WASTES IN RELATION TO AGRICULTURE AND FORESTRY 



11 



can adversely affect production of a succeeding 

 crop. 



Although problems pertaining to the handling 

 of crop residues may not be regarded as top pri- 

 ority, new and better information is needed to 

 economically handle these wastes without detri- 

 mental side effects. 



Trash in Forests and Forestry Operations 



Twenty-five million tons of logging debris are 

 left in woods during the average year. This is a 

 reservoir for tree diseases and insects. It is also 

 an exceedingly serious fire hazard. The average 

 size of forest fires originating in logging waste 

 is more than seven times that of fires originating 

 in uncut areas where trash has not accumulated. 

 Average annual losses from forest fires are $600 

 million. In the average year, wild forest fires pro- 

 duce 160 cubic miles of smoke, 34 million tons of 

 particulates, and 338,000 tons of hydrocarbons. 

 Forest burns have excessive runoff and very high 

 sediment delivery. They contribute to flood 

 damages. 



The trash and deadwood from elms killed by 

 Dutch elm disease and oaks killed by oak wilt 

 must be destroyed or treated to prevent vector 

 transmission of the disease to healthy trees. 



At the present time, research has produced 

 no economically feasible technique to dispose of 

 forest trash en masse other than by controlled 

 burning. Chipping is useful in isolated instances. 



Research needs to be expedited towards the im- 

 provement of techniques for controlled burning 

 that reduce atmospheric contamination. All pos- 

 sible effort must be allocated to research that would 

 aid in reducing the incidence of wild fires orig- 

 inating in forest trash. 



Processing Wastes 



Oxygen-demanding wastes from processing of 

 agricultural and forestry products include runoff 

 or effluent from sawmilling; pulp, paper, and 

 fiberboard manufacturing; fruit and vegetable 

 canning; cleaning dairies; slaughtering and proc- 

 essing of meat animals; tanning; manufacturing 

 cornstarch and soy protein; sugar refining; malt- 

 ing, fermenting, and distilling; scouring wool; 

 and wet processing in textile mills. These wastes, 

 on entering a stream, greatly increase the demand 

 for oxygen. They may make the water unsightly, 

 unpalatable, and malodorous. 



The oxidative requirements of the effluent from 

 the woodpulp, paper, and paperboard industries 

 exceed those of the raw sewage from all of the 

 people in the United States. 



In a year's time, the canning industry produces 

 effluent with oxidative demands that are double 

 those of the raw sewage from Metropolitan De- 

 troit; the meatpacking industry, double those of 

 Metropolitan Chicago; and the dairy industry, 

 four times those of Metropolitan Boston. 



Research has contributed to the abatement of 

 processing wastes by (a) developing a commer- 

 cially useful product out of that which had been 

 a waste — the manufacture of insulating board 

 out of sugarcane bagasse ; (b) improving the pro- 

 cedure so that less wastes are produced — a new 

 polysulfide modification of the kraft process of 

 pulping results in greater pulp yields, less waste, 

 and reduced air and water pollution; and (c) de- 

 veloping methods of waste treatment before dis- 

 posal in stream — development of oxidative lagoons 

 for potato-processing wastes. 



Because of the tremendous contribution of 

 processing wastes to the oxidative demands on our 

 streams, it is obvious that research on farm and 

 forest products should be enhanced by every means 

 possible to give much greater emphasis to (1) 

 developing useful products out of materials that 

 are now considered wastes ; (2) developing and im- 

 proving processing procedures that lessen waste 

 production; and (3) improving techniques for 

 processing waste treatment. 



Dilution of Organic Wastes in Streams 



Depletion of dissolved oxygen in a stream is 

 conditional upon the load of oxygen-demanding 

 wastes added to a stream and the amount of 

 streamflow available to waste assimiliation. Low 

 flows in late summer and fall in many rivers and 

 streams may be only one-fifth or one-tenth the 

 average annual. Capacity of the stream to as- 

 similate organic wastes is concomitantly affected. 

 Hence, river basin planners must give major em- 

 phasis to operational plans that would minimize 

 low flows. This will involve both structural and 

 land treatment measures. Forest management and 

 land treatment can affect water yield and abate 

 low flows, but structural measures will undoubted- 

 ly have the major influence. 



In view of the major emphasis being given to 

 comprehensive river basin planning at this time. 



