Category Archives: Alley Cropping

Shoot Pruning and Impact on Functional Equilibrium Between Shoots and Roots in Simultaneous Agroforestry Systems

Click to access InTech-Shoot_pruning_and_impact_on_functional_equilibrium_between_shoots_and_roots_in_simultaneous_agroforestry_systems.pdf

For that kind of intensive shoot pruning management (coppicing), it is important to select trees species that store adequate amounts of carbohydrates in the roots to provide the energy for resprouting and rapid regrowth of above ground parts. Shoot regrowth from other less intensive shoot pruning (pollarding or lopping) could be energetically supported from carbohydrate stores in stems and roots of the pruned tree stump.
The implications for associated crop management are several. Since shoot pruning removes competition for light between the tree and associated crop, it also provides a time window of almost one month when no competition in the soil can be expected between tree and crop roots for plant available nutrients. Transplanting of crop seedlings can then be made at shoot pruning to aid the early growth of seedlings. Depending on the needs of the crop, another shoot pruning of the agroforestry trees may be needed during the life of the crop, preferably before the onset of the reproductive phase of crop development.
Handarayan et al. (1997) suggested that the nitrogen mineralisation rate of prunings may be manipulated by mixing different quality materials such as high quality tree prunings of G. sepium and low-quality legume tree prunings such as Peltophorum dasyrachis (Miq.) Kurz. Pruning two weeks before transplanting vegetable seedlings and mulching with pruning may confer more efficient nutrient use on the agro-ecosystem.
The delay of hedge pruning until after the annual crop is established could result in greater water utilisation by the hedges and consequently, reduced evaporation.

Marc Bonfils

Marc Bonfils is a spiritual mentor of mine, and little did I realize that he had done some strange work on fodder trees. I’m including a number of documents of his as well.

Pollarding and Coppicing

Examples of trees that do well as pollards include broadleaves such as beeches (Fagus), oaks (Quercus), maples (Acer), black locust or false acacia (Robinia pseudoacacia), hornbeams (Carpinus), lindens or limes (Tilia), planes (Platanus), horse chestnuts (Aesculus), mulberries (Morus), redbud (Cercis canadensis), tree of heaven (Ailanthus altissima) and willows (Salix), and a few conifers, such as yews (Taxus)

In the days of charcoaliron production in England, most woods in ironmaking regions were managed as coppices, usually being cut on a cycle of about 16 years. In this way, fuel could be provided for that industry, in principle, indefinitely, as long as the nutrient mineral content of the soil was appropriately maintained. This was regulated by a statute of Henry VIII, which required woods to be enclosed after cutting (to prevent browsing by animals) and 12 standels (standards or mature uncut trees) to be left in each acre, to be grown into timber. The variation of coppicing known as coppice with standards (scattered individual stems allowed to grow on through several coppice cycles) has been commonly used throughout most of Europe as a means of giving greater flexibility in the resulting forest product from any one area. The woodland provides not only the small material from the coppice but also a range of larger timber for jobs like house building, bridge repair, cart-making and so on.

The splitting of large logs, whether for firewood or fencing, was a custom adopted by Americans in response to the conditions of their forests: vast numbers of huge trees covered the continent when the first settlers moved westward. In preindustrial Europe, the notion of growing a tree to a great size, only to chop it into small pieces, was seen as wasteful of human energy. Poles and timbers were grown to the size needed, and no more, while fire-wood was cut at just the dimension required for stoves and fireplaces.

Oak, ash, beech, and elm were commonly the standards, while hazel, alder, lime (linden, Tilia cordata), willow, and hornbeam were often grown in the understory. Hazel yielded not only edible nuts, but fodder from the young shoots, and like willow, made excellent basketry, while lime leaves were eaten and the trees usually allowed to flower before harvesting, to provide a flavored honey crop. Lime was also made into greenwood furniture, while hornbeam went for fuel, and alder (a nitrogen-fixer) bolstered soil fertility. Many of these same species have additional medicinal or craft use, providing dyes, seeds, and flowers of value.

Overstory and underwood were usually of different species. This made the woodland ecologically resilient, as canopy and ground cover exploited not only different soil layers and nutrients, but grew at different seasons. The coppice and groundcovers did about two-thirds of their photosynthesis for the year before the overstory came into leaf.


