The field experiments were conducted on sandy loam soil at New Delhi, during 2007 and 2008 to investigate the effect of conservation tillage, irrigation regimes (sub-optimal, optimal and supra-optimal water regimes), and integrated nutrient management (INM) practices on soil biological parameters in wheat cultivation. The conservation tillage soils has shown significant (p<0.05) increase in soil respiration (81.1%), soil microbial biomass carbon (SMBC) (104%) and soil dehydrogenase (DH) (59.2%) compared to the conventional tillage soil. Optimum water supply (3-irrigations) enhanced soil respiration over sub-optimum and supra-optimum irrigations by 13.32% and 79% respectively. Soil dehydrogenase (DH) activity in optimum water regime has also increased by 23.33% and 8.18% respectively over the other two irrigation regimes. Similarly, SMBC has also increased by 12.14% and 27.17% respectively in soil with optimum water supply compared to that of sub-optimum and supra-optimum water regime fields. The maximum increase in soil microbial activities is found when sole organic source (50% Farm Yard Manure+25% biofertilizer+25% Green Manure) has been used in combination with the conservation tillage and the optimum water supply. Study demonstrated that microbial activity could be regulated by tillage, water and nitrogen management in the soil in a sustainable manner.

Experiments were conducted to evaluate the plant tolerance to Fe and its phytotranslocation by Jatropha curcas L. from an iron rich wasteland soil. The soil was collected from wasteland soil (WLS) of a small town Sandila, (Hardoi, U.P.) India, and three Jatropha clones were cultivated in WLS amended or not with sand or cowdung in a ratio of 3:2. The WLS had high pH, elevated electric conductivity (EC) and was rich in organic carbon and total NPK. Iron and Mn were 2-3 folds higher than that in the normal field soil. Net root and shoot elongation as well as fresh and dry biomass of the plants were only slightly affected at 100 d in WLS as compared with that grown in non-polluted soil. Tolerance index (TI) of J. curcas was significantly higher in cowdung amended WLS in comparison to that in WLS, or WLS amended with sand. Translocation factor (TF) from the soil to plants for Fe was significantly higher in WLS than that in the normal field soil. Bio-concentration factor (BCF) and concentration index (CI) for Fe were 0.12 to 0.37, 1.0 to 6.2 respectively. The results indicate that Jatropha plantation is suitable for phytoremediation of Fe-contaminate wasteland soils, and also that these polluted fields could be used to cultivate this important biodiesel plant species.