FARM NOTES

Te Awamutu Courier, Volume 55, Issue 3938, 11 August 1937, Page 5

FARM NOTES

VALUE OF FLAMETHROWER. WAIRARAPA MAN’S EXPERIENCE One minute an “old man” gorse bush—a thing of beauty to the town dweller, in all the splendour of its spring mantel of green and gold, but appealing to the farmer only as one of the worst pests listed in the category of noxious weeds—the next a lifeless, scorched and blackened skeleton of its original vigorous self. This transformation was effected before our eyes on a Wairarapa farm one day recently, the medium being a blast of liquid fire from a flamethrower. The scene of the demonstration was the farm of Mr. W. G. K. Wiggins, Greytown, Wairarapa. Mr. Wiggins is enthusiastic regarding its merits. Up until six months ago, Mr. Wigginshad been engaged upon an expensive, but more or less fruitless war upon gorse, broom and blackberry, which had taken control of about ten acres of the lighter land upon his efficiently managed 60-acre farm. It represented an annual liability, for the attempted control of the strong-growing weeds by cutting, or grubbing called for the employment of outside labour and involved quite a considerable annual outlay. Mr. Wiggins stated in the course of conversation that three men, at 12s per day, would cut out about four acres of gorse in a week, so that it was costing about £4 4s per acre to cut the gorse, with the knowledge that the control was only temporary and that it was only a question of time before the whole costly performance would have to be repeated again. This season, for the first time, Mr. Wiggins has applied a flame-thrower to this, his major problem, and the results already speak for themselves. In the course of a good day’s work with his flame-thrower, he stated that he can single-handed, cover the four acres of heavy gorse infestation which it would take three men a week to cut, and the total cost involved is for approximately five gallons of Diesel fuel oil at 9%d per gallon, or approximately Is per acre per burn. He has shown that three burnings are all that are required to completely destroy gorse, or broom, leaving only blackened stumps. Any aftermath that comes away in the following season will naturally be weak and spindly and can be speedily and. completely exterminated in the incipient stage of growth with one further spraying. With the use of the flame-thrower, Mr. Wiggins considers that he can thus achieve complete and final eradication of the gorse and broom on his farm at a cost of about 4s per acre, compared with a recurring bill. Equally valuable service is being given by the flame-thrower on this farm in the clearance of vegetation

from the sides of water races. There are some 60 chains of water races on the farm, and Mr. Wiggins stated that the work of clearing these in fne past called for the employment of outside labour also, took from three to four weeks, and cost about £l2 per year (under present labour conditions, the cost would be nearer £l6). This year, he did the job himself with the flame thrower in less than a week, and used approximately 20 gallons of fuel at a cost of about 16s. He estimates that the use of the flame-thrower on the sides of the races twice a year will keep them in perfect order. PASTURE TOPDRESSING. AUCKLAND PROVINCE CONCLUSIONS. During the twelve months ended 31st January, 1936, over 1,500,000 acres of grassland were top-dressed in the North and South Auckland Land Districts as follows (says the Journal of Agriculture): Fertilisers only, 904,192 acres; lime only, 44,769 acres; fertilisers and lime, 583,515 acres—a total of 1,532,476 acres. Phosphates, chiefly superphosphate, formed almost the entire bulk of the fertilisers applied, and only about one-third of the land received lime in addition to phosphates. In the last review of Auckland top-dressing trials the conclusions reached were: “The results of the top-dressing trials . . confirm general farm practice. Superphosphate ‘is generally the cheapest and most efficient phosphate for pasture top-dressing, but on some soils lime is necessary to enable the best results to be obtained from superphosphate. Slag is also quite efficient, but is not superior to superphosphate or superphosphate and lime. Rock phosphates are generally inferior to superphosphate or slag. Potash responses are not frequent, and, when responses are secured, they are generally slight.” During the past two years experimental work has greatly extended our knowledge regarding the use of potash and lime. Bell has described areas where very definite and payable potash responses are obtained; and in other districts some slight potash responses have been recorded. Our knowledge regarding the use of lime has also increased, particularly through the work of the Soil Survey Division of the Department of Scientific and Industrial Research, enabling lime responses to be more definitely correlated with soil

type. “Can nobody give us an answer—the truth and the whole truth of the operation of lime upon soils?” So the question was framed eighty years ago. and now, although the whole truth still eludes us, the action of lime in improving soil fertility is better understood: it frequently plays a controlling part in soil fertility, preventing or correcting the conditions of

“acidity” or “lack" of basicity” (commonly called “sourness”) that are unfavourable to many cultivated plants. Acidity in a soil commonly occurs in wet climates and is caused by the washing out ot the bases from the original soil by percolating water. In acid soils soluble iron, aluminium, and manganese compounds are frequently present in sufficient quantities to injure plants, but so long as the soil reaction remains about neutrality the compounds of these metals present in the soil are practically insoluble and do not affect plant growth. This does not apply to red-brown-soil group, which may require lime although the soil is near neutrality. Although it is impossible to ascertain the amount of lime necessary for a soil except by actual field trials, the appearance of the soil profile—i.e., the measure of soil leaching—is a fair guide as to whether a soil will or will not respond to lime. Young soils are not responsive to lime, leached soils are acid, frequently contain toxic amounts of soluble iron and aluminium compounds, and respond to lime. The broad outlook on liming fits in quite well with the lime responses obtained in the Auckland Province. The young soils (volcanic ash showers) of the Bay of Plenty and Central Plateau do not respond to lime, the slightly podsolized soils of the Waikato give a slight response, and the mature podsols and red-brown soils of South and North Auckland show marked lime responses. In the Bay of Plenty super alone generally gave a good response, and in only three out of twenty-two trials did the addition of lime cause definite improvement. In the Central Plateau area super alone was consistently good, and only in one trial out of ten did lime give an appreciable improvement; the effect of lime was often detrimental. Most of the trials in the Waikato were placed on land that had previously been top-dressed with phosphates for many years, and the relative response to phosphates and lime is not as marked as in othei districts where top-dressing is a newer practice. As in the Waikato, the experiments in South Auckland were laid down on land previously top-dressed, and the response to superphosphate was relatively slight, particularly in the first year; on the claps and some of the red-brown soils lime and super has given better results than supc’- alone. In North Auckland supei- and lime have given definitely better results than super alone.

Except for the Waihi and some peat soils of the Waikato, potash responses are not very marked in Auckland. Trials laid down on sandy peat in North and South Auckland, although few in number, indicate that potash is a necessary fertiliser on this soil type.

As has been quoted above, in the last summary of top-dressing experiments in Auckland the statement was made that “superphosphate is generally the cheapest and most efficient for pasture top-dressing, but on some soils lime is necessary to enable the best results to be obtained from superphosphate. Slag is also quite efficient, but is not superior to superphosphate or superphosphate and lime.” Further trials of super and slag have been carried out in North and South Auckland (red-brown soils and gumland podsols). On these soils alone slag is better than super alone, lime and super is generally better than slag alone, super and lime and slag and lime are about equal, although there is an indication that slag and lime may be slightly better than super and lime.