No. 7. DEPARTMENT OF AGRICULTURE. 241 



who can find out what a soil needs is the man who cultivates it, and 

 he must do it by careful experimentation year after year with the 

 various forms of plant food separately and in combination as com- 

 pared with check plots, and in this way can come rery closely to 

 what his soil is deficient in and what he need not buy. Crops vary 

 too as to what they take from the soil, and the needs of special 

 crops as well as the needs of the soil must be studied. One point I 

 have reserved till now. This is the preparation of the soil for crops. 

 A deeply prepared seed bed is of course important, but we must go 

 slow in the deepening of a soil that has been plowed shallow for 

 generations. Then whether subsoiling will pay or not will depend on 

 the nature of the land. A flat clay that needs underdrainage will 

 not be benefited by subsoiling till the drainage is made good. But 

 on most of our roiling lands with a clay subsoil once in each round 

 of a four year rotation will be found of advantage. But one thing 

 is important, and this is a complete pulverization of the surface 

 after plowing. I have found that in the preparation for fall grain 

 every time the harrow went over the land till completely fined and 

 compacted I was adding bushels to the crop. 



When finally all our farmers know these things and practice them 

 we may some day reach the time when we will be to a great extent 

 independent of the seasons, and will find the day, which Secretary 

 Wilson imagines is already here, when we will have no crop failures. 



The extent to which the wheat growers have learned that the 

 buying of commercial nitrogen is needless is shown by the fact 

 recently stated by a fertilizer manufacturer in Baltimore, which is 

 the headquarters of the fertilizer trade, that over 80 per cent, of the 

 fertilizers now sold there consist of phosphoric acid and potash with- 

 out any nitrogen. 



In a recent number of the Ohio Farmer, Dr. Thorne, the Director of 

 the Ohio Experiment Station, sums ap the consideration of the value 

 of humus in the soil thus: ''The humus of the soil is, therefore, the 

 great storage battery of its elements of fertility, mineral as well as 

 nitrogenous. It is in this store, chiefly or altogether, that our crops 

 find their sustenance. When this store is exhausted they starve, 



and in proportion as it is reduced they suffer hunger Sand and 



clay are but the skeleton of the soil; humus is its life." 



MR. NELSON: Is there no circulation of sap in the heartwood 

 of a tree? 



PROF. MASSE Y: No, none at all. Hold on a moment, heartwood, 

 as you know, lasts longer than sap. Decay starts in where there 

 has been death. There has been no death in the heart, hence there 

 is no decay, which starts in there, no blue mould as there is in sap 

 wood. This dead matter lives on sap. It don't live on the heart. 



'MR. NELSON: I have an oak tree in my corn field, and I cut a 

 groove around in it an inch deep on the fifth of May a year ago. I 

 have done that several times and it is leaving out this spring and in 

 blossom, just as nice as it ever did, and it will do that the next four 

 years. 



PROF. MASSEY: Well, it will die. I know that they will do 

 that sometimes, but it will die. 

 16—7—1906. 



