III. CLIMATE AND AGRO-ECOLOGICAL ZONES

Climate
Due to its the tropical situation, Indonesia experiences wet and dry seasons (Ischak, 1994). The dry season is from June to September when a dry wind blows from Australia. The wet season is from December to March when the moisture-laden monsoon blows from Asia and the Pacific Ocean. The transition periods are from April to May and from October to November. Rainfall ranges from 1 000 mm to 3 500 mm with 67 to 200 rainy days annually. The air temperature ranges from 14.8o C to 35.0o C with 28o C on the coast, 26o C in the hills and with 23o C in the mountains. Relative humidity ranges from 50 to 90% in the dry-land and wet land areas, respectively. Based on the length of wet and dry seasons, the climatic zone classification is as follows (Manik et al, 1977; Ischak, 1994) : Climatic zone B, nine months wet and three dry; zone C, seven months wet and five dry; zone D ,six months wet and six month dry; zone E ,five month wet and seven dry; zone F, four months wet and eight dry. In Irian Jaya, except in some mountain areas, rain every day is frequent; while in dry areas like Sumba island nine months without rain is not uncommon.

Land use classes
To identify potential land for agriculture, the land is grouped into eight classes; the risk of land degradation and the magnitude of inhibiting factors increase with the class number (Deptan, 1988). Classes I – IV are suitable for agriculture; while class V – VIII are unsuitable or costly for agriculture. The classes are:

• Class I flat, deep soil, suitable for all kinds of agriculture; particularly food crops
• Class II slightly sloping, sensitive to erosion. With terracing it can be used for annual and perennial crops
• Class III sloping land, shallow soil. With terracing, cover crop and crop rotation it can be used for perennial crops
• Class IV land with 15 – 30% slope. Food crops rotated with cover crops for forage and green manure for 3 – 5 years
• Class V flat land, permanently waterlogged. Unsuitable for crops but can be used for forage and fodder productions
• Class VI land with 30 – 45% slope. Unsuitable for crops. Can be used for permanent forage and fodder
• Class VII land with 45 – 65% slope. Can be used for forage and fodder or forestry with strategic lopping to prevent soil erosion.
• Class VIII land with more than 90% slope. It should not be used for forage, fodder and wood production, but kept as natural vegetation and protected forest.

IV. RUMINANT PRODUCTION SYSTEMS

In 1995 the total investment in livestock was Rupees 1,105 billions comprising 40% pre-production, 35% production and 25% post production (Anon, 1996). During 1991 – 1995 there was a 77.61% increase in livestock investment. In 1993 of 21 700 000 farm households 24.81% had livestock; 82.4% were smallholders (Soehadji, 1991). Livestock numbers and details of meat and milk production were given in Table 2.

Feeding Systems
In the rice area three crops are taken each year, forage is cut and carried. In the rain-fed area stock are stall-fed in the crop season and tethered when the land is fallow. In clove and vanilla plantations stock are always stall-fed; under coconuts, oil-palm and rubber stall-feeding or tethering may be used. Free grazing is only practised on uncropped land. Cut and carry is usual in intensive food and plantation crop systems in Java; tethered grazing in semi-intensive farming in Sumatra, Sulawesi and Kalimantan islands. Free grazing is common in extensive systems in the West Nusa Tenggara and East Nusa Tenggara provinces. In the intensive crop area, crops are the main activity, ruminants are kept for draught and saving. In semi intensive plantations the ruminant is a weeder and manure producer. In the extensive dry-land area ruminants are the main enterprise, and food crops a side line. In the wet-land area revenue from livestock is 29% of the farm income; while in dry-land farming it is 49% (Soehadji, 1990).

Limitations

Biological
In Eastern Indonesia, where the rainy season is only three to four months, water is a limiting factor; goats are more important, since they are more efficient in using water than cattle (TSFS, 1993). Water shortage can be partially overcome by developing farm-size water catchments. Feed shortage during the dry season is not uncommon in Nusa Tenggara province. In prolonged dry seasons, which usually occur every five years ,farmers sell their livestock at very low prices. Fodder shrubs and trees have been used to overcome such feed shortage. Indigenous breeds such as Bali cattle, Madura cattle, thin-tail sheep and Kacang goats are small and grow slowly, in line with natural forage availability. In areas such as Central Java and West Sumatra, where forage and fodder have been developed, imported feeder cattle, Etawah dairy goat and/or Friesian Holstein dairy cattle have been introduced to increase productivity.

Socio-economic
In intensive farming the land is mainly used for crops, so there is little space to keep livestock and grow feed; farmers prefer small ruminants to cattle and buffalo. In the extensive system, land is not limiting, but water and feed become limiting so farmers again prefer small ruminants. Smallholders keep livestock as savings. Chickens and pigs are sold to meet daily household needs; small ruminants are sold to meet seasonal needs (e.g. school fees, clothing); large ruminants are sold to meet occasional needs (e.g. weddings, special religious ceremonies). In some areas the cow is considered a cold animal ("shoots do not die because cut by tongue"), while the goat is a hot animal ("shoots die because cut by dental pad"), so some farmers prefer cattle to goats. In Madura bulls are kept for racing; in West Java bucks are kept for fighting; in West Bali buffalo are selected for racing and in North Bali steers are kept for rhythmic walking.

