CROP PRODUCTION 



"Agriculture is an art that renders those who understand it rich, but 

 leaves those who do not understand it, however hard they may labour in 

 it, to live in poverty. 11 — Xenophon. 



SOIL CULTIVATION 



J. H. GRISDALE, Director, Dominion Experimental Farms, Ottawa. 



We cultivate our fields and sow our seed to produce crops. The quality and 

 quantity of our yields depend upon the strength and rapidity of the growth made by 

 the crop. The requirements of strong, rapid plant growth are (1) Moisture, (2) Warmth, 

 (3) Plant Food. 



Let us briefly consider these requirements and the extent to which they may be 

 controlled or influenced by the farmer through cultural or other farming operations. 



(1) MOISTURE 



The moisture supply depends primarily on precipitation. Precipitation, or rain- 

 fall, is, however, not controllable. It is necessary, therefore, to so handle soils as to 

 enable them to conserve or retain the moisture received until required for crop pro- 

 duction. 



Drainage a Factor in Moisture Conservation 



Several factors influence moisture conservation in soils. Of these good drainage 

 is probably the most important. Well drained soils are free from the danger 

 of baking or puddling, that is, they are friable and loose on the surface, so'j pre- 

 venting evaporation. Well drained soils being free from hydrostatic or free water to 

 a considerable depth are in shape to absorb rain as it falls and preserve it in the form of 

 capillary or hygroscopic water. It is only as capillary or hygroscopic water that 

 moisture can be retained for any length of time in the soil in dry weather, hence good 

 drainage is an absolute necessity where moisture conservation is a matter of importance, 

 just as it is an indispensable condition where seasons are short or rainfall very great in 

 order to carry off the surplus water and allow air to enter the earth to reach plant 

 roots and raise the soil temperature. 



Ploughing and Cultivating as Methods of Controlling Soil Moisture 



Shallow ploughing and deep cultivation are, after drainage, probably the most 

 important influences making for moisture conservation. Shallow ploughing by keeping 

 the humus near the surface greatly increases the moisture holding power of that, the 

 most important soil layer. Deep cultivation by stirring the lower stratum of soil 

 helps disintegrate the stiff and probably waterlogged upper subsoil, and so very greatly 

 increases the amount of capillary water readily available near the surface layer for crop 

 requirements. 



Surface Cultivation Conserves Moisture 



No matter what the condition of the surface soil and upper subsoil as influenced by 

 ploughing and subsoil stirring, no matter how well drained the lower subsoil, if no pre- 

 caution be taken to prevent evaporation, a very large amount of moisture is sure to be 



