They were then allowed to rest on a wire screen until gravitational water 

 had drained away. One thousand grams of each moist substance were then 

 used in a test of their power to retain water against air drying. Each mass 

 of moist material was wrapped in polyethylene film with a ruler protruding 

 from one end to simulate a plant stem and the possible loss of moisture 

 through this seal. The results given in the upper part of Table 10 show that 

 at the end of 13 days the peat retained more water than the bark. Also the 

 old bark retained more water than the new bark. 



The four shredded barks were tested for water loss in an oven to deter- 

 mine differences in rate of v/ater loss at high temperature, also differences 

 in water holding capacity on this basis. For a sample, 400 grams of water- 

 soaked bark were used after drainage of gravitatural water. Samples were 

 placed on paper squares in an oven at 80° C. Periodic weights were taken for 

 one week, as presented in the lower part of Table 10. Thus it is shown the 

 old bark had a much greater water retaining capacity than the new. 



To test the effects on survival of living plants, nine rose plants were 

 packed with each kind of bark and with peat. Polyethylene film was wrapped 

 around the packing material. After the plants had been wrapped for a week 

 and stored in a 60°F. greenhouse, observations were taken. For the first 

 ten days the shredded bark kept the plants as healthy looking as did the 

 peat. After the second week, the leaves of the old softwood treated roses 

 showed a very slight wilting. At the end of the third week the peat-wrapped 

 roses showed only a slight wilting while the old bark roses were quite wilted. 

 Those in new shredded bark showed slightly more wilting than those in 

 peat, but still looked vigorous. The above tests indicate that shredded bark 

 may be used to good advantage as a moisture-holding packing material for 

 shipping or storing live plants. 



Part II Field Plots 



In order to determine the possible use of waste bark for improving field 

 crop production, a field experiment was started on a plot of moderately 

 level land in Madbury, New Hampshire. The soil type was Bamstead fine 

 sandy loam and very uniform in texture. Soil samples showed an average 

 pH of 5.2 and nutrients were present only in traces or were entirely lacking. 

 The total area, 140 feet x 300 feet, was divided into 30 plots 20 feet x 

 70 feet each. The treatments for the different series were: 



1. No organic matter (control). 



2. Manure, 1.5 tons per plot. 



3. Old softwood bark, 120 cu. ft. per plot. 



4. New softwood bark, 120 cu. ft. per plot. 



5. Old hardwood bark, 120 cu. ft. per plot. 



6. New hardwood bark, 120 cu. ft. per plot. 



Each treatment was replicated five times in a randomized block design. 



Five different crops were grown, as follows: (a) potatoes, Yampa the 

 first year, and Kennebec the second year; (b) squash, Baby Blue; (c) 

 beans, Jacobs Cattle; (d) bachelor button, Centaurea cyanus; and (e) 



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