USE OF NITROGEN

Ellesmere Guardian, Volume LII, Issue 55, 10 July 1931, Page 8

USE OF NITROGEN

EFFECT ON GRASS.

PROLONGING PRODUCTION,

COMBINATION WITH PHOSPHATE.

The use of nitrogenous fertilisers, especially on the better class of pasture, has come into greater favour in New Zealand in recent times. In 1928 the Department of Agriculture confmenced experiments with English synthetic fertilisers of this type and in the two succeeding years some thousands of tons have been used on the Dominion's grass lands. The records of 74 trials carried out in the 1928-29 season and of the 84 trials conducted in the 1929-30 season, have been made available lately by the department. Each trial embraced two fields, one manured with phosphate and another manured with phosphate and nitrogen, in the form of sulphate of ammonia. Results in 1928-29 showed that an average of 44.5 cow-days per acre, which is equivalent to a gain* of approximately 421b. butter-fat, and also 7.7 dry-stock days per acre was obtained for the use of nitrogen. The average gain for each hundredweight of nitrogenous manure used was equivalent to 13.51b. butter-fat. The results in 1929-30 showed that an average increase of 37.6 cow-days per acre, equivalent to a gain of approximately 371b. butter-fat and also two dry-stock days per acre were obtained. The average gain for each hundredweight of nitrogenous manure' was 18.51b. butter-fat. Average Increase. The average increase for each hundredweight of nitrogenous fertiliser applied in late winter was 20 cowdays per acre. The average increase for each hundredweight of nitrogenous fertiliser applied in autumn was 13.3 cow-days per acre. It is explained that it has not been possible to estimate the effect on subsequent production of milking cows of having early "out-of-season" grass. It is agreed, however, that this effect may be considerable. An application of nitrogen in July on a good grass sward will, it is stated, give feed a fortnight to a month earlier than usual. On some trials! the effect of the July application has been continued through the summer. In others the effect has disappeared with the advent'of dry conditions^. Application With Phosphjate.' Pastures of naturally high produc- j tion and containing a fair amount of the better grasses, especially ryegrass, have responded better to nitrogen than fields of lower production, generally deficient in the better j grasses. Nitrogen appears to have given better results when the phos-i phatic dressings were applied at the! time, or within a few w^eeks of the early nitrogen application^ a fact which is taken as indicating the value j of ammoniated super. That the Department of Agriculture officials recognise the importance of "out-of-season" grass can be gathered from the following points mentioned in the report of the trials published in a recent issue of the Journal of Agriculture:—"Unfortunately, the trials give no information regard- j ing the effect of "out-of-season" i grass on the cow production over the season as a whole. Extra early grass must have an effect in this respect by bringing cows to the lactation peak earlier. Unfortunately, the point could be determined only by an elabrj orate and costly experiment extend- { ing over a considerable period." \ The report further states:—"lt would be unfair only to use the. in-] crease in cow-days as represented by so" much butterfat as a measure of the value of nitrogen dressings. Apart from the value of extra early or extra late grass- in reducing the amount of supplementary feed required, considerable value must be attached to the early grass, especially i for early-calving herds in bringing J foi|ward the peak period of production."