**4. Conclusion**

Rates of seed-row placed ammonium sulfate above 20–30 kg S ha-1 were associated with significant reductions in emergence and biomass of many *Brassica* species/cultivars. Addition of 15 – 30 kg P2O5 ha-1 MAP along with AS often caused further reductions in emergence and biomass, although these were generally not large with *B. napus* cultivars. Differences in tolerance to seed row placed S and P were observed among cultivars. The cultivar 45H26 RR was the most tolerant of cultivars tested, while the most sensitive to seedrow placed S and S+P were *B. rapa, B. juncea* cv. Dahinda, and *Camelina sativa.* Further study is required in the field to establish whether seeds grown under different growing conditions and soil types have similar responses.

#### **5. Acknowledgements**

The financial support of Canola Council of Canada is greatly appreciated. *Brassica* and *Camelina* cultivar seeds for this study were obtained from Sherrilyn Phelps, Crop Development Specialist, Saskatchewan Ministry of Agriculture. Soil analysis was provided by ALS Laboratory Group, Saskatoon SK.

#### **6. References**


MAP were typically smaller with the *B. napus* and *B. carinata*. The *B. rapa* and *B. juncea cv. Dahinda* appeared more sensitive to the addition of the P along with S. Among these, the *B. rapa cv. ACS- C7* was particular sensitive to P addition for both rates (15 and 30 kg P2O5 ha-1). When AS alone was used, the injury in this cultivar was observed at AS rate of 40 kg S ha-1; but the reduction of emergence with both rates of P addition was observed at AS rate of 10 kg S ha-1 (Table 3). For the two cultivars of *B. juncea*, the *Dahinda* cultivar was less tolerant to AS with MAP than *Xceed 8571* (Table 3). The seed sample from which the *Dahinda* was taken was two years old, which may have affected seed vigour and reduced germination. Seeds with lower vigour result in greater reduction in emergence (Canada Canola Council

Overall, while the high rate (30 kg P2O5 ha-1) sometimes reduced emergence and biomass production compared to the low rate (15 kg P2O5 ha-1), often the reductions were not large (Table 3) for most cultivars tested. This agrees with earlier findings that the adverse effect of MAP-P on seed germination and biomass of canola became pronounced at rates over 30 kg

Rates of seed-row placed ammonium sulfate above 20–30 kg S ha-1 were associated with significant reductions in emergence and biomass of many *Brassica* species/cultivars. Addition of 15 – 30 kg P2O5 ha-1 MAP along with AS often caused further reductions in emergence and biomass, although these were generally not large with *B. napus* cultivars. Differences in tolerance to seed row placed S and P were observed among cultivars. The cultivar 45H26 RR was the most tolerant of cultivars tested, while the most sensitive to seedrow placed S and S+P were *B. rapa, B. juncea* cv. Dahinda, and *Camelina sativa.* Further study is required in the field to establish whether seeds grown under different growing conditions

The financial support of Canola Council of Canada is greatly appreciated. *Brassica* and *Camelina* cultivar seeds for this study were obtained from Sherrilyn Phelps, Crop Development Specialist, Saskatchewan Ministry of Agriculture. Soil analysis was provided

Brandt, S.A., Malhi, S.S., Ulrich, D.J., Kutcher, H.R., and Johnston, A.M. 2007. Seeding rate,

Canada Canola Council. 2005, Factors Affecting Canola Survival from Seeding to 21 Days after Emergence, Canola@Fact April 21, 2005, Winnipeg, MB Canada R3B 0T6. http://www.derekerbseeds.com/pdf/agronomy/canola/planting\_factorsaffecting

canolasurvivalfromseedingto21daysafteremergence.pdf

fertilizer level and disease management effects on hybrid versus open pollinated canola (*Brassica napus* L.). Canadian Journal of Plant Science, 87(2), pp. 255-

2005).

**4. Conclusion** 

P2O5 ha-1 (Qian and Schoenau, 2010).

and soil types have similar responses.

by ALS Laboratory Group, Saskatoon SK.

**5. Acknowledgements** 

**6. References** 

266.


 http://www.topcropmanager.com/index.php?option=com\_content&task\_content &task=view&id=896&Itemid=182


**4** 

 and Chunyun Guan5 *1Department of Plant Nutrition,* 

 *College of Resources and Environment, Hunan Agricultural University,* 

 *Agricultural Resources Use, Changsha,* 

*5National Center of Oilseed Crops Improvement,* 

*Common University, Changsha,* 

 *Fertilizer Resoureces, Changsha,* 

 *Hunan Branch, Changsha,* 

 *China* 

**Nitrogen Efficiency in Oilseed Rape** 

*3Hunan Provincial Key Laboratories of Farmland Pollution Control and* 

*4National Engineering Laboratory of High Efficiency Utilization of Soil and* 

N fertilizer application can guarantee the high yield of crop; it is a general method to improve the yield of crop (Zhang et al., 2010). However, not only N use efficiency was declined, but also environment contamination was serious day by day because of N fertilizer over application (Zhang et al., 2010). So, control and reduction in the amount of N fertilizer application is very important, it is necessary to dredge up the potential of N absorption and N use efficiency of crop. Oilseed rape (Brassica napus L.) is an important oil production crop in China. However, the N use efficiency and N efficiency of oilseed rape are very low (Schjoerring et al., 1995). The N application amount has reached 200-330kgN per ha (Schjoerring et al., 1995; Wiesler et al., 2001a) and it is increasing year by year. But the studies on differences of N efficiency in different oilseed rape varieties and breeding research of the oilseed rape with high N efficiency were relatively slower than other cereal (Liu et al., 2009). Oilseed rape requires high amounts of N for growth, but the N efficiency (seed yield per unit of accumulated N in plant) is very low. Consequently, it is necessary to improve the N efficiency (Rathke et al., 2006). In generally, N efficiency has two components: N uptake efficiency and N utilization efficiency (Sattelmacher et al., 1994). The differences of N efficiency between oilseed rape genotypes are significant (Wiesler et al., 2001b; Christian et al., 1999). Kessel et al., 1999 has been measured N concentration of organs in different oilseed rape genotypes, results suggested that oilseed rape possess the 2 physiological characteristics (low N concentration in dropped leaves, high N harvesting

Zhen-hua Zhang1,2,3,4, Hai-xing Song1,2,3,4

**1. Introduction** 

 

Corresponding Author

 **and Its Physiological Mechanism** 

*2Hunan Provincial Key Laboratory of Plant Nutrition in* 

Qian, P., Schoenau, J. J., and Huang, W. Z. 1992. Use of ion exchange membranes for the routine soil testing. Comm. Soil Sci Plant. Anal. 23(15 & 16): 1791-1804 SAS Institute. 2008. Version 9.2. SAS Inst. Inc., Cary, NC.
