0652-B5

INVOLVEMENT OF LOCAL PEOPLE IN AGROFORESTRY FOR DISASTER AND ENVIRONMENTAL MANAGEMENT

A.K. Charles ¹ and R.S. Kanoje ²

Abstract

In the central part of India Annual rainfall is nearly 1200 mm. even though this is fact that 50% of the population facing acute water shortage in the lean months. it local people may encourage to involve in agroforestry the situation can be improved.

The phenomenal increase in urban population and industrial growth during the past few decades has resulted the major problems of a basic nature confronting mankind such as those of quantity and quality of food, feed, drinking water, disposal of sewage and industrial wastes and of conservation of natural resources. Indiscriminate use of chemical fertilizers and biocides (pesticides, heavy metals, etc. which are lethal to biological organisms) for harvesting higher yield from agriculture without associating tree components and release of industrial wastes with their confrontation with multipurpose tree species have resulted in enviornmental pollution.

Environmental advantages attributable to the presence of trees in agroforestry systems are numerous. Canopy of trees permits greater resistance and buffering capacity to booth macro and microclimate extremes of moisture and temperature. Tree roots improve soil structure and water infiltration capability, can reduce the potentially disastrous impact of rainfall and serve to anchor and stabilize soils and reduce erosion. Leaf and twig biomass return to the soil through litter fall improves recycling of nutrients thereby minimizing the dependence on indiscriminate use of chemical fertilizers. The synergistic effects of increase floral diversity can deter insect buildup and promote increased number of wildlife (Boudowski, 1987).

SOIL EROSION CONTROL - THROUGH AGROFORESTRY

Multipurpose tree species grown in combination with agricultural crops and known to have direct bearing on rainfall erosivity, soil erodibility, and soil surface protection. Just to enter plant trees in croplands and especially on clean cultivated steep slopes may sometimes aggravate soil erosion. Although the volume of rain reaching the ground is reduced somewhta by interception of tree canopy, there is an increasing problem from leaf drip which develops a drop size larger than uninterested rain drops and creates a fall distance greater than that intercepted by ordinary crop covers. Both drop size and fall distance will add to the kinetic energy hence increase soil detachment and erosion (Morgan, 1986). A dense canopy of low tree of shrubs, such as provided by coffee or tea bushes, reduces erosivity, although the shade trees in plantation increases it (Wiersum 1986). In spatial mixed agroforestry system, therefore any such effect will depend on the height of the canopy. In spatial zoned systems, including hedgerow intercropping, the canopy is usually low but it is not vertically above the cropped land. Thus, maintenance of a ground surface cover of 60% or more, formed by any combination of living herbaceous plants with plant litter, has a high potential to reduce erosion, and should be the primary objectiv e in agroforestry design. It is stated that the effectiveness of agroforestry in controlling erosion should rest on a foundation of experimental measurement of erosion rated under actual agroforestry systems. Management practices are the main deciding factors and determine the merits and demerit of various agroforestry practices whether they are controlling or aggravating the soil erosion (Table 1) Hedgerows of Leucaena and Gliricidia at two and fourm spacings were compared with no tillage and conventional ploughing without hedgerows. The results showed that the mean rates of soil loss over two year (t/ha/year) were 8.75 under ploughing, 6.95 under hedgerow inter cropping (mean of two hedge species, two spacings) and 0.02 under no tillage. Reduction of run off and nutrient losses followed the same pattern thus, although hedgerow intercropping was not effective as no tillage, it reduced soil and nutrient losses and run off, to well below acceptable limits (Lal, 1988).

On steep slopes in Colombia (humid climate, rainfall 4000 mm) one year record soil losses of 23-38 t/ha/year under maize reduced to 13 t/ha/year (on both 49 and 75% slopes) by hedgerows of Gliricidia (van Eijk- Bos and Mozeno, 1986).

NFT IN AGROFORESTRY AND IMPROVING SOIL FERTILITY.

