Sustainable agroforest land technology (Salt-3)

SALT-3 is a two-hectare model of a small-scale reforestation integrated with food production. The farm is devoted to about 40 percent agriculture and 60 percent forestry. This "food-wood" intercropping, as designed by the Mindanao Baptist Rural Life Center in Bansalan, Davao del Sur, shows that it can effectively conserve the soil, thereby providing abundant food, wood and income to hilly-land farmer.

Sustainable agroforest land technology

This information material will guide you on how to establish SALT-3.

Agroforestry -- the system of land management whereby both forest and agricultural crops are produced on the same piece of land - has been regarded with high hopes by many sectors as the most probable answer to deforestation and degrading food production. SALT-3 is a variant of agroforestry and here is how to establish it on your hillyland.

Step 1: Set up the agroforestry nursery. Ensure sufficient supply of planting materials for your agroforest farm by setting up your own nursery. Establish an accessible nursery (10 meters by 25 meters) with the' following fixtures: potting shed, transplant shed and seedbeds. Basic materials like sprinklers, shovel and spade should also be made available.

Set up the agroforestry nursery

Step 2: Care for and manage your seedlings. For better growth and field survival, the production of healthy and vigorous planting stock is necessary.

Sowing the seeds. Most forest seeds are hard to germinate so they need scarification either by
mechanical or hot-water treatment. The most common problem encountered in seed germination is damping off and insect defoliators. One way of avoiding this is to treat the seeds with chemicals. In some instances, seeds can be planted directly in plastic bags.

Sow the seeds in a sterilized soil to avoid damping off. Sterilization may be done by pouring boiling water in the soil media where you will sow the seeds. Keep the seedbeds moist at all times. Mulch and shade the plants. Transfer the seedlings later on into plastic bags.

Sowing the seeds

Transplanting. Prune the roots of species that can be outplanted bare root (mahogany, teak, etc.). Do not allow weeds to compete with your transplants. Fertilizer may be applied in conjunction with watering long before transplanting. Dissolve complete fertilizer (14-14-14 or 15-15-15) at the rate of 10 g/l water. If commercial fertilizer is not available, liquid fertilizer from leguminous trees may be used.

Before transplanting them to the field, harden the seedlings first by gradually exposing them to more adverse conditions. Do this three to six months before transplanting. Seedlings ready to be planted should have sturdy, well-developed crowns and many fine, fibrous lateral roots.

Step 3: Find the contour lines and establish your hod crops on the lower half of the farm. Find the contour lines of the farm's lower half portion using an A-frame. Plant the identified contours with any of the following hedgerow species: Flemingia macrophylla, Desmodium renzonii, Gliricidia septum, Leucaena diversifolia and L. leucocephala. In acidic soils, Cassia spectabilis and/or C. siamea may be planted.

Find the contour lines

Plant preferred short-term crops (examples: ginger, corn, upland rice, sweet potato, mung bean, melon, etc.) in every first and second strip. Plant long-term crops (citrus, cacao, coffee, banana, black pepper, etc.) on every third strip. These can be intercropped with fruit trees (rambutan, durian, lanzones, guava, mangosteen etc.) following appropriate planting distances. Multistorey cropping may also be practiced (e.g., pineapple + cacao + durian) in one strip.

The earlier you establish your food and cash crops, the better off you will be in meeting your immediate needs. Follow the SALT-1 steps in establishing your food crops.

Step 4: Prepare the site for your wood crops. Locate the woodlot at the upper half of the project so that the agricultural component on the lower portion will benefit from the conserved moisture and nutrients from the wood crops.

Prepare the site for your wood crops

On areas with steep slope and with erodible soil, extra care must be exercised so as not to induce soil erosion when clearing the area. You can use either partial or complete removal of vegetation whichever is more favorable to you. Avoid burning.

Compartmentalize and space your wood crops

Step 5: Compartmentalize and space your wood crops. For a threefold objective of soil rehabilitation, firewood production and timber growing, you can minimize the use of land space by following the high density strategy of establishing small-scale woodlots.

As jointly designed by representative foresters, agriculturists, farmers and countryside developers consulted by MBRLC in developing SALT-3 (2 ha), the following were recommended:

An intercropping layout of Samanea saman and rattan

An intercropping layout of Samanea saman and rattan

An intercropping layout of mahogany or narra and Sesbania sesban

An intercropping layout of mahogany or narra and Sesbania sesban

TABLE 1: SPACING OF TREES IN SALT - 3.

