4 CIRCULAR 77, U. S. DEPARTMENT OF AGRICULTURE 
Pending further investigation, the validity of this relationship may 
well be assumed in the use of paper mulch with crops in temperate 
climates. 
APPLICATION OF MULCHING PAPER 
PAPERS 
There are at present two general types of mulching papers used 
during the growing season. These types are based on durability. 
Papers made for use with a single crop are designated as type A, 
while those made for use with two or more crops or for home gar- 
dens are designated as type B. 
The type-A papers comprise those suitable for annual crops in 
field culture. They are designed to last as long as or somewhat 
less than the period during which the crop plants are in the field. 
The type-B papers comprise the papers suitable for perennial 
crops in field culture, for a succession of annual crops in field cul- 
ture, and for all home-garden purposes. They are appreciably 
stronger and more durable than the type-A papers. The paper that 
is used in pineapple culture is of type B. 
METHODS 
There are at present three principal methods of applying paper: 
(1) The placing of small squares of paper at regular distances, (2) 
the use of extended strips of paper with alternate uncovered soil 
areas of approxi- 
mately the same 
extent, and (3) the 
use of paper in 
strips without any 
uncovered soil ex- 
cept that exposed 
FIGURE 1.—Method of applying small squares of paper mulch incidental BOs b . 
as used with certain vine crops in field culture ’ establishment of the 
: = crop plants. 
In the first method as apphed to the growing of such crops as. 
muskmelons, watermelons, cucumbers, squashes, etc., sections 3 by 3 
feet were cut. from 36-inch rolls of type-A paper. Holes of suitable 
_Size to permit field seeding or transplanting were then cut in the 
- center, and the sections then were placed in the field. The seeds were 
planted just before the paper was placed over the prepared seed bed, 
or at any subsequent time. The best results were obtained, however, 
when the application of the paper was made before the seeds germi- 
nated. ‘Transplanting into the field before the laying of the paper 
gave better results than transplanting through holes in the paper, as 
in the latter case it was difficult to firm the soil about the plants. 
The mulch-paper sections were made to’ hold “hot caps” in place 
when these were used. The type-A papers used in the above manner 
should be about disintegrated at the time of harvest. If they still 
remain intact, it indicates that a less durable and less expensive paper 
might be as effective. This method is outlined in Figure 1. 
in the first method, as applied to the establishment of fruit and 
nut orchards, vineyards, shade and forest trees, etc., sections 3 by 3 
feet were cut from 36-inch roils of type-B paper. Cross-shaped slits 
