Path analysis of soil zinc fractions and rice yield as influenced by zinc enriched organic manures.

摘要

A pot experiment was conducted with rice (var. ADT 36) as test crop using five levels of zinc (Zn) (0, 1.25, 2.50, 3.75 and 5.0 mg Zn/kg) and four sources of organic manures, to investigate the relationships between soil Zn fractions and rice yield by employing path coefficient analysis. The sources of organic manures are farmyard manure (FYM), FYM+green leaf manure (GLM), composted coir pith (CCP), and CCP+GLM. The grain and straw yield of rice per pot were recorded. Direct effects of zinc fractions was in the order of water soluble+exchangeable Zn>complexed Zn>occluded Zn>organically bound Zn>residual Zn. The data also showed that the indirect effect of water soluble+exchangeable and complexed Zn fractions through its association with occluded form was found to be positive and significant. Whereas the contribution of occluded and residual Zn fraction through organically bound fractions was significant through the other fractions..