Pisum Genetics
2010-Volume 42
Research Papers
Potential of the intercrops of normal-leafed and semi-leafless pea cultivars for forage production
Cupina, B.1, Krstic, D. 1, University of Novi Sad, Faculty of Agriculture, Novi Sad, Serbia
Antanasovic, S. 1, Eric, P. 1, Pejic, B. 1 institute of Field and Vegetable Crops, Novi Sad, Serbia
Mikic, A. 2 and Mihailovic, V. 2
Pea (Pisum sativum L.) is one of the most ancient food and feed crops in the Balkan Peninsula. Its traditional use in animal husbandry on the territory of modern Serbia has been in the form of forage, either fresh or dry, as well as in mixtures with small grains or as a pure stand (1). The first Serbian forage pea cultivars were autumn-sown, with excellent winter-hardiness and delayed flowering resulting in high quality and stable forage yields (2). The semi-leafless types of pea entered the Serbian market and breeding programs during the last decade of the last century and are exclusively associated with dry grain production. Recently, it was demonstrated that it is possible to develop autumn-sown semi-leafless dry pea cultivars for the conditions of Serbia (3), and that the semi-leafless cultivars may provide high quality forage yields with enhanced seed production due to their prominent lodging tolerance (4).
Numerous contemporary systems involving monocultures require chemical fertilizers and pesticides, and result in decreased soil and water quality and reduced biodiversity. On the other hand, intercropping systems with carefully and appropriately selected species where legumes serve a prominent role provide many advantages in contrasting environments (5). Along with the traditional intercropping of legumes with small grains in many European regions (6, 7), attempts have been made recently to examine intercrops of perennial and annual legumes, such as field pea in establishing red clover (8), as well as mutual intercropping of annual legumes for forage production (9). The goal of this research was to assess the potential of the mutual intercrops of pea cultivars with different leaf types for forage production.
Materials and Methods
A small-plot trial was established during the 2008-2009 and 2009-2010 growing seasons at Rimski Sancevi, near Novi Sad (45°20' N, 19°51' E and 84 masl) on a slightly carbonated chernozem soil (Table 1). Compared to the long term average (1964-2010), the growing season of 2008/09 was much warmer and much drier, while the growing season of 2009/10 was slightly warmer and significantly wetter (Table 2).
Pisum Genetics
2010-Volume 42
Research Papers
The trial included four dry pea cultivars in total, namely the autumn-sown semi-leafless cultivar 'Dove' (France), the autumn-sown normal-leafed cultivar 'Frijaune' (France), the spring-sown semi-leafless cultivar 'Jezero' (Serbia) and the spring-sown normal-leafed cultivar 'Javor' (Serbia). These four cultivars were grown in pure stand and intercropped with the complementary genotype within the same crop type such that one had good standing ability (supporting crop, Dove and Jezero) while the other was lodging-susceptible (supported crop, Frijaune and Javor). There were six treatments in total: four pure stands and two intercropped treatments, i.e. Dove with Frijaune and Jezero with Javor.
The trial was set up as a randomized complete block design, with four replicates, and plot size of 10 m2 and a row spacing of 20 cm. The pure stands were sown with 120 viable seeds m-2. The intercropped treatments were composed of 50% of each variety. The autumn treatments were sown on October 11, 2008, and October 15, 2009, while the spring treatments were sown on March 14, 2009, and March 22, 2010.
Pure stands were cut at full bloom, while the intercrops were cut when the first of the two components reached full bloom. The varieties in the combined treatments flowered at similar times. The autumn-sown treatments were cut on April 17, 2009, and April 25, 2010, while the spring-sown treatments were cut on May 7, 2009, and May 17, 2010. Green forage yield (t ha-1) and forage dry matter yield (t ha-1) were monitored. The Land Equivalent Ratio (LER) was calculated as (10):
LER = Sdic / Sdps + Sgic / Sgps
, where SdIC is the supported component forage yield in the intercrop, SdPS is the supported component forage yield in its pure stand, SgIC is the supporting component forage yield in the intercrop and SgPS is the supporting component forage yield in its pure stand. The values for both green forage yield (LERGFY) and forage dry matter yield (LERFDMY) were calculated separately.
The analysis of variance was performed using Statistica 8.0 software, with a Fisher's LSD test used at P = 0.05.
