Changes in soil fertility under multipurpose tree species in Thar Desert of Rajasthan

A study was conducted to investigate the effect of multipurpose tree species namely Prosopis cineraria, Acacia senegal and Tecomella undulata on the physical and chemical properties of soils representing Typic Haplocambids. The plantations of Prosopis cineraria and Acacia senegal were even aged, while that of Tecomella undulata was relatively young. The soils had an overall low status of SOC (<0.50%), low to medium P (8.2–15.7 kg/ha) and medium to high K (276–498 kg/ha). There was improvement in water holding capacity and decrease in surfacesoils bulk density under these tree species when compared to field without plantation. Slight decrease in pH of the soils under these tree species was noticed, whereas changes in EC were not appreciable. Significant improvement in soil organic carbon (0.12 to 0.27%), available P (9.70 to 13.36 kg/ha) and K (336 to 393 kg/ha) was observed under these tree species compared to field without plantation. The content of Fe, Mn, Zn and Cu was 15, 31, 101 and 86 percent, respectively higher under these tree species than the field with out plantation. The amount of nutrients returned to the soils through litter fall followed the order of Ca>K>Mg>P>Fe>Mn>Zn>Cu undertree species and variationinthe amount of nutrient returned to the soils among the different tree species and field without plantation explained by the quantity of litter production and its chemical composition. The present study also indicated that these available nutrients had significant and positive correlation with organic carbon content across the land uses.