Physico-chemical properties and macrofauna of soils under various farming systems of cold arid region in Balochistan, Pakistan

Barshore is a small village in the Pishin District, Balochistan, Pakistan, with dry summers and cold rainy winters. This is an agrarian region, mostly with orchards of various fruit trees. This study investigated the physico-chemical properties and macrofauna of soils under various agricultural management practices of this region. The concentrations of soil organic matter (SOM), soil organic carbon (SOC), nutrients, pH, electrical conductivity, soil texture, and the abundance and number of species of soil macrofauna of the agricultural fields were measured. Fifteen agricultural fields were sampled. Fourteen fields were orchards of apple, apricot or the mixture of apple and apricot trees and one field was a cropland, cultivated with wheat as a monocrop. The orchards were under conservation agricultural practices; whereas, the cropland was under conventional management. These agricultural lands were 2-26 years old. The concentration of soil organic matter (SOM) in the upper 0-10 cm depth of these field sites ranged from 11.6 g kg-1 to 32.8 g kg-1 soil. As compared to cropland, orchards had significantly higher concentration of SOM and SOC. A total of 18 soil macrofauna species were found and the most common and abundant were ants (Monomorium minimum, Camponotus pennsylvanicus, Solenopsis invicta, and Lasius niger) followed by Arion ssp. (Brown Slug) and earthworm Lumbricus terrestris. Regression analysis revealed non-significant relationship of the age and the concentration of SOM with the number of macrofauna species and with the concentrations of total mineral nitrogen, bioavailable phosphorus and clay. The existence of ants had no relationship with the concentration of SOM; whereas, existence of Lumbricus terrestris tended to had a positive relationship with the concentration of SOM. The field of tree-based intercropping system was 2 years of age since the land was converted from rangeland to a cropland, had two ant species coexisting. This indicates the positive influence of crop diversification on soil macrofauna.