80 BULLETIN 47'.), V. S. DEPARTMENT OF AGRIOTjLTtfBE. 



Two classes of fertilizers may be distinguished: "Complete" fer- 

 tilizers, which contain all the important elements necessary for plant 

 growth, and "incomplete" fertilizers, which furnish only one or 

 more of these elements. 



COMPLETE FERTILIZERS. 



Stall manure, consisting of the animal excrement and the litter on 

 which it is found, is a very effective fertilizer, not only because it 

 contains the most essential plant foods — nitrogen, potassium, and 

 phosphoric acid — but because it improves the physical qualities of 

 the soil and by numerous microorganisms increases its activity and 

 fermentation. Sheep and horse manure are richest and decompose 

 rapidly. Cattle manure decomposes less rapidly. The former is best 

 for application to compact, the latter to loose soil. As manure is not 

 usually to be had in sufficient quantities at a nursery and is often 

 difficult and expensive to obtain, it is frequently used in compost. 



Where humus can be obtained it has been found to be excellent, 

 both as a fertilizer and for its effect in improving the physical 

 quality of the soil. 



The value of compost as a fertilizer is decided by the material 

 entering into it and the treatment given compost heaps. Organic 

 substances of every kind may be used for this — weeds, raw humus, 

 turf, and even street sweepings. To this material is added quick- 

 lime for more rapid decomposition and horse manure, in layers. 

 Ashes may also be used to strengthen it. "Weeds hoed from the 

 nursery mny be used alone for compost. In such cases it is neces- 

 sary to mix them in thin layers with quicklime, allow the heaps to 

 remain untouched for some time, and then stir repeatedly. When 

 thoroughly decomposed it is ready for use. 



One of the German head foresters gives the following formula 

 for making good compost: The first layer, about \ inch thick of 

 organic substances, grass, heather, weeds, sawdust, etc., is sprinkled 

 with a thin layer of unslaked lime, then another layer of grass and 

 weeds is added, then a layer of lime, etc. In this manner it is heaped 

 up like charcoal but shaped broader and lower so as to catch the 

 rain, and then covered on all sides with carefully crushed earth. 

 The slaking of the lime begins after a few days and in from 2 to 4 

 days later is completed. During this time the heaps should be 

 examined twice a day and all crevices in the earth covering closed in 

 order to keep the heat, steam, and ammonia from escaping. After 

 from 4 to 6 weeks the material is ready for use. 



