134 INTERPLANTING. 
The disc is from 9 in. to 14 ft. in diameter, with a hole in the middle 
1d in. or 2in. in diameter, and a slit leading up to it fin. or #in. 
wide, so that the dise can be easily slipped on to the planted tree with 
a little bending of the disc. The disc is preferably made of thin sheet 
zinc. It stops all weed-growth near the planted tree, and keeps the 
ground around it as clean as in a garden. ee: 
It is stated that there 1s an overproduction of zinc in America, and 
various new uses for the metal are suggested. A disc weed-stopper in 
countries where labour is as costly as in New Zealand seems one new 
use for sheet zinc. 
The placing or the moving of the dise is light labour, whereas “ cut 
and mulch’ is heavy work that may have to be repeated more than 
once with trees that grow at first slowly. 
The disc work could be done by partially disabled returned soldiers, 
or by rangers in the course of their rounds. The disc is not removed 
till the planted tree has established its own “* covert ’’—viz.. In two, 
three, or more years. The planting-dise gives almost the only chance 
for successful in situ seed-sowing in bush like that of New Zealand I 
have used disc weed-stoppers in India, but there is little scope for 
labour-saving devices in a country where labour is so cheap that railway 
embankments are made by a procession of women and children carrying 
baskets of earth on their heads! 
Besides economy in the number of trees required, interplanting has 
other advantages in a New Zealand forest, viz..— 
(1.) Thinnings, for which there is often no sale, would be saved. ‘The 
first thinning is generally unremunerative in every country. 
It averages about £1 per acre in young pine forests in South 
Africa, with labour one-third the price of that in New Zea- 
land, so that here is all the cost of the interplanting saved in 
this first item. 
Cleaning and weeding may be less and be more easily replaced 
by mulching. 
Pitting in the soft and open forest soil is never wanted. 
Rabbit fencing is very rarely necessary in the native forest. 
Fire-protection is easier. 
As against bad sparse planting, and even with some trees close- 
planted, the cost of side pruning would be saved or greatly 
reduced. 
(7.) Trees planted in the ‘‘bush’’ get shelter from wind, which 1s 
often so serious a drawback in New Zealand, and that modi- 
cum of shade in youth which even many light-demanding 
species love—the Tulip tree for instance. | 
(8.) Planting in the ‘‘ bush ’’ means necessarily a certain gain in the 
quality of the soil, since the forest soil is the net result of 
centuries of soil-improvement. 
(9.) Lastly, there is the great prospective gain of the valuable foreign 
trees spreading naturally in the forest, as does so much intro- 
duced vegetation in the open. 
Against the above nine items has to be set some lopping, ring-barking, 
or felling required to prevent the interplanted standard trees becoming 
dominated ; but this would rarely be a serious item, and is compara- 
tively light-labour work which many discharged soldiers would find con- 
genial and others would take on in the intervals of farm-work. 
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