In recent years, a number of alternative sources of organic matter have been discovered, such as products made of waste
materials and recycled into composts or as meal of meat and bone. Meat and bone meal, a by-product of the meat industry,
is rich in N and P and hence it can be a viable alternative to mineral fertilizers. This study determined the direct effect of
different doses of meat and bone meal (MBM) used as fertilizer on the content of mineral N in soil. The effect of MBM
fertilizer applied at rates of 1.0, 1.5, 2.0, and 2.5 t ha
-1 was compared with no fertilization. The experiment was conducted
in the years 2007-2009 at the research station in Bałcyny, Poland. MBM was applied every year for 3 yr, with the following
crop sequence: 2007 winter wheat (
Triticum aestivum
), 2008 winter rape (
Brassica rapa
L. subsp.
oleifera (DC.) Metzg.), and
2009 spring wheat. Determination of mineral N (NO
3--N and NH
4+-N) were taken from the 0-30 cm layer, each year, during
the full plant vegetation. The study found that changes in the mineral N content in soil depended on the dose of MBM and
the crop species in a sequence. Each 0.5 t of MBM above 1.0 t ha
-1 increased the mineral N content by an average of 4 mg.
MBM applied every year at 2.0 and 2.5 t ha
-1 produced a 2.33- and 2.56-fold increase in the mineral N content compared
to unfertilized soil. The rate of release of NOσ 3
--N was found to be the highest at those sites in all the years of study, while
that of NH
4+-N was highest during the first 2 yr of study. The levels of NO
3--N lay within the range of very low fertility.
A strong correlation was found between NO
3--N and NH
4+-N content in soil and the N content in winter and spring wheat
(
Triticum aestivum L.) grain and in winter rapeseed (
Brassica rapa L. subsp.
oleifera (DC.) Metzg.) The NO
3--N and
NH
4+-N compounds released from MBM were a good source of N for the plants.
