Evaluation of Soil Tests for Zinc in Semi Arid Soils for Maize

Abstract

A greenhouse experiment was conducted with 20 soils representing semiarid soils of Coimbatore district to peredict the most reliable soil test method for determining the available Zn status in the soil. Therewere four levels of Za (0, 2.5, 5.0 and 7.5 ppm) and cach treatment was replicated two times. Maize (Ganga 5) was used as the test crop and the crop was allowed to grow for seven weeks. The results showed that among the six extractants tried, EDTA + (NH4)2 CO3 and DTPA were found to be the most reliable soil test methods as compared to the other four methods employed. Between the two methods, DTPA soil test method could be recommended for determining the available Zn status in the soils of Coimbatore district as it had given higher relationship with the actual yield, Bray's per cent yield, Zn content in leaves and leaf sheath and stem