The search for addressing the environmental degradation problems facing the uplands and hilly lands in most parts of Asia, Africa and Latin America inevitably ends up in the selection of an agroforestry-based intervention strategy. Perennials such as trees are an important component of such stabilization strategy. However, some of the best designers of widely adopted traditional agroforestry systems have been the farmers themselves. One such example is the Polycultural, Multistoried cropping system of Cavite, Philippines, where over 12,285 hectares of land are devoted to agriculture planted to various crops which could include coconut, coffee, banana, papaya, pineapple, upland rice, tuber crops and different kinds of fruit trees along with the shade-producing Gliricidia septum. This agroforestry system was developed by the farmers themselves and has evolved over the years. This article discusses various technical aspects of this approach as practiced by the majority of the Cavite farmers.
THE AGROFORESTRY SYSTEM DESIGN
Typically, coffee, upland rice, banana, pineapple, papaya, Glidoidia, fruit trees and low-growing tuber crops are grown together. However, variations are abundant. The following are some of the more common crop combinations which can be seen in Cavite:
1. coconut + papaya pineapple + banana + taro
2. coconut + upland rice + pineapple + daisy + banana + sweet potato + chayote + ginger
3. coffee + upland rice + corn + papaya + pineapple + peanut (sometimes it includes coconuts and/or fruit trees)
4. coconut + banana + lanzones + coffee + palay + taro + ginger + guava + santol + mango
The above combination, however, is sequentially established. It usually starts with a core pattern depending on land ownership and financial capabilities. These are (1) coconut + papaya + pineapple and (2) coconut + papaya + pineapple + coffee + banana. All over annual indoor permanent crops are introduced after the first harvest of pineapple is made, 14-18 months. In some cases, fruti trees like lanzones, jackfnuit, mango, santol and others are either planted earlier or are already established in the field. A step-by-step outline of the sequential planting strategy used by farmers is shown in Table 10. The upland rice, which will be eventually replaced even as the coffee seedlings are planted, and the pineapple crops which will replace it keep the soil in between the coffee (usually grown on slopy land) covered and protected from erosion But, more importantly, along with the interplantings of papaya, it brings in income even in the first few years when the coffee is still getting established and too young to bear fruit. The choice of pineapple, which will occupy the land for most of the first two ro four years, is based on sound principles of ecology and economics. Pineapples are drought-tolerant and also typhoon-resistant. Pineapples compete well with weeds, and eventually, when established, will smother the growth of weeds cuffing down the weeding costs entailed in any young coffee plantation. Pineapple residue is used in cattle feed. Finally, insects and diseases are minimal. The papaya and cuttings of Gliricidia septum provide shade to the area.
Gliricidia which is planted the same time as the coffee is specially important as a shade crop throughout the first few years of the establishment of the coffee crop. As the coffee starts yielding, the pruning of Gliricidia becomes critical in the rainy season, when the cloud cover is heavy and solar radiation is reduced. But in summer, the shade improves the micro-climate reducing evapo-transpiration and so no pruning in summer is advised. Gliricidia is also used for preparation of farm tools such as ploughs, pruning aids and in animal feeds or in the control of ticks. Mulch from leaf droppings and prunings serves to fertilize the soil.
Bananas used to be an important component of the system, if only the typhoons would spare thern. The potential for increasing the income from the system is greatly increased with bananas. As with Gliricidia, it is effective in manipulating solar radiation, reducing soil temperatures and improving water conservation. Eventually, pineapple can give way to more intense banana-based cropping. Root crops such as taro, cassava and yam are randomly sown within the system and provide feed for livestock and food for the family.
With this combination of crops in a polycultural system, there is an assurance of income as early as three months (from upland rice). The cash flows into the household are spread across the year rather than one season only. Table 11 indicates what the harvesting schedule for the more important crops from such a system could be.
