12 MASS. EXPERIMENT STATION BULLETIN 339 



was used and allowed to drain through at the rate of 1 liter in 24 hours. All 

 chemically pure salts were recrystallized. Copper was used at the rate of 0, 

 .05, .15, .50, 1.0, and 5 parts per million of sand; and zinc at the rate of 0, .05, 

 .10, 10, and 30 parts per million of sand. 



The preliminary results clearly indicated that .05 and .15 parts of copper 

 per million were decidedly stimulating to tomato plants. The extreme care in 

 purification resulted in the relative absence of boron, the results of which were 

 visible on the meristem of all tomato plants. One or more parts per million 

 of copper were decidedly toxic to tomato plants, a? were also ten or more parts 

 per million of zinc. 



Distribution of Nitrogen in Soils Mixed with Different Plant Tissues 

 and Allowed to React for Two Months. (Walter S. Eisenmenger.) Tobacco 

 planted in rotation with corn or timothy is frequently subject to brown root-rot, 

 while tobacco following tobacco and certain weeds, such as ragweed and horse- 

 weed, seems less susceptible to the disease. 



The ground tissues of tobacco, ragweed, horseweed, red top, corn, and 

 timothy were placed with soil in crocks in the greenhouse in quantities so 

 that each contained equal amounts of nitrogen. They were allowed to stand 

 for two months. 



It was found that the total nitrogen at the end of the reaction period was 

 higher for timothy, corn, and red top. 



In general, the water soluble nitrogen was higher for corn, timothy, and red 

 top. 



Nitrate nitrogen was higher in the crocks containing horseweed, ragweed, 

 and tobacco as was also amide nitrogen. 



Protein and ammonia nitrogen were higher in the crocks containing timothy, 

 red top, and corn. 



No particular relationship was indicated for alpha amino acid and humin 

 nitrogen. 



The object of the experiment was to attempt to correlate conditions obtained 

 in the field with those in the laboratory. 



Pasture Experiments. (William G. Colby.) The schedule of fertilizer 

 applications was maintained on the seven permanent pasture plots in Worcester 

 County. Mid-season observations showed that the greatest response was to 

 "complete fertilizer," although the response to nitrogen and lime was nearly 

 as great. In the applications of single elements, the greatest response was to 

 nitrogen, followed in turn by lime, potash, and phosphorus. In no case was 

 there abundant growth of white clover. Although treated for several years 

 with mineral fertilizers, none of the plots had established a really good pasture 

 sod. Either the soil fertility level had not yet been raised sufficiently high to 

 support the best type of pasture vegetation or some other mineral elements 

 necessary for plant nutrition were deficient. It is evident from these experi- 

 ments that the problem of renovating permanent pasture sods is still a live one. 



Pasture Breeding. (William G. Colby and Hrant M. Yegian.) Breeding 

 work with several common species of perennial pasture plants was begun with 

 the extensive collecting of seed from many old pasture fields. The superior 

 strains of this material supplemented with improved strains of the same species 

 introduced from other regions will constitute the basic stock to be used for 

 extended breeding operations. 



