MetHops or HarvEsTING. 5 
provides a food substance of which, in the case of potassium nitrate, both 
base and acid can be used, and are used, by, the plant, but any strong 
alkalinity prevents the commencement of the nitrification processes. In 
other words, the complete burning off of a dense forest may produce an 
immediate deterioration in the surface soil from which recovery may be 
slow and difficult. On such soils, crops like potatoes, which have relatively 
high potash requirements, are eminently suitable, and give good results if 
the amount of alkaline potash is not too great. 
DroucHut.—With very few exceptions, these being mainly forage plants, 
no economic plants of any great value show a pronounced power of 
resistance to drought conditions, cereals being among the most resistant of 
ordinary crops. Most cultivated plants suffer severely, and are stunted and 
dwarfed, even by moderate drought. This applies especially to all fruits, 
vegetables, and root crops, where the parts eaten are succulent and closely 
dependent upon free supplies of water. It follows, therefore, that drought 
conditions favour weeds at the expense of cultivated plants. Temporary 
periods of very severe drought favour rapidly growing and freely seeding 
weeds, or plants perennating in dry periods by means of underground 
bulbs or tubers. Less intense, but more prolonged and generalized drought 
conditions, favour deeply rooting permanent weeds, and encourage the sur- 
vival of scrubby, spiny, or more or less leafless shrubs, as well as of a~* 
few drought-resisting trees. Many supposed drought-resisting trees survive 
only because their roots reach permanent ground water, and such trees are 
really only resistant to ter.porary or superficial drought. 
Although most weeds, as compared with cultivated plants, are relatively 
favoured by drought conditions, many of the more luxuriant ones thrive 
especially well on moist ground. Thus the finger-grass or crab-grass, 
Panicum sanguinale, thrives to such an extent on well-watered garden soil, 
that by a false association of ideas some gardeners have termed it the Yan 
Yean water weed, or water grass, supposing that the water brought the 
seeds. This plant is a specially good case of a useful fodder plant, which 
is a troublesome weed in gardens and cultivated ground out of its proper 
place. The same applies to the Johnson grass (Amdropogon halepensis), 
which on this account has actually been proclaimed in California, so 
troublescme has it become as a weed of cultivated ground. Since this 
latter plant.is only of use for fodder, and not for grazing, it may also be 
classed as a weed under the prevailing conditions in Victoria. 
MetHops or Harvestinc.—Cleanly, thorough, and timely harvesting 
is as important a factor in keeping the ground clean and free from weeds as 
is cultivation. The barbaric method of harvesting wheat by the combined 
reaper and harvester, leaving the straw standing, is fortunately only a pass- 
ing phase of agriculture, and will cease as the land becomes more valuable 
owing to the increase of population and spread of closer settlement. Among 
the standing straw, all kinds of pernicious weeds ripen and shed their seed, 
‘and since many of these seeds retaini the power of germination for three to 
ten years, or more, the fouling of the land increases steadily along with 
its impoverishment. Very little land will stand treatment, or rather lack 
of treatment, of this kind, even for so short a period as ten years, without 
its value and productive capacity being seriously impaired, and where pre- 
historic land-scratching methods of agriculture prevail it is futile to com: 
plain of the spread of weeds, or to: expect their suppression by an’ Act 
or proclamation. . 
‘Even if the standing straw is burnt off, this is usually done after most 
of the weed seeds are shed, and besides being an extremely dangerous prac+ 