Nitrogen fixing trees and shrubs, growing within practical agroforestry systems, are capable of fixing about 50-100 kg N/ha/year. The nitrogen returned in litter and pruning may be 100-300 kg. N/ha/year, fourthly derived by recycling of rertilizer nitrogen. The major role of trees it to improve the efficiency of nutrient cycling, the mechanisms are uptake from Lower horizons reduction of leaching loss by tree root system, balanced nutrient supply and improvement in the ration between available and fixed minerals. For a tree leaf biomass production of 4000 kg. DM/ha/year. The potential nutrient return in litter, as kg/ha/year, is the order of 80-120 kg for Nitrogen 8-12 kg for Phosphorus 40-120 kg for Potassium and 20-60 for Calcium. Pruning of green parts of MPTs under agroforestry systems and their incorporation in soils before leaf fall is beneficial over fall as nutrient content in living leaves are higher than in litter (Gill 1996(. Deciduous trees typically trans locate nutrients from leaves to perennial organs well before leaf fall (Bernhard Reversat 1987, Talsma et al, 1987).

RATES OF EROSION IN TROPICAL FOREST AND TREE CROP SYSTEM

AMELIORATION OF ENVIRONMENT BY MPTS UNDER AGROFORESTRY SYSTEM.

The indiscriminate felling of trees to expand foods production and the harvesting of forest products in recent past have begun to impact directly on the economic and environmental health of many countries particularly in the developing one. Pressure on temperate forests would have substantially following centuries of clearing for agriculture. Unfortunately, chemical stresses from air pollution and acid rain today place a substantial share of European forests at risk. Trees covering some 31 million ha in Central and Northern Europe are showing signs of damage linked to air pollution.

Conversion to cropland is by far the leading direct cause of the less of forest in tropical countries. Popullation growth inequitable land distribution and the expansion of exports agriculture have greatly reduced the area of cropland available for subsistence farming, forcing many peasants to clear virgin forest to grow food. These displaced cultivators often follow traditions of continuous cropping that are ill suited to fragile forest soils. Eventually the soils get so depleted that peasant colonists must clear more forest to survive Population pressures have also transformed fuelwood collection into an unsustainable practice, particularly in Africa and Asia.

Fortunately, reforestation/agrooforestry is also proceeding somewhat faster than official estimates indicate Spontaneous tree planting by villages around farm fields, as wind breaks, or along roadways is frequently not counted. Indeed agroforestry statistics typically ignore trees outside of forests, even though in many areas they are primary source of fuelwood, fodder and building materials.

CARBON CYCLE AND AFFORESTATION

MPTs play acrucial role in the global cycling of carbon. The earths vegetation and soils hold some 2x10 milion tonnes of carbon, roughly triple the amount stored in the stamosphere. When trees are cleared or harvested, the carbon they contain as well as some of the carbon in the soil is oxidized and released to the air, adding to the atmosphere store of CO₂ This release occurs rapidly it the trees are burned but slowly if the decay naturally.

MPTS. AND GLOBAL WARMING

Although the cutting and bushing of MPTs clearly adds significantly to the CO₂ buildup, the way ramaining forests worldwide respond both to the buildup itself and to the resulting planetary warming could boost an even greater influence on the earth future climate.

Higher CO₂ levels might enhance the growth of trees, causing them to remove more carbon from the atmosphere, which is turn would dampen the washing Greenhouse operators take advantage of this rertilizing effect to boost crop production by setting the CO₂ concentration in greenhouse air two to three times higher than in the natural atmosphere, however, no comparing evidence suggests that natural forest would respond in this way.

If respiration exceeds photosynthesis for an extended period trees would stop growing and ultimately die.

BETTER USE OF SEWAGE THROUGH TREE PLANTATION.

In order to combat the disastrous effect of sewage water following points may be taken into account:

1. Sewage should not stagnate so as to produce foul smell and act as breeding ground for mosquitoes.
2. It should not percolate down to contaminate ground water and raise water table thus, water should either evaporate or be consumed.
3. It should not increase the salinity of the soil and/or make it unproductive by means of accumulation of toxic elements.
4. Any vegetation raised at such places should not be directly consumed by human beings.
5. It should be economical rather revenue generating.

