Abstract:
Application of chemical fertilizers is the general fertilization practice in
the potato (Solanum tuberosum L.) farming system. Present trend is
application of animal manure along with reduced rates of chemical
fertilizers in potato farming. Precise impacts of incorporation of organic
farming system into conventional farming system was evaluated by means
of potato productivity and soil fertility using major potato growing fields
in Sri Lanka. Three clusters were selected on the basis of different
fertilizations, and physical and chemical properties of soils were analyzed.
Productivity and production costs of potato were also assessed in all
clusters from 2003 to 2005. Major nutrient levels were higher than the
required amounts for potatoes in all clusters in both manure amended
systems (MASs) and manure unamended systems (MUSs), but there was
no significant difference in major nutrient levels between MASs and MUSs.
However, the tuber yield was not affected by incorporation of organic
farming system and showed a strong positive linear correlation with sand
: clay ratio of soil. Animal manure amended systems reduced the potato
production costs by 3.0-7.2% without affecting the tuber yield, and thereby
increasing the benefit to cost ratio.
