The Bulletin. 7 



all they need. As a result, artificial fertilizers, or commercial fertil- 

 izers as they are commonly called, have been introduced, and in many 

 instances their use has proved more advantageous than stable manure. 

 These fertilizers are different materials which contain some form of 

 ammonia, potash, or phosphoric acid, derived either from organic or 

 inorganic sources. Complete fertilizers contain all three of these prin- 

 cipal plant-food ingredients. When fertilizing material of this kind 

 is depended upon exclusively, the use of some soiling crop or other 

 source of vegetable matter becomes of the utmost importance in order 

 to supply the soil with a sufficient amount of humus. The use of 

 fertilizers alone, without the addition of plenty of vegetable matter, 

 will soon leave the land in an impoverished, unproductive condition. 

 As each particular crop requires a certain amount of the necessary 

 elements of plant food, and as most soils vary considerably in their 

 content of these elements in an available form, growers can learn from 

 personal experience the kind and amount of fertilizing material that 

 can best be applied for the production of their crops. 



ROTATION. 



Few people realize the amount of income that can be directly and 

 indirectly derived from the systematic planting and cultivating of their 

 land, particularly when devoted to the growing of truck crops. Too 

 often the planting ceases with the first crops sown, and when these 

 have been harvested, the fertile soil is either allowed to produce a 

 magnificent crop of weeds, or else remains idle until the following 

 season. The systematic rotation of farm crops has been advocated for 

 some time, the principal end in view being an improvement of soil fer- 

 tility. A well-planned rotation of truck crops brings about this same 

 result, and, in addition, accomplishes two other purposes : It affords 

 a possible increased income and, to a certain extent, it aids in the 

 control of certain insect pests and diseases. As a rule, most insects and 

 diseases attacking truck crops can be controlled by the application of 

 suitable poisons and chemicals in the form of spray materials. How- 

 ever, some of these troubles, particularly these diseases occurring in 

 the soil, are hard to control in this way. Rotation often proves the 

 only remedy in instances of this kind; hence the advantage of having 

 a well-planned system of growing the different crops. Insects and 

 diseases thriving on plants belonging to a certain family or class of 

 plants will often find the plants of a different family entirely unsuited 

 to their use. For instance, beets, turnips, and parsnips are seldom 

 affected with the same troubles that prove destructive to cucumbers, 

 cantaloupes, and watermelons, and vice versa. Here, too, a carefully 

 planned rotation often proves an effective means of control for these 

 various troubles. 



