19 January 1996

Granular fertiliser gives silage a boost

DAILY intake and liveweight gain of heifers fed silage fertilised with a granular fertiliser is greater than that of heifers fed silage fertilised with a blend or straight nitrogen.

That was the result of a Scottish Agricultural College trial carried out during the 1995 first-cut silage season on behalf of Kemira Fertilisers.

The trial aimed to compare the effects of fertilisers on grass yields, grass and silage quality, and the dry matter intake and liveweight performance of dairy heifers.

Treatment included comparisons of a 20.8.12 granular fertiliser (Kemira Premier Cut), a 20.6.12 blended fertiliser, straight nitrogen and nitrogen with slurry. In each case the total nitrogen applied was 125kg/ha of nitrogen (100 units/acre).

Treatments were applied on Mar 21 to achieve applications at least eight weeks before cutting for silage on May 23. No additive was used.

Finished silages were fed to livestock for six weeks (see table). The granular fertiliser silage produced over 0.5t/ha extra of silage dry matter, an increase in yield of 15%, says Kemira.

As a result stock fed on this silage achieved a 27% increase in liveweight a hectare over the six-week period compared with those fed on silage produced by the blended fertiliser. &#42

Average silage dry matter intakes and liveweight gain of heifers

Fertiliser typeNN + SlurryBlendGranular

Premier Cut

Intake (kg DM a day)3.473.604.164.35

Liveweight gain (kg a day)0.550.580.630.73