V. FORAGE AND FODDER RESOURCES

Backer and Bakhuizen van den Brink (1963) showed that there are about 238 plant families with about 952 genera and 1 047 species in Java and Madura. In the small island of Bali there are 50 genera of grasses and ground legumes and 55 species of fodder shrubs and trees used as ruminant feed (Nitis et al., 1980).

Agroforestry, which has existed in Indonesia for 100 years and has evolved through trial and error, is not only a way of increasing the timber, energy, feed and food production, but also contributes to conservation of the environment. Depending on the dominant and specific production of its components, agroforestry can be specified into many variants (Nitis, 1997). The transition leading to dominance of either the silvicultural system, pastoral system, or agrosilvopasral system depends on ecological and socioeconomic conditions. During the land reforms of 1963 many forests were cleared for smallholder farming and many grasslands converted into semi-intensive farming, thus increasing the planting of shrubs and trees for livestock feed. Grain, pulses and tubers are the main food crops. Wild grass and legumes in food crops are considered weeds. After harvest, the field is either bare or invaded by volunteer herbaceous species. No land is specially allocated to grow forage. Grass, legumes, shrubs and trees are grown on the bunds, on sloping land along terraces and on field boundaries.

Grasses and legumes growing wild under plantation crops are thought weeds and are cleared periodically. Leguminous trees and shrubs, on the other hand, are grown as supports for vanilla, shade for coffee, or green manure for the crop. They are also grown along plantation edges and lopped periodically to prevent shading.

Based on its leaf canopy, the forest can be classified into evergreen and deciduous forests. Because light intensity becomes the first-limiting factor, forage growing under forest is shade-tolerant. In the mixed deciduous forest, the main undergrowth consists of Bambusa, Imperata, Eulalia, Casearia, Euphorbia, Acroceras, Morinda, Acacia, Poecia, Leersia and Eupatorium species. In abandoned swidden, the plants are Eulalia, Leersia, Sida, Solanum, Thysanolaena, Acroceras, Ageratum and, Bambusa. In the dry season no green forage is left, because the forest floor is covered with dried leaves, shoots and pods.

In the dry-land farming area, farmers crop the land continuously for three years then leave it fallow for four to six years. During the fallow grasses and herbs colonise the field. This fallow is used to tether cattle and goats; tethered grazing is usually very intense, so no forage is left for the dry season.

Forage and fodder in natural grassland
Natural grassland develops as a result of shifting cultivation and the degradation of climax forest (Deptan, 1988) and is maintained by overgrazing and uncontrolled burning. Large areas of grassland are found is Sumatra, Kalimantan, Sulawesi, Nusa Tenggara, and Irian Jaya (Ivory and Siregar, 1984). The pasture consists of many grasses and legumes, with the commonest genera being Imperata, Paspalum, Chloris, Eleusine, Themeda, Tetrapogon, Polytrias, and Desmodium. During the dry season the land is almost bare, because of overgrazing and uncontrolled burning. Imperata cylindrica occupies 16 000 km2 and is increasing by 1 500 km2 annually (Surjani, 1970).

Critical land is that which is no longer capable of playing a role in production, hydrology, or ecology (Deptan, 1988). It develops as a result of overgrazing, continuous cultivation, bush-fires, and deforestation of marginal land. Forage in such areas is dominated by annuals, which grow quickly and produce plenty of seeds during the wet season but withers in the dry season. Shrubs and trees, grow well during the wet season but become stunted during the dry season.

Table 3. Native pasture yield (tonnes/dry matter/ha) during wet season in Bali ¹)

1)Nitis et al. (1980). * Not in lowlands.

Forage and fodder yields
Botanical composition is affected by season and land utilization (Nitis et al., 1980). In the wet season, the wet land, dry-land, and plantation areas are dominated by genera of Axonopus, Chrysopogon and Sehima, respectively; in the dry season crop land is dominated by genera of Paspalum. Yield of native pasture is affected by season, by climatic zone, topography, land utilization and soil conditions. In the wet season the highest pasture yield is in climatic zone F in the hills (Table 3); in the dry season the highest yield is in climatic zone E in the uplands (Table 4). Lopping yield (amount lopped to be fed to ruminants) of 43 species of fodder shrubs and trees in the wet season varied from 0.10 – 20.23 kg DM per tree; in the dry season the yield of 55 species varied from 0.13 – 23.24 kg DM per tree. In the wet season the highest yield of shrub and tree fodder is in climatic zone E in coastal area (Table 5); while in the dry season the highest yield is in climatic zone E in dry-land area (Table 6).

Table 4. Native pasture yield (tonnes DM/ha) during dry season in Bali province¹)

1)Nitis et al. (1980). * Not in lowland area.
 

Table 5. Shrub and tree leaf yields (kg DM/tree) during the wet season in Bali¹)

1)Nitis et al. (1980). * Not in lowland area.

