BARNYARD, STABLE, GREEN MANURES 89 



weight may give as much or larger returns than fresh manure. There 

 are, however, only a few conditions under which its use can be superior 

 to that of using fresh material. The rotted manure may be used for 

 intensive crops when availability is important, and especially on land 

 where weeds, entailing hand work, become a serious problem. In fresh 

 manure the weed-seeds that may have been in the feeds are likely to be 

 largely viable, and give rise to trouble in the field. Thorough fermenta- 

 tion generally destroys the viability of weed-seeds in manure. 



To Which Crops Should Manure be Applied? Next to tune of haul- 

 ing may be considered the crops to which manure can be most advan- 

 tageously applied. Direct applications of fresh manure are thought to 

 be injurious to the quality of tobacco, to sugar beets and to potatoes. 

 It should, therefore, not be applied to these crops directly. It may be 

 applied to the crop preceding, or decomposed manure may be used. As 

 a rule, manure should be applied directly to the crop in the rotation 

 having the longest growing season, or the greatest money value. For 

 example, in a rotation of corn, oats, wheat and mixed grasses, corn not 

 only has the longest growing season, but also the greatest food and cash 

 value. It is, therefore, considered good practice to apply the manure 

 directly to the corn. Since the benefits of manure are distributed over 

 a number of years, the crops which follow will benefit by its residual 

 effect. 



To What Soils Should Manure be Applied? Character of soil may 

 also determine where the manure should be applied. If mechanical con- 

 dition is a prime consideration, fresh manure may be applied to heavy, 

 clay soils and well-rotted manure to light, sandy soils. On the other 

 hand, the sandy soils in a favorable season are more likely to utilize coarse 

 manure to advantage than heavy soils. In such soils decomposition will 

 proceed more rapidly, thus rendering available the plant-food constituents 

 of the manure. On sandy soils manure should be applied only a short 

 time before it is likely to be needed, in order to prevent the danger of loss 

 by leaching. On heavy, clay soils the benefits from applying fresh manure 

 are likely to be rather slight the first year, because of slow decomposition 

 of the manure. This, however, is not serious, because in such soils the 

 plant food as it becomes available is held by the soil with little or no 

 loss. 



Climate Affects Decomposition. Climate may also be a factor in- 

 fluencing the use of fresh manure. In a warm, damp climate it matters 

 little whether the manure is fresh or well rotted when applied. Under 

 such conditions decomposition in the soil is sufficiently rapid to make 

 fresh manure readily available. The character of season may also be a 

 factor determining the relative merits of fresh and rotted manure. In 

 a very dry season excessive applications of fresh manure show a tendency 

 to burn out the soil, and this is more marked in light, sandy soils than in 

 the heavy soils. Furthermore, heavy applications of strawy manure 



