Includes bibliography and appendices.

Soil acidity and ensuing phosphorus (P) deficiency are the major constraints to crop production in acidic soils. Lime and P application is recommended to overcome these limitations. However, given the widely perceived negative interactions of lime and P with Zn, they could be expected to reduce the availability, uptake and translocation of zinc (Zn) in plant, with its obvious implications for grain nutritional qualities and human health. Field and pot experiments were therefore conducted to test the hypothesis whether lime and P application adversely affects Zn nutrition of maize, and if so, whether Zn application can mitigate the negative interaction of lime and P with Zn, increasing thereby the yield and nutritional qualities of maize on acidic soil of Meghalaya. The treatment consisted of three levels of lime (L0 – no lime, L0.5 – furrow application @ 500 kg ha-1 and L3.0 – broadcasting @ 25% lime requirement i.e. @ 3 t ha-1), two levels of P (P0 – no P and P60 – 60 kg P205 ha-1) and two levels of Zn (Zn0 – no Zn and Zn5 – 5 kg Zn ha-1) in factorial combination, with each treatment replicated thrice. In general, growth and yield parameters responded positively to lime, P and Zn application. Grain yield was significantly improved with L0.5 (19%) and Zn5 (42%) application, with yield gain due to P addition being non-significant. At any level of lime and P addition, Zn application improved grain yield, with the best response (6.44 t ha-1) being obtained when Zn was applied along with lime (furrow applied @ 0.5 t ha-1) and recommended dose of P. Contrary to the beneficial effects of lime and P fertilization on grain yield, they tended to reduce the Zn concentration and increase the P/Zn ratio (signifying lower Zn bioavailability) in maize grains, indicating the reduction in nutritional qualities. However, such deterioration in nutritional qualities was reverted by Zn application by virtue of increased Zn content and reduced P/Zn ratio. While lime and P application increased soil pH and P availability, Zn availability remained unaffected, which was increased significantly (39%) by Zn application. This observation rules out the possibility of negative interaction of Zn with lime and P in soil, which was apparent mostly in plant. Results of pot experiment were by and large consistent with those of field experiment. Benefit/Cost ratio was also significantly increased (18%) by liming (furrow application @ 500 kg ha-1) and Zn application (33%). On the whole, while application of lime and P increased the grain yield, they tended to reduce the concentration and bioavailability of Zn in maize grains. However, inclusion of Zn along with recommended dose of lime and P could successfully revert the trend. Moreover, the yield benefit from Zn application was higher than that from lime and P application. Thus, application of Zn @ 5 kg ha-1 along with recommended dose of lime (furrow application @ 500 kg ha-1) and P (60 kg P2O5 ha-1) can be recommended for improving the yield and nutritional qualities of maize as well as farm income in acidic soils of the region.