The Effect of Nitrogen Rate on Field Pennycress 

Seed Yield and Oil Content 

H. Rukavina1, D.C. Sahm1, L.K. Manthey2 and W.B. Phippen1

1School of Agriculture, Western Illinois University, Macomb, IL, USA

2USDA-ARS, National Center for Agricultural Crop Utilization Research, Peoria, IL, USA 

ABSTRACT

Field pennycress (Thlaspi arvense L.) is a new potential oilseed crop 

that is currently being evaluated as a domestic source of biodiesel fuel. The 

research based information about pennycress nitrogen requirements will help 

producers apply optimal nitrogen rate and minimize production costs. 

Therefore, this study was initiated to evaluate the effect of nitrogen 

fertilization rate on pennycress seed and biomass yield and oil content. 

A growth chamber experiment was conducted on the spring annual 

pennycress breeding line ‘Spring-32’ from Montana, with five nitrogen rates 

ranging from 25 to 125 lbs. of nitrogen per acre. In addition, the effect of 

nine nitrogen fertilization treatments on yield and oil content of the winter 

breeding line ‘W-12’ was evaluated in a field experiment. 

The greatest seed and biomass yields of 0.32 and 0.48 g per plant 

respectively, were achieved with 50 lbs. of nitrogen per acre in a growth 

chamber environment. Greater nitrogen rates did not result in further seed 

and biomass yields increasing. A rate of 50 lbs. of nitrogen also resulted in 

the greatest pods number per plant. The greatest seed number per plant was 

achieved with 75 lbs. of nitrogen per acre. Height of the plants that received 

the rate of 25 lbs. of nitrogen per acre was higher than that of non-fertilized 

control but did not differ from height achieved with increased nitrogen rates. 

In the field study, the greatest seed yield of 793 lbs. per acre respectively 

was achieved with amount of 50 lbs. of N per acre when one half of nitrogen 

was applied in the fall and another half in the spring. Greater fertilizer rates 

of 75 and 100 lbs. of nitrogen per acre applied in fall did not result in greater 

seed yield. Nitrogen fertilization rates had no effect on the oil content in the 

seed in both studies. 

Our results indicate that the optimal nitrogen rate in pennycress 

production is likely 50 lbs. of nitrogen per acre when fertilizer application is 

divided on fall and spring. This information will be further evaluated in the 

field experiments with pennycress populations from different geographical 

regions.

This project was supported by the Agriculture and Food 

Research Initiative competitive grant # (2010-85117-20535) 

of the USDA National Institute of Food and Agriculture.

RESEARCH FUNDING

MATERIALS AND METHODS

Growth chamber experiment:

A growth chamber experiment was conducted on the non-dormant spring 

pennycress breeding line ‘Spring-32’ from Montana (Figure 1). Growth 

chamber conditions were set on 18 hour photoperiod (7.9 μE/m2/sec ) with 

day and night temperatures of 24°C and 20°C, respectively. The pennycress 

seed was planted for germination into seeding trays filled with germination 

medium. After germination, five replicate uniform seedlings for each 

nitrogen treatment were transplanted into individual 7.5 cm square pots. 

Nitrogen treatments comprised of non-fertilized control and five nitrogen 

rates representing a range from 25 to 125 lbs. of nitrogen per acre. The 

source of nitrogen was granulated urea fertilizer (46-0-0). Fertilizer was 

hand applied at the time of seedlings transplanting. Plants were watered by 

wicking system throughout the experiment. Plants were hand harvested 

approximately 60 days after transplanting at the time of full maturity. 

Field experiment: 

A field study was conducted at the Western Illinois University Agricultural 

Research Farm in Macomb, IL. The dormant winter pennycress breeding 

line ‘W-12’ was planted at a rate of 4 lbs. of seeds per acre in September of 

2010. The experiment was laid out as a completely randomized design with 

four replicates. Nitrogen fertilization comprised of non-fertilized control 

and eight different treatments (Figure 2). Treatments included: fall 

application of 25, 50, 75 and 100 lbs. of nitrogen per acre (25 N, 50 N, 75 N, 

and 100 N); fall application of 25 and 50 lbs. of nitrogen per acre with 

application of 25 lbs. of nitrogen in spring (25 NF + 25 NS and 50 NF + 25 

NS) and fall application of 25 and 50 lbs. of nitrogen combined with 10 lbs. 

of sulphur per acre (25 N + 10 S and 50 N + 10 S). The source of sulfur was 

Disper-Sul (90%). All plots were hand harvested in June of 2011. Seed and 

biomass yields were assessed after drying the plant material and seed. 

