98 Commercial Gardening 



and many years of cultivation to induce such a soil to bear even reason- 

 ably good crops. The very worst soils can be brought into a state of 

 fertility in time, but it will never pay the commercial horticulturist to 

 waste his time upon them. 



A man need not be a chemist to be able to distinguish the differences 

 between a sandy, loamy, peaty, chalky, or clayey soil, and although each 

 one contains essential plant foods in varying proportions it would be a 

 mistake to assume that they are all equally valuable or available. 



These remarks relate chiefly to the soil when it is to be worked in 

 a natural condition by the grower of fruits, flowers, and vegetables in 

 the open air. Although the grower under glass is not hampered so much 

 with the natural soil and the weather, it is nevertheless to his advantage 



O 



to select the best possible soil on which to erect his glasshouses, espe- 

 cially if he intends to embark on the culture of such crops as Grapes, 

 Tomatoes, Cucumbers, Peaches, Nectarines, or any other crop which is to 

 root in the natural soil. For Melons, Ferns, Cyclamen, Chrysanthemums, 

 Carnations, Bulbs, Zonal Pelargoniums, Heaths, Marguerites, Roses, and 

 many other crops, soils have to be brought in and mixed in various 

 proportions before use. The labour and expense of these operations are 

 great, in addition to which large sums have to be spent on the erection 

 of greenhouses and heating apparatus, the purchase of pots, &c. 



4. HOW SOILS HAVE BEEN MADE 



It is from the sedimentary, organic, and igneous rocks that the farmer 

 and gardener obtain the soil in which to grow their crops. When these rocks 

 have been broken down into small particles and mixed in various propor- 

 tions with organic material, they are capable of yielding up certain foods 

 to plants with a proper supply of moisture and at a certain temperature. 



The various rocks have been converted into soil by natural and artificial 

 agencies. Amongst natural agencies the most important are the gases of 

 the atmosphere, water (including rain, rivers, streams), wind, heat and cold 

 (frost and snow), and vegetation. Amongst what may be called artificial 

 agencies are the cultural operations of man ploughing, digging, hoeing, 

 harrowing, and manuring. 



The natural agencies may be embraced in one word, " weathering ", and 

 the cultivator should impress upon his mind what important and powerful 

 friends he has in them. The action of the weather rain, frost, snow, sun- 

 shine, wind never ceases; it is wearing away the face of the hardest rocks 

 and flints, as well as the surfaces of cultivated soils, both day and night, 

 and bringing them into a more fertile condition. This important work 

 costs nothing, but how many realize that it is always going on! 



It may be as well to consider the individual action of each of the natural 

 agents. 



Water. Whenever rain falls it brings down a small quantity of 



