igSS The Cornell Reading Courses 



evaporation of moisture from the soil is hindered, all vegetation wall suf- 

 fer.^ The purposes of cultivation are several and differ slightly from those 

 of earlier soil working, generally called tillage. These purposes are as 

 follows : 



1. Conservation of soil moisture. The maintenance of a dust mulch 

 over the entire surface of the soil will effectively prevent excessive loss 

 of moisture and will also offer conditions that are favorable for the entrance 

 of rains. 



2. Aeration. If proper cultivation is given, the roots of the plants are 

 permitted much freer access to the air, which is essential to their develop- 

 ment. 



3. Modification of the soil temperature. The maintenance beneath 

 the surface mulch of a suitable amount of moisture tends to prevent wide 

 fkictuations in soil temperature. 



4. Improved physical condition. The improvement is due to loosening 

 of the soil, retention of the water, and aeration. 



5. Increased action by bacteria. This results from the improved physical 

 condition of the soil. Decomposition of plant-foods is hastened, thus 

 rendering them readily available. 



6. Prevention of erosion. With a good surface m.ulch the soil is enabled 

 to take up a larger amount of water than is possible if the surface is not 

 stirred. This prevents to a considerable extent the loss of soil particles, 

 humus, and valuable plant-food. 



7. Weed eradication. Weeds rob the soil of its moisture and plant- 

 food, thus removing essentials from cultivated plants. Above ground 

 weeds produce such strong growth that they tend to shade the useful 

 plant. A plant robbed below ground and above ground is soon dwarfed 

 and of very little value. 



It is impossible to follow any fixed rules in regard to cultivating the 

 garden; however, some suggestions are given here concerning the most 

 advisable time. In general the correct time to cultivate is when the soil 

 has dried slightly following a rain, although a very sandy soil may be worked 

 when rather wet. If heavier soils, such as silt or clay, are cultivated when 

 wet, puddling or the formation of hard clods results. Such soils will work 

 up more easily and better when they are dry enough to crumble. In case 

 the soil becomes hard, or a crust is formed before rain comes, the surface 

 soils should be worked in order to prevent evaporation of moisture. 

 Many good gardeners cultivate every week or ten days, thus assuring the 

 maintenance of a soil mulch and killing the weeds when they are small 

 and more easily kept in check. It is impossible to injure garden plants 

 by over-much timely and thorough cultivation. 



>Soil moisture and crop production. By Elmer O. Pippin. Cornell reading course for the farm, Vol. Ill, 

 No. 70. 



