Meat bone meal as fertiliser for barley and oat

The traditional production of mineral N and P fertilisers is unsustainable due its reliance on fossil fuels in the case of N, and on limited mineral resource stocks in the case of P. The use of alternative or complementary fertilisers that originate from organic waste materials is gaining interest. Organic farms, especially arable organic farms without livestock, need usable sources of plant nutrients. Meat bone meal (MBM), a potential organic fertiliser for agricultural crops, contains considerable amounts of nutrients (on average 8% N, 5% P, 1% K and 10% Ca). In EU countries, Commission regulation (EC) No 181/2006 authorised the use of MBM as an organic fertiliser. In this study, MBM was compared to conventional mineral NPK fertiliser. Two randomised complete block split-plot field experiments were conducted: one with spring barley (Hordeum vulgare) in two years; and another with oat (Avena sativa) for three years, including a fourth year of testing for residual effect. Compared to mineral fertiliser (20% N, 3% P and 9% K), MBM was applied at three N levels: 60, 90 and 120 kg N ha-1. The grain yield of both cereal species supported by MBM, did not differ from the yield obtained with the mineral fertiliser at any N level. At 120 kg N ha-1, the grain yield level with either type was ca. 4500 kg ha-1 of barley and 5000 kg ha-1 of oat, representing fair averages for Finnish conditions. Moreover, MBM and mineral fertilisation showed no differences in quality in terms of 1000-grain weight, test-weight, protein content and protein yield. Since MBM has a low N/P ratio, P was applied in surplus to attain comparable N levels. Therefore MBM fertilisation should be fitted for crop rotation and for meeting environmental requirements.