In the light of above, technology involving forestry/agroforestry has been developed wherein waterlogging, stagnation and thus pollution is eliminated by utilizing the irrigation and nutrient potential of these waste waters, right in the area of their production.

The MPTS plants use the water and nutrients of sewage for their growth and boidrains excess water without any harmful effect on the environment Each tree acts as small biopump absorbing water from the soil and releasing it in the environment through transpiration. Normally, the applied effluent disappears within 12 to 18 hours resulting no water stagnation which in turn lowers production of foul smell eliminating breeding place for mosquitoes and checks rise in water table. There is no adverse effect of sewage disposal on toxicity or efficiency of any nutrient, heavy metal or salinity stresses on plants.

This techniques utilizes the entire biosystem as living filter for supplying nutrients to soil and plant irrigation renovates the effluent for atmospheric recharge and ground storage. It also conditions the humidity of the environment and conserves the resources right in th area of their production.

It builds up the soil ferfility with respect to soil available P,N,K 20, C and micronutrients. It decreases the soil pH from highly alkaline to neutral levels without significantly building up the salinity. At CSSRI, Karnal the results showed that the pH of the plots receiving sewage water daily dropped from 8.40 to 7.4 in 4 years. At Nilokheri (near Karnal), where pH of the original soil was 9.60 it dropped to 8.10, simply that it also ameliorates the sodic soil (Chhabra 1990)

Further, as forest plants are to be used for fuelwood, timber or pulp, there is no chance of pathogens, heavy metals or organic compounds entering the human food chain system point which is a limiting factor when vegetables or other crops are grown with sewage.

Suitable tree species

Though most of the plants are suitable for utilizing the effluent, yet, those tree species which are fast growing can transpire high amount of water and are able to withstand high moisture content in the root environment are most suitable for such purposes. Eucalyptus hybrid which has the capacity to transpire large amount (80 litre/DAU) of water, and remains active throughout the year. Other species suitable for this purpose are Poplar and Subabul.

Out of the tree species, Poplar is the most responsive in utilizing sewage however, being deciduous it remains dormant in winter and thus can not bio drain effluent during winter months. Keeping this in view, Eucalyptus seems to be the best choice, for such purpose. However, if area is available and the volume of effluent is small combination of Poplar with Eucalyptus is the best proposition.

CONCLUSION

Developments in the field of agroforestry has been rapid since early 1980 Today, there is tlittle need to promote agroforestry to a doubtful scientific and development community. The rapidly expanding interest in agroforestry in recent years, witnessed by a myriad of research and development activities, leaves no doubt the agroforestry as an approach to land development is now accepted by most, if not all disciplinary scientist and development speciallists. Increased concern at the highest International Policy levels about the sustainability of agricultural development. In the light of the apparent rapid depletion of the natural resource base, has brought agroforestry even further even further into the limelight. Trees and shrubs, if properly chosen and managed, have a potential to cope up with disaster and create a congenial environment in addition to conserving the soils productive capacity Soil conservation is not seen in its traditional, narrow sense of preventing water and wind erosion, but in the broader and much more important sense of maintaining soil fertility. We know that it is impossible to reduce the soil loss to zero Limits to be set as targets for the design of land use system. There need to be set low enough such that there will be a serious or progressive decline in crop production yet high enough to be realistically achievable. The concept of tolerable erosion or soil loss tolerance has often misleadingly used. It originated at the time when erosion was viewed primary as physical loss of soil material, which is really disastrous and poses environment degradation and creates impediments in the developmental activities.

