Sawdust system 'puts paid' to waste claims
By ELISABETH TACEY
A SAWDUST litter bed for pigs that saves money and effort puts paid to farmers' claims that meeting new rules on waste will be difficult and expensive, according to the Agriculture and Fisheries Department.
Researchers involved with the system accused farmers of having only political aims when demanding compensation for changing their pig-rearing ways.
In a standard concrete sty, fresh sawdust was scattered each day over the toilet area while keeping half the pigs' pens clear for them to stand and lie on. The simple system took the toil out of hosing down the sties and removed the environmental hazard, said department pig husbandry officer Lo Yuen-yin.
Fresh sawdust added each day or two days built up over the 20 weeks of the pig's growth before it was sent to market. The farmer did not even have to mix the sawdust with the rotting layers underneath because the pig liked to dig in the manure and would do the job itself, she said.
''They will turn it and help the decomposition process.'' Water from the pig's urine would evaporate and the dung would rot. The manure produced had no smell and was excellent for landscape gardeners or crop growers, Ms Lo said.
All farmers needed to do was have their pens in a well-ventilated building instead of a closed one, to aid the breakdown process.
Ms Lo had been working on the litter method at the department's Ta Kwu Ling Pig Breeding Centre near Fanling with the Kadoorie Agricultural Research Centre of the Hong Kong University near Tai Mo Shan.
When a pig went to market, the compost was simply collected into bags for landscape gardeners to take away.
The only cost was the sawdust, and even that would be provided free by the gardeners, who were desperate for the compost.
The department estimated yearly demand for the fertiliser at 50,000 cubic metres just from landscapers. ''Even if all farmers are producing this, they can only produce 20,000 cubic metres,'' she said.
There were advantages other than preventing the waste being washed into the rivers, as happened now. For instance, ''crop farmers could use the fertiliser to improve the soil and use less chemicals''.
''It will save a lot of labour. The daily routine work is just add some litter [sawdust],'' Ms Lo said.
Farmers who claimed it did not work had probably not learned the method thoroughly. ''It's not difficult. It's not something you can't handle, it's just something they have to learn properly.'' The department would be giving talks to the farmers next month on the system, and ''if they are interested they can always come to see our farm''. ''We are open and we welcome them'', Ms Lo said.