Use alley cropping

Overall effectiveness category Awaiting assessment
Number of studies: 1
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Effectiveness

not assessed
Certainty

not assessed
Harms

not assessed

Calculating overall effectiveness category

Background information and definitions

This agroforestry intervention grows crops between hedgerows or tree lines planted at regular intervals across crop fields or along slope contours. Hedges may be pruned and the foliage used as mulch or green manure on the adjacent crop alleys. The technique may control weeds and insect pests in a number of ways, for example by modifying the field’s climate, disrupting pest movement and weed growth, increasing crop vigour, providing habitat for natural enemies and using the insecticidal properties of hedgerow foliage. Studies that plant/allow trees around the edges of fields are included in 'Plant new hedges'. Arbuscular mycorrhizal fungi are a group of fungi that live around the roots of plants. By living together, the fungi and host plant benefit each other: the fungi can live in a habitat without having to compete for resources and receive a supply of carbon from the plant, while they give an enhanced supply of nutrients back to the plant, improving plant growth, the ability to reproduce and tolerance to drought. Arbuscular mycorrhizal fungi colonise a wide variety of host plants, including grasses, herbs, agricultural crops and legumes (Bardgett 2005). A phylotype is a way of classifying an organism by its phylogenetic (or evolutionary) relationship to other organisms.

Bardgett R. (2005) The Biology of Soil: A Community and Ecosystem Approach. Oxford University Press, Oxford.

Study locations

Key messages

A controlled, randomized, replicated study from Canada found that intercropping with trees resulted in a higher diversity of arbuscular mycorrhizal fungi.

SOIL TYPES COVERED: sandy-loam.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A randomized, controlled, replicated study in 2008 on sandy-loam soil in Ontario, Canada (Bainard et al. 2012) found a greater diversity of arbuscular mycorrhizal fungi (AMF) under tree-based intercropping (6 phylotypes) compared with conventional cropping (4.7 phylotypes). Colonization of corn Zea mays roots was greater than 50% in both intercropped and conventional treatments, and AMF richness was similar in both treatments. Different tree species supported distinctive AMF communities. Trees were intercropped annually with corn, soybean Glycine max, winter wheat Triticum aestivum or barley Hordeum vulgare using no-till cultivation. The tree rows accounted for 16% of the crop area and were spaced 12.5-15 m apart. Tree species included silver maple Acer saccharinum , white ash Fraxinum americana , hazelnut Corylus avellana , black walnut Juglans nigra , Norway spruce Picea abies, hybrid poplar Populus deltoides, red oak Quercus rubra, black locust Robinia pseudoacacia, willow Salix discolor and white cedar Thuja occidentalis.
Study and other actions tested
Referenced paper
Bainard L.D., Koch A.M., Gordon A.M. & Klironomos J.N. (2012) Temporal and compositional differences of arbuscular mycorrhizal fungal communities in conventional monocropping and tree-based intercropping systems. Soil Biology & Biochemistry, 45, 172-180.

Please cite as:

Key, G., Whitfield, M., Dicks, L.V., Sutherland, W.J. & Bardgett, R.D. (2020) Enhancing Soil Fertility. Pages 613-634 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Soil Fertility

Related Actions

Actions	Effectiveness	Studies	Category
Grow cover crops beneath the main crop (living mulches) or between crop rows Action Link	Likely to be beneficial	6	Synopsis Link
Retain crop residues Action Link	Trade-off between benefit and harms	6	Synopsis Link
Use alley cropping Action Link	Awaiting assessment	1	Synopsis Link