SUPPLY BAHAN BAKAR KAYU YANG BERKELANJUTAN DI NEGARA-NEGARA YANG SEDANG BERKEMBANG

Abstrak
Umumnya penduduk di negara miskin dengan pendapatan yang rendah akan terus menggunakan sumber energi dari kayu untuk pemenuhan kebutuhan energi domestic dan sebagai sumber pendapatan. Diperkirakan bahwa 1,700 juta ton bahan bakar kayu dihasilkan secara global. Tingkat konsumsi yang sangat tinggi terhadap kayu bakar di negara miskin berpotensi terhadap penurunan sumberdaya hutan. Selain itu, keterbatasan supply kayu bakar dewasa ini juga diprediksikan akan memberikan konsekwensi sosial ekonomi yang sangat serius bagi penduduk miskin di dunia (Danish et al, 2003:279).
Penelitian ini bertujuan untuk memberikan kontribusi terhadap keberlanjutan dari supply bahan bakar kayu dengan penekanan beberapa kebijakan untuk memenuhi permintaan akan bahan bakar kayu tanpa menimbulkan kerusakan lingkungan. Penelitian pustaka ini dilaksanakan dari bulan Maret sampai bulan Juni 2008 termasuk di dalamnya adalah wawancaralangsung dan jarak jauh dengan beberapa pakar kehutanan dan lembaga kehutanan. Study ini khususnya difokuskan kepada sumber-sumber bahan bakar kayu dan kebijakan yang menunjang tercapainya keberlanjjutan supply bahan bakar kayu. Dari hasil penelitian ini ditunjukkan bahwa pelibatann penduduk local dalam pengelolaan supply bahan bakar kayu melalui pentuan tingkat harga dan penerapan kebijakan pajak telah berhasil dipraktekkan di beberapa negara berkembang. Kebijakan lainnya adalah agroforestry dan konservasi energi melalui pengenalan kompor yang hemat energi.

Abstract
Many people in developing countries will continue to depend on wood energy whether as fuel for their daily energy needs or as a source of income. It is estimated that 1,700 million tons fuel wood now harvested each year globally. This huge consumption of fuel wood in the developing world has led to predictions of potentially devastating depletion of forest resources. Besides that, the perceived widening shortages of fuel wood are also expected to have serious negative socio-economic consequences for the rural poor.
This report aims to give a contribution to the sustainability of fuelwood supply by emphasizing some policies in order to fulfill the demand of fuelwood without degrading the environment in developing countries. Library research was carried out from March to June 2008 and included direct and long-distances interviews with foresters and forest institutions. The study focused especially on the types of fuelwood sources and enhancing the sustainability of fuelwood supply. This research has shown that involving the local community in fuel wood supply management trough pricing and taxation systems has been successfully implemented in some developing countries. Other policies which help are agroforestry or tree plantation and energy conservation through introducing improved stoves.
Keywords: fuel wood, sustainable, developing countries.



INTRODUCTION
Two billion people or about 40 percent of the total world population depend on fuel wood as their primary energy source (Arnold and Persson, 2006:379). The majority of households in poor countries, especially those in the low-income bracket, rely entirely on fuel wood, either firewood or charcoal for cooking and space heating. Many of them face a daily struggle to find enough fuel to warm their homes and cook their food (Ellegar, 2004:2).
The dependency on fuel wood by people in developing countries as their principal domestic fuel is not only for household consumption but also for rural industry consumption. For rural industries in most parts of the developing world, including the Asia and Pacific region, energy in the form of heat is an important input to the production processes, such as brewing processes in Africa, brick kilns in India and coconut processing industries in Sri Lanka (FAO, 2000:28).
A number of countries have launched programs to address these problems in terms of achieving sustainability in fuel wood supply. This paper provides an overview of the experience of and lessons learnt from some programs, such as local participatory approach, taxation systems and energy conservation. I will argue that the programs that have been implemented have better managed the natural wood resources and ensured the rural population benefits more from wood resources. It means the demand for fuel wood in developing countries can be achieved without degrading the environment.
METHODOLOGY

Developing countries are the research focus due to their dependency on fuelwood as a energy resource and income resource. This research was conducted in 2008 under the direct supervision of the School of Resources, Environment and Society (SRES) at the Australian National University. While collecting qualitative data in some libraries, searching internet, additional information through interviews with foresters and forest institutions can add important relevance to research. The process of analysis begins at the beginning of the research project and continues through the writing process. There is an ongoing dialogue between the researcher’s understandings of the social actions studied. The diversity of data collection methods I used enriched the research itself.




