Evaluation and Presentation of Intercropping Advantages

It is proposed that two distinct objectives should be recognized in the evaluation of intercropping advantages: (i) a biological objective to determine the increased biological efficiency of intercropping and (ii) a practical objective to determine the advantages that are likely to be obtained by a farmer. The sole crop systems with which intercropping must be compared to satisfy these objectives are defined. Evaluation in relative, absolute, monetary and nutritional units is discussed and some aspects of presenting intercropping data in graphical form are illustrated. [1]

Cereal–Legume Intercropping Systems

This chapter describes the various aspects of cereal-legume intercropping systems. Intercropping is the growing of two or more crop species simultaneously in the same field during a growing season. The intercropping of legumes with cereals offers scope for developing energy-efficient and sustainable agriculture. The main types of intercropping include mixed intercropping, row intercropping, and strip intercropping. Crop combinations differ with geographical location and there may be intercropping of tree crops, intercropping of tree and field crops, or intercropping of field crops. Combinations of crops are determined primarily by the length of the growing season and the adaptation of crops to particular environments. Different indices have been suggested for evaluating productivity and efficiency per unit area of land of cereal-legume intercrop systems. These include comparisons of absolute yields, protein yields, caloric equivalent, and in economic terms, gross returns from intercrops and sole crops. Differences in competitive ability affect the relative performance of component crops and thus the land equivalent ratio values of different cereal-legume intercrop systems. It is found that phosphorus is a major nutrient that determines the production potential of most grain legumes usually intercropped with cereals. [2]

A Role for Intercropping in Modern Agriculture

Agriculture in developed nations relies on mechanization and petrochemicals and typically uses monocultures. Monoculture is subject to several problems that intercropping can alleviate. Intercropping has potential as an economic and ecological alternative fully compatible with modern agriculture.[3]

Percentage Yield Difference, an Index for Evaluating Intercropping Efficiency

Aim: To evaluate intercropping efficiency using percentage yield difference (PYD) and to    compare the index with other indices.

Study Design: The design was a 2 X 5 factorial in a randomized complete block design, and replicated three times.

Location: The study was carried out at the Lower Niger River Basin Development Authority, Ejiba (18°18°N, 5°39°E), Kogi State in the Southern Guinea Savannah Zone of Nigeria in 2008 and 2009 cropping seasons.

Methodology: Erect and prostrate cowpeas and maize were mixed at five population ratios. The five population ratios were: 100%C: 75%M, 100%C:50%M, 100%C:25%M, 75%C:25%M and 50%C:50%M (were C and M represented Cowpea and Maize respectively). Sole crops of each crop at full population were included as control treatments. Land Equivalent Ratio (LER), Area Time Equivalent Ratio (ATER), Monetary Equivalent Ratio (MER) and Percentage Yield Difference (PYD) were estimated and compared.

Results: Results of this study showed that LER, ATER, and PYD values were similar for the two cultivars in the two years.LER values ranges between 1.18 and 1.27 in 2008 and 1.12 and 1.30 in 2009. MER did not follow the same trend as LER and ATER. Lower values were obtained particularly in 2009. However, the highest MER 1.35 and 1.23 in 2008 and 2009 respectively were obtained in prostrate cowpea / maize mixture at population ratio of 100:50. The PYD advantage varies between 5-33% in the two years.

Conclusion: The comparable values of PYD with other indices suggest that it can be used to evaluate/ intercropping efficiency in crop mixture.[4]

Study of Grass-Legume Intercropping System in Terms of Competition Indices and Monetary Advantage Index under Acid Lateritic Soil of India

Association of sabai grass (Eulaliopsis binata) and blackgram (Vigna mungo) was studied under three intercropping ratios viz., 1:1, 1:2 and 3:5 for two years under acid lateritic soil. Both sabai grass and blackgram were grown as sole crop for comparison. It was found that leaf yield of sabai grass was significantly higher in intercropping than in monoculture system with the maximum value under 1:2 ratio. Higher land equivalent ratio (up to 2.01) and monetary advantage index (as high as US $ 207.0) was recorded under 1:2 intercropping ratio. The growth and yield of blackgram were affected when intercropped with sabai grass as compared to sole crop. Intercropped blackgram recorded up to 68.7% decrease in grain yield when compared with sole blackgram.[5]

Reference

[1] Willey, R., 1985. Evaluation and presentation of intercropping advantages. Experimental agriculture, 21(2), pp.119-133.

[2] Ofori, F. and Stern, W.R., 1987. Cereal–legume intercropping systems. Advances in agronomy, 41, pp.41-90.

[3] Horwith, B., 1985. A role for intercropping in modern agriculture. BioScience, 35(5), pp.286-291.

[4] Afe, A.I. and Atanda, S., 2015. Percentage yield difference, an index for evaluating intercropping efficiency. Journal of Experimental Agriculture International, pp.459-465.

[5] Mahapatra, S.C., 2011. Study of grass-legume intercropping system in terms of competition indices and monetary advantage index under acid lateritic soil of India. Journal of Experimental Agriculture International, pp.1-6.