Mulching 111 



eters placed in a strawberry field, part of which was 

 mulched and part unmulched. The temperature was 

 found to be from one-half to three and one-half degrees 

 lower over the straw than over bare ground ; the readings 

 were taken several times before sunrise. He concluded : 

 "In some instances there appears to be suflBcient differ- 

 ence in temperature to cause a frost on straw, while the 

 unmulched portion might escape." Many of the com- 

 mon mulching materials are full of weed seeds ; this is 

 one of the most serious objections to the practice. The 

 chief disadvantage of the winter mulch, however, is the 

 expense, amounting to five to fifty dollars an acre, ac- 

 cording to conditions. More growers are mulching now 

 than ever before, which indicates that the advantages 

 usually outweigh the disadvantages. 



MULCH MATERIALS 



The choice of mulch material is governed fully as much 

 by availability and cost as by adaptation for the purpose. 

 If wheat straw costs eight dollars a ton, the grower will 

 endeavor to find a cheaper substitute. Any coarse vege- 

 table material that will not pack so tightly over the 

 plants as to smother them may be used. 



Manure. 



In early years, the winter mulch was commonly of 

 strawy horse manure. Manure is so likely to be full of 

 the seeds of timothy, clover and various weeds that it is 

 rarely used now, except in the home garden or in small 

 fields under intensive culture. The weed difficulty may 

 be overcome, in part, by securing the manure in early 

 summer and turning it over several times before fall. 