Results and Discussion
There were statistically significant differences at the p = 0.05 level between green forage yield among treatments (Table 3). On average, green forage yields were higher in the 2009/10 growing season compared to the 2008/09 growing season. Pure stand green forage yield varied from 28.5 t ha-1 for the normal-leafed spring-sown Javor in 2008/09 to 34.0 t ha-1 for the spring-sown semi-leafless Jezero also in 2008/09. In the 2008/09 growing season, the autumn-sown and the spring-sown intercrops produced similar total green forage yield (33.9 t ha-1 and 33.8 t ha-1), while, in the 2009/10 growing season, the autumn-sown intercrops produced higher yields (34.5 t ha-1) than the spring-sown intercrops (33.9 t ha-1). The supported component of the autumn-sown intercrops benefitted much more than the supporting crop in both years, while in the spring-sown intercrops the two component varieties were more balanced in their contribution to the total green forage yield. These results suggest that semi-leafless pea cultivars may have great potential for forage production (11).
Both autumn-sown and spring-sown intercrops had two-year LERGFY average values greater than 1 (1.09 and 1.11) suggesting that intercropping the two varieties was economically justified for green forage production.
Pisum Genetics
2010-Volume 42
Research Papers
Average forage dry matter yields in pure stands were statistically significant (Table 4). Yield ranged from 5.5 t ha-1 in the spring-sown semi-leafless Jezero in 2008/09 and 8.0 t ha-1 in the autumn-sown, normal-leafed Frijaune in 2009/10. The trend of forage dry matter yield was not the same as green forage yield due to different forage dry matter proportion in individual cultivars and individual years.
In 2008/09, forage dry matter yield in the autumn-sown intercrop (7.7 t ha-1) was significantly greater compared to the forage dry matter yield in the spring-sown intercrop (6.4 t ha-1). In 2009/10, the autumn-sown intercrop was significantly more productive (8.4 t ha-1) than the spring-sown intercrop (6.5 t ha-1). Similar to the case of green forage yield, there was a balance between the two components in the spring-sown intercrop, while the supported component had much greater contribution in the autumn-sown intercrop.
The LERFDMY values suggest that both autumn-sown and spring-sown intercrops were economically justified, although the former was significantly more productive (1.13) than the latter (1.03).
The obtained results give a solid basis for further research on intercropping legume varieties with contrasting leaf types for forage production. One of the advantages the mutual dry pea intercropping may have in comparison to the traditional annual forage legume cultivation is a prominent earliness, especially in the autumn-sown treatments, allowing the possibility of sowing a succeeding crop in a regular sowing term. Future research in the mutual pea and other annual legume intercropping must include evaluation of additional above and below ground characteristics.
Pisum Genetics
2010-Volume 42
Research Papers
Projects 20083 and 20090 of the Ministry of Science and Technological Development of the Republic of Serbia (2008-2010).
1. Mihailovic, V. and Mikic, A. 2010. Biotechnology in Animal Husbandry 26(special issue) 1: 81-90.
2. Mihailovic, V., Warkentin, T., Mikic, A. and Cupina, B. 2009. Grain Legumes 52: 20-21.
3. Mihailovic, V., Ellis, T. H. N., Duc, G., Lejeune-Henaut, I., Eteve, G., Angelova, S., Mikic, A. and Cupina, B. 2008. Proceedings of the International Conference Conventional and Molecular Breeding of Field and Vegetable Crops, Novi Sad, Serbia, 24-27 November 2008, 443-446.
4. Warkentin, T., Klassen, E., Dengjin, B., Lopetinsky, K., Kostiuk, J., Barlow, B., Ife, S., Tar'an, B. and Vandenberg, B. 2009. Canadian Journal of Plant Science 89: 661-663.
5. Malezieux, E., Crozat, Y., Dupraz, C., Laurans, M., Makowski, D. and Ozier-Lafontaine, H. 2009. Agronomy for Sustainable Development 29: 43-62.
6. Mihailovic, V., Eric, P. and Mikic, A. 2004. Grassland Science in Europe 9: 457-459.
7. Bedoussac, L. and Justes, E. 2010. Plant and Soil 330: 19-35.
8. Cupina, B., Krstic, D., Mikic, A., Eric, P., Vuckovic, S. and Pejic, B. 2010. Turkish Journal of Agriculture and Forestry 34: 275-283.
9. Mikic, A., Dordevic, V., Peric, V., Cupina, B., Mihailovic, V., Srebric, M. and Krstic, D. 2010. Biotechnology in Animal Husbandry, 26(special issue) 2: 269-275.
10. Kadziuliene, Z., Sarimaite, L. and Deveikyte I. 2011. Field and Vegetable Crops Research 48: 183-188.
11. Koivisto, J.M., Benjamin, L. R., Lane, G. P. F. and Davies, W. P. 2003. Forage potential of semi-leafless grain peas. Grass and Forage Science 58: 220-223.