No. 4.] COMMERCIAL FERTILIZERS. 137 



Mr. BowKKU. Tlu'ii what did Dr. Hall mean in his 

 article ? 



Dr. VooRiiEES. There is no question hut that each one of 

 the constituents has its own peculiar function, and the pres- 

 ence of a normal sup]>lj of phosphoric acid simply encourages 

 that )>lant to nuike a normal development. In many instances 

 we don't want abnornud development. A man grows pota- 

 toes, and he gets vines and not a proportionate yield of 

 potatoes, although his land is good and capable of fully 150 

 barrels to the acre. He gets vines because he has put in or- 

 ganic matter containing nitrogen and has not a sufficient 

 abundance of available minerals. The plant will take up the 

 nitrogen, but it hasn't enough of the mineral to balance the 

 ration. 



Mr. BowKER. The potato growers of Aroostook County 

 are experts. To insure the abnormal growth of tubers, not 

 jiotato balls, say, oOO bushels to the acre, they apply an 

 excess of plant food, and especially an excess of available 

 phosphoric acid. Aroostook County is as far north almost 

 as Quebec, but in my judgTuent it could not produce the 

 enormous potato crop it does if it did not use from 1,200 to 

 1,500 i)ounds of a w^ell-balanced fertilizer per acre, which 

 is no doubt an excess, and also if that fertilizer did not con- 

 tain as much of soluble and available phosphoric acid as it 

 contains of potash, and twice as much as it does of nitrogen. 

 The commercial farmer should not stint a growing crop any 

 more than he would stint a lusty, growing calf. 



I was glad to hear Dr. Voorhees emphasize the importance 

 of changing from general farming to specialized farming. 

 Here in Massachusetts we cannot afford to raise small grains 

 or grass except in the course of a rotation. We should 

 practice intensive agriculture, and grow the finer crops, such 

 as onions, lettuce, celery, tobacco, ensilage, fruits and 

 flowers, which as a rule are not only abnormal crops, but 

 usually more profitable crops. 



I w^as also glad to hear him advise the use of more fer- 

 tilizer or plant food than is apparently needed. To pro- 

 duce abnormal growth this is necessary. The late Joseph 



