54 Experiment Station Bulletin 363 



from the bare plots as from the rye plots. Thus, the advantages of grow- 

 ing winter rye in minimizing soil erosion and increasing the yield of po- 

 tatoes are grown continuously in an accelerated production program 

 were definitely indicated during the past season, the fifth in the sequence 

 of potato culture on the experimental plots. 



Topsoil-subsoil interrelations with soil fertility were studied in 

 greenhouse trials with Paxton sandy loam, a soil type valuable for potato 

 culture. That losses of topsoil and a mixture of subsoil by tillage proc- 

 esses may markedly depress yields is strikingly indicated in the following 

 table. 



*Yield represents average of two pots and consists of oven dry tops, including grain. 

 **N, equals 100 lbs. of nitrogen as 16% N-aNOg. 



P equals 400 lbs. of P^Oj as 20% superphosphate per 2,000,000 lbs. of soil. 



K equals 100 lbs. of K2O as 60% KCL. 



The effect is apparently greatest upon phosphate, inasmuch as the 

 topsoil phosphate reserve was initially limiting to a greater degree than 

 the topsoil nitrogen reserve. Chemical and physical studies of this same 

 problem are being carried forward in the laboratory, and field plots with 

 per cent, 50 per cent, and 100 per cent of the topsoil removed were 

 established this spring. 



L. T. Kardos 



The Influence of Soil Texture, Soil Moisture, and 

 Soil Aeration on the Growth of Plants 



Two soil types, a fine sandy loam and clay loam, were sifted into a 

 coarse fraction and a fine fraction. Plants of corn, barley, and tw^o va- 

 rieties of tomatoes were grown in these and in natural or unsifted soil. 

 Tomato and cabbage plants were grown in sand cultures of two tex- 

 tures. Cabbage plants also were grown in cinders sifted into two frac- 

 tions. Modifications of these with aeration and with additions of colloidal 

 clay and a hydrophillic, organic colloid, methocel (methyl cellulose) were 

 tested also. 



The yields of dry weights from corn and barley in soil were re- 

 versed in relation to each other, barely showing greater yield with clay, 

 while corn showed greatest with sandy loam. The sifted fractions with- 

 in a given soil type did not show outstanding differences. Apparently, 

 within the limits of these experiments, texture does not influence growth 

 of these grain crops materially. This is in agreement with results re- 