COMPONENTS ON TOP-DOWN SEQUENCE		SPACING
	ha	Initial	Final	Duration
Samanea saman	1/4	1 × 1	8 × 8	Long term
Calamus merillii (as intercrop of S. saman)	1/4	8 × 8	8 × 8	Long term
Pterocarpus indicus	1/8	2 × 2	4 × 4	Long term
Sweitenia macrophylla	1/8	2x 2	4 × 4	Long term
Sesbania sesban(as intercrop of P. indicus and S.macrophylla)	1/4	1 × 1	1 × 1	Short
Acacia auriculiformis	1/16	2x2	2x2	Medium term
Acacia mangium	1/16	2 × 2	2 × 2	Medium term
Sesbania formosa	1/8	1 × 1	1 × 1	Short term
Leucaena diversifolia	114	1 × 1	1 × 1	Short term
Bambusa spp. (boundary)	on bordor	4-5 m	4-6 m	Long term

Step 6: Outplant the trees. This may be done at the start or up to the middle of the rainy season so that seedlings can get established prior to the dry season.

You can also follow the contour when outplanting although it is not so imperative. Be sure not to break the earth-ball when setting the seedling into the planting hole. The upper part of the earth-ball should be level or slightly deeper than the edge of the hole. Soil is filled into the spaces and tamped firmly all around.

Outplant the trees

For fast recovery of the seedlings, follow basal application of 50-100 grams of complete fertilizer mixed with an equal amount of urea. Mulch the seedlings to insure higher linability.

Step 7: Intercrop your tree crops. Short and medium-term food and cash crops (ginger, sweet potato, yam, bean, cassava) can be intercropped in the forestry component during the first two years. Long-term ones like black pepper and rattan can be incorporated at the start of the second year. Geese or sheep may be raised underneath the tree crops during the following years.

For effective soil management, see to it that non-legume short-term crops are replaced by leguminous ones and vice versa in every cropping.

Do tree stand improvement

Step 8: Do tree stand Improvement. Apart from regular ring-weeding and liberation cutting, improve the stand of your trees. Remove the malformed trees. Replant the missing hills if you feel the replanted trees can still catch up.

However, replanting is laborious and expensive and should be done only to maintain required spacing or density. This is also performed when mortality is more than 30 percent.

Do tree stand improvement - continue

Step 9: Harvest your agroforest products regularly. Timely harvesting of crops saves waste. All households and useful products must be gathered, processed and marketed. In the forestry components, forage from tree prunings, fuel wood and roundwood from thinnings commence during the second year. Thin out regularly your forestry area until the timber crop spacing requirement is complied with. In some instances, minor forest crops can be planted under the trees.

Harvest your agroforest products regularly

Step 10: Maintain your SALT-3 farm. For one, trim the hedgerows regularly. Trim the hedgerows once they start to shade the agricultural crops. Spread trimmings evenly throughout the field to check weeds and also conserve soil moisture. Practice crop rotation in your food crop production.

TABLE 2: HARVESTING PLAN OF TREES IN SALT -3.

YEAR	SPECIES	HARVESTING METHOD	USE
1	None	Selective	Fuelwood/charcoal, fodder etc.
2	Sesbania sesban	All-out	-do-
3-5	S. sesban	All-out	-do-
	Leucaena diversifolia	All-out	-do-
	Samanea saman	Selective	-do-
	Sweitania macrophylla	Selective	Fuelwood and light construction, etc.
	Pterocarpus indicus	Selective	-do-
	Acacia mangium	Selective	-do-
	Acacia auriculiformis	Selective	-do-
6-14	Bamboo	Selective	Light construction, furniture, etc.
	Rattan	Selective	-do-
	A. mangium	All-out	Fuelwood and light construction, etc.
	Acacia auriculiformis	All-out	-do-
	P. indicus	Selective	Timber and furniture
15-25	Rattan	All-out	-do
	P. indicus	All-out	-do
	S. macrophylla	All-out	-do-
	S. saman	All-out	-do-

All-out harvesting refers to the harvesting of trees planted during the first year of establishment. While doing selective cutting, it is highly recommended that replanting be done.

Establishing a two-ha SALT-3 farm needs about P6,000. Cost and return analysis on the 5th year of operation shows that the technology can generate a cash net profit of P1,547.43 per month. Its return on investment (ROI) is 7.97 percent. But on top of this economic benefit, an upland farmer who follows the system has a farm that is well-protected and ameliorated soil due to integration and diversification scheme, thus resulting to a sustainable farming system.

Note: This system which was started in 1987 is still being monitored. The crops mentioned earlier are only suggestions and farmers can use any other crops suitable in their respective areas.

Sources:

Laquihon, GA., WA. Laquihon and H.R. Watson (1992).

Sustainable Agroforest Land Technobgy. A Paper presented during the 4th CEMARRDEC Symposium and Highlights.

Tacio, H.D. (1989). Sustainable Agroforest Land Technology. The PCARRD Monitor.