Scientific Agriculture 



172 



[February, 1909. 



where in other cases scarifiers and 

 rollers would have to be used. The 

 digger buries grass and weeds deeply 

 down, so that they do not get a chance 

 to grow through the furrows. More- 

 over, the vegetation gets rotten about 

 the time the ear of corn is filling, and 

 helps materially to form food for the 

 plant at a time when it requires it. 

 There is, as already stated, a danger of 

 turning up too much sour land, so that 

 the seed does not grow away quickly. 

 This must, of course, be guarded against. 

 The plough will plough no deeper than 

 where it is set. I know of people who 

 quickly discard the digger because they 

 cannot make them do good work. The 

 fault is, very often, that an attempt is 

 being made to turn over a furrow too 

 wide for the depth. The result is that 

 the desired crumbling, feathery state of 

 the land is not attained. As a rule, 

 people do not, on clay lands, desire to 

 plough deeper than 6 or 7 inches. 

 Roughly speaking, 1 inch of depth re- 

 quires 2 inches of width. Thus a furrow 

 inches deep should not have a greater 

 width than 12 inches. A furrow (5 inches 

 by 15 inches would be a failure, in my 

 experience. In marking out, the front 

 wheel should be lowered in order that 

 the front plough shall not plough too 

 deeply, and throw up too high a ridge. 

 In finishing, much the same method is 

 adopted as with an ordinary plough. 

 It is well to repeat that the first time of 

 ploughing must not be too deep. The 

 soil on the top after ploughing is all 

 brought up from the bottom of the 

 furrow. A paddock may easily be 

 spoiled for a year or two because of too 

 deep ploughing with the digger. They 

 are often spoken of as horse-killers, but, 

 as a matter of fact, they are not more so 

 than an ordinary plough. They certainly 

 require more strength, but they will 

 turn over four acres a day, where an 

 ordinary plough will only do between 

 3 and 3^ acres in the day. In ground 

 where they have never been used before, 

 the work is harder than on land where 

 they are frequently used, because there 

 is a certain amount of subsoil to be 

 turned up for the first time. In ordinary 

 cases five horses will work them as 

 easily as four will work a plain plough, 

 and, as I have said, they will do from 

 half acre to one acre more work. The 

 mould-board is shorter, but there is less 

 friction, because it has only to clear its 

 way, whereas a plain plough has to be 

 dragged through the ground like a 

 wedge. 



I shall conclude by saying something 

 about the latest pattern of plough— the 

 disc plough. They are coming into use 

 slowly* and are excellent for certain 



kinds of work on certain kinds of land. 

 For cross-ploughing in autumn they do 

 good work, breaking up the ground 

 thoroughly so that but little after-work 

 is needed to make a good seed bed. 

 They do well on stubbles in the autumn, 

 and get over a lot of ground in a day. 

 They are made somewhat on the principle 

 of the disc harrow, and require more 

 power than an ordinary plough. If they 

 are set narrow, and the ground is level, 

 four horses will make them on stubble, 

 turnip land, or fallow, aud five on lea 

 land. Generally speaking, however, 

 they require five horses for the former 

 kind of land and six on the latter, 

 especially if the ground is hilly. They 

 are not suitable ior turnip land which 

 has been tramped and poached by stock 

 in the winter, as they leave the ground 

 too lumpy and rough. It is on the 

 twitchy land that the disc plough is 

 most serviceable. In fact, it will throw 

 about land infested with couch, yarrow, 

 and other plants with creeping roots in 

 splendid style, where a plain furrow 

 plough will scracely touch it. Paddocks 

 which have been given up as unworkable, 

 by reason of a mat of twitch or couch, 

 have been brought into cultivation 

 again by the disc plough. It throws 

 the furrows in the air, and leaves them 

 lying up to the sun and weather in such 

 a manner that the plants are half-killed 

 before after-cultivation is started upon. 

 Moreover, the furrow, instead of being 

 packed hard, so that no disc harrow or 

 cultivator can touch it, is left so that 

 these implements can smash them about 

 splendidly. Some farmers break up 

 twitchy land with the ordinary plough, 

 and then put the disc plough on to 

 cross-plough, with very satisfactory 

 results. In my opinion, the disc plough 

 is an implement that materially reduces 

 the fear that twitch and couch, and such 

 like weeds will utimatelv get possession 

 of our arable lands,— A New Zealand 

 Farmer in "The New Zealand Farmer," 

 — Queensland Agricultural Journal, 

 VolXXL, Fart 4, October, 1908. 



THE DUST MULCH. 



Direct evaporation from the soil can 

 be checked by keeping the upper 2 or 

 3 inches of the surface well cultivated, 

 so as to form a dust blanket, or dust 

 mulch. When the ground is kept 

 covered with a thick layer of dry, loose 

 soil, evaporation is slight, but when the 

 soil surface is not kept dry and loose, 

 evaporation goes on very rapidly. The 

 tools required for maintaining the dust 

 mulch are a common harrow, a weeder, 

 and various forms of cultivators. The 

 strokes after, is all that is requirea f 



