Landwirtschaftliche Anwendung
Slurry is a paste consisting of a suspension of finely
divided solids in a liquid. Slurrying technique is used in
the manufacture of phosphoric acid by wet process. For
example, a slurry prepared out of microbial cultures (like
Rhizobium, Azotobacter, Azospinllum cultures, etc) in
water is applied to seeds before sowing so as to facilitate
the root-nodule production for nitrogen-fixation,
especially in legumes.
Slurry fertilizers are fluid mixtures containing
dissolved and undissolved plant nutrients which are used
because of their low cost, availability of higher grades,
capacity for mixing easily with sparingly soluble
micronutrients, herbicides and insecticides. To ensure
homogeneity, these materials are continuously agitated
mechanically.
Slurry fertilizers have grades like 7-14-21, 3-10-30,
and 4-12-24. Secondary nutrients and micronutrients
from relatively cheap sources, herbicides and pesticides
can be blended satisfactorily. Also as there is no problem
of salting-out, high analysis grades can be formulated
easily. The most popular phosphate material used in
slurry fertilizer is ammonium polyphosphate.
The major disadvantages of slurry fertilizers are their
higher viscosity and settling characteristics. Hence, they
are not easy to handle and store. All nutrients are not
immediately available to crops through slurry fertigation.
The slurries transmit diseases that can be controlled, if slurries are used only on arable land. The harmful
organisms die if slurries are stored for at least 60 days.
