Utilization of Pressmud as Organic Amendment to Improve Physico-Chemical Characteristics of Calcareous Soil under Two Legume Crops

The soils of Dera Ismail Khan are calcareous in nature and are particularly low in organic matter, N, P and micronutrients; especially Zn. Use of only NPK fertilizers has also disturbed the C: N ratio. Consequently, the soil resource base has been degraded and factor productivity has declined. Application of organic fertilizers improves crop yield, soil physico-chemical characteristics and recycles wastes in environment friendly manner. To achieve these objectives pressmud was applied to mung bean and lentil crops in pots having 20 kg soil @ 2, 4, 6, 10, I5 and 20 tonnes ha^-1. Treatments having recommended dose of N: P2O5: K2O (30:60:45 kg ha^-1) were also included in the experiments. Maximum increase for most of the yield parameters of lentil was recorded in NPK treatment, followed by P6 receiving 20 tonnes ha^-1 press mud. The post harvest analysis of soils treated with pressmud showed progressive increase in EC, organic matter content, Na^+, HCO^- 3, CI^1- and SO4 ^2- with increasing levels of pressmud. The concentration of NPK, Zn, Cu, Fe and Mn in the treated soil samples also increased and was maximum where pressmud was applied @ 15 and 20 tonnes ha^-1.