FIELD EXPERIMENTS IN I914. 4/ 



further seen that three bushels per acre have given very nearly 

 as good a yield as five bushels, ^^/hy the yield of grain from 

 the plot with 14 pecks of seed should be so much lower than 

 those on either side of it is not clear. Apparently it was not due 

 to the rate of seeding. The yield of straw was as high as on 

 most of the other plots. 



It is planned to continue these experiments for several years. 

 In this way it is hoped to be able to answer the question as to 

 the proper amount of seed for Aroostook conditions. 



Sulphate of Ammonia Compared with Nitrate of Soda as 

 A Source of Nitrogen in Potato Fertilizers at Aroostook 

 Farm in 1914. 



A few years ago there was quite a general failure of the crop 

 of potatoes in Aroostook County where a certain brand of fer- 

 tilizer was used. This fertilizer was analyzed by the Station 

 chemists and found to be high grade. While it was not quite up 

 to its guaranty in some particulars it did carry enough nitrogen^ 

 potash and phosphoric acid to more than grow a good crop of 

 potatoes. This fertilizer carried none of its nitrogen in the 

 form of nitrate of soda, but it was all in the form of sulphate of 

 ammonia and high grade organic materials. This led to the 

 stronger reaffirming of the position which the Station had taken 

 relative to the use of nitrate nitrogen on the potato crop. In 

 earlier publications it has been pointed out that the potato makes 

 its demands for nitrogen early in the season and that in the cold,, 

 late springs so common in Aroostook County, the crop demands 

 'that part of the nitrogen should be immediately available. For 

 this reason the Station has strongly urged that about one-third 

 of the nitrogen in a potato fertilizer be nitrate nitrogen. 



In the process of making gas and coke from coal there is 

 developed a large amount of sulphate of ammonia, which in 

 many coke and gas plants is still going to waste. In some plants 

 this now is being conserved and many thousand tons of sulphate 

 of ammonia are thus obtained each year. With the increasing 

 use of high grade organic nitrogen for food of animals, the price 

 of tankage has been going higher and higher year by year. It is, 

 of course, desirable, if it can be done, that as much as possible 

 of this sulphate of ammonia which is a comparatively cheap 

 source of nitrogen be used in Maine fertilizers. Because of 



