The relationship between mineralized NH4+-N and NO3+ N and relative response of dry matter production on corn on regosol soil of Kediri (Indonesia)
1981
Priyono, S. | Dharmaputra, T.S. (Universitas Brawijaya, Malang (Indonesia). Fakultas Pertanian. Departemen Teknologi Pertanian)
Twenty Regosol soils of Kediri were incubated for 14 days based on the method of Bremner. Incubation was done without and with nitrogen application (90 and 180 kg/ha application rate). After 14 days NO3- N and NH4+- n were determined. Corn, Arjuna variety, was planted into a plastic pot containing 1 kg soil sample (with and without nitrogen application). At 35 days of age the corn was harvested. The relative response of dry matter production to mineralized nitrogen was investigated. It was found that the relative response of corn dry matter production to (N03 - N + NH4 - N) was a quadratic one. The same response was found when relative response of total nitrogen uptake was used instead of relative total dry matter production. Application of Cake and Nelson's method, resulting in critical levels of 50 ppm NO3- + NH4+-N).
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