Oil and data analysis: 

Total oil content was determined by nondestructive pulsed NMR (Bruker

Minispec PC 120, 180-mm absolute probehead) on whole pennycress seed. 

Medium-chain triglycerides were extracted and derivatized into fatty acid 

methyl esters for gas chromatography analysis. The fatty acid methyl esters 

were analyzed using an Agilent 6890 gas chromatograph with a flame 

ionization detector. Analysis of variance (ANOVA) was performed with 

SAS software. Levels of statistically significant factors were compared with 

Student Newman Keuls (SNK) method for multiple comparisons.

INTRODUCTION

Field pennycress (Thlaspi arvense L.) is a new potential oilseed crop that is 

currently being evaluated as a domestic source of biodiesel fuel. Pennycress 

belongs to Brassicaceae family and grows as a common weed throughout 

temperate climate in North America. The seed contains between 20-36 wt % 

of oil with high contents of erucic, linoleic and other unsaturated fatty acids 

(Moser et al., 2009). This oil profile enables production of biodiesel with a 

high cetane number and excellent low temperature properties.

Nitrogen is one of the most expensive agricultural inputs in oilseed 

production (Gan et al., 2008). Literature indicates that important oilseed 

crops from the Brassicaceae family, like rapeseed and canola, have high 

demands for nitrogen (Balint at al., 2008; Gan et al., 2008). Currently, no 

information is available on the response of pennycress to nitrogen and other 

nutrients. Producers need information on pennycress nitrogen requirements to 

apply optimal nitrogen rate and minimize production costs.

A growth chamber and the field experiment were consequently initiated to 

evaluate the effect of nitrogen fertilization rate on pennycress seed and 

biomass yield, yield components, and seed oil content and constituents. 

RESULTS

Growth chamber experiment:

Nitrogen fertilizer rate was a significant factor influencing pennycress seed 

and biomass yield, pods and seeds number per plant as well as final height of 

the plants. Nitrogen fertilization had no effect on total oil content in 

pennycress seed. Seed and biomass yields increased as fertilizer rate was 

increased from 0 to 50 lbs. of nitrogen per acre (Figure 3). Further nitrogen 

rate increasing did not contribute to greater seed and biomass yield. 

Likewise, the number of pods and seeds per plant increased as nitrogen rate 

increased to 50 and 75 lbs. per acre respectively. Nitrogen rate of 25 lbs. per 

acre increased plant height relative to non-fertilized control; nitrogen rates 

greater than 25 lbs. of nitrogen per acre did not result in further height 

increase. 

Field experiment: 

Nitrogen fertilization had a significant effect on pennycress seed and biomass 

yield, tillering, and plant stand in the field. Nitrogen fertilization effect was 

not significant for plant height. Nitrogen rate of 50 lbs. per acre split on fall 

and spring application increased the seed and biomass yield as compared with 

non-fertilized control. The same yields were achieved with fall nitrogen of 75 

and 100 lbs. per acre and with combination of 50 lbs. of nitrogen and 10 lbs. 

of sulphur. The nitrogen rate of 100 lbs. per acre and 50 lbs. of nitrogen 

combined with 10 lbs. of sulphur per acre were the only fertilization 

treatments that increased plant stand relative to non-fertilized control. There 

were no differences among fertilizer treatments regarding tiller number but 

some treatments produced more tillers than non-fertilized control. Nitrogen 

fertilization treatments had no effect on total oil, oleic and erucic content in 

pennycress seed. The significant effect of fertilization on linolenic acid 

content is a consequence that 50 NF +25 NS treatment resulted in slightly 

higher linolenic acid content as compared with other treatments. 

