Journal of Food, Agriculture and Environment

Variations of the amount of N₂ fixation and yield with soil inorganic N concentration in soybean in black soil (Haplocryoll) in Northeast China

Author(s):

Jun Yan, Xiao-Zeng Han *

Recieved Date: 2013-09-22, Accepted Date: 2014-01-16

Abstract:

Variations of the amount of N₂ fixation of soybean with different soil inorganic N concentration in black soil (Haplocryoll) in Northeast China were evaluated in this study. A pot experiment was conducted to quantify and investigate the amount of N₂ fixation of soybean with soil inorganic N concentration ranging from 19.5 to 90.6 mg kg^-1, which derived from split application of fertilizer N (urea). The amount of N₂ fixation of Hefeng 35 was calculated by N difference method with little modification. The nodule number, dry weight and size at R2 stage were also determined. N fertilizer had effect on the soil inorganic N availability, which was the direct factor to soybean nodulation, N₂ fixation and yield. The maximum amount of N₂ fixation of Hefeng 35 (3.15 g pot^-1) was produced with soil inorganic N concentration 32.1 mg kg^-1 in the N2 treatment. The maximum yield was produced of Hefeng 35 (51.8 g pot^-1) with soil inorganic N concentration 57.7 mg kg^-1 in the N4 treatment. The amount of N₂ fixation and yield decreased 53.3% and 5.2%, respectively, in the N6 treatment with soil inorganic N concentration 90.6 mg kg^-1 than that of in the N1 treatment. Reduction in N₂ fixation with soil inorganic N concentration has been ascribed to inhibition of nodule number, dry weight and size. Both the amount of N₂ fixation and yield had second order polynomial response curve to soil inorganic N concentration. Otherwise, the required soil inorganic N concentration for the highest soybean yield and N₂ fixation were different. The soil inorganic N concentration should be maintained 32.1-45.8 mg kg^-1 for biological requirement; maintained 45.8-71.3 mg kg^-1 for production requirement; maintained 45.8 mg kg^-1 for ecological requirement in Black soil in Northeast China. The soil inorganic N concentration should be regulated with N application in terms of requirement in practice in black soil in Northeast China.

Keywords:

Nitrate, N accumulation, N difference, symbiotic fixation, soybean

---

Journal: Journal of Food, Agriculture and Environment
Year: 2014
Volume: 12
Issue: 1
Category: Environment
Pages: 378-384

---

Full text for Subscribers

---

Information:

Note to users

The requested document is freely available only to subscribers/registered users with an online subscription to the Journal of Food, Agriculture & Environment. If you have set up a personal subscription to this title please enter your user name and password. All abstracts are available for free.

Article purchasing

If you like to purchase this specific document such as article, review or this journal issue, contact us. Specify the title of the article or review, issue, number, volume and date of the publication. Software and compilation, Science & Technology, all rights reserved. Your use of this website details or service is governed by terms of use. Authors are invited to check from time to time news or information.

---

Purchase this Article:   20 Purchase PDF Order Reprints for 15

---

Share this article :