Family labor utilization is evenly spread and maximized. The entire growing season is utilized. The system is entirely rainfed. With the introduction of fruit it trees such as soursop and star apple, which do not have dense shade-inducing canopies, further diversification of income is brought about.
The intensive planting of trees of various heights in the same system tends to use the vertical space above the ground very effectively and efficiently. The tree-mix improves the microclimate around the coffee, thus reducing air temperatures during January to May periods, thus improving fruit setting.
POSSIBLE IMPROVEMENTS TO THE SYSTEM
As can be seen from Table 10, the system is dependent on frequent chemical fertilization, given the intensive land usage pattern and the inadequate biomass output of sparsely planted Gliricidia. Here are some changes being introduced into the already sophisticated farmer-derived system, in order to reduce the current dependence on chemical fertilizer and to reduce typhoon losses:
· Increasing the number of nitrogen-fixing trees (plant population) so as to increase nitrogen contribution and reduce the current dependence of coffee trees on chemical fertilizers.
· Increasing the diversity of cultivars and species of nitrogen-fixing trees. Besides the Gliricidia currently used, Calliandra calothyrus, Flemengia congesia.
Leucaena diversifolia, Desmodium gyroides, Desmodium rensonil and Tephrosia candida can be used. Selective pruning from 4-5 fl high at the outset of the rainy season is essential to increase the solar radiation to coffee during the cloudy days in the rainy season. Ipil-ipil should be cut above 6 ft as a protection against psyllid infestation.
Reduced radiation from overshading could mean reduced coffee yields. Dense planting of such trees in the spaces between coffee has drastically reduced weed growth.
Introducing more soursop fruit trees and bananas into the system to diversify income. If the number of multipurpose trees (MPTS) is increased as suggested above, the losses of bananas from typhoons will be greatly lessened, thus allowing farmers to increase the population of bananas. All banana residues are returned to the soil.
With the increase in numbers of multipurpose trees, black pepper can be raised and more income is generated, without in anyway reducing yields of coffee or without occupying additionai space.
More MPTS mean more fodder for livestock, permitting the farmers to retain more animals on the farm. This means more income to the farmer given his only investment is the cost of animals. But equally important is the animal manure contribution which at present is rarely used because of lack of adequate quantity. Replacing at least some of the chemical fertilizers used by farm yard manure means higher net returns from the coffee. By introducing livestock on the farm, the farmers might reduce their risks from crop losses in the typhoons/droughts or by drops in market prices.
Livestock numbers can be increased significantly if farm grown fodder and feeds are available.
Perennial tree-based systems are less affected by typhoons.
Diversified cropping provides assured regular income and reduced risks from price fluctuations.
Assured income flows even in the first year of planting coffee trees from interplanted short duration crops.
The use of space, light and land space is maximized.
Erosion and weeding costs are minimized due to the growth of pineapple between coffee trees.
The food, fuel and fodder needs of the family are met.
The use of chemical fertilizers is reduced due to the presence of leaf litter, leaf mulch and leaf trimmings from nitrogen-fixing trees.
Family labor is maximized throughout the year.
Tillage is minimized.
Micro-climate is improved.
Biological activity is also improved.
Year 1 - Upland rice, rootcrops, papaya, vegetables
Year 2 - Pineapple, papaya, rootcrops, banana
Year 3 - Banana, pineapple (some coffee)
Year 4 - Coffee, fruit trees, bananas, black pepper, shadetolerant tubers (example: taro).
TABLE 10. SEQUENTIAL PLANTING IN A MULTI-STORIED SYSTEM.
TABLE 10. SEQUENTIAL PLANTING IN A MULTI-STORIED SYSTEM. (continued)
TABLE 10. SEQUENTIAL PLANTING IN A MULTI-STORIED SYSTEM. (continued)
TABLE 11. CROPPING PATTERN.