CONCLUSIONS

The greatest pennycress seed yield in a growth chamber and the field 

experiment was achieved with a total nitrogen fertilizer rate of 50 lbs. per 

acre. In the field experiment, the greatest seed yield of 793 lbs. per acre was 

achieved when the nitrogen rate of 50 lbs. per acre was divided on fall and 

spring application. Seed yield increase obtained with 50 lbs. of nitrogen was 

480 lbs. per acre or approximately 60 gallons of biodiesel. Nitrogen 

fertilization cost would likely be less than the profit obtained with such yield 

increase. 

LITERATURE CITED

Balint, T., Z. Rengel, and D. Allen. 2008. Australian canola germplasm differs in 

nitrogen and sulphur efficiency. Aust. J. Agric. Res. 59: 167-174. 

Gan, Y., SS. Malhi, S. Brandt, F. Katepa-Mupondwa, and C. Stevenson. 2008. 

Nitrogen use efficiency and nitrogen uptake of juncea canola under diverse 

environments. Agron. J. 100: 285-295. 

Moser, B.R., G. Knothe, S. F. Vaughn, and T. A. Isbell. 2009. Production and 

evaluation of biodiesel from field pennycress (Thlaspi arwense L.) oil. Energy 

Fuels 23: 4149–4155. 

Figure 1. The stage of flowering of field pennycress spring breeding 

 line ‘Spring-32’ in the growth chamber nitrogen rate 

 evaluation study. 

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0 25 50 75 100 125

Seed yield (g/plant)

Nitrogen rate (lbs./acre)

b

b

a

a

a

a

Figure 3. The effect of nitrogen fertilizer rate on pennycress seed yield in a growth

 chamber experiment. Yield values marked with the same letter are not 

 significantly different at 0.05 probability level. 

Trait

Seed yield 

(lbs./acre)

Biomass yield 

(lbs./acre)

Stand density 

(plants/acre)

Number of tillers 

per plant

Plant height 

(cm)

ns#

Total oil content 

(%, dry weight 

basis)

ns

C18:1d9

Oleic acid 

content (%)

ns

C18:3d9

Linolenic acid 

content (%)

C22:1

Erucic acid 

content (%)

ns Fertilization 

treatment

0 N* 313.1 c 1,175.8 c 13,403 c 11.5 b 78.3 34 9 21.5 b 37.2

25 N 531.7 bc 2,041.0 bc 22,450 bc 15.5 a 86.5 34.5 9.1 21.7 b 36.7

50 N 557.3 bc 2,212.0 bc 34,345 abc 15.5 a 82.5 34.8 9.1 21.6 b 36.8

75 N 810.3 ab 3,307.5 ab 42,219 abc 14.0 ab 86.3 34.6 9 21.8 b 37

100 N 994.9 a 4,151.8 a 62,156 a 16.8 a 85.5 34.6 9 21.8 b 36.6

25 NF + 25 NS 793.0 ab 3,035.3 ab 28,649 bc 14.3 ab 88.3 34.3 9.1 21.7 b 36.8

50 NF + 25 NS 611.5 bc 2,480.6 bc 44,230 abc 15.0 a 85.8 34.8 9 22.2 a 36.5

25 N + 10 S 547.4 bc 2,184.1 bc 30,659 bc 15.5 a 88.5 36.2 8.9 21.6 b 36.6

50 N + 10 S 840.7 ab 3,474.9 ab 49,591 ab 14.3 ab 85.8 34 9 21.7 b 36.8

Table 1. Mean values of field pennycress seed and biomass yield, stand, tillering, height, total oil content and content of oleic, linolenic, and erucic acid 

 obtained with nine fertilization treatments in the field experiment. 

* , N: nitrogen rate (lbs./acre); NF: nitrogen rate applied in fall; NS: nitrogen rate applied in spring; S: sulfur rate applied.

# , Within columns, means followed by the same letters are not significantly different at 0.05 probability level. ns: not significant.

Figure 2. Pennycress field plots, (A) non-fertilized control (O N),

 (B) field plot treated with 50 lbs. of nitrogen per acre 

 split on fall and spring application (25 NF + 25 NS). 

 Photo taken on June 14, 2011. 

A B