Analyzing Rapeseed (Brassica napus L.) Yield Gap using Comparative Performance Analysis (CPA) in Khorramshahr

Document Type : Scientific - Research

Authors

• Hamid Matourian ¹
• Aydin Khodaei Joghan ²
• Mohamad Reza Moradi Telavat ¹
• Seyad Ataollah Siadat ¹
• Benyamin Torabi ³

¹ Department of Plant Production and Genetics, Faculty of Agriculture, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran.

² Department of Plant Production and Genetics Engineering, Faculty of Agriculture, Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Iran.

³ Department of Agronomy, faculty of Plant Production , Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.

10.22067/agry.2021.67226.0

Abstract

Introduction
Food security is one of the most important challenges facing humankind. Therefore improving crop yields are essential to meet the increasing pressure of global food demands. The loss of high-quality lands, increasing fertilizer use, and its effect on the environment indicate that we need to develop new strategies to increase grain yields with less impact on the environment. One strategy that could help address this concern is by narrowing the yield gaps using improved management. Comparative Performance Analysis (CPA) is an approach for studying yield gaps; it defines quantified yield-gap functions. Assessing the yield gaps in major field crops can help us understand yield variability and potential. Rapeseed is one of the world’s most important oilseeds, and its production has economic and agronomic advantages. Rapeseed oil is considered a healthy ingredient and the third most used oil in foods. There is a difference between the average yield and the maximum expected yield of rapeseed in Khorramshahr. There are potential lands in this region that, by investigating the reasons for low yield, farmers can be encouraged to cultivate rapeseed on their farms. Therefore, this study aimed to determine the yield gap and the limiting management factors in rapeseed cultivation of Khorramshahr.
Materials and Methods
This study was carried out to investigate management factors causing the rapeseed yield gap in Khorramshahr during the 2018-2019 growing season. This study recorded information from 57 farms with variation in the area under cultivation, farm management and yield based on information from local experts and field studies. The comparative performance analysis (CPA) method was used to evaluate the yield gap. All information related to management practices was either measured or recorded. From the relationship between all measured variables (quantitative and qualitative) yield model was obtained through stepwise regression. By putting the best-observed value of the variables in the model, the maximum attainable yield was calculated, and the difference between them was considered a yield gap.
Results and Discussion
The yield observed in the surveyed farms, and the yield predicted by the model show a significant relationship. In this regard, the correlation coefficient was 93%, which indicates the high accuracy of the model for predicting the yield gap of the studied rapeseed fields. Based on the model, nine independent variables were selected from all studied variables. Then actual and attainable yield and contribution of each variable to the yield gap were determined by using the model. Results showed that the average yield, achievable yield, and yield gap of rapeseed were 1663, 3197, and 1533 kg.ha^-1, respectively. The most important variables in the rapeseed yield gap were the use of the leveler, farmer’s education level, phosphate fertilizer application, time and amount of potassium fertilizer application and method of removing crop residues of the previous year, irrigation frequency, and sowing machinery. Factors that had the highest share of yield gap were potassium application time (27.14%), application of superphosphate (26.85%), potassium rate (25. 9%), crop residues removing method (9.63%), and use of lever (9.13%). According to the findings, the highest contribution to the yield gap was related to potassium fertilizer application time and superphosphate fertilizer application. These variables caused a yield gap of 416 and 411 kg.ha^-1, respectively.
Conclusion
This study showed a difference between the actual yield and potential yield of rapeseed fields in Khorramshahr, which can be reduced by modifying crop management. The observed yield gap was 1533 kg.ha^-1 (48%). The results of this study indicate that fertilizer management of Khorramshahr rapeseed fields, especially potassium and phosphorus fertilizers, is important and should be considered by farmers in the region. More than half of the rapeseed yield gap can be reduced by using phosphorus fertilizer and changing the time and rate of potassium application in Khorramshahr.
 
 

Keywords

• Actual yield
• Field optimal management
• Increasing production
• Potential yield
• production constraints

20.1001.1.20087713.1401.14.2.4.2

Main Subjects

• Agroecology and Indigenous Knowledge

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References

Abravan, P., Soltani, A., Majidian, M., and Mohsenabadi, G., 2017. Study of field management factors and underlying reasons limiting yield of oilseed rape in east of Golestan province using CPA method. Journal of Agroecology 7(2): 46-60. (In Persian with English Summary)

Affholder, F., Scopel, E., Neto, J.M., and Capillon, A., 2003. Diagnosis of the productivity gap using a crop model. Methodology and case study of smallscale maize production in central Brazil. Agronomy 23: 305-325.

Beddows, J.M., Hurley, T.M., Parley, P.G., and Alston, J.M., 2015. Rethinking yield gaps. University of Minnesota, Department of Applied Economics. Minneapolis, USA.

Cunningham, S.A., Attwood, S.J., Bawa, K.S., Benton, T.G., Broadhurst, L.M., Didham, R.K., McIntyre, S., Perfecto, I., Samways, M.J., Tscharntke, T., Vandermeer, J., Villard, M.-A., Young, A.G., and Lindenmayer, D.B., 2013. To close the yield-gap while saving biodiversity will require multiple locally relevant strategies. Agriculture, Ecosystems and Environment 173: 20-27.

De Bie, C.A.J.M. 2000. Yield gap studies through comparative performance analysis of agro-ecosystems. International Institute for Aerospace and Earth Science (ITC), Enschede. The Netherlands, 234 p.

Dehghan, E., and Rahnama, A., 2009. The effect of planting methods and seed rates on yield of canola in saline soil. Journal of Agricultural Engineering Research 2: 11-30. (In Persian with English Summary)

Due Preez, C.C., Kotze, E., and Steyn, J.T., 2001. Long term effects of wheat residue management on some fertility indicators of a semi-arid plinthosol. Soil and tillage Research 63: 25-33.