AGRO-CLIMATIC DATA(Silang Cavite)
800 to 1500 feet
Type 1 (Distinct Wet
(May-December) and Dry
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(January to April
annual average of 2000-
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Agroforestry, as a land-use scheme, has long been advocated by various hill tribes/dwellers in the Philippines. In the Cordilleras, for instance, the practice of growing agricultural and forest crops along with the raising of livestock in home lots have been observed for centuries, even before the term agroforestry developed.
The system is expressed in the ancient practice of mayong (Ifugao term for family-owned forest). And closer to this is Baguio's own version of home gardens.
Home garden is basically a multistoried agroforestry system where the canopies of the component species are arranged to occupy different vertical strata. Tall fruit trees, plants of medium height and small-growing vegetable species are raised concurrently in the same unit of land. In Bagulo, the technology has evolved from an unplanned or typical/traditional concept to a systematic type of land-management practice that it is now.
Although dwellers still employ their own indigenous ways of backyard farming, other existing agroforestry practices are adopted, thus elevating home gardens into a more updated practice and, consequently, more responsive to the needs of the uplanders.
MULTILAYERED AGROFORESTRY SYSTEM
Agricultural crops, tree crops and animals are produced in the same unit of land. The plants have spatial arrangement that is generally not well planned. It attempts to copy the multistoried structure of the tropical rainforests. The upper layer is dominated by trees such as pine trees, alnus, mango, rimes, acacia (Samanea saman), santol and caimito. The middle layer is composed of smaller fruit crops such as coffee, nangka, guava, citrus, banana and papaya. The ground layer is planted with a variety of vegetable crops, spices and medicinal plants. Small animals like pigs, chicken, dogs, turkey, geese, ducks, etc., are also components.
BENGUET PINE-COFFEE COMBINATION
Deferent coffee species (C. arabica, C. robusta) are grown under old Benguet pine (Pines kesiya) trees. In developing a new plantation, the Agroforestry Communication (1986) recommends planting pine trees five to seven years ahead at 3 × 3 meters spacing. At sixth to eighth year, coffee can be planted between the pine trees, which are about four meters high by that age. The pines may be harvested at the twentieth year with uninterrupted coffee growing of 15 years.
AKLENG PARANG-AGRICULTURAL CROPS COMBINATION
AkJeng parang (Albizia procera) trees are planted at about 45 trees per hectare. Other tree species like avocado, dita, akle and mahogany may also be grown with akleng parang. On individual small plots of 100-150 sq m, upland rice, ube (yam), banana, pineapple, sweet potato, com and ginger are planted. Most crops are planted from May to July and harvested in December. After two to three months fallow, corn and beans are planted.
Coffee arabica and C. robusta are grown under alnus (Alnus japonica) trees at 2 × 2 m spacing to as wide as 15 × 15 meters. Alnus trees provide nitrogen and shade to coffee. Its branches, pruned at a height of 3 to 5 meters from the ground, are used as fuelwood.
Alnus trees are used as living posts where a network of wires are attached. Chayote (Sechium edule), an edible fruit-bearing vine, is allowed to climb over the netted wires which are suspended 1.5-2.0 m high from the ground. Farmers use sinus as guide posts because replacement is not made onen unlike when they use bamboo poles or lumber.
MAHOGANY-AGRICULTURAL CROPS COMBINATION
Mahogany (Swietenia macrophylla) trees, planted at 10 × 10 m spacing and with a diameter of about 6-10 cm and a height of 5-8 m, are used as living trellis of either ube or tugui being grown near their base. Gabi, pineapple, ginger and banana are also intercropped. Manual weeding is done by cultivating the soil and uprooting the weeds, which are later used as mulch in between rows of crops.
ALNUS-COFFFE-SWEET POTATO COMBINATION
In this mulbstorey cropping, farmers grow coffee under sinus trees and sweet potatoes beneath the coffee. According to the farmers, this practice produces healthy growth of coffee and robust stems and fruits of sweet potato compared to those planted separately.