RESULTD AND DISCUSSION
1. Types of fuel wood sources
Leach and Mearns (2005:11) clarify that generally there are five main sources of fuel wood; the relative importance of each various greatly from place to place.
1.1. Tree cutting directly for fuel
This source is exploited especially to make charcoal and occurs around some cities where close to main roads or railway lines. The cutting system may be intensive, but is usually more selective, in that only larger trees or suitable species are felled. This system prevails around Blantyre, Malawi and has seriously degraded the woodland (FAO, 2005:1). The larger trees have gone, leaving a dense patchwork of smaller trees interspersed with patches of maize and vegetable crops. The sustainability of this source depends on whether trees are replanted and on cutting rates compared with the rates of natural regeneration in the affected areas (Roberts et al., 2004:80).
2.2. Dedicated fuel wood plantations
This system is common only in Asia as a source of urban fuel wood and in a few cities in Africa, such as in Addis Ababa in Ethiopia (FAO, 1997:167). Their economic viability depends mostly on whether single-purpose industrial or mixed small holder methods are used and on the price structures of urban fuel woods transport and markets (Neth et al., 2004).
2.3. By-product wood
This source stems from various tree growing activities, for example, multi purpose farm trees, commercial forestry for timber or specialized farm tree crops such as Gum Arabic in Sudan and tannin from small woodlots of wattle in Kenya (Leach and Mearns, 2005:11). The complexities of urban market structures and prices are some factors that influence the amount of fuel wood supply to urban people.
2.4. Dead branches and twigs
Generally dead branches and twigs are picked off the ground or cut from the tree. Many surveys confirm that these sources are non-destructive sources (Remedio, 2002:13). It can sometimes be taken from state-owned forests and woodlands or from managed tree and other woody resources on farmlands and village commons as well (Kirubi et al., 2000:49).
2.5. Surpluses arising from agricultural land clearances
These sources usually greatly exceed local fuel wood needs, even though many trees may be left standing as part of the farming system, while others are burned to provide soil nutrients or simply to clear the land (Leach and Merns, 2005:25). Farmers think that it is normally much more profitable to use land within of urban markets to grow food for the city than to leave it under tress and sell the wood. The pressures to clear such land of trees, sell any salvage wood to the city, and then farm it, are almost irresistible (Bembridge, 2000:46).
2. Fuel wood Consumption Trends

Table 1 shows the FAO projections of fuel wood consumption in the main developing regions. As shown in this table, aggregate consumption of fuel wood and wood for charcoal in Africa is growing from year to year. Even in some African countries, such as Mauritania, Rwanda and Sudan, fuel wood demand is already ten times the sustainable yield. Arnold and Person (2003:380) estimate that the consumption of fuel wood in this region is growing at a rate close to that of population growth.

Table 1. FAO projections of fuel wood and charcoal consumption to 2030 in the main developing regions.


1970 1980 2000 2000 2010 2020 2030
Fuel wood (million cubic metres)
South Asia 234.5 286.6 336.4 359.9 372.5 361.5 338.6
Southeast Asia 294.6 263.1 221.7 178.0 139.1 107.5 81.3
East Asia 293.4 311.4 282.5 224.3 186.3 155.4 127.1
Africa 261.1 305.1 364.6 440.0 485.7 526.0 544.8
South America 88.6 92.0 96.4 100.2 107.1 114.9 122.0
Charcoal (million tons)
South Asia 1.3 1.6 1.9 2.1 2.2 2.4 2.5
Southeast Asia 0.8 1.2 1.4 1.6 1.9 2.1 2.3
East Asia 2.1 2.3 2.3 2.2 2.1 2.0 1.8
Africa 8.1 11.0 16.1 23.0 30.2 38.4 46.1
South America 7.2 9.0 12.1 14.4 16.7 18.6 20.0
Source: Arnold and Persson, 2003:380

Several factors are responsible for increasing consumption of fuel wood and wood for charcoal in most developing countries. Rapidly growing population in many developing countries creates increasing demands for firewood and charcoal. Another factor that has resulted in increasing fuel wood demand is low income per capita of society. The World Bank Energy Sector Management Assistance Program (ESMAP) has undertaken a survey in 46 cities in 12 developing countries (Arnold and Persson, 2003:382). This survey found that income per capita has an important influence on the level of fuel wood use. Consumption of both fuel wood and charcoal usually decreases with an increase in income as people can afford to pay for electricity, gas or petroleum products (Arnold and Persson, 2003:383).
In this survey, it can be noted that the lower income per capita in many developing countries contributes to increasing demand for fuel wood (Neth et al., 2004:57). The reason is their income is not enough to switch energy demand of fuel wood into another energy source that is absolutely much more expensive, such as LPG. However, based on my own experience in Indonesia, even though rural people have enough income to use LPG, they prefer using fuel wood for certain occasions.
In Indonesia, when they have a party that requires much energy to cook many dishes with large portions, such as a wedding party, the cooks always use fuel wood to save money. The high demand for fuel wood for a wedding party is not only for cooking fuel, but also for preparing fires traditional ceremonies that need much fuel wood. Furthermore, many households could use multiple fuels for the same end (such as fuel wood and LPG for cooking). Regarding saving money on cooking fuel, rural people are more likely to use fuel wood to cook food that needs a longer cooking time and LPG to cook food with a shorter cooking time, such as just preparing tea in the morning and cooking sauces.
3. Potential Impacts of fuel wood energy resource

In many places fuel wood resources are dwindling because of deforestation which is caused to varying degrees by the need for farming land, and by over grazing, commercial logging, uncontrolled fires and tree cutting for fuel (FAO, 1997:167). As wood resources diminish and recede, millions people that obtaining fuel woods whether in cash or time for gathering them have suffered, especially for marginal households. These impacts are greatest for the poor and for women, who normally bear the responsibility for fuel provision and use.
The sale and trading of fuel wood provide an income for huge numbers of people. Plas and Hamid (2003:2) explain that in 1991, in Chad, a Sub-Saharan African country, there were at least 9000 persons active in the fuel wood supply chain, from cutting to transforming, transporting and selling. Likewise there were about 125,000 people producing or selling charcoal for use in the city of Dar es Salaam, Tanzania, in the 2000s (Rolf et al., 2006:9)
However, besides creating jobs and providing an income source for rural people, using fuel wood had negative impacts on the health of household members and environmental aspects as well. The most serious direct health impacts, especially for women and children, are respiratory infections and chronic lung disease (Ellegard, 1994). These occur when fuel wood is burned indoors without either a proper stove to help control the generation of smoke or a chimney to vent the smoke outside. Besides deforestation, increasing fuel wood energy consumption would result in reduced agricultural productivity by depriving the soil of recycled nutrients that would have been available from trees, crops and animal residues (FAO, 2006).
Great efforts will be needed to reduce these impacts, prevent them spreading, and provide sustainable and adequate energy supplies at affordable costs for fast-growing populations.
4. Enhancing the sustainability of fuel wood supply

Fuel wood supply as part of sustainability issue has led to a number of many responses that can be categorized into supply- and demand-side measures or interventions. The supply-side measures are implemented independently or integrated with a participatory local community approach, the taxation system and agroforestry projects. The objective of these projects would be to increase fuel wood supply from existing tree plantations or develop new policies for the same purpose.
The sustainability problems have also been addressed indirectly through demand-side measures, that is, by promoting energy efficiency and conservation. In particular, in the case of fuel wood, efforts have focused on the design and dissemination of improved cook stoves.
5.1. Participatory local community approach

A sustainable solution for fuel wood supply will be difficult to conceive and implement unless the local community truly benefits from these resources. Many trees, typically forests on public land, are controlled by government agencies in order to extract revenues from legalized commercial extraction and to protect them from illegal over exploitation (Fleuret, 1983). However, generally, the government agencies, such as in Chad and Niger, face many problems in managing all the resources in their country, such as location of resources and poor road construction to reach the location (FAO, 2002)
Given public institutional weaknesses to properly manage forestry resources, it was decided by the government in Chad in 1994 through the new law (No. 36/PR/94) that this management would be transferred from the national to the village level (Plas and Hamid, 2003:1). Involving the local community in management of natural resources is undertaken to address this shortcoming and create a capacity to manage wood resources at the village level and enable villages.
Several community forestry projects have been successfully established in India, Africa and Niger (Bembridge, 2000:43). India is possibly the global showcase for joint forest management and forest policy reform. According to the World Bank, some 40,000-village communities are now protecting about 4,5 million hectares of forest, under a wide range of land -lease or land-sharing arrangements with state forest department (Cunningham and Cunningham, 2002:285).
In India, the source of wood for timber and pulp production was switched to farm plantations in 2005, while forests were managed, not to earn revenue, but for their environmental and ecological benefits and to meet the minimum needs of local people for fuel wood (Sonaton et al., 2004:159).
Plas and Hamid (2003:1) explained that villages in Chad have signed a long-term contract with the Ministry of Environment to manage their own territory, under a program called Village Exploitant Rationellement son Terroir (VERT). There were 55 villages, which became village VERT in 2002 and are managing 350,000 ha, based on management plans. In practice, they work on and allow cutting of only one out of ten parcels each year and the total volume to be cut is guided by a quota system. The quota is based on the estimated Mean Annual Increment (MAI) for the standing stock in that village (Plas and Hamid, 2003:5).
As a result, many forest areas that have implemented a local community participatory approach are apparently now stabilized and this is a huge relief from the worries of total deforestation and the fuel wood crisis. This has been achieved not by government intervention, but by mental revolution followed by the creation of new market, patterns of ownership and institutional environments (Remedio, 2002:18).
5.2. Taxation systems
Another strategy used by governments to avert the fuel wood crisis has been the imposition of a tax system to prevent the right of villagers in terms of setting up small fuel wood business. The tax system that has been introduced by Law 36 in Chad allows villages to prevent encroachment by outsiders and to benefit from fuel wood business and the fuel wood transport levy (Plas and Hamid, 2003:5).
Plas and Hamid (2003:6) show the benefits obtained by villages. Before the village became a VERT, the local communities would not receive amounts anywhere near as much. However, after implementing villages VERT the 55 villages collected about F.CFA 29 million as their part of the tax, and they also earned an estimated F.CFA 112 million for the 90,000 bags of charcoal they produced in January to June 2003 (Robert et al., 2004:163).
The tax was imposed for a unit of either one bag of charcoal (of about 40 kg) or one stere of wood (about 350kg). A bag of charcoal is sold in town for about F.CFA 4000, and a tax of F.CFA 600 would increase the price by 15% (Plas and Hamid, 2003:7). The consumers can buy fuel wood cheaper at a lower tax in village VERT. The preferential tax is 50% lower for a villages VERT than for all other fuel wood production zones in the supply basin of N'Djamena.
5.3. Agroforestry
"Agroforestry is the collective name for all land use systems and practices in which woody perennials are deliberately grown on the same land management unit as crops and/or animals" (Arnold and Persson, 2003:8). This type of land use system gives direct economic benefit in terms of the availability of fuel wood and increases the quality of environment as well, such as preventing erosion and increasing soil nutrients.
The Koro Village Agroforestry Project (VAP) in Mali's fifth Region, Africa was implemented in mid 1986 (Leach and Mearns, 2005). The Koro VAP engaged in extension for tree planting activities, which included windbreaks, interspersed field trees, fruit and shade trees and live fences. The biggest challenge for this program is the management of live fences during the project. Rural people could reject this project because the potential of loss of grass fields to feed their livestock (Danish et al., 2003:280).
Another agroforestry projet is Gia Lai Agroforestry Extension Project in Vietnam, funded by the New Zealand Overseas Development Administration (ODA) since 1997 (FAO, 2002). The objective of this project is improve the ability of female and male smallholder farmers to better organize grassroots-level resource management and build the response capacity to rural development needs and opportunities within the Extension Service, Gia Lai Women's Union and the farming community
5.4. Wood energy conservation: promotion of improved stoves
One strategy that has been introduced to decrease the demand for fuel wood is promoting new cooking stoves in the rural sector of developing countries (Ellegard, 1994). Traditional stoves and fireplaces that commonly used in developing countries are believed to have low cooking efficiencies and are detrimental to women's health because of smoke they produce in the kitchen (Salariya, 1983).
In order to reduce consumption of fuel wood and eliminate smoke from traditional kitchens, much effort has been devoted to designing and distributing stoves, which are both smokeless and more efficient. Gill (1985:3) argued that such stove programs would improve women's health and reduce time spent cooking and in collecting fuel. If this stoves program could be adopted on a widespread scale, then firewood consumption would fall, thereby reducing pressure on forests.
The nafacama stove that has been introduced in Chad, has reduced fuel consumption by saving about seven bags of charcoal per household per year (Ellegard, 1994). Furthermore, introducing this improved stove has created job opportunities for rural people. More than 50 stove makers have received training and blueprints of the stove model.
Like wise, the lorena stove in Srilanka has been promoted to rural people with expected lifetime is about 2 years. About 10,000 have been sold at a level of about 200-500 per month (Inglis, 2005:7).
However, it has been discovered that many problems arise regarding the implementation of this program. Stove users regard cooking speed as a very important factor rather than fuel efficiency. Gill (1985) argues that the rural people in Tanzania were more concerned about being able to cook quickly than about fuel efficiency.
Besides that, people are likely to be more attracted to a new stove if it offers a variety of benefits. Bembridge (2000:45) argues that rural households in Ciskei, South Africa have apparently not been exposed to the possibilities of using wood to economize on fuel wood. They thought the designers of the fuel economy-cooking stove ignored the need for internal heating in winter, as well as the light thrown out by stoves.
Based on that reason, people prefer using traditional stoves that produce light, heat and smoke all of which may be considered useful. Heat from the fire can be used for cooking food, brewing beer, providing space and heat and drying. In Zimbabwe, for example, the 3-stone fireplace is used to support a large oil drum for brewing beer as well as for cooking (FAO, 2005:2).
Rural people in Indonesia also prefer using traditional stoves because traditional stoves and fireplaces are often highly versatile and can burn different fuels, such as crop residues. Generally, women use the traditional 3-stone fireplace outside the house, but have specific kitchen at the back of the house to avoid smoke coming inside and reducing the potential respiratory diseases.
CONCLUSION
Many people in developing countries will continue to depend on wood energy whether as fuel for their daily energy needs or as a source of income. Even if rising national incomes and urbanization drive the shift towards using modern fuels, the fact is people in developing countries with lower income per capita can not afford to buy other alternative fuels.
Addressing the high demand for fuel wood, some policies have been implemented to achieve sustainability of fuel wood supplies, either from the demand side or the supply side. Involving the local community in fuel wood supply management trough pricing and taxation systems has been successfully implemented in some developing countries. Other policies are that help are agroforestry or tree plantation and energy conservation through introducing improved stoves.
However, there are some remaining challenges in implementation of these policies, such as superstitions which still remain in society, lack of women's participation and lack of tenure security. Greater efforts are therefore required to achieve the sustainability of fuel wood supply by removing these constraints from government, environment and energy associated agencies and society itself.

REFERENCES
Arnold, M., Kohlin, G., Persson, R. and Stepherd G., 2003. 'Fuelwood revisited: what has changed in the last decade?', CIFOR Occasional Paper, 39:35.
Arnold, M. and Persson, R., 2003. 'Reassessing the fuel wood situation in developing countries', International Forestry Review, 5(4): 379-383.
Bembridge, T., 2000. 'Woodlots, woodfuel and energy strategies for Ciskei', South African Forestry Journal, 155:42-50.
Cunningham, W. and Cunningham, M., 2002. Principles of environmental science: Inquiry and Applications, McGraw-Hill, New York.
Danish, M., Romel, A. and Mohammad B., 2003. 'Biomass fuel use by the rural households in Chittagong Region, Bangladesh', Biomass and Bioenergy, 24(4-5):227-283.
Ellegard, A., 1994. 'Stoves in Zambia: pollution or efficiency?', http://www.sei.se/red/red9408e.html. (21/4/2008)
FAO, 1997.'Regional study on wood energy today and tomorrow in Asia', No.50:167
FAO, 2005. The Use of Wood Fuels in Rural Industries in Asia and Pacific Region, Field Document, Bangkok.
FAO, 2002. 'Wood energy and environmental security', http://www.fao.org/docrep/v9728e/v9728e06.htm. (11/03/2008).
Fleuret, A., 1983. Factors affecting fuel wood use in Taita, Kenya, Working Papers in African Studies Association Meetings, Boston
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Inglis, A., 2005. Rural women and urban men: fuel wood conflicts and forest sustainability in Sussex village, Sierra Leone. ODI-Social Forestry Network, London.
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Leach, G, and Mearns, R., 2005. Beyond the woodfuel crisis: people, land and trees in Africa, Earthscan Publication Ltd, London.
Neth, T., Nobuya, Shigetako and Toshio, 2004. 'Variation in woodfuel consumption patterns in response to forest availability in Kampong Thom Province Cambodia', Biomass and Bioenergy, 27(1):57-68.
Plas, R. and Hamid, A., 2003. "Can the woodfuel supply in sub-Saharan Africa be sustainable? The case of N'Djamena, Chad", Energy Policy.
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Robert, N., Louis, S. and Bjorn E., 2004. 'Woodfuel yields in short rotation coppice growth in the north Sudan savanna in Burkina Faso', Forest Ecology and Management, 189(1-3):77-85.
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PENCEMARAN TANAH AKIBAT PENGGUNAAN PESTISIDA PADA KEGIATAN PERTANIAN

BAB I

PENDAHULUAN

A. LATAR BELAKANG

Pencemaran lingkungan adalah masuknya atau dimasukkannya makhluk hidup, zat energi, dan atau komponen lain ke dalam lngkungan atau berubahnya tatanan lingkungan oleh kegiatan manusia atau oleh proses alam sehingga kualitas lingkungan turun sampai ke tingkat tertentu yang menyebabkan lingkungan menjadi kurang atau tidak dapat berfingsi lagi sesuai dengan peruntukannya (UU Pokok Pengelolaan Lingkungan Hidup No. 4 Tahun 1982).
Pencemaran dapat timbul sebagai akibat kegiatan manusia ataupun disebabkan oleh alam (misal gunung meletus, gas beracun). Ilmu lingkungan biasanya membahas pencemaran yang disebabkan oleh aktivitas manusia, yang dapat dicegah dan dikendalikan.
Karena kegiatan manusia, pencermaran lingkungan pasti terjadi. Pencemaran lingkungan tersebut tidak dapat dihindari. Yang dapat dilakukan adalah mengurangi pencemaran, mengendalikan pencemaran, dan meningkatkan kesadaran dan kepedulian masyarakat terhadap lingkungannya agar tidak mencemari lingkngan.


B. MAKSUD DAN TUJUAN

Maksud dan tujuan penyusunan makalah ini, antara lain yaitu :

• Sebagai bahan kajian para mahasiswa mengenai dampak terhadap pencemaran lingkungan terutama pencemaran tanah yang diakibatkan oleh kegiatan pertanian.
• Sebagai cara untuk mencari berbagai cara untuk menanggulangi dampak pencemaran yang sedang dikaji.
• Sebagai metode pengumpulan data tentang pencemaran lingkungan




BAB II

TINJAUAN PUSTAKA

A. Pestisida dan Pencemaran Tanah

Kita semua tahu Indonesia adalah negara yang sangat kaya akan sumber daya alamnya. Salah satu kekayaan tersebut, Indonesia memiliki tanah yang sangat subur karena berada di kawasan yang umurnya masih muda, sehingga di dalamnya banyak terdapat gunung-gunung berapi yang mampu mengembalikan permukaan muda kembali yang kaya akan unsur hara.
Tanah merupakan tempat kehidupan mikroorganisme yang secara makro menguntungkan bagi mahkluk hidup lainnya, termasuk manusia. Mikroorganisme yang menghuni tanah dapat dikelompokkan menjadi bakteri, fungi, aktinomisetes, alga, dan protozoa. Jumlah dan jenis mikroorganisme tanah dipengaruhi oleh perubahan lingkungan.
Namun seiring berjalannya waktu, kesuburan yang dimiliki oleh tanah Indonesia banyak yang digunakan sesuai aturan yang berlaku tanpa memperhatikan dampak jangka panjang yang dihasilkan dari pengolahan tanah tersebut. Dengan semakin meningkatnya ilmu pengetahuan yang dimiliki oleh manusia, semakin tinggi pula daya saing untuk mencapai tingkat kemudahan dalam setiap aktifitas hidupnya sehari-hari. Satu hal vital yang tidak luput dari proses pengaplikasian pengetahuan memberikan dampak besar terhadap kegiatan pertanian tanah air yang notabene merupakan sumber pencaharian terbesar sebagian masyarakat negara agraris ini. Untuk mendapatkan hasil yang maksimal dengan waktu yang seefisien mungkin dalam kegiatan pertanian maka diwujudkanlah hal tersebut dengan penggunaan pestisida selama aktifitas pertanian tersebut berlangsung.
Untuk memenuhi perkembangan ekonomi yang saat ini semakin meningkat, maka sangat dibutuhkannya Ilmu pengetahuan mengenai pupuk dan pestisida. Karena menyangkut hal-hal tentang pertanian dan perkebunan yang merupakan aspek utama dalam perekonomian Negara Indonesia yang beriklim tropis.
Penggunaan pestisida sintetis pada pertanian merupakan dilema. Di satu sisi sangat dibutuhkan dalam rangka penyediaan pangan, di sisi lain tanpa disadari mengakibatkan berbagai dampak negatif, baik terhadap manusia, hewan mikroba maupun lingkungan. Pemakaian pestisida haruslah sesuai dengan persyaratan dan peraturan perundangan yang berlaku. Penggunaannya haruslah diperuntukkan membasmi organisme pengganggu tanaman secara selektif dan seminimal mungkin merugikan organisme dan target.
Belum banyak disadari hingga saat ini bahwa pemanfaatan bahan-bahan agrokimia yang berlebihan untuk menggenjot produksi menyebabkan kerusakan lingkungan dan hilangnya lapisan tanah yang mengandung nutrisi. Di samping itu, kualitas produksi yang dihasilkan pun akan menurun. Di Indonesia polusi tanah ini merupakan masalah yang harus dihadapi. Pemakaian pupuk dan pestisida dalam jumlah yang besar menimbulkan pencemaran bagi tanah dan air tanah dengan kadar racun yang beraneka ragam. Degradasi tanah pertanian sudah makin parah dan dengan sudah mengendapnya pestisida maupun bahan agrokimia lainnya dalam waktu yang cukup lama. Padahal, untuk mengembalikan nutrisinya tanah memerlukan waktu ratusan tahun, sedangkan untuk merusaknya hanya perlu beberapa tahun saja. Hal ini terlihat dari menurunnya produktivitas karena hilangnya kemampuan tanah untuk memproduksi nutrisi.
Ada beberapa pengaruh negatif lainnya pemakaian pestisida sintetis secara tidak sesuai. Pertama, pencemaran air dan tanah yang pada akhirnya akan berpengaruh terhadap manusia dan makhluk lainnya dalam bentuk makanan dan minuman yang tercemar. Kedua, matinya musuh alami dari hama maupun patogen dan akan menimbulkan resurgensi, yaitu serangan hama yang jauh lebih berat dari sebelumnya. Ketiga, kemungkinan terjadinya serangan hama sekunder. Contohnya: penyemprotan insektisida sintetis secara rutin untuk mengendalikan ulat grayak (hama primer) dapat membunuh serangga lain seperti walang sembah yang merupakan predator kutu daun (hama sekunder). Akibatnya setelah ulat grayak dapat dikendalikan, kemungkinan besar tanaman akan diserang oleh kutu daun. Keempat, kematian serangga berguna dan menguntungkan seperti lebah yang sangat serbaguna untuk penyerbukan. Kelima, timbulnya kekebalan/resistensi hama maupun patogen terhadap pestisida sintetis. Berdasarkan pertimbangan tersebut, setiap rencana penggunaan pestisida sintetis hendaknya dipertimbangkan secara seksama tentang cara penggunaan yang paling aman, di satu sisi efektif terhadap sasaran, di sisi yang lain aman bagi pemakai maupun lingkungan.
Sebenarnya tidak semua jenis insekta, cacing (nematode) dan lain-lain merupakan hama dan penyakit bagi tanaman, akan tetapi racun serangga telah membunuhnya. Tetapi makhluk-makhluk kecil ini sangat diperlukan untuk kesuburan tanah selanjutnya. Apabila penyemprotan dilakukan secara berlebihan atau takaran yang dipakai terlalu banyak, maka yang akan terjadi adalah kerugian. Tanah disekitar tanaman akan terkena pencemaran pestisida. Akibatnya makhluk-makhluk kecil itu banyak yang ikut terbasmi, sehingga kesuburan tanah menjadi rusak karenanya. Bukan tidak mungkin tragedi kegersangan dan kekeringan terjadi.
Dan akibat yang paling parah, kesuburan tanah di lahan-lahan yang menggunakan pestisida dari tahun ke tahun menurun.Dunia pertanian modern adalah dunia mitos keberhasilan modernitas. Keberhasilan diukur dari berapa banyaknya hasil panen yang dihasilkan. Semakin banyak, semakin dianggap maju. Di Indonesia, penggunaan pestisida kimia merupakan bagian dari Revolusi Hijau, sebuah proyek ambisius Orde Baru untuk memacu hasil produksi pertanian dengan menggunakan teknologi modern, yang dimulai sejak tahun 1970-an.
Gebrakan revolusi hijau di Indonesia memang terlihat pada dekade 1980-an. Saat itu, pemerintah mengkomando penanaman padi, pemaksaan pemakaian bibit impor, pupuk kimia, pestisida, dan lain-lainnya. Hasilnya, Indonesia sempat menikmati swasembada beras. Namun pada dekade 1990-an, petani mulai kelimpungan menghadapi serangan hama, kesuburan tanah merosot, ketergantungan pemakaian pupuk yang semakin meningkat dan pestisida tidak manjur lagi, dan harga gabah dikontrol pemerintah.Revolusi hijau memang pernah meningkatkan produksi gabah.



Namun berakibat:
1. Berbagai organisme penyubur tanah musnah
2. Kesuburan tanah merosot/tandus
3. Tanah mengandung residu (endapan) pestisida
4. Hasil pertanian mengandung residu pestisida
5. Keseimbangan ekosistem rusak; dan
6. Terjadi peledakan serangan dan jumlah hama.

Apabila pestisida dipakai dalam batas-batas kewajaran sesuai dengan petunjuk penggunaan kiranya merupakan tindakan yang bisa memperkecil lingkup risiko yang harus ditanggung manusia dan alam. Pemakaian pestisida secara membabi buta bisa mengundang bencana.
Oleh karena itu masalah pestisida menuntut perhatian semua pihak, tidak hanya para pejabat, tidak hanya sipemakai jasa. Kita semua memikul tanggung jawab bersama atas lingkungan hidup kita sendiri. Pestisida bukan hanya menjadi tangung jawab pabrik panghasil, dan tanggung jawab pemrintah yang memberi izin produksi, tapi menjadi tanggung jawab semua pihak, semua bangsa dan semua negara.
Jikalau di suatu negara suatu jenis pestisida sudah diteliti, dinyatakan berbahaya dan dilarang untuk dipergunakan, semestinya semua Negara dunia juga harus mengerti akan hal itu dan ikut melaksanakannya. Bersikap mendua dalam mengambil langkah kiranya kurang membantu. pemakaian pestisida dilarang tetapi tetap diproduksi dan bahkan diekspor kenegara tetangga.
Setiap usaha pembrantasan harus melibatkan semua pihak dan bersifat menyeluruh, kalau diharapkan berhasil. Mudah-mudahan di masa mendatang kasus-kasus akibat pemakaian atau produksi pestisida mulai mengecil atau bahkan hilang sama sekali. Meskipun sulit, kita semua berjuang agar risiko bagi lingkungan itu makin diperkecil.



B. Penanganan yang Harus Dilakukan
Pencemaran tanah juga dapat memberikan dampak terhadap ekosistem. Perubahan kimiawi tanah yang radikal dapat timbul dari adanya bahan kimia beracun/berbahaya bahkan pada dosis yang rendah sekalipun. Perubahan ini dapat menyebabkan perubahan metabolisme dari mikroorganisme endemik dan antropoda yang hidup di lingkungan tanah tersebut. Akibatnya bahkan dapat memusnahkan beberapa spesies primer dari rantai makanan, yang dapat memberi akibat yang besar terhadap predator atau tingkatan lain dari rantai makanan tersebut. Bahkan jika efek kimia pada bentuk kehidupan terbawah tersebut rendah, bagian bawah piramida makanan dapat menelan bahan kimia asing yang lama-kelamaan akan terkonsentrasi pada makhluk-makhluk penghuni piramida atas. Banyak dari efek-efek ini terlihat pada saat ini, seperti konsentrasi DDT pada burung menyebabkan rapuhnya cangkang telur, meningkatnya tingkat Kematian anakan dan kemungkinan hilangnya spesies tersebut.
Dampak pada pertanian terutama perubahan metabolisme tanaman yang pada akhirnya dapat menyebabkan penurunan hasil pertanian. Hal ini dapat menyebabkan dampak lanjutan pada konservasi tanaman di mana tanaman tidak mampu menahan lapisan tanah dari erosi. Beberapa bahan pencemar ini memiliki waktu paruh yang panjang dan pada kasus lain bahan-bahan kimia derivatif akan terbentuk dari bahan pencemar tanah utama.
Olehnya itu ada beberapa langkah penanganan untuk mengurangi dampak yang ditimbulkan oleh pencemaran tanah. Diantaranya:
• Remidiasi
Remediasi adalah kegiatan untuk membersihkan permukaan tanah yang tercemar. Ada dua jenis remediasi tanah, yaitu in-situ (atau on-site) dan ex-situ (atau off-site). Pembersihan on-site adalah pembersihan di lokasi. Pembersihan ini lebih murah dan lebih mudah, terdiri dari pembersihan, venting (injeksi), dan bioremediasi.
Pembersihan off-site meliputi penggalian tanah yang tercemar dan kemudian dibawa ke daerah yang aman. Setelah itu di daerah aman, tanah tersebut dibersihkan dari zat pencemar. Caranya yaitu, tanah tersebut disimpan di bak/tanki yang kedap, kemudian zat pembersih dipompakan ke bak/tangki tersebut. Selanjutnya zat pencemar dipompakan keluar dari bak yang kemudian diolah dengan instalasi pengolah air limbah. Pembersihan off-site ini jauh lebih mahal dan rumit.
• Bioremediasi
Bioremediasi adalah proses pembersihan pencemaran tanah dengan menggunakan mikroorganisme (jamur, bakteri). Bioremediasi bertujuan untuk memecah atau mendegradasi zat pencemar menjadi bahan yang kurang beracun atau tidak beracun (karbon dioksida dan air).

















DAFTAR REFERENSI

Makalah Pencemaran Tanah « Son_Earth’s Zone The Last Geolog in the World.htm.
Soekarto. S. T. 1985. Penelitian Organoleptik Untuk Industri Pangan dan Hasil Pertanian. Bhatara Karya Aksara, Jakarta. 121 hal.
Wikipedia. 2007. Pencemaran Tanah (On-line). http://id.wikipedia.org/wiki/pencemaran_tanah. diakses 26 Desember 2007.
Bachri, Moch. 1995. Geologi Lingkungan. CV. Aksara, Malang.
Kusno S, 1992, Pencegahan Pencemaran Pupuk dan pestisida. Jakarta : Penerbit Swadaya.

Ekha Isuasta,1988, Dilema Pestisida. Yogyakarta : Kanisius .