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and appeared to lack both nitrogen and water. Puddling very seriously 

 interfered with root growth. In one set of cultures, after incorporation 

 of the alfalfa which underwent anaerobic decay in the subsequently 

 puddled soil, the soil was allowed to dry thoroughly after planting; 

 the growth was very poor. The unfavorable soil condition prevailed for 

 a period of three months, as evidenced by unsatisfactory development 

 of a second crop sown after that length of time. The results were at- 

 tributed to the persistence of toxic products of anaerobic decomposition. 

 These authors stated that "the productivity of puddled soils may be 

 seriously reduced by the incorporation of organic matter while the 

 puddled condition still exists" and, "in utilizing organic matter in the 

 rebuilding of soil structure productivity may be lost, even though the 

 structure is regained, if proper precautions are not taken in the use of 

 organic matter." 



Unsatisfactory response of tomato plants was obtained with treble 

 superphosphate and both ammonia and nitrate nitrogen additions to 

 puddled soils as compared with the same additions to the same soils in 

 the unpuddled state. The effect of the puddled soil condition on nitrifi- 

 cation (iy) has already been mentioned. In the opinion of these inves- 

 tigators, lack of adequate aeration in the alkaline calcareous soils of 

 Arizona may produce a deficiency in carbon dioxide with the resultant 

 formation of normal carbonates and hydroxides. Plant growth is then 

 affected by an unfavorable pH which produces a phosphate deficiency. 



In other experiments McGeorge and Breazeale examined phosphate, 

 potassium, and calcium uptake by means of Neubauer tests with rye. 

 It was found that soil puddling reduced the availability of these nu- 

 trients. 



Interpretation by Gorbunov of his experiments with nonreplaceable 

 potassium (j6) involves a relationship between soil structure and the 

 availability of this element. Gorbunov estimated the amount of replace- 

 able potassium in potassium-saturated samples of chernozem soils and 

 a podzol clay by electrodialysis. Except for a control, the materials, 

 after saturation and before electrodialysis, had been previously dried 

 for 18 hours at different temperatures (40-105 C.) and, presumably, 

 with different degrees of completeness thereby, before re wetting and 

 maintaining wet for 72 hours. The electrodialysis which followed 



