THE SOIL AND ITS IMPROVEMENT 89 



bacteria. (5) Chemical clianges ■ are set up whicli are of 

 benefit to the soils and gardens. 



- The value of stable manure depends largely upon the care 

 with which it has been handled. The liquid manure should 

 all be well absorbed by litter. Manure which is saved for 

 future use should not be placed in large heaps to heat. The 

 heating destroys much of its value. Neither should it be 

 placed where much water, as from the roof of a barn, m.ay 

 wash out the plant-food ; the nitrogen, which is most expensive, 

 is lost^ quickly. 



Comijost. — Young gardeners should early learn to make 

 a good compost. By this means manure is allowed to rot 

 under very favorable conditions, and is in good condition for 

 use in gardens, flower beds, hotbeds and greenhouses. A com- 

 post heap is made by spreading a layer of barnyard manure, 

 then a layer of tough sods from a meadow, or a layer of leaves. 

 On each of these two layers is sprinkled some lime or .wood 

 ashes. The layers are repeated until the manure is all in a 

 compost. Rainfall will usually be sufficient to prevent the 

 compost heap from heating, and will allow the rotting to 

 continue gradually. The layers of sod or other fibrous matter, 

 such as leaves or straw, alternating the layers of manure, save 

 much of the plant-food from leaching out. 



Weed seeds, which are usually abundant in all stable 

 manures, are usually killed in a compost heap. During the 

 process of rotting the bulk of the manure heap is greatly 

 reduced during rotting ; the plant-food is unlocked ; the injur- 

 ious effect which fresh manure has on such crops as potatoes 

 is much reduced. Good gardeners usually keep a compost 

 heap in a comer of the garden ready for use at all times. 

 Fresh, coarse manure is often placed in the bottom and the 

 rotted portions of an old compost heap are thrown on top. 

 The coarse portions become rotted before they are needed 

 for use in the garden. 



