Effect of paper mulches on soil temperature, soil moisture and yields of certain crops

Abstract

The writer, discussing the results of other workers, notes that the most general use of mulch paper at present is in the Hawaian pineapple industry, where an asphalt-impregnated, non-perforated black paper is used and ammonium sulfate is applied both before and after the laying of the paper. The investigations described here aimed rather at testing the effect of soil temperature and moisture of different types, grades and colours cf paper. Separate trials were made each year from 1925-1928. In 1925 the paper was used without any crop at all. In 1926 a grain sorghum was used as indicator, in 1927 and 1928 potatoes. It was found that on a brown loam soil at Davis, California, during the dry season, under unirrigated conditions, the non-perforated black paper was the most effective for conserving moisture in the surface 4" of the soil, this being due to condensation underneath the paper. Soil temperatures were raised by black, reduced by grey papers. Under perforated paper the temperatures were the same as or lower than in the unmulched plots. Weeding was necessary where the perforated types were used. Both crops gave a slight increase in yield, but the author does not think the use of any type of paper at the present time under Californian conditions an economic proposition. Source: CAB