Soil Quality and Sustainability Indices as Influenced by Potassium Distribution in Submontaneous Tract of Punjab

In Ballowal Saunkhari, Sadh Di Khad and Takarala watersheds the cultivated land use system had higher amounts of available and total potassium compared with the remaining three land use systems for both the years which was attributed due to addition of fertilizers and farm yard manure. In the Kular watershed, forest land use system has significantly higher values of available and total potassium compared with pasture land use system followed by undisturbed and cultivated land use systems for both the consecutive years of sampling. The higher levels of available potassium in forest land use system were due to the regular addition of organic matter in the form of leaf litter. The profiles of cultivated and forest land use systems in the Ballowal Saunkhari, Sadh Di Khad and Takarala watersheds had higher levels of available potassium, which showed strong correlation with content of clay and organic matter. The magnitude of available and total potassium generally decreased with depth in all the profiles. Whereas, the profile of Kular watershed showed higher levels of available and total potassium in forest and pasture land use systems compared with undisturbed and cultivated land use systems. Soil quality indices with respect to available K and total K were higher in forest and cultivated land use system respectively in all the four watersheds. The overall picture of sustainability showed that all the four watersheds were sustainable (S.I. >1) with respect to total K content whereas, Ballowal Saunkhari and Takarala watersheds were sustainable with respect to available K. The Kular and Sadh Di Khad watersheds were non-sustainable (S.I. <1) due to their existence on degraded and poor fertility soils.