Feb. II, 1918 Effect of Season and Crop Growth on Soil Extract 341 



Table VIII. — Crop yield of 191$ 



Soil. 



Yolo siltv clay loam : 



No. lA 



No. iB 



No, 2A 



No. 2B 



No. 3 A 



No. 3B 



No. 4A 



No. 4B 



No. 5 A 



No. 5B 



Yolo clay loam: 



No. 6 A 



No. 6B 



Hanford fine sandy loam: 



No. 7A 



No. 7B 



Fresno fine sandy loam : 



No. 8A 



No. 8B 



Kimball fine sandy loam : 



No. 9A 



No. 9B 



Te junga fine sandy loam : 



No. loA 



No. loB 



Madera fine sandy loam : 



No. iiA 



No. iiB 



Arnold fine sandy loam: 



No. 12A 



No. 12B 



Standish fine sandy loam : 



No. 14A 



No. 14B 



Average variations between 

 duplicates 



Total 

 yield of 

 air-dry 

 grain 

 and 

 straw. 



Gm. 

 2, 092 

 1,904 

 2,038 

 1,649 

 1,421 

 1,083 



1,331 

 1,187 

 1,863 

 1,742 



2, 287 

 2, 182 



1,115 

 1,059 



2, 136 

 2, 022 



I, 066 



1, 096 



1,401 



•1,337 



2, 020 

 2, 194 



796 



775 



1,364 

 1,359 



Gm. 



73° 

 73° 

 605 

 548 

 474 

 333 

 534 

 459 

 529 

 420 



739 



705 



432 

 363 



827 

 780 



405 



495 

 500 



742 

 774 



242 

 214 



390 



403 



Grain 



(pounds 

 per acre). 



5,614 

 5,614 

 4,653 

 4,215 

 3,646 

 2,561 

 4, 106 



3,530 

 4,069 

 3,230 



5,684 

 5,422 



3,323 



2, 792 

 6,361 



6, 000 



2,984 

 3,115 



3,807 

 3,846 



5,707 

 5,953 



1,862 

 I, 646 



3,000 



3, 100 



Grain 

 (bushels 

 per acre). 



93-6 

 93-6 

 77-5 

 70.3 

 60.8 

 42.7 

 68.5 

 58.8 

 67.8 

 53-8 



94-7 

 90.4 



55-4 

 46.5 



106. o 

 100. o 



49-7 

 SI- 9 



63-5 

 64. I 



95-1 

 99.2 



31.0 

 27.4 



50.0 

 51-7 



Variation 



from 



maximum 



yield of 



grain. 



Per cent. 

 II. 7 



II. 7 

 26. 9 



33-7 

 42. 6 



59-7 

 35-4 

 44- 5 

 36.0 

 49.2 



10. 7 

 14.7 



47-7 

 56.1 



5-7 



53-1 

 51.0 



40. I 

 39-5 



10.3 

 6.4 



70.8 

 74. 2 



52.8 



51.2 



Differ- 

 ence 

 between 

 dupli- 

 cates. 



O. O 

 6.8 



17. I 



9. I 



13-2 



4.0 



8.4 



5-7 

 2. I 



0.6 



3-9 

 3-4 

 1.6 



5-8 



In order to compare the two seasons' crops on a uniform basis and 

 also to allow for the mean and maximum difference in duplicates, all 

 results of the yield of grain have been calculated to the percentage of 

 variation from the highest yield. The figures given for the duplicate 

 containers have been substracted and expressed in a separate column. 

 The difference between soils 3A and 3B was the maximum, amounting 

 to 17. 1 per cent, while that of soils 5A and 5B was 13.2 per cent. The 

 mean figure given by the above was 5.8 per cent. These differences 

 have been expressed diagrammatically in figure 7. Here it is seen that, 

 by taking the maximum variation between duplicates as the standard, 

 soils 8, 11,6, and i have practically an equally high production. Soil 2 

 is significantly lower, and the others range lower, down to soil 12. 



