EFEK PERTANIAN TERHADAP

LINGKUNGAN

Diabstraksikan oleh: smno.jurstnh.fpub.sept2013

Bahan kajian pada MK. Pertanian Berlanjut

PENGELOLAAN LAHAN

Diunduh dari sumbernya:

PENGELOLAAN LAHAN

Lahan merupakan lingkungan fisik yang meliputi iklim, relief, tanah, hidrologi, dan vegetasi. Faktor-faktor ini hingga batas tertentu

mempengaruhi potensi dan kemampuan lahan untuk mendukung suatu tipe penggunaan tertentu.

Tipe penggunaan lahan ("major kind of land use") adalah golon gan utama dari penggunaan lahan pedesaan, seperti lahan pertanian tadah hujan,

lahan pertanian irigasi, lahan hutan, atau lahan untuk rekreasi.

Tipe pemanfaatan lahan ("land utilization type, LUT") adalah suatu macam penggunaan lahan yang didefinisikan secara lebih rinci dan detail

dibandingkan dengan tipe penggunaan lahan.

Diunduh dari sumbernya:

PENGELOLAAN LAHAN

"Karakterisik lahan" merupakan atribut lahan yang dapat diukur atau diestimasi. Misalnya kemiringan, curah hujan, tekstur tanah, kapasitas air

tersedia, biomasa vegetasi, dll. "Kualitas lahan" adalah kompleks atribut lahan yang mempunyai peranan

spesi fik dalam menentukan tingkat kesesuaian lahan untuk suatu penggu naan tertentu. Contohnya ketersediaan air, resistensi erosi, bahaya banjir, dan

aksesibilitas.

"Kriteria diagnostik" adalah suatu peubah yang mem-punyai pengaruh tertentu terhadap hasil (atau input yang diperlukan ) pada penggunaan tertentu,

dan peubah ini juga berfung si sebagai dasar untuk menilai kesesuaian suatu bidang lahan bagi penggunaan tersebut. Peubah ini bisa berupa kualitas lahan, karak teristik lahan, atau fungsi dari beberapa karakteristik lahan.

Diunduh dari sumbernya:

PENGELOLAAN LAHAN

Beberapa macam kualitas lahan