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Observations of Some Tree Root Systems in Agroforestry Intercrop Situations, and their Graphical Representation

Published online by Cambridge University Press:  03 October 2008

M. R. Rao
Affiliation:
International Centre for Research in Agroforestry (ICRAF), PO Box 30677, Nairobi, Kenya
P. Muraya
Affiliation:
International Centre for Research in Agroforestry (ICRAF), PO Box 30677, Nairobi, Kenya
P. A. Huxley
Affiliation:
International Centre for Research in Agroforestry (ICRAF), PO Box 30677, Nairobi, Kenya

Summary

Root systems of unpruned Cassia siamea and Leucaena leucocephala trees and regularly pruned hedges of C. siamea, L. leucocephala and Gliricidia sepium were examined in a semi-arid area in Kenya. Trenches were dug across rows of trees or hedges, soil profiles washed, and different sized roots counted in small 5 × 5 cm grids fully covering both faces of the trench. The roots were displayed using two computer software programmes written for this purpose: a spline technique that displays smoothed root densities in different shades; and a random dot method which displays roots as dots, using any specified scale. The fine roots of four-and-a-half-year-old C. siamea penetrated the soil to meet with rocks at depths between 0.60 and 2.0 m, and spread laterally to 9 m, traversing adjacent crop plots. Roots of eight-year-old L. leucocephala covered an extensive soil volume and included a greater density of fine roots than C. siamea at comparable distances. Above-ground pruning restricted the roots of hedges to a depth of 1.5 m, although roots of different hedges spaced 5 m apart intermingled freely in the alley space. L. leucocephala roots filled the alley very densely while those of G. sepium were sparse, particularly in the middle of the alley. Rooting density of C. siamea was intermediate. The dot method is more precise when rooting densities are low but when densities are high the splining method appears to be more visually helpful. These graphical methods greatly facilitate overall comparisons of sections of tree root systems, but quantification of root densities at different distances away from trees is still needed to understand more precisely the competitive effects of trees and associated crops.

Systemas de raices de los árboles

Type
Research Article
Copyright
Copyright © Cambridge University Press 1993

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References

Atkinson, D. (1980). The distribution and effectiveness of the roots of tree crops. Horticulture Review 2:424490.CrossRefGoogle Scholar
Bohm, W. (1979). Methods of Studying Root Systems. Berlin: Springer-Verlag.CrossRefGoogle Scholar
Bowen, G. D. (1985). Roots as a component of tree productivity. In Attributes of Trees as Crop Plants, 303315 (Eds Cannel, M. G. R. and Jackson, J. E.). Abbots Ripton: Institute of Terrestrial Ecology.Google Scholar
Cassidy, D. S. M. & Kumar, D. (1984). Root distribution of Coffea arabica L. in Zimbabwe. 1. The effect of plant density, mulch cover planting and shade in Chipinge. Zimbabwe journal of Agricultural Research 22:119132.Google Scholar
Foley, J. D. & Van Dam, A. (1982). Fundamentals of Interactive Computer Graphics. Reading: Addison-Wesley.Google Scholar
Gillespie, A. R. (1989). Modelling nutrient flux and interspecies root competition in agroforestry interplanting. Agroforestry Systems 8:257266.CrossRefGoogle Scholar
Gregory, P. J. & Reddy, M. S. (1982). Root growth in an intercrop of pearl millet/groundnut. Field Crops Research 5:241252.CrossRefGoogle Scholar
Huxley, P. A. (in press). Multipurpose trees: biological and ecological aspects relevant to their selection and use. In Tree Crop Ecosystems, (Ed. by Last, F.). Amsterdam: Elsevier.Google Scholar
Huxley, P. A., Darnhofer, T., Pinney, A., Akunda, E. & Gatama, D. (1989). The tree/crop interface: A project designed to generate experimental methodology. Agroforestry Abstracts 2:127145.Google Scholar
Johnsson, K., Fidjeland, L., Maghembe, J. & Hogberg, P. (1988). The vertical distribution offine roots of five tree species and maize in Morogoro, Tanzania. Agroforestry Systems 6:6369.CrossRefGoogle Scholar
Kerfoot, O. (1963). The root systems of tropical forest trees. Commonwealth Forestry Review 42:1926.Google Scholar
Kushwah, B. L., Nelliat, E. V., Markose, V. T. & Sunny, A. F. (1973). Rooting pattern of coconut (Cocos nucifera L.). Indian journal of Agronomy 18:7174.Google Scholar
Nair, P. K. R. (1987). ICRAF Field Station at Machakos. Agroforestry Systems 5:383393.CrossRefGoogle Scholar
Pinney, A., Huxley, P. A. & Akunda, E. (in preparation). Lessons for agroforestry experimentation from ICRAF's tree/crop interface project. Proceedings of a Regional Conference on Agroforestry Research and Development in the Miombo Ecozone of Southern Africa,16–22 June, 1991,Lilongwe, Malawi.(Special issue of Forest Ecology and Management).Google Scholar
Rao, M. R., Sharma, M. M. & Ong, C. K. (1990). A study of the potential of hedgerow intercropping in semi-arid India using a two-way systematic design. Agroforestry Systems 11:243258.CrossRefGoogle Scholar
Rao, M. R. (compiler) (1990). Fact Sheets on Demonstrations and Trials at ICRAF's Field Station, Machakos, Kenya. Nairobi: ICRAF.Google Scholar
Roger, J. H. & Rao, M. R. (1990). Agroforestry field experiments: discovering the hard facts, Part 1. Statistical considerations. Agroforestry Today 2(1):47.Google Scholar
Roger, J. H. & Muraya, P. (1991). Datachain: Database for Experimental Data, Version 2, with User's Manual. Nairobi: ICRAF.Google Scholar
Schuurman, J. J. & Goedewaagen, M. A. J. (1971). Methods for the Examination of Root Systems and Roots (2nd edition). Wageningen: Pudoc.Google Scholar
Singh, R. P., Ong, C. K. & Saharan, N. 1989. Above- and below-ground interactions in alley cropping in semi-arid India. Agroforestry Systems 9:259274.CrossRefGoogle Scholar
Van Noordwijk, M., Hariah, K., Syekhfam, M. S. & Flach, E. N. (1991). Peltophorum ptrlocarpus (DC.) Back (Ceasalpiniaceae), a tree with a root distribution suitable for alley cropping on acid soils in the humid tropics. In Plant Roots and their Environment, 526536 (Eds McMichael, B. L. and Persson, H.). Amsterdam: Elsevier.CrossRefGoogle Scholar