97. 



. I-er cent of clay in various soils. 



Generally we can say th*.-.t clay forms, in; 



ry sandy soil, about 1-3- 

 Ordinary sand 3"1^/ 

 loom 10-1 1//'. 

 Clay loam 15-25/ 



'-I' . Is 2i>-3. 



heavy clays 35*4 5/.< 



v*;ry lev soils in I over J>0/ . '*'he 



lass than 30; of clay. Heavy adobe clays 



of the . lands of 'yoming, Kan- 



s and Texas arc very hoAvy clays; they look loke organic matter and 



Lu. , , *t arc ro-'.lly clay. 



;_. oinuB content of v?rrio^ ID. 



.11 the organic matter in the soil, t'ost soils con- 



'.n soruc organic jaat oriels, In clay lands a larger amount of humus is 

 required to produce any effect than in sand land, In clay land there 



.us; s:\ndc ar-...- ,;oud with lialf t.l .ourt 



or l-3/' A ci 11 can, or, take care of as much aa 10-1^ of 

 Jiout : Eiuck; 8/ of hu. --Jces t I mucic soil. ?ree 

 sk suffer on ov^-r 1^ of muck, therefore pe^t soils do riot raise good trees 

 k l.Pat f-.icl may cc ,,, or less of organic material* 



ju iiust soils. 



jnt soils are very interesting to t)ie forester. Such are the 

 3 and putty soils of the .loath, and 30 e of tiie ;jl- ; ?cial 



... They are regular milky rivers, formed from the finest 

 ;e soils are lar.je aiiiOjnt of vor^; uniform fine silt forming 

 ervious eoil, due to the property it possesses of pack- 

 iiiij i or into a very coherent inasa on account of the fineness and 

 unif c . of the particles. Cypress ponds of the south with cypress 



are due to t of t*= I ..*o uniform silt pr event- 

 running of water, 



.e following of a putty soil is given from Hilgard 



Soil separates ^iam. 



Sand 0.1- 0.1> 44 * characteristic 



silt () 0.070 7 



" (b) 0.050 



(c) 0.036 b.5 



(a) 0,025 this 



11 (e) 0.016 18 -*odd thing in soil 

 Clay 7-5 



The?e duRt or putty soile behave very ciuch like heavy clay, tho 

 7 contain t'sunh n^nd wnd little clay. Iliey aro very aifficult to plow, 

 y become impervious in spite of tillage, and act like putty. If till- 

 ;>ecome like extremeiy )in.rd clods. They occur often in pine lands 

 and ai-v very rich in t)\e finer 



Kardpan in California and otlier places underlies snnay loams. 

 Tni? ImrdpB.ri oet ircperviou^ to water, nnd when dry is as hard as a 

 rock. It is rich in the finest silts, and lacks clay. An analysis of a 

 haroonn is ^iven at the top of tho next p^ . 



