14 UxiviiRsiTv OF Xkw Hami'siiirk [Sta. Bull. 324 



It has already been noted that commercial potato growers in New 

 England now commonly apply more than one ton of fertiHzer of a formula 

 such as was used in this experiment. While there are many factors in- 

 volved, such as the opportunity for producing high yields, due to favor- 

 able climate and rainfall, and the possibility of getting a fair price for the 

 crop, which affect the amount of fertilizer that should be used, it would 

 seem that if conditions are favorable, more than one ton of fertilizer can 

 economically be used. 



It is interesting to note, however, that the yield for the one and one- 

 half l<in application of 4-8-7 is almost exactly the same as for the 4-16-7 

 treatment (Table I). In this experiment the 4-16-7 formula was made up 

 by using one ton of 4-8-7 and adding to it one-half ton of 16% super- 

 phosphate, which, of course, amounts to the ecjuivalcnt of one ton of 4- 

 16-7 fertilizer. The effectiveness of this formula |)r<)vcd lo be just as great 

 as the addition of the extra half-ton of 4-8-7 in the one and one-half ton 

 treatment, but at just about half the extra cost. This lends considerable 

 weight to the idea that the formula, or balance of nutrients, is important for 

 economy in potato production. 



High and Low Analysis Fertilizers Compared 



In the Lane farm test, high and low analysis fertilizers were compared 

 for the six year period using equal amounts of plant food. 



TABLE XII. Six-year average yields of Lane farm potatoes 

 with high and low analysis fertilizers. 1933-38. 



Trealnient Yield per acre I '. E. Ditif. from check P. E. 



1 Ton 4-8-7 239 ± 5 



l/z Ton 8-16-14 269 ±7 30 ±9 



Both fertilizers were of regular commercial mix, and the results ap- 

 pear strongly in favor of the double strength nr high analysis formula 

 so far as the potato crop is concerned. 



Hill and Broadcast Applications 



Another point under test in the Lane farm experiment was concerned 

 with broadcast applications and band placement of the fertilizer on both 

 sicles of the row on the level with the seed piert-. The results secured in- 

 dicate an increased yield for the bancl placement. 



TABLE XIII. Effect of fertilizer placement on six-year average yields 



of potatoes on the Lane farm. 



Treatment Yield per acre P. E. DilY. from check I'. E. 



1 Ton 4-8-7 broadcast 239 ± 5 



1 Ton 4-8-7 in hill 256 ±8 17 ±9 



W'hile the reported increase is not statistically significant, the increases 

 have been fairly consistent from year to year. Much work has been done 

 on different methods of fertilizer placement l)y various workers, most of 



