Integrating Effects of Applied Zn with Organic Amendments for Enhanced Maize and Wheat Yields at Two Diverse Calcareous Soils

Organic amendments need different management strategies and integration with chemical fertilizers for maximum benefits. The influence of various organic amendments in Zn nutrition was evaluated in two diverse calcareous soils. Amendments including FYM, PM and BC were applied at 20 t ha -1 with 0, 3 and 6 kg Zn ha -1 to maize-wheat cropping system in low limed Charsadda (6.6 % CaCO 3 ) and high limed Peshawar (16.6% CaCO 3 ) soils. Growth and grain yields of first season maize and succeeding wheat crop increased with increase in Zn levels and amendments with relatively higher response in Peshawar than in Charsadda soil that may be attributed to initially lower fertility status of Peshawar soil. The application of Zn with amendments also significantly increased the grain Zn and postharvest soil [Zn] in both soils. Among amendments, PM showed better performance in increasing crop growth and yields in both locations followed by FYM in maize but in succeeding wheat the biochar became more effective withstanding statistically at par to both PM and FYM. This increasing promising effect of BC with time reveals its slower but long lasting effects in crop production. FYM and BC required relatively higher amounts of Zn than PM and as such integration of 3 kg Zn ha -1 with PM, and 6 kg Zn ha -1 with FYM and BC is recommended for enhanced crop production. Furthermore more, the application of BC is recommended for long lasting results but its initial higher cost may hinder its application at large scale.