10 MASS. EXPERIMENT STATION BULLETIN 436 



Dust collected showed 0.46 percent moisture, while the parent soil had a 26.0 

 percent moisture content. 



Where the formation of aggregates in dry soils was increased by chemical 

 treatment, their tendency to blow was decreased. Soils treated with ground 

 limestone, burnt lime, urea, and lithium carbonate showed decreased losses with 

 the treatments in the order mentioned; the finer the texture of the soil, the more 

 pronounced the effect. Calcium and sodium silicates tended to bind the soil into 

 aggregates and so reduced soil losses. Organic matter when applied in the form 

 of raw lignin lowered the initial velocity at which the soils began to blow and also 

 increased the rate of wind erosion. The lignin used was not comparable to soil 

 humus or organic matter. The organic matter produced in a soil from the de- 

 composition of yearly applications of sawdust reduced the amount of wind erosion 

 and also raised the initial velocity at which the soil began to blow. Soil taken 

 from under a manure pile dried into a coarse lumpy condition which was quite 

 resistant to wind erosion. 



A study of the deflocculating effects on the soil of the mono-valent elements in 

 period one of the "Periodic Tables of Atoms" showed that, upon drying, the soils 

 had experienced an aggregated condition which increased in the following order 

 of the elements tried: lithium, sodium, potassium, rubidium. The pH value of 

 the soils was greatly increased by this chemical treatment. The rate of increase 

 of the pH values was in the reverse order to the aggregating effect. 



To study the rate of wind erosion on fields of various crops and the relation of the 

 cultural practices to dust blowing, a portable dust collector was developed. These 

 studies show that the soil blows more on areas growing vegetables like onions 

 and lettuce than on areas used to grow tobacco and potatoes. There was a direct 

 relationship between pH and amount of dust collected. These observations were 

 confirmed in the wind tunnel studies where soils from two experimental plots 

 were tested. Soil from a plot having a yearly appliqation of limestone had a pH 

 of 6.9 and eroded considerably more than soil from a plot which had not received 

 any lime and had a pH of 4.8. It is believed that the flocculating effect of con- 

 tinuous liming has produced a soil surface condition more susceptible to wind 

 erosion. 



Use of Snow Fencing in Controlling Wind Erosion. The results of this test, 

 which was described in detail in the annual report of 1944-1945, were not very 

 conclusive this year owing to the lack of dust storms during the exceptionally 

 wet season of 1945. The anchorage of the snow fencing with iron pipes, 43^ to 5 

 feet long, driven 18 inches into the ground and spaced a rod apart, held the 4-foot- 

 high lath fencing throughout the entire season. Frost action did not tend to 

 heave the anchorage out of the ground. 



Black Root Rot of Tobacco. (C. V. Kightlinger.) Strains of Havana Seed 

 tobacco that yield well under black root rot promoting conditions often produce 

 tobacco that is not fully acceptable to all of the tobacco trade when grown under 

 favorable producing conditions. Therefore an attempt is being made to breed 

 strains which will produce tobacco of acceptable type and quality in profitable 

 amounts under both these growing conditions. 



Havana Kl and Havana K2 and other new strains thus far produced are now 

 being grown commercially to ascertain their suitability for general use in the 

 Connecticut Valley. These strains yield well under different growing conditions; 

 and so far, the tobacco produced seems to be receiving greater approval for type 

 and quality by the tobacco trade than that produced by Havana 211 and other 

 previously produced strains. It is too soon, however, to know whether these new 

 strains will be entirely satisfactory. 



