Rice-wheat is the most popular cropping system followed on around 13.5 million ha of land in the South Asian countries of Pakistan (2.2 m ha), India (10 m ha), Nepal (0.5 m ha) and Bangladesh (0.8 m ha) extending across the Indo-Gangetic alluvial plain. To vacate the fields for the timely sowing of wheat, farmers burn rice straw in the fields. To overcome this problem, Zero-Till Seed-cum-Fertilizer Drills can be used for sowing of wheat without any pre-sowing irrigation in the standing straw of rice (after the combine-harvesting of rice). This can help in more efficient management of crop residue, irrigation water and nutrients. Hence, field experiments were initiated during summer 2002 for quantification of saving in energy, organic carbon, irrigation water, fertilizer N and plant nutrient with Zero Tillage (ZT) in wheat in rice-wheat rotation. Rice (cv. Sugandha-2, fine quality fragrant Basmati rice) was grown in rotation with wheat (cv. WL-343) on sandy loam soil in Gurgaon, Haryana, India. Six, 15 by 10 m plots, were arranged in two blocks. Micro plots of 1.2 by 1.2 m were maintained in each plot for N-15 studies. At maturity, rice crop was simulated combine-harvested in one block of 3 plots, leaving the anchored rice-straw and stubbles in the field. In the other block of 3 plots, rice was harvested up to ground level and the straw was removed from the field. Wheat was sown with a Zero-Till Seed-cum-Fertilizer-Drill in the standing rice straw with residual moisture in one block of three plots (no pre-sowing irrigation for wheat). In the other block of 3 plots, pre-sowing irrigation was given and wheat sown when soil came to workable conditions by Conventional Tillage practice (CT) providing two hoeing followed by planking. Total crop residue of rice returned to the soil surface in rice-wheat rotation with ZT than with CT (to wheat) was 3.13 t ha-1. Mean amount of N, P2O5 and K2O in the residue returned to the soil was 16.6, 7.91 and 59 kg ha-1. Total amount of organic carbon added to the soil through the above ground straw of rice in the ZT plots was 1.25 t ha-1. On an average, 40% more of OC and around 45% more of N, P and K were returned with ZT as compared to CT practice. This practice of zero-tillage will prevent, on an average, 4.6 t ha-1 of CO2 from emanating to the atmosphere. Saving in 35 HP-tractor running time with ZT was 10.88 h ha-1, which is equivalent to a net saving of 32.64 L of diesel per hectare. Relatively less water needed to irrigate the ZT plots was due to the compactness of the soil surface, as the field has not been tilled before sowing. In CT plots, water was absorbed rapidly; therefore, it took more time to fill the plots as water moved slowly to the other end of the field. This was true for subsequent irrigations also. Total amount of water needed to irrigate the wheat crop to full maturity was less by 1016.5-kilo L ha-1 in ZT treatment and there was a net saving of 100 mm ha-1 water in wheat. Water use efficiency in terms of kg wheat grain per ha per mm was higher by 16% in ZT plots as compared to CT treatment. Post-harvest moisture content in the soil profile (0-1.2m) in ZT treatment was 30 mm higher than in CT plots. Fewer evaporation losses due to mulching effect of rice-straw in wheat could be the reason for higher moisture content in 0-1.2m-soil profile in ZT plots. Tillage treatment had little effect on dry matter production. ZT wheat had lower N concentration than corresponding CT wheat indicating lower availability with zero tillage. Total N uptakes of N in wheat at harvest were lower in ZT (144.6 kg ha-1) as compared to CT plots (184.37 kg ha-1). However, percent N derived from fertilizer at 44.62 was almost 8% higher than CT treatment, which were only 36.05. Soil N content at 2612 kg ha-1 in CT plots was higher by 200kg ha-1 than ZT plots at 2420 kg ha-1. This could be ascribed to immobilization of the N, as residue decomposition is very slow in ZT plots due to lack of mixing. A mulched, non-plowed tillage system can potentially affect mineralization perhaps due to altered temperature and altered soil moisture content. Thus, conversion from conventional tillage to zero-tillage for wheat in rice-wheat cropping system will help in reducing CO2 loss from cropland due to burning of the rice-straw in the Indo-Gangetic plain. Our data indicate saving in fuel and more efficient use of irrigation water in zero till treatment. This helps in improving the soil quality for sustaining this production system.