Fanaei, H.R., Galavi, M., Kafi, M., Ghanbari Bonjar, A., and Shirani-Rad, A.H., 2009. Effect of potassium fertilizer and irrigation levels on grain yield and water use efficiency of rapeseed (Brassica napus l.) and Indian mustard (Brassica juncea L.) species. Iranian Journal of Crop Sciences 11(3): 271-289

Fattahi, S., Binaeian, A., and Rezvanfar, A., 2015. Factor analysis of the challenges influencing sugar beet producers in Harsin city. Journal of Sugar Beet 31: 93-107. (In Persian with English Summary)

Foley, J.A., Ramankutty, N., Brauman, K.A., Cassidy, E.S., Gerber, J.S., Johnston, M., Mueller, N.D., O'Connell, C., Ray, D.K., West, P.C., Balzer, C., Bennett, E.M., Carpenter, S. R., Hill, J., Monfreda, C., Polasky, S., Rockstrom, J., Sheehan, J., Siebert, S., Tilman, D., and Zaks, D.P.M., 2011. Solutions for a cultivated planet. Nature 478: 337-342.

Godfray, H.C.J., Beddington, J.R., Crute, I.R., Haddad, L., Lawrence, D., Muir, J.F., Pretty, J., Robinson, S., Thomas, S.M., and Toulmin, C., 2010. Food security: the challenge of feeding 9 billion people. Science 327: 812–818

Hajjarpoor, A., Soltani., A., and Torabi, B., 2016. Using boundary line analysis in yield gap studies: Case study of wheat in Gorgan. Electronic Journal of Crop Production 8: 183-201. (In Persian with English Summary)

Nekahi, M., Soltani, Z., Siahmarguee, A., and Bagherani, A., 2014. Yield gap associated with crop management in wheat (Case study: Golestan province-Bandar-Gaz). Electronic Journal of Crop Production 7: 135-156. (In Persian with English Summary)

Nezamzadeh, E., Dastan, S., Soltani, A., and Ajam Norouzi, H., 2019. Evaluation of yield gap associated with crop management in rapeseed production using comparative performance analysis (CPA) and boundary- line analysis (BLA) methods in Neka region. Applied Field Crops Research 32(2): 76-107. (In Persian with English Summary)

Nourgholipour, F., Khavazi, K., and Khoshkam T.G., 2002. Effect of soil application of phosphate with Thiobacillus and phosphate solubilizing microorganisms on yield quality and quantity of corn. 3^ed National Conference, Development and Application of Biological Materials Using Fertilizers and Pesticides in Agriculture. Karaj, Iran p. 303-307. (In Persian)

Poma, I., Venezia, G., and Gristina, G., 1999. Rapeseed (Brassica napus L.) echophysiological and agronomical aspects as affected by soil water availability. In: 10^th International Rapeseed Congress, Canberra, Australia, 26-29 september 1999, p. 8-11.

Rabiee, M., and Tousi Kehal, P., 2011. Effects of nitrogen and potassium fertilizer levels on nitrogen use efficiency and yield of rapeseed (Brassica napus l.) as a second crop after rice in gilan region. Iranian Journal of Field Crop Sciences 42(3): 605-615. (In Persian with English Summary)

Reddya, A., Chaitanya, K., and Vivekanandanb, M., 2004. Drought-induced responses of photosynthesis and antioxidant metabolism in higher plants. Journal of Plant Physiolgy 161: 1189-1202.

Rezaei, A., and Soltani, A., 1998. An Introduction to Applied Regression Analysis. Isfahan University of Technology Publications, Esfahan, Iran.306 (In Persian)

Sakhvatifar, S., Rahemi Karizki, A., Nakhzari Moghaddam A., and Mollashahi, M., 2020. Identification of canola yield limiting factors using performance comparison analysis. Journal of Crops Improvement 2(1): 13-25. (In Persian with English Summary)

Sohrabi, N., Bagheri, A., Mondani, F., and Nosrati, E., 2017. Assessment of various agronomic and social factors impacts on the yield of chickpea (Cicer arietinum L.): A case study, Kermanshah Province, Sanjabi Rural District. Journal of Agroecology 4: 1203-1216. (In Persian with English Summary)

Soltani, A., Torabi, B., Galeshi, S., and Zeinali E., 2009. Analyzing Wheat yield constraints in Gorgan with Comparative Performance Analysis (CPA) method. (Research Report). Gorgan University of Agricultural Sciences and Natural Resources. 65 p. (In Persian with English Summary)

Talebizadeh, E., Abbasmanesh, G., and Movahedi Naeini, S.A.R., 2012. Potassium quantity-intensity curves for soils of different specific surface area. Journal of Water and Soil Conservation 19(2): 23-41. (In Persian with English Summary)

Torabi, B., 2011. Analysis of the yield limitations in Gorgan using simulation model and hierarchical process (AHP). Ph.D. Dissertation, Gorgan University of Agricultural Science and Natural Resources, Iran. (In Persian with English Summary)

Torabi, B., Soltani, A., Galeshi, S and Zeinali, E. 2011. Analyzing wheat yield constraints in Gorgan. Journal of Crop Production 4(4): 1-17

Van Icterus, M.K., Classman, K.G., Grissini, P., Wolf, J., Tattnall. P., and Hochman, Z., 2013. Yield gap analysis with local to global relevance, a review. Field Crops Res. 143: 4-17. Field Crops Research 143: 4-17.

Yarnia, M., and Piroozkhah, S., 2011. Effect of potassium levels on tolerance to drought stress in Rapeseed. Regional Conference on Crops Eco-Physiology. Shoushtar, Iran. 19 May 2011. (In Persian)