ORCHARD MANURING

Nelson Evening Mail, Volume LXXIII, 25 June 1940, Page 9

ORCHARD MANURING

GREATER USE OF NEW ZEALAND PRODUCTS JOINT RECOMMENDATIONS | BY DEPARTMENT OF AGRICULTURE' ij AND CAWTHRON INSTITUTE j The progress of the war suggests j that great difficulty will be experi- j enecd in obtaining from Europe certain types of fertilisers which have been in common use by orchardists and market gardeners in the Nelson district. The overthrow of France will effectively prevent the export of all potash manures which formerly came from Alsace-Lorraine. In addition, it is probable that amI monium sulphate and other artificial nitrogenous fertilisers will he required to ail increasing extent both for munitions and for English agriculture. This must seriously curtail the amount of ammonium sulphate ’ available for export to New Zea- 1 ‘ land. Under these conditions, it is imperative to adjust manurial pro--1 grammes, making the greatest possible use of fertilisers produced within New Zealand. This state- j ment is issued by the Department of agriculture and Cawthron Institute, which make the following joint recommendations:— While it is probable that the continuation of the war will greatly limit the export of New Zealand fruit, it is nevertheless desirable that orchards be 1 maintained in a satisfactory condition so that on restoration of peace, production of crop may be quickly restored to an optimum level. Orchards which have been well manured over a period of years are not likely to suffer unduly by a considerable curtailment of the manurial programme for two or three years. Experience has shown 1 ■ that nitrogenous manures are essen- • tial, particularly on the Moutere Hills soil, for the maintenance of tree growth and yield of fruit. Potassic manures are not so important on several of the deeper soils of the district, but their value has been very definitely shown i for the Moutere Hills and other soils derived from this formation On such soils, potassic manures not only im-1 prove the quality of the crop, but are 1 important for tree growth. It must be j pointed out that the use of cover crops and good cultivation are extremely important in reducing the need for nitro- I , genous fertilisers, and in obtaining the j best results from the limited amounts •of fertilisers which will be used. In i I the Nelson district, zlue lupins have given great satisfaction for cover crop l purposes, and their use is particularly! ' recommended under war-time condi- ' tions. It must be noted that a good 1 crop of blue lupins will supply the! equivalent of 3 to 4 cwt. of ammonium i sulphate per acre, besides providing notable quantities of phosphase and. potash in a form available to the trees. | STANDARD RECOMMENDED In the past, many orchardists in the j Nelson district have adopted as a stan- j dard manure a mixture containing 31bs j superphosphate, lib muriate of potash, ! and 21 bs sulphate of ammonia per tree.! It is now recommended that during the period of the war, the following standard be aimed at: 21bs superphosphate and lib sulphate of ammonia per tree. If supplies of potassic manures are available, Ilb of muriate of potash per tree could be added to the above formula, but in all probability it will be necessary to reserve the potassic manures for (he treatment of weak trees and highly coloured varieties, particularly on the Moutere Hills soil type. NITROGENOUS MANURES In regard to ammonium sulphate, this manure must be replaced in many orchards by the use of other nitrogenous manures. Several fertilisers containing nitrogen are available in New Zealand, and could be used to supplement the standard manure given above*. Blood and bone containing 7.5 per cent nitrogen and 9 per cent, phosphoric ' acid: dried blood containing 12 per cent, nitrogen, and Sanford’s fish manure containing 6 per cent, nitrogen and 12.5 per cent, phosphoric acid could all bo used for this purpose. Alternative formulae would be as follows: ! (1) 2Jibs blood and bone and lib superphosphate per tree. ] (2) 21bs superphosphate and lslbs i dried blood per tree, j (3) 31bs Sanford’s fish manure per tree. j At present-day ppces dried blood and i Sanford's fish manure give rather dearer values for nitrogen than is the case with the blood and bone manure j specified above. Limited supplies of nitrate of soda are available. This fertiliser is not recommended for mixture with superphosphate, but is best used separately as a topdressing on weak trees, at the rate of lib per tree. In those cases where curtailment of manurial programme is likely to affect growth of tree, the desirability of 1 heavier pruning must be pointed out. This would ensure the maintenance of tree vigour without a serious reduction in cropping capacity.