tailieunhanh - Seasonal dynamics of nitrogen in cultivated soil at Giao Thuy district, Nam Đinh province

This paper focuses on evaluating the nitrogen mineralization and NH4 + and NO3 - leaching from the root zone in cultivated soils of Giao Thuy district, Nam Dinh province using Synthetic accumulation (SIA) method. Main findings reveal that total N content in vegetable fields and rice-vegetable-rotational fields ranges from – kgN ha-1, and from – kgN ha-1, respectively. | Vietnam Journal of Science and Technology 56 (2C) (2018) 187-193 SEASONAL DYNAMICS OF NITROGEN IN CULTIVATED SOIL AT GIAO THUY DISTRICT, NAM DINH PROVINCE Ly Thi Thu Ha1, 2, *, Ngo The An 1, Nguyen Thi Ha 2, *, Andreas Schwarz3, Minghua Zhou4, Nicolas Brüggemann4, Wolf-Anno Bischoff3 1 Faculty of Environment, Vietnam National University of Agriculture, Trau Quy, Gia Lam, Ha Noi, Viet Nam 2 Faculty of Environment, Hanoi University of Science, 334 Nguyen Trai, Thanh Xuan, Ha Noi, Viet Nam 3 Gutachterbüro TerrAquat Germany, Schellingstr. 43, 72622 Nürtingen, Germany 4 Institute of Bio-and Geosciences-Agrosphere, Forschungszentrum Jülich, Leo-Brandt-Strasse, Jülich, Germany * Email: ; nguyenthiha@ Received: 8 May 2018; Accepted for publication: 22 August 2018 ABSTRACT This paper focuses on evaluating the nitrogen mineralization and NH4+ and NO3- leaching from the root zone in cultivated soils of Giao Thuy district, Nam Dinh province using Synthetic accumulation (SIA) method. Main findings reveal that total N content in vegetable fields and rice-vegetable-rotational fields ranges from – kgN ha-1, and from – kgN ha-1, respectively. Total N is also significantly different between saline paddy-fields and fresh-water fields, varies between – kgN ha-1 and from – kgN ha-1, respectively. NO3- accounts for a larger proportion in vegetable fields and accumulated higher during the dry season; NH4+ predominates in paddy fields and accumulated mainly in rainy season. The N leaching losses decreased in the following order: vegetable, rice-vegetable rotation, non-saline and saline soil. Keywords: fertilizer application, nitrogen fertilizer, leaching. 1. INTRODUCTION The role of soil nitrogen (N) mineralization is essential for the plant uptake in all agricultural systems [1]. The N cycle is complicated but it’s process generally consists .