320 ILLINOIS STATE ACADEMY OF SCIENCE 



TABLE 2. 



Percent phosphorus recovery from Tennessee rock phosphate and 

 double acid phosphate after different soils were treated with these 

 substances in proportion of 4 mgs. of phosphorus per 25 gms. of soil; 

 fifth normal nitric acid was used for extraction. 



Percent 

 Phosphorus c 



Recovery , o 



Description of soils. |S *| |_§ | ^ gjj" 



K§ c O 2ts CS° C33 = ^£ 



• S Z OpL, O^-ft > + £w £0,S 



ra £ fe Q Q <J 



PRAIRIE SOILS. 



1 Brown silt loam 7729 45.5 48.3 — 2.8 7.84 11.4 



2 Brown silt loam passing 



into yellow clayey 



o iT-n 11 "i V*" ":£L 7730 35.3 36.8 — 1.5 2.25 11.4 



3 Yellow clayey silt with 



A T3 tU1 "mVi 7 ?31 0.2 0.0+0.2 .04 0.2 



4 Brown silt loam 7741 55 2 61 5 Zq .3 39.70 10.6 



5 Brown silt loam with 



some yellow ........ 7742 47.7 47.7 0.0 10.7 



6 Yellow clayey silt with 



some brown 7743 43 5 44.2—0.7 .49 11.3 



7 Brown silt loam 7765 502 49 2 +10 100 n . 3 



8 Brown silt loam with 



some yellow. 7766 37 7 33 5 +4-2 17.64 11.2 



9 Yellow clayey silt, more 



m -o, sil , ty , witl ? depth. 7767 42.5 41.5 + i.o 1.00 11.0 



10 Black clay loam to dark 



„ t. br ,° wn .; • V 7840 66.3 65.8+0.5 .25 12.4 



11 Drab to black clay loam 7 g4i 66 . 64.5+1.5 2.25 12.6 



12 Yellow to brownish yel- 



low and drab clay... 7842 53.0 53.8 — 0.8 .64 11.9 



13 Black clay loam with 



some sand 7825 58.0 55.7+2.3 5.29 12.2 



14 Black clay loam, some 



gravel and sand 7826 49.5 50.0 — 0.5 .25 12.1 



15 Drab to olive colored 



clayey silt 7827 45.3 43.5 +1.8 3.24 11.8 



16 Drab clay loam, dark.. 7843 60.0 59 +1.0 1.00 10.0 



17 Drab clay loam, lighter 



at 12" 7844 56.7 65.0 —8.3 68.90 10.2 



18 Drab silty clay, pebbles 



and lime 7845 18.0 27.2 — 9.2 84.64 10.5 



19 Brown gray silt loam 



on tight clay 7801 61.5 68.7 — 7.2 51.84 9.3 



20 Gray silt loam 7802 58.7 58.7 +0.0 8.9 



21 Yellow to grayish clayey 



silt 7803 37.5 37.0 +0.5 .25 4.7 



22 Brown sandy loam 7849 66.3 67.2 — 0.9 .81 9.8 



23 Brown sandy loam, 



some sand 7850 56.8 53.5 +3.3 10.89 10.1 



24 Yellow sand, some silt. 7851 45.8 42.5 +3.3 10.89 4.2 



TIMBER SOILS. 



25 Yellow gray silt loam 



on gravel 7816 54.7 49.2 +5.5 30.25 12.0 



26 Yellow silt loam 7817 46.0 43.0+3.0 9.00 11.9 



27 Yellow clayey silt, some 



gravel 7818 50.5 45.8 +4.7 22.09 11.8 



28 Yellow silt loam, brown- 



ish, gravelly 7858 70.5 68.5+2.0 4.00 10.6 



29 Yellow silt loam to 



yellow sandy loam.. 7859 63.8 66.8 — 3.0 9.00 11.4 



30 Yellow silt to gravelly 



sandy silt 7860 62.3 62.0 +0.3 .09 11.7 



31 Yellow gray sandy 



loam, some brown... 7S55 73.0 73.5 — 0.5 .25 12.0 



32 Yellow sandy loam, 



some gray 7856 68.7 73.2 — 4.5 20.25 12.1 



33 Yellow sand, little silt.. 7857 68.0 69.5 — 1.5 2.25 12.1 



