KEVIKW OK rUV. HOOK 299 



humus tn:iy be a <letMilc<l dinnilvantn^o. Cull ntti'iition to the fact 

 thiit in vory wiinly rt'^'ioiis the soil tuny l>o nunie no loose aiiti 

 open nixl Hue as to bo exposol to niuoh ilntun^ro by wimiH. In 

 new countries hnmiis may bo nioi-o abiuuiant than in olil litnda: 

 whyf Are tlie lands in your tn'i;.'hbo:hood in need of liumnsf 

 IlluHtrate when green-crops Hhould be plowed under for the piir- 

 po!«u of piviiiu the best results. Whnt is the danger of plowing 

 them under too late in tiie season (7l»i'f 



Explain what drainaijo is. What is surface drainajre and 

 under-tlraina;;ef How mny surface drains bf constructed so as 

 to interfere least with airricultnral operatioii>f What efffct has 

 nnilerMlrainn;;e on the soilf What efTt-et dots a warm shower in 

 spring hare on land that is perfectly drained f What effe "t dois 

 • eoni summer shower havef Explain sonio of tho practices of 

 tile driining, as to depth of drain, distance apart of the different 

 drains (7(ia, 7«!'»). What ndation does unilcr-drainago have to 

 tap-rooted (dants (?'*«) f What is mi-ant by the "soil r<'s»'rvoirf " 



How doi's tilla^'e enable the soil to hold nioistur»'T How docs 

 increaning the capillarity increase tho nioistiire-hoMing capacity? 

 What is the general direction of tliH movement of n)oisture by 

 means of capillary attractionf May soil be made too fine! What 

 is meant by "pmldling" of soils f 



What is meant by the "conservation of moisture!" How does 

 moisture escape from tho land? What is meant by the "surface 

 mulch " or the "soil-mnlchT " About how much wafer is required 

 to produce a pound of dry matter (81^ if How does tillage save 

 the nioisturi-f 



Explain i \) the general direction of movement of soil water 

 iTi the growinir a«'ason ; ("J) how tho moiifnre-holding capacity of 

 tho noil may be iiii-ri>aiitMl ; ( .1 \ how Kurfacc evaporation may be 

 leHScned. 



Chapttr ./ 



Tho tillapf of the sdH may now \>o con- 

 siilero*!, for wo liavo lonruo<l how iiiinortniit 

 tlio physical condition of tlio soil is, ain! also 



