HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Zhao, R.-F. Articles by Römheld, V. Search for Related Content PubMed Articles by Zhao, R.-F. Articles by Römheld, V. Agricola Articles by Zhao, R.-F. Articles by Römheld, V. Related Collections Nutrients Maize Management Maize Nutrient Management Nitrogen

Fertilization and Nitrogen Balance in a Wheat–Maize Rotation System in North China

^a Dep. of Plant Nutrition, China Agricultural Univ., Beijing, 100094, P. R. China
^b Dep. of Plant and Soil Sciences, Oklahoma State Univ., Stillwater, OK 74078, USA
^c Institute of Plant Nutrition, Univ. of Hohenheim, 70593 Stuttgart, Germany

View larger version (16K): [in a new window]   Fig. 1. Method of optimizing N fertilization for winter wheat (left) and summer maize (right) is based on the plant N demands and soil N supply at three growth stages. Soil Nmin was tested in the effective root depth at different growth periods. Nmin target value included N demand by wheat/maize shoot and N demand by root. In the first year (1999–2000), for winter wheat, Nmin target value from regreening to shooting was 120 kg N ha–1, and from shooting to harvest was 125 kg N ha–1. In the years of 2000–2001, 2001–2002, and 2002–2003, the Nmin target value from regreening to shooting was adjusted to 90 kg N ha–1 and the Nmin target value from shooting to harvest was adjusted to 110 kg ha–1.

View larger version (26K): [in a new window]   Fig. 2. Effect of N fertilization treatments (No N: no N fertilization; Con. N: conventional N fertilization; and Opt. N: optimized N fertilization) on grain yields of winter wheat and summer maize in the 4 experimental yr. Different letters indicate significant differences among treatments at P = 0.05.

View larger version (25K): [in a new window]   Fig. 3. Nitrogen fertilization strategies and concentrations of nitrate (NO3)–N in soil depths of 0 to 30, 30 to 60, 60 to 90, and 0 to 90 cm during the 4 experimental yr. No N, Con. N, and Opt. N represent no N fertilization, conventional N fertilization and optimized N fertilization treatment, respectively.

View larger version (32K): [in a new window]   Fig. 4. Distribution of nitrate (NO3)–N in 0- to 200-cm soil profile before winter wheat planting in 1999/2000 and after winter wheat and summer maize harvest from 1999 to 2003. No N, Con. N and Opt. N represent no N fertilization, conventional N fertilization, and optimized N fertilization treatment, respectively.