46 MISC. PUBLICATION 4 3 4, U. S. DEPARTMENT OF AGRICULTURE 



elm appeared more tolerant of alkalis but was adversely affected where 

 total soluble salts constituted 8,160 pounds per acre or 2,380 parts per 

 million (table 9). 



Table 9. — Comparison of 1-0 nursery stock from alkali and nonalkali portions of 



tree nurseries i 



Measurement 



Green ash 



From 



normal 



areas 



From 

 alkali 

 areas 



American elm 



From 



normal 



areas 



From 

 alkali 



Length of top 1 inches.. 



Length of root do 



Diameter of stem do 



Oven-dry weight of tops grams.. 



ven-dry weight of roots do 



Oven-dry weight of total plant do 



Estimated cull stock 2 percent. _ 



10.2 

 11.6 



1.38 



1.89 



3.27 



20 



3.3 

 9.2 

 K* 



.18 

 .25 



16.2 

 13.3 



4.35 



4.73 



9.08 



15 



9.2 

 10.1 



1.24 

 2.07 



' Averages of 10 plants selected at random. 

 2 This figure based on all trees in each area. 



Tests made by the junior author on recently germinated seedlings in 

 pure solutions of sodium sulfate and also sodium carbonate indicated 

 that Russian-ohve, desertwillow, honey] ocust, and Siberian elm were 

 the most alkali tolerant of some 20 species used commonly in shelter- 

 belt planting in the prairie plains. The tests would indicate that, in a 

 nursery where the alkalinity occurs only in certain blocks, the more 

 alkali-tolerant species might have more chance of survival in the 

 alkali portions of the nursery. Besides the above, it is certain that 

 the salt cedar is also one of the more alkali-tolerant species. 



What happens chemically to the plants on alkali spots is indicated 

 in an analysis made of chlorotic and nonchlorotic seedlings in two 

 nurseries (table 10). In both nurseries content of nitrogen, magne- 

 sium, sodium, sulfur, and chlorine was higher in the alkali-sick seedlings 

 and iron content was considerably lower. At Pierre, S. Dak., phos- 

 phorus content was lower in the trees from the alkali area. "Iron 

 hunger" is a direct cause of the yellowing of the foliage termed 

 "chlorosis." Lack of available iron interferes with photosynthesis, the 

 formation of chlorophyll, and the manufacture of food in the leaves. 

 With the normal metabolism of the plant thus upset, the result is a 

 puny, off-color seedling. 



Table 10. — Chemical content percent of seedlings from, portions of forest nurseries 

 in South Dakota of variable salinity ! 



Nursery, species, and con- 

 dition of seedlings 2 



Nitro- 

 gen 



Phos- 

 phorus 



Cal- 

 cium 



Magne- 

 nesium 



Sodium 



Man- 

 ganese 



Sulfur 



Chlo- 

 rine 



0.790 



0.171 



0.481 



0.165 



0. 0249 



0. 0011 



0.214 



0.033 



1.315 



.142 



.547 



.274 



.0278 



.0014 



.292 



.041 



.815 



.079 



.675 



.176 



.0227 



.0007 



.193 



.052 



1.150 



.083 



.850 



.218 



.0238 



.0008 



.202 



.064 



Iron 



Pierre, S. Dak.: 



Vigorous green ash 



Stunted and chlorotic 



green ash 



Midway, S.Dak.: 



Vigorous American elm. 



Stunted and chlorotic 



American elm 



0.0456 

 .0206 

 .0480 



1 Analyses by Soils Department, University of Wisconsin, using standard quantitative methods, with all 

 values expressed in percent. 



2 All stock 1 year in seedbed. 



