22 Station Bulletin 372 



There were fewer instances of 1-man and 1-double unit combinations to 

 observe. But one operator was found who approached the synthetic pattern 

 closely. He prepared the cows too far in advance but milked quickly and 

 followed a definite sequence. The time and sequence pattern for this com- 

 bination indicated that one man could milk 18 cows and take care of the milk 

 in 39.6 minutes. The actual time was 37.5 man minutes. 



The combinations involving two men have been difficult to check with 

 the pattern. Several records were made of 2-men and 3-single unit combina- 

 tions but in each case the sequence and timing were poor. Unless the two 

 men work well as a team, the cows are prepared too far in advance or indivi- 

 dual cows are milked too long. In one case, the combination of 2-men and 2- 

 double units was observed. The cows were prepared too far in advance and 

 the hand stripping was delayed too long. In several instances about 20 min- 

 utes had elapsed between preparation of the cows and the completion of strip- 

 ping. 



The timing, analysis, and charting of milking detail this year indicate 

 that most farmers can improve their milking practices. 



H. C. WooDWORTH, J. C. Holmes, K. S. Morrow 



CROPS 



Rotation, Fertility, and Cultural Experiments with 

 Potatoes in Northern New Hampshire 



This experiment is designed to test the nutrient needs of potatoes for 

 minor elements on New Hampshire soils and to discover the relationships of 

 the various plant food nutrients to quality as measured by specific gravity. 

 Particular attention is devoted to the chloride-sulphate relationships in the 

 greenhouse at Durham and in the field at Northwood Ridge and at Colebrook. 



At Colebrook, on Coffin Field No. 2, potatoes are being grown in a two- 

 year rotation with lime, manure, calcium sulphate, boron, and magnesium as 

 variables, and which includes plots in which potassium sulphate is substituted 

 for the chloride. Two cover crops, oats and crimson clover, are being grown 

 in alternate years in the two-year rotation, with one series of plots under con- 

 tinuous culture. The effect of cover crops will not be evident until the 1947 

 crop is harvested. 



The five-pound application of borax treatment gave the highest yield of 

 any series, higher than the 20-pound level of borax, indicating that potatoes 

 on this soil need small amounts of borax but not as much as 20 pounds per 

 acre in a band application. 



No explanation is apparent for the depressing effect of lime on potato 

 yields, but a decline in yield because of the omission of magnesium was an- 

 ticipated. This study is being continued. 



Studies at Colebrook, in 1946, included tests on the sulphate-chloride 

 relationship of potatoes of the Green Mountain and Katahdin varieties. The 

 lower yield of Katahdin in comparison with Green Mountain was caused by 

 poor stands. 



It is apparent, from a study of the average quality rating of Green Moun- 

 tains, that the substitution of potassium sulphate for the chloride raises the 



