Field experiments were set up in an acid alluvial sandy loam soil to evaluate relative
efficacy of organic manures in improving productivity and pest tolerance of an okra
crop cv Arka Anamika (IIHR Sel 10). Three commercial manures, processed
municipality waste (PMW), vermicompost (VC) and oil cake pellets (OCP), were
assessed in relation to farmyard manure (FYM) alone and in combination with
microbial culture (FYM+MC). All were compared to commercial fertilizer (CF).
Among the organic manures tested, FYM produced maximum fruit and shoot yield.
The uptake of N, P and K and micro-nutrient in FYM treatment was significantly
superior to all other commercial manuring and CF. Increase in fruit yield with FYM
application was attributed to higher retentivity of soils for water and nutrients, and
higher uptake of major and minor nutrients. However, the tolerance of crop-plants to
attack by pests in terms fruit yield was highest in the treatment with FYM. The
quantity and the proportion of N, P and K coupled with minor elements available
from nutrient sources were mainly responsible for differences among nutrient sources.
Varying influence of organic manures on soil properties also caused differences in the
performance of nutrient sources.