22 i. TALKS OX MANURES. 



and in the best manner. No weeds choke the wheat plants or rob 

 them of their food ; but that field does not produce as much wheat 

 by 30 bushels per acre as the season is capable of producing. 

 Why? The answer is evident. Because the wheat plants do not 

 find food enough in the soil. Now, anything that will furnish 

 this food, anything that will cause that field to produce what the 

 climate or season is capable of producing, is manure. A gardener 

 may increase his crops by artificial heat, or by an increased supply 

 of water, but this is not manure. The effect is due to improved 

 climatic conditions. It has nothing to do with the question of 

 manure. We often read in the agricultural papers about ' shade 

 as manure.' We might just as well talk about sunlight as ' ma- 

 nure.' The effects observed should be referred to modifications of 

 tlic climate or season; and so in regard % to mulching. A good 

 mulch may often produce a larger increase of growth than an ap- 

 plication of manure. But mulch, proper, is not manure. It is 

 climate. It checks evaporation of moisture from the soil. We 

 might as well speak of rain as manure as to call a mulch manure. 

 In fact, an ordinary shower in summer is little more than a mulch. 

 It docs not reach the roots of plants ; and yet we see the effect 

 of the shower immediately in the increased vigor of the plants. 

 They are full of sap, and the drooping leaves look refreshed. We 

 say the rain has revived them, and so it has ; but probably not a 

 particle of the rain has entered into the circulation of the plant. 

 The rain checked evaporation from the soil and from the leaves. 

 A cool night refreshes the plants, and fills the leaves with sap, pre- 

 cisely in the same way. All these fertilizing effects, however, 

 belong to climate. It is inaccurate to associate cither mulching, 

 sunshine, shade, heat, dews, or rain, with the question of manure, 

 though the effect may in certain circumstances be precisely the 

 same." 



Charley evidently thought I was wandering from the point. " Yon 

 think, then," said he, " manure is plant-food that tlie soil needs f" 



" Yes," said I, " that is a very good definition very good, 

 indeed, though not absolutely accurate, because manure is manure., 

 whether a particular soil needs it or not." Unobserved by us, the 

 Deacon and the Doctor had been listening to our talk. " I would 

 like," said the Deacon, " to hear you give a better definition than 

 Charley has given." "Manure," sikl^I, "is anything containing 

 an element or elements of plant-food, which, if the soil needed it, 

 would, if supplied in sufficient quantity, and in an available con- 

 dition, produce, according to soil, season, climate, and variety, a 

 maximum crop." 



