 manured become more open and pervious to both air and mois- 

 ture. On such clays alfalfa revels, and when plowed up and 

 other crops are planted on the land, it is astonishing to see with 

 what vigor they grow, revealing plainly the very great benefit 

 that the alfalfa has been to the soil, both by adding nitrogen 

 through the decay of its leaves and roots, and by bringing up 

 mineral matters from the sub-soil, and by decaying and leaving 

 air and water passages through the clay, alwa3-s before too dense 

 to permit these helpful agents to work their will. And when 

 alfalfa is sown again upon these clays after one or two years of 

 grain or hoed crops, manure being scattered over the land in the 

 interval, it is found that the alfalfa responds wonderfully and 

 yields better than it did from its first seeding. 