SUMMARY

Agroforesty is an inter disciplinary, multi-sector approach of land use. Its prime objective is over all optimization and to protect the environment and maintain the ecological integrity. Agroforestry is primarily the technology of using perennial vegetation in combination with seasonal or perennial field crop, fodder, or other crops of economic value in agriculture. In the developed agroforestry systems, there are three components i.e. the woody perennials, the agricultural crops and the animals. However, in all the agroforestry system the presence of the tree component is must and it plays the dominant roles- the trees have two major roles the productive role (fuel, fodder, food, fruit and fertilizer) and the service roles (soil and moisture conservation wind break, shelter belts, shade, etc.). Trees have established themselves as insurance against natural disasters like environmental pollution. floods and droughts. Agroforestry also extends greater diversity for wildlife and landscape improvement. Development activities of agroforestry leads to control of erosion either through barrier approach or by cover approach, maintenance of soil fertility by way of organic matter maintenance, nitrogen fixation nutrient cycling and augmentation of nutrient uptake i.e. trees associated mycorrhizal system However, in defth studies are needed over a range of environmental conditions for improving soil fertility and reducing the dependence on chemical fertilizers. Incorporation of multipurpose trees species with crop can also enhance groung recharge. The paper deals in the role of agroforestry in controle of natural disastur and enhancement of environment.

SUGGESTIONS

(1) Involment of local self Government.
(2) Implications through N.G.O.s
(3) Emphasis of field level realities through ppA and RRA.
(4) JFM. should be strengthen and given top priority
(5) Strong partnership between donor agency, NGO. local people concerned with the forest and watershed development.
(6) Forest, tourism and eco tourism can be developed for poverty alleviation programme.
(7) Horticulture, floriculture, sericulture and apidulture should be developed in the area with the help of NGO.
(8) Trans boundary cooperation and exchange of ideas should be promoted.
(9) In order to ensure long term investement efforts by stakeholders a plateform should be formed and the programmes will be implemented.

BIBLIOGRAPHY

Bernhard Reversat F. (1987) les cycles de elements minerauxdans UN peuplement Accacia seyalet leurmodification en plantation d'Eucalyptus au Senega. Acta Oecologica B. 3 19

Budowski, G. (1987) Applicability of agroforestry system. Agroforestry in the African Humid Tropicals (L.H. MacDonald, ed.) Ibadan Nigeria, UNU pp. 13-16

Chhabra, R. (1990) Wasteland and use of sevage for raising trees. Proc. Summer Institute of afforestation of salt affected soils, CSSRI. Karnal (May 1-19)

Gill, A.S. (1996(. Afuel/fodder production system using Sesbania grandiflora. NFT Research report. 4:19

Lal, R. (1988) Soil erosion control with alley cropping. Paper presented to the 5 ^th International Soil conservation conference, Bangkok, Thailand.

Morgan, R.P.C. (1986) Soil erosian and conservation. London Harlow (UK, 298 pp

Talsma, D.J. W.H.O. Ernest, R.A. Verwaij and R. Vooija (1987) seasonal variation of nutrient concentration in a semi arid Savanna ecosystem in Botswana. J.Ecol. 75, 755-770

Thingran A.G. and B. Lal (1989(. Bioaccumulation of 14C labeled DDT in various tropic levels of aquatic environment nat. Symp. on Nuclear Techniques in the study of pesticides in food, agriculture and environment, organised by Department of Atomic Energy Bhabha Atomic Research Centre, Bombay held at UAS, Bangalore (Feb 8-10)

VAn Eijk-Bos, C. and L.A. Mozeno (1986) Barriers Vivas de Gliricidia sepium (Jaco) Stend (Matarraton) Y su stc. Sobre le perdids de sueto en terenes de colinas bagas. Uraba (Colombia), Bogota, Colombia, Conf. Informa, pp. 16

Wiersum, K.F. (1984) Surface erosion under various tropical agroforestry systems, Symposium on effect of forest land use on erosion and slope stability (C.L.O. Longhlin and A.J. Oearce. ed.) Honolulu, Hawaii, USA East West Centre, pp 231-239.

Wiersum, K.Fl. (1986) Ecological aspects of agroforestry with special emphasis on tree- soil interactions. Lecture notes. FONC project communication 1986, 16-Jogjakari Indonesia, Fakultas ken Huanam University, Gadjah, Mada. pp.73

¹ President Wainganga Samudaik Vikas Kendra
² Asst. Conservator of Forest