LONG TERM EFFECTS OF ORGANIC LAND USE SYSTEMS ON SOIL QUALITY IN A SEMI-ARID CLIMATE OF PUNJAB, INDIA.

The impact of five long term (10 years) organic land use systems viz. agroforestry (Poplar + turmeric (LS1)), vegetables (bottle gourd -- broccoli (LS2)), basmati -- wheat (LS3), sugarcane fodder (LS4) and maize + summer moong-wheat (LS5) was studied on soil quality. Results showed that LS1 has significantly higher soil organic carbon (SOC) content, mean weight diameter (MWD) of aggregates and soil moisture retention. Significantly higher soil pH, saturated hydraulic conductivity (Ks) and infiltration rate (IR) in LS4, bulk density (BD) in LS5 while significantly lower electrical conductivity (EC) in CS3 were observed. The LS1 has significantly better soil quality index (SQI) than all the other land use systems. The SQI was in the order of LS1 > LS2 > LS3=LS5> LS4. The order of overall contribution of MWD, particle density, soil moisture retention, Ks and IR to SQI was 45.3, 29.3, 16.6, 6.4 and 2.5% respectively. [ABSTRACT FROM AUTHOR]