Forage and fodder quality
In the wet season, native pasture contains more crude protein (CP), major minerals K and Mg and trace minerals Zn and Mo than that in the dry season (Table 7). In the dry season the highest CP content is in native pasture in climatic zone C in the hills (Table 8). In the wet season shrub leaves contained less CP than during the dry season; while the reverse is true for tree leaves (Table 8). The highest CP content of the shrub leaves during both seasons is from the legumes Leucaena leucocephala and Gliricidia sepium,; while the highest CP content of the tree leaves during the wet and dry seasons is from the legumes Wrightia calveina and Erythrina lithosperma, respectively. For Gliricidia sepium the highest CP content is in the wet land farming area; while for the Erythrina variegata the highest CP content is climatic zone B, (Table 10).

Table 6. Shrub and tree leaf yields (kg DM/tree) during the dry season in Bali¹

¹Nitis et al. (1980). * Not in lowland area.

Table 7. Proximate and mineral compositions of native pasture in Bali¹

¹ Nitis et al, 1985. ² From 15 species.

Table 8. Crude protein content (% DM) of native pasture in the dry season in Bali¹

¹Nitis et al. (1980). * Not in lowland area.

Deleterious compounds found in forages and fodder are: cyanoglucosides, fluoroacetic acid, tannin, prussic acid, mimosine, latex and oxalic acid (Table 10). Some fodders such as Bauhinia variegata may cause decrease in milk yield, Bridella retusa may cause dysphagia, Albizia stipulata may cause haematuria, Ficus hispida may cause abortion and Schima wallichii may cause hair loss and skin disease (Table 11). Ways to overcome the anti-nutritive factors include supplementation, dilution, simple treatment, and rumen microbial activity (Lowry, 1989). Mimosine in Leucaena can be toxic to some ruminants if there is no 3,4 DHP – detoxifying bacteria in their rumens (Jones, 1986); ruminants can be inoculated or put in contact with resistant ruminants (Munoz and Seifert, 1991).

Table 9. Proximate composition of shrubs and tree fodders in Bali¹

¹ Nitis et al., (1985).
² 13 spp in wet season and 14 spp in dry season.
³30 spp in wet season and 41 spp in dry season.

Utilization of forage and fodder
Roughage fed to ruminants consists of wild herbage, fodder and crop residues. Fodder is shrub and tree leaves and crop residues are straw and stover(Nitis, 1998). In Bali goats are fed more shrub and tree leaves than cattle, while buffalo are fed little (Table 12). Rice straw, corn stover and banana pseudostems are not fed to goats, but cassava tops are fed when available. Cattle in the dry-land farming are fed more leaves than those in plantations and rice areas (Table 13); in the rice areas they are fed straw; in dry-land farming and plantation areas they are fed maize stover and cassava tops.

Limitations to forage and fodder production
No land is allocated to grow livestock feed in smallholder farming area, so forage and fodder are grown on bunds, around fences, fallow and land not suitable for crops. In some places farmers have other priorities than fodder for plants. Ficus benjamina is a holy tree so it is not lopped. Imperata cylindrica is used for thatching special houses, so that it is only tether-grazed during very early regrowth after harvesting every two years. Artocarpus integra is not lopped regularly, otherwise it does not fruit. Coconut fronds are not commonly fed to livestock since the young leaf is used as accessory in ceremonies, the old fronds are used as firewood.

Pests cause little damage on properly managed forage and fodder. However a psyllid (Heteropsylla cubana) outbreak was reported in Hawaii in 1984 and in the Asia and Pacific regions in 1985 (NFTA, 1989). In seriously infested areas in Indonesia, control measures using resistant Leucaena varieties, effective predators, insecticides and management have had varying degrees of success. In some areas Gliricidia is infested with an aphid (Aphis craccivora) particularly at the onset of the rains, which causes blackening of the leaf surface and in severe cases the death of the leaf primordia and shedding of young leaves (Nitis et al. 1989). The aphid exudate causes yellowing and even death of the Cenchrus ciliaris grown with Gliricidia. Evaluation of the 16 provenances of Gliricidia sepium showed that 3 provenances (G14, G17 and N14) are quite resistant to aphid infestation (Nitis et al., 1991).

VI. OPPORTUNITIES FOR IMPROVING FORAGE RESOURCES

Improved planting material
The Directorate General of Livestock Service, Jakarta in 1995 distributed 2 400 000 stakes of fodder trees (Anon, 1996). During 1991 – 1995 the number of stakes distributed increased by54.73%. The province receiving most stakes was Central Java. Seeds of 17 improved grasses and 13 improved legumes have been distributed covering various climatic zone, topography, land utilization and soil condition (Anon, 1996). On-farm trials in dry-land farming in Bali showed that Gliricidia sepium as a multipurpose shrub producing fodder, cutting, firewood and seed is best planted in clusters (Nitis, et al., 1997a); for seed production it should be planted in alleys (Nitis et al., 1996).

Table 10. Crude protein (CP) content (% DM) of Gliricidia sepium and Erythrina variegata in Bali province¹