Subscribe Now Subscribe Today
Research Article
 

Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes



M. Begdelo, A.H. Shirani Rad, G. Noormohammadi and A.A. Tajalli
 
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail
ABSTRACT

Field experiment was conducted in Qazvin, Iran during 2009-2010 growing season aimed at optimizing nitrogen rates under different irrigation regimes for production of turnip rape (Brassica campestris L.-cv. Goldrush). The experiment was conducted using a randomized complete block, factorial design with three replicates. Experimental treatments were irrigation in four levels (I: I1= irrigation on the basis of 80 (control), I2 = 100, I3 = 120 and I4 = 140 mL evaporation from the class A pan) and four nitrogen fertilizer rates (N: N 1= 0, N2 = 50, N3 = 100, N4 = 150 kg ha-1). It was shown that increasing irrigation rate significantly increased 1000 seeds weight, seed yield, seed oil yield, biomass yield and harvest index as control irrigation (80 mL evaporation from the class A pan) had a significant preference in comparison to 140 mL evaporation from the class A pan. Generally application of 100 and 150 kg N ha-1 in control irrigation had a significant preference in comparison to other treatments. The highest seed yield and seed oil yield obtained by application of 150 kg N ha-1 in control irrigation by average of 5586 and 2348 150 kg ha-1, respectively. The interaction effect of irrigationxnitrogen had not a significant increase on harvest index.

Services
Related Articles in ASCI
Search in Google Scholar
View Citation
Report Citation

 
  How to cite this article:

M. Begdelo, A.H. Shirani Rad, G. Noormohammadi and A.A. Tajalli, 2011. Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes. Asian Journal of Agricultural Research, 5: 243-249.

DOI: 10.3923/ajar.2011.243.249

URL: https://scialert.net/abstract/?doi=ajar.2011.243.249
 
Received: August 18, 2011; Accepted: November 01, 2011; Published: December 14, 2011



INTRODUCTION

Edible oil is one of the most important food sources for human and consumption of it is necessary due to providing energetic and essential fatty acids. Production of edible oil in Iran is not in a desirable level, therefore it is necessary to have a long term and consistent schedule aimed to independence in edible oil production. Increase of edible oil production could be possible by introducing oilseed crops which is adaptable with weather condition in Iran in addition to amending planting methods and improving cultivars with high oil rate and enhancing yield. Recently production of rapeseed as a well adapted oilseed crop with weather condition in Iran taking into consideration (Bala-Deh, 2000). Agricultural cultivars of rapeseed (Brasssicaseae) belonging to two species of common rapeseed (Brassica napus L.) and turnip rape (Brassica campestris L. or Brassica rapa L.) (Azizi et al., 1998a). Turnip rape has been cultivated since about 2000 years ago in an extend area from west Europe to China and Korea and from Norway to African desert and India (Hedge, 1976) and its seeds contains 40-45% oil and 20-25% protein (Nuttall et al., 1987).

Nitrogen is the most important nutrient affecting yield quantity and quality and one of the most important factors determining crop production as providing nutrient needs during cultivation in a crop such as turnip rape economically would be highly beneficial for farmers and industrialists. No awareness of turnip rape nutrient needs followed by inappropriate application of chemical fertilizers not only do not increase yield, also cause environmental pollutions, disorder in agro-ecosystems balance, water table pollution, agricultural soils compression and decrease of efficiency and profitability. Soil total harvested nitrogen in production of 1 ton seed ha-1 of rapeseed is about two times more than soil total harvested nitrogen in production of the same rate of wheat (Azizi et al., 1998a). Researchers reported nitrogen affecting seed yield by increasing number of branches and buds in plant (Grant and Bailey, 1993). Nitrogen application increase the number of flowering branches, flowering stage period, total dry weight and silique dry weight (Zangani, 2001). Study of nitrogen rates effect on turnip rape seed yield revealed that application of 120 kg N ha-1 increased yield (Ali et al., 1996). Australian researchers reported nitrogen fertilizer increased turnip rape seed yield although its effect on dry weight, silique length, 1000 seeds weight, number of seeds per silique, seed oil content and nutrients concentration rate in silique and seed was negligible (Mason and Brennan, 1998). Chauhan et al. (1993) also reported increasing nitrogen rate increased number of siliques but had not a prominent effect on 1000 seeds weight and number of seeds per silique (Chauhan et al., 1993).

Water stress could influence germination percentage and rate and the reaction of various plants seed and various species of a plant to this stress have an extended range (Azizi et al., 1998a). Water stress decrease seed yield mainly by decrease of number of silique per plant (Ghasemi and Isfahani, 2006). Combination of appropriate irrigation and high rates of nitrogen increase rapeseed yield at a rate of four times and this increase was more than two times of total increase of these factors when applied separately. The significant interaction effect of irrigation and nitrogen on seed yield revealed that sufficient rates of water and nitrogen probably cause to increase of root development and nitrogen use efficiency (Krogman and Hobbs, 1975).

Therefore, the main objective of this study was to assess the effects of nitrogen rates on 1000 seeds weight, seed yield, seed oil yield, biomass yield and harvest index under different irrigation regimes.

MATERIALS AND METHODS

An experiment was conducted at experimental farm in Qazvin, Iran (49°57'E, 36°18'N; 1314 m a.s.l) during 2009-2010 growing season aimed to assess nitrogen rates and irrigation regimes effects on some agronomic traits of turnip rape (Brassica campestris L.). Qazvin is a semi arid region and receives average annual rainfall of 312 mM. The soil type where the experiment took place was a clay loam soil. The experimental design was a factorial arrangement in the form of randomized complete block design with three replications. Treatments were included two agents: irrigation in four levels (I: I1 = irrigation on the basis of 80 (control), I2 = 100, I3 = 120 and I4 = 140 mL evaporation from the class A pan) and nitrogen fertilizer in four levels (N: N1 = 0, N2 = 50, N3 = 100, N4 = 150 kg N ha-1) in the form of Urea. N fertilizer applied in three stages: one-third in 2-4 leaves stage, one-third in stemming stage and one-third in flowering stage. Each experimental plot consisted of 4 rows, 4 m long with 30 cm spaced between rows and 4 cm distance between plants on the rows. Goldrush (Brassica campestris L.-cv. Goldrush) was used as the turnip rape cultivar. P and K were applied at a rate of 75 kg P2O5 ha-1 and 50 kg K2O ha-1 pre-plant in the form of di-ammonium phosphate and K2SO4, respectively and were incorporated in the soil before sowing. Seeds were planted on 4 Oct. 2009. The plants were thinned after complete emergence in the 6 leaf stage as keeping on rows about 4 cm. The final harvest was performed at physiological maturity on 8-11 Jun. 2010. At harvest stage the two middle rows were used for sampling and measured parameters. For sampling ten plants from the middle of each plot were harvested. Also the crop was kept free of weeds by applying 2.5 L ha-1 Trifluralin pre-plant.

Studied traits: One Thousand seeds weight, seed yield, seed oil yield, biomass yield and harvest index. Analyses were performed using the MSTATC software. A factorial analysis of variance (ANOVA) was performed for all parameters. In addition the Duncan’s Multiple Range Test (DMRT) (p = 0.05) was used to conduct mean comparison.

RESULTS AND DISCUSSION

1000 seed weight (TSW): The results of factorial analysis of variance revealed that the simple effect of irrigation and nitrogen and the interaction effect of them on 1000 seeds weight were significant at p = 0.01 (Table 1). Comparison of means in different irrigation regimes showed that 1000 seeds weight decrease by irrigation rate reduction as the highest 1000 seeds weight by average of 4.75 g and the lowest 1000 seeds weight by average of 3.15 g obtained in I1 and I4, respectively (Table 2). Generally 1000 seeds weight is the function of rapidity and duration of seed filling which provided by current photosynthesis and re-translocation in plant. Therefore, 1000 seeds weight reduction due to decrease of irrigation rate is the result of water shortage effects in seed filling period which cause to reduction of absorption and translocation of water and nutrients in plant and reduction of nutrients translocation rapidity to seeds (Azizi et al., 1998a).

Table 1: Factorial analysis of variance components (irrigation, nitrogen and their interactions) for assessed traits
Image for - Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes
*, **significant at 5 and 1%, respectively, ns: not significant

Table 2: Effects and means comparisons (simple effect) of irrigation and nitrogen on assessed traits
Image for - Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes
Any two means not sharing a common letter differ significantly from each other at 5% probability

Image for - Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes
Fig. 1: Interaction effect of N rate and irrigation on 1000 seeds weight (g)

Also 1000 seeds weight significantly increased by increasing nitrogen rate as the highest 1000 seeds weight by average of 4.5 g and the lowest 1000 seeds weight by average of 3.1 g obtained in N4 and N1, respectively (Table 2). These results agree with the results obtained by some other researchers (Ghasemi and Isfahani, 2006; Krogman and Hobbs, 1975; Jang et al., 1987).

Study of interaction effect of irrigation and nitrogen revealed that the highest 1000 seeds weight by average of 5.5 g and the lowest 1000 seeds weight by average of 2.5 g obtained in I1N4 and I4N1, respectively (Fig. 1).

Seed yield: The results of factorial analysis of variance revealed that the simple effect of irrigation and nitrogen and the interaction effect of them on seed yield were significant at p = 0.01 (Table 1). Comparison of means in different irrigation regimes showed that the highest seed yield by average of 4688 150 kg ha-1 and the lowest seed yield by average of 1711 150 kg ha-1 obtained in I1 and I4, respectively (Table 2). According to previous studies seed yield increase in response to irrigation rate increase is mainly due to increase of number of silique per plant and seed weight which agree with our results. Also seed yield increased by nitrogen rate increase. The highest seed yield by average of 3991 150 kg ha-1 and the lowest seed yield by average of 2381 150 kg ha-1 obtained in N4 and N1, respectively (Table 2). Generally increasing nitrogen application enhance seed yield as non application of nitrogen cause to a prominent decrease of seed yield (Zangani, 2001; Ali et al., 1996; Mason and Brennan, 1998; Chauhan et al., 1993; Ghasemi and Isfahani, 2006).

Study of interaction effect of irrigation and nitrogen showed that the highest seed yield by average of 5586 150 kg ha-1 and the lowest seed yield by average of 1286 150 kg ha-1 obtained in I1N4 and I4N1, respectively (Fig. 2). These results agree with Fathi et al. (2002).

Seed oil yield: The results of factorial analysis of variance revealed that the simple effect of treatments and their interaction on seed oil yield were significant at p = 0.01 (Table 1). Comparison of means in different irrigation regimes showed that seed oil yield decreased by irrigation rate reduction as the highest seed yield by average of 1956 150 kg ha-1 and the lowest seed yield by average of 627.8 150 kg ha-1 obtained in I1 and I4, respectively (Table 2). The significant reduction of seed oil yield by irrigation rate decrease could be attributed to genetic dependence of this trait to seed oil content which shows the same reaction to water stress. Appropriate irrigation regime could increase seed oil yield in this plant (Faraji et al., 2005).

Image for - Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes
Fig. 2: Interaction effect of N rate and irrigation on seed yield (kg ha-1)

Image for - Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes
Fig. 3: Interaction effect of N rate and irrigation on seed oil yield (kg ha-1)

Also the reduction of seed oil yield in no nitrogen application in comparison to nitrogen application observed as the highest seed oil yields by average of 1519 and 1565 150 kg ha-1 obtained in N3 and N4, respectively and the lowest seed oil yield by average of 924.8 150 kg ha-1 obtained in N1 (Table 2). These results agree with the results reported by some other researchers (Grant and Bailey, 1993; Zangani, 2001; Mason and Brennan, 1998; Chauhan et al., 1993; Ghasemi and Isfahani, 2006).

Study of interaction effect of irrigation and nitrogen on seed oil yield revealed that the highest seed oil yield by average of 2348 150 kg ha-1 and the lowest seed oil yield by average of 469.6, 150 kg ha-1 obtained in I1N4 and I4N1, respectively (Fig. 3).

Biomass yield: The results of factorial analysis of variance revealed that the simple effect of irrigation and nitrogen and the interaction effect of them on biomass yield were significant at p= 0.01 (Table 1). Comparison of means in different irrigation regimes showed that biomass yield decrease by irrigation rate reduction as the highest biomass yield by average of 14940 150 kg ha-1 and the lowest biomass yield by average of 8838 150 kg ha-1 obtained in I1 and I4, respectively (Table 2). These results agree with Azizi et al. (1998b). The biomass yield was affected by different N rates and increased with N fertilization as the highest biomass yields by average of 13530 and 12960 150 kg ha-1 obtained in N4 and N3, respectively and the lowest biomass yield by average of 9920 150 kg ha-1 obtained in N1 (Table 2),these results agree with Azizi et al. (1998b).

Image for - Nitrogen Rates Effect on Some Agronomic Traits of Turnip Rape under Different Irrigation Regimes
Fig. 4: Interaction effect of N rate and irrigation on biomass yield (kg ha-1)

Study of interaction effect of irrigation and nitrogen on biomass yield revealed that the highest biomass yields by average of 17190 and 16350 150 kg ha-1 obtained in I1N4 and I1N3, respectively and the lowest biomass yields by average of 7921 and 8762 150 kg ha-1 obtained in I4N1 and I3N1, respectively (Fig. 4).

Harvest index (HI): The results of factorial analysis of variance revealed that the simple effect of treatments on harvest index were significant at p= 0.01 (Table 1). Comparison of means in different irrigation regimes showed that the highest harvest index rates by average of 30.78 and 28.95% obtained in I1 and I2, respectively and the lowest harvest index by average of 19.23% obtained in I4 (Table 2). Also harvest index significantly increased by nitrogen application as the highest harvest index rates by average of 26.77, 28.26 and 28.66% obtained in N2, N3 and N4, respectively (the same statistical group) and the lowest harvest index by average of 23.19% obtained in N1 (Table 2).

The interaction effect of irrigation and nitrogen on harvest index was not significant.

CONCLUSIONS

According to our results the interaction of irrigation and nitrogen had a significant effect on assessed traits except on harvest index. Achievement to the highest rates of seed yield and seed oil yield was the most important goal in this study. Application of 150 kg N ha-1 was the most appropriate rate of nitrogen due to production of the highest seed yield and seed oil yield by average of 3991 and 1565 150 kg ha-1, respectively. Also irrigation on the basis of 80 mL evaporation from the class A pan (normal irrigation) produced the highest seed yield and seed oil yield by average of 4688 and 1956 150 kg ha-1, respectively. Application of 150 kg N ha-1 under normal irrigation had an additive effect on seed yield and seed oil yield. Therefore, to produce the highest seed yield and seed oil yield on turnip rape (Brassica campestris L.-cv. Goldrush) in the same condition application of 150 kg N ha-1 under normal irrigation recommend. Also it would be a good suggestion to carry out the same consecutive studies in the similar regions.

REFERENCES

1:  Bala-Deh, T.B., 2000. Rapeseed Brassica napus cultivation. Ministry of Agriculture, Agricultural Jihad Organization of Guilan Province, Iran

2:  Azizi, M., A. Soltani and S.K. Khorasani, 1998. Rapeseed-Physiology, Agronomy, Plant Breeding and Biotechnology. Jahad-e-Daneshgahi of Mashhad Press, Iran

3:  Hedge, I.C., 1976. A Systematic and Geographical Survey of the Word Cruciferae. In: The Biologhy and Chemistry of the Cruciferae, Vaughan, J.G., A.J. MacLeod and B.M.G. Jones (Eds.). Academic Press, New York, London, pp: 1-45

4:  Nuttall, W.F., H. Ukrulentz, J.W.B. Stewart and D.T. Spurr, 1987. The effect of nitrogen, sulphur and boron on yield and quality of rapeseed (Brassica napus L. and B. campestris L.). Can. J. Soil Sci., 67: 545-559.
CrossRef  |  Direct Link  |  

5:  Azizi, M., A. Soltani and S.K. Khorasani, 1998. Rapeseed. Jahad-e-Daneshgahi of Mashhad Press, Iran

6:  Grant, C.A. and L.D. Bailey, 1993. Fertility management in canola prodaction. Can. J. Plant Sci., 73: 651-670.
Direct Link  |  

7:  Zangani, A., 2001. Study of nitrogen rates effect on growth and quantitative and qualitative seed yield of two rapeseed cultivars for autumn planting in Ahvaz. M.Sc. Thesis, University of Shahid Chamran, Ahvaz, Iran.

8:  Ali, M.H., S.M.H. Zaman and S.M.A. Hussain, 1996. Variation in yield, oil and protein content of rape seed (Brassica compestris) in relation to levels of nitrogen, sulphur and plant density. Indian J. Agron., 41: 290-295.

9:  Mason, M.G. and R.F. Brennan, 1998. Comparison of growth response and nitrogen uptake by canola and wheat following application of nitrogen fertilizer. J. Plant Nutr., 21: 1483-1499.
Direct Link  |  

10:  Chauhan, A.K., S. Manak and B.K. Daolhowal, 1993. Effect of nitrogen level and row spacing of performance of rape (Brassica napus L.). Indian. J. Agron., 37: 851-853.

11:  Ghasemi, K.A. and M. Isfahani, 2006. Study of time and rate of nitrogen fertilizer application effect on yield and yield components of rapeseed. J. Agric. Sci. Ind., 20: 63-72.

12:  Krogman, K.K. and E.H. Hobbs, 1975. Yield and morphological response of rape (Brassica campestris L. C. V. span) to irrigation and fertilizer treatments. Can. J. Plant. Sci., 55: 903-909.

13:  Jang, Y.S., J.K. Bang, S.K. Kim, C.B. Park, S.P. Rho, J.I. Lee and Y.S. Kim, 1987. Seed yield and oil content of rape as affected by increased application of nitrogen in spring transplant system. Res. Rep. Rural Dev. Admin., 29: 162-171.

14:  Fathi, G., A.B. Saeedi, A. Siyadat and F.E. Poor, 2002. Nitrogen rates and plant density effects on seed yield of rapeseed cultivars (Pfv045 and 91) in Khoozestan weather condition. Sci. J. Agric., 25: 43-57.

15:  Faraji, A., S. Sadeghi and M. Asadi, 2005. Study of nitrogen and irrigation effects on yield and yield components of rapeseed cultivars in Gonbad. J. Agric. Sci. Nat. Resour., 12: 63-72.

©  2021 Science Alert. All Rights Reserved