Abstract
In the present study, integration of nitrogen (N) and zeolite on growth, photosynthesis, yield and yield components, nitrate reductase activity, and plant nutrient content on canola (Brassica napus L. cv. SLM046) was evaluated during two growing seasons (2010 and 2011) at East Azerbaijan Research Center for Agriculture and Natural Resources, Tabriz, Iran. The experiment was conducted as a 4 × 5 factorial design with three replications. Different levels of zeolite (0, 4, 8, and 12 ton ha−1) and nitrogen (N; 0, 150, 200, 250, and 300 kg ha−1) were added and mixed with soil thoroughly. According to combined analysis of variance, effect of year was significant only on silique number per plant, respiration rate, and iron (Fe) content. Also results indicated that N fertilizer increased plant height, silique number per plant, seed number per silique, 1000-seed weight, and finally seed yield. Similarly, zeolite increased yield and yield components whereas plant height was not affected by zeolite in the second year. Oil yield decreased due to N and zeolite application. In addition, photosynthesis and respiration improved on account of N and zeolite treatments. Nitrate reductase activity significantly was promoted by N and zeolite. Furthermore, micro- and macroelements were affected by N or zeolite application, so that N and zeolite decreased P content whereas N increased N, K, Fe, and zinc. In general our results demonstrated that zeolite application can increase canola growth and production, which may be through increasing N-use efficiency and improving soil physical characteristics.
Acknowledgments
The research was carried out in the framework of a project (4-35-10-9001) funded by Iranian Ministry of Jahade Agriculture, AREEO (Agricultural Extension, Education, and Research Organization).