94. 



i. this is uuc- to 

 ;, clirar . 



effect is shown by 

 aa on the 



climate r- soil. Irrigation cor.ou in hen 

 iture . -ice versa. 

 cottonwood in 



i . 



Th~t soil does have 



vadi 



tho 



D) Relation of '/nrious noils to Tree Growth W ;ricultur . 



a.. Good no lot loam lands I ood for raising all the species 



.ro'nr i : :i f-li 1 i . Timber ood growth and reproduc- 

 tion. Vitli - >;ocd cli^nte nnd favorable topography such lands are nor- 



ly a^ricul: . .in nature they are stocked with hardwoods 

 until an aver iy temperature below ^'0 F, is reached, vhen they 

 ,o conifer, -,, in the nort 



JD. j'eavy olnys.iro hard for tl.e farmer to handle; they are 

 stron ; and endure. I'uch organic fertilizer is requirea to keep them 



. :hoy ar-.-' fair for forent. Hardwoods gro',v readily oven on Uie 

 hardest of clys, especially in Michigan and Ohio. But these lands us- 



.i cultural 



. Lean clays^ which arc derivative of shales, occur in iJ 



Carolina, arid luiv-: a fair growth of hardwoods, but often 

 o a ocrub ^ro^fth ' sc . and usually to a mixture of liardwoode 



ny nre nor really clay lands, but are soils in which 

 r si 1 t;i predominate and are really aificient in true clay. 



&. "-ands tend to pine. The coarser and leaner of ther-e sands are 



ed with scrub pi ;id other forms of ho.rd pinen. unly 

 oak ir. tiitj United otates coiapetcg aa a scrub on these snndy lands. They 

 arc ri cultural lands unless the climate and markets make certain 

 as po. , as intensive work for certain induatrien. They are 

 largely forcot lands. In arid districts the sands are not poor, but are 

 . ch chc,:dcally, bee of the Irxck of moisture to iSRCh the 

 a of the soil; irrigation trniasfornis tliese sands to fertile 

 soi ; . 



. Very dry soils raay be either poor sands, as in humid country, 

 or ari4? lands in dry country of deficient rainfall. 



. Swamps, or -et soils furnish a variety of conditions: 



1) Good clny or oilt soils, the boat of agricultural lands, 

 often stocked with normally big timber, largely hardwoods. Only in ex- 



ve cases do they tend to conjf- x, -/liidi then are cypress, cedr,etc 



2) Jluck soils, containing a jnodornte Amount of inor^nic con- 

 stituents, arid stocked with hardwoode. If organic material predominates 



;s these soils tend to pent; the h.'irdv/ocda recede and cedar, 

 id spruce coino in, in the United States. In the , lu v/orld 

 . ne roplacos t .-k, ^itJi "birch. 



U) History and Literature of ^oils and Soil Vtudy. 



idy ;. follov/ing topics: 



a. '.hat soils are made of. 



b. How they ars made. 



. uoil characters and qualities: chemistry, pliycics, biology, 

 fertility, arrangeioent and topography. 

 d. 3oil cover. Forest cover. 



