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University of California Publications in Agricultural Sciences [Vol. 3 



spaced. The final number of plants varied, but was almost always six. 

 An attempt was made to reduce at least partially the shading and 

 exposure effects. The pots were periodically changed from position 

 to position on the bench. 



The total dry weights produced on the several soils are interesting 

 (tables 73-78, and fig. 33). The grains gave more uniform results in 

 this crop than in the first. Soils nos. 14 and 23 show the best crops, 

 and they are the ones that have the highest amounts of total nitrogen. 

 The legumes selected must have been particularly well adapted to the 

 growing conditions and the soils, because the growth was enormous. 

 In the amount of dry matter produced the parallelism between the 

 two legumes from soil to soil is close. It is noteworthy that soil no. 14, 



Wheat 

 Bur Clover 

 Oats 

 ^N^Melilo+us 

 2g Darle^ 



Fig.3£ 



Fig. 32. Graph showing the total dry matter produced by barley, wheat, 

 oats, rye, bur clover, and Melilotus indica on the eight samples of San Joaquin 

 sandy loam. First and only crop. 



which showed the highest total nitrogen and produced the most dry 

 matter from the grains, gave the poorest crop of legumes. The notes 

 taken during the growing period show that the relative appearances 

 quite early and throughout the period of growth are usually a good 

 index to the relative amounts of dry matter produced. This is so, 

 even though the photographs of the mature plants do not show dif- 

 ferences nearly as great in magnitude as do the dry weights. 



This type does not show any marked tendency for the several soils 

 to approach a more uniform crop producing capacity through being 

 kept under the same conditions. In fact, the second crop shows 

 greater variations than the first. And this type does not show that 

 these nine soils, mapped under a single type name, are closely similar 

 to one another in crop producing power. 



