Effect of different levels of nitrogen on leaf chlorophyll content and performance of maize under varying soil nitrogen status in rainfed Alfisols of Karnataka.

摘要

A field experiment was conducted in two stages under rainfed conditions to study the leaf chlorophyll content and the response of maize crop in terms of yield to graded levels of applied nitrogen (N₁:0, N₂:50, N₃:100, N₄:150, N₅:200 and N₆:250 kg ha-1) under varying soil N fertility strips (F₁: very low, F₂: low, F₃: medium, F₄: high and F₅: very high). For this the technique of field experimentation involving creation of wide soil fertility variation in one and the same field is adopted following the STCR approach. Results showed that among the different fertility strips, highest total chlorophyll content was noted in the high fertility strip (F₄) with a mean value of 0.344 mg g-1 of fresh weight followed by F₃ with 0.323 mg g-1 of fresh weight. There was very good response in terms of grain yield up to the application of 250 kg N ha-1 (N₆) in the low (F₂) and medium (F₃) fertility strips whereas in the high N fertility strip (F₄), yield showed a plateau beyond 200 kg N ha-1 of applied N. The varying N levels produced similar trend in the stover yield as that of grain yield in different fertility strips.