FARMING PROBLEMS.

Taranaki Daily News, Volume LII, Issue 128, 28 June 1909, Page 4

FARMING PROBLEMS.

PASTURE LANDS. HOW THEY SHOULD BE MANURED, j lIIXTS BY GOVERSM.ENT CHEMIST. "The Manuring of Pastures in New Zealand" was the title of an interesting paper read before tile Dairy Conference iit Paliiierstou North on Wednesday by Mr. B. C. Aston, the Chief Government Chemist.

A 'MIXED CHOP.

Mr. Aston began by saying that po manent pasture was a mixed crop of very heterogeneous description. J? or the purpose, however, of studying the lnanurial requirements of pasture*, they could place the component species of plants in the following three divisions: Gramineal, the grass family including cereals; leguminosae, the pea or pod* bearing plants; and miscellaneul, or misceHaiicoiiA* plants of value, such aft sheep's burnet, jarrow, chicory, parsley, , lilgrass, etc., and weqds of no value. 1 Therefore the farmer who wished to | cater for the requirements of pastures had to hear in mind the diverse nature of the crop and the limited means of af> plying manures by top-dres6ing. Fertile isers to be applied to gnu's should he those which were soluble in rain wat'sr, | or would become so by decomposition ! in contact with the soil. Very solute nitrogenous' fertilisers, which, unlike soluble phoephatic compounds, were not fixed in the soil, if used ut all, must be applied in frequent s'mall quantities rather than in one large dose, otherwise there was danger that they would bt ''leached" out in the drainage, Or would lose a portion of their most expensive manurial free nitrogen. If necessary, they could apply lOcwt of basic slag per aero to pasture with the curtain knowledge that in time value in increased crop would be obtained for every ounce. Of 'the seventeen plant foods, all existed in sufficient quantity in all s'oils except nitrogen, phosphorus, and potassium, or their compounds. It was, however, the practice to supply some of these elements in large quantities for reasons other than that of sup plying food. IMPORTANCE OF MANURING. The importance of manuring pasture would be realised when it was remembered that a hay crop would remove from the soil as much more of every essential ingredient except phosphoric acid and silica than would a wheat crop. If the theory of "dominant in-1 gredicnts" for fertilisers were to be applied to New Zealand pastures, thev would be dosed with nitrogen and pastures, as the pastures were, or should be, composed of grasses and clovers'. Current practice, however, was entirely opposed to such treatment, and those few field experiments which had been carried out with pasture and hay crops supported the practice of abandoning nitrogen. In the Waerenga experiments so little was thought of nitrogen that no member of the scheme contained any appreciable quantity of it. As to the reas'on why this constituent 1 should 'lms in so little requisition as ft , grass fertiliser—us had been shown by many experiments carried out—theory pointed to the probability of there being an excess of nitrogen in an available condition in Xew Zealand soils, especi* i ally those of the North Is'land. An- ; alytical results proved that available phosphoric acid was deficient in most i North Island soiis examined. The soil • of the Dominion, with the exception of ! those resting directly on limestone, were deficient in limcj, the principal i limiting factor probably betug phos- , phoric acid. In order to overcome this • want, quicklime would bo the best to use, on clay s'oils, while for the lighter soils carbonate of lime would be most suitable. Lime liberated plant food i from the insoluble silicates of the soil, , and thus acted as an indirect fertiliser, • its beneficial effects having been speci- : ally noticeable at Waerenga. VALUE OF POTASII.

Experinients conducted elsewhere in the North Island had proved the value of potash on the grass crops. Generally speaking, soils which were very dark or black in color, due to excess of humus, would respond well to potash. Soils, i'Jso, which 'were essentially sandy usually lacked potash. It was the thiril fertiliser ingredient, phosphoric acid, in which New Zealand soils were most deficient. and to which all crops responded the quickest. Superphosphate, bonedust, and basic slag were the three most popular forms. .Mixtures of the first two gave good results', but the last was better when applied bv itself. Superphosphate was <|uite soluble in water; basic slag and bonedust were insoluble. Last season some experiments were made to determine the value of coarse particles of slag on pastures, the results suggesting that fineness as a factor in success had been somewhat overrated. Of all fertilisers, basic slag had given the most favorable results" on pastures, as had been shown at Waerenga, where a thirty-fohl increase had been secured I

on the unmauurcd plot. Experiments a soil quite deficient iu available phosphoric acid hut well supplied with other plau't food had shown that the main essential to success in the improvement of the pasture was' to hierea>e the store of phosphates in the soil. To cU'eet this a generous droning of sing was recommended, the result of the application being '-that 2 1 /-. sheep more to the acre could be carried. SLAU AXI) RAIX. A point to remember iwus that basic shig would not give as good results' as top-dressing h\ a dry climate. It was bard to say where the line should be drawn, .but as a tentative standard lite was inclined to adopt forty inches of rain per annum, below which it would be preferable to apply superphosphate rather than slag. On all hmd requiring phosphate where the rainfall was copious' and frequent slag was sure to elieit response, Jbut in situations subject to drought and drying winds superphosphate would -prove superior. Mr. Aston also declared that to increase the store of humus in clay and sandy soils s'houhl be the aim of every farmer. This could

bo accomplished by ploughing in green manure, such as clovers, pcas'e, and beans, or oven by growing tlicm in rotation. _ The best fertilisers to stimulate leguminous plants were .potash and slag or supcrphospbali's, according to climate. Where potash was plentiful it could be dispensed with, and slag or superphosphate applied alone. At the conclusion of the paper a few questions were put bv delegates desiring further elucidation of the points' raised. Mr. Aston was accorded a very heartv vote of I,hanks, 011 the motion of Mr. Marx, seconded by Mr. Dingle.