AGRICULTURAL RESEARCH IN NEW HAMPSHIRE 51 



lated instead of one-third of them, as in 1943. As of July 1, 31,000 have 

 been inoculated and this number will probably increase to at least 40,000. 



E. F. Waller, R. C. Ringrose, A. C. Corbett 



SOILS 



Methods for Controlling Erosion on New Hampshire Potato Farms 



During 1943, the winter rye cover crop plots at Northwood yielded 

 approximately 13 per cent more potatoes than the non-cover crop plots. 

 The average yield of the potato plots at Northwood was approximately 1.5 

 times that of the erodible plots at Strafford Ridge 



Determination of volume weight, capillary, and non-capillary porosity, 

 total aggregation (by wet sieving and dry sieving) and aggregate stability 

 have been made on core samples taken from the Northwood plots. The 

 data indicate that the structural condition of the plots has continued to de- 

 teriorate except in the case of cover crop plots. The average values for 

 the total of water stable aggregates in excess of 0.5 mm follows: 



Percentage Aggregates in excess of 0.5 mm 

 Plot 1940 1941 1942 1943 



No. 2 No cover crop 55.6 54.1 47.4 44.5 



No. 3 Winter rye cover crop 51.9 49.1 43.5 45.3 



The results to date indicate that in the fourth tillage year, after plow- 

 ing under an excellent grass hay sod, soil and water losses may remain 

 relatively unimportant when potatoes are grown on a contour. Although 

 soil structure has degraded, the degree of degradation is not yet great 

 enough to contribute to serious erosion. This information will be of con- 

 siderable significance to farmers who participated in expansion of potato 

 acreage in New Hampshire from 6800 acres, in 1942, to 9200 acres, in 

 1943, particularly since the increased acreage w^as derived in great measure 



from hay land. 



L. T. Kardos 



The Influence of Soil Texture, Soil Moisture, 

 And Soil Aeration on the Grov^^th of Plants 



Work was continued with the same widely differing soil types that 

 were used with potatoes last year ; namely, a loamy fine sand, a fine sandy 

 loam, and a clay. Because of lack of labor, freshly sifted soil was not pre- 

 pared and the tomato and corn plants were grown in the same containers 

 in which potatoes were grown previously. Later, a toxicity developed from 

 the corrosion of the walls of the pails used as containers and subsequent 

 crops were grown in freshly sifted soil and re-waxed pails. In order to 

 restrict the number of variables, only fine sandy loam and clay soils, and 

 coarse and fine fractions were used. Daily weighing of the plants to main- 

 tain constant soil moisture was also omitted, the water being applied by 

 ■hose as needed. In the first series, corn showed considerable fluctuation 

 of yield within the different types. The second crop of corn, which was 