World Agroforestry Systems

For example, leeks, corn, and strawberries are grown in peach orchards in Ontario, Canada; oats are grown in some New York apple orchards; and potatoes, grains, soybeans, squash, and peaches have been planted in pecan (Carya illinoensis) orchards in the southern United States (Williams and Gordon, 1991). Approximately 10% of all fruit and nut orchards in Washington State (USA) are intercropped with vegetables for home use, and in another 25% of the orchards cattle or sheep are grazed during part of the year (Lawrence et al., 1992).

One of the most widely intercropped group of trees is the poplar species (Populus spp.) and their hybrids; these species were traditionally planted for short rotation fiber and fuel production. Poplar plantations in Europe and eastern Canada have been interplanted with corn, potatoes, soybeans, and other cereal and tuber crops, in different temporal sequences, for the first three to six years after tree establishment (Gold and Hanover, 1987). Many of the poplar plantations are only grown for an additional five to ten years after crop harvest before harvesting and establishment of the next rotation. In China, sesame, soybeans, peanuts, cotton, indigo, and various vegetable crops are grown in both hybrid poplar (Figure 25.2) and Paulownia tomentosa plantations (Figure 25.3); the poplars are widely planted in a variety of other crop-border configurations (Farmer, 1992). In Australia, various melon and squash crops are grown for two years, followed by permanent pasture, with cattle grazing on both the pasture and branches lopped from the poplars. Poplar is also frequently planted on plot boundaries of wheat and barley fields in northern India and Pakistan.

The vast majority of research on silvopastoral systems in North America has focused on pine forest with deliberate management of both pasture and trees. These systems are most important in the Southern Coastal Plain under slash pine (Pinus elliottii), and longleaf pine (Pinus palustris); they are popularly known as “pine-and-pasture” or “cattle-under-pine” systems. The earliest studies on pasture improvement in these systems, initiated in the 1940s, indicated that mechanical site preparation and fertilization were essential for forage establishment, and that production of established pasture declined with increasing tree-canopy closure (Lewis and Pearson, 1987). Among the most productive pasture species were Pensacola bahiagrass (Paspalum notatum), annual lespedeza (Lespedeza striata), and white clover (Trifolium repens), with Pensacola bahiagrass being the most shade tolerant.


Legumenous Fodder Trees in the Farming System



The intensive feed garden (IFG)

This is a relatively new concept which is currently receiving a lot of research attention at ILCA. The IFG aims at intensive cultivation of fodder trees and grasses on a small plot of land, usually close to the farmer’s animal holding area. It is especially suitable for situations where alley farming may be inappropriate for one reason or the other, and can also be used, in some cases, to supplement feed resources from alley farms.

The prototype IFG contains the legumes leucaena and gliricidia on one half and the grasses Panicum maximum and Pennisetum purpureum on the other. The gardens are 200 m and predicated on intensive nutrient cycling through the application of manure or fertilizer to maximise feed production from a limited area. The goal is to have gardens which will provide the major feed requirements for 4-6 animals.

Current research aims at further intensifying the gardens through modifications in spacing and design (spatial arrangement of trees and grasses), as well as quantification of their productivities and carrying capacities.

Wikipedia Inga Alley Cropping


For Inga alley cropping the trees are planted in rows (hedges) close together, with a gap, the alley, of about 4m between the rows. An initial application of rock phosphate has kept the system going for many years.

When the trees have grown, usually in about two years, the canopies close over the alley and cut off the light and so smother the weeds.

The trees are then carefully pruned. The larger branches are used for firewood. The smaller branches and leaves are left on the ground in the alleys. These rot down into a good mulch (compost). If any weeds haven’t been killed off by lack of light the mulch smothers them.

The farmer then pokes holes into the mulch and plants his crops into the holes.

The crops grow, fed by the mulch. The crops feed on the lower layers while the latest prunings form a protective layer over the soil and roots, shielding them from both the hot sun and heavy rain. This makes it possible for the roots of both the crops and the trees to stay to a considerable extent in the top layer of soil and the mulch, thus benefiting from the food in the mulch, and escaping soil pests and toxic minerals lower down. Pruning the Inga also makes its roots die back, thus reducing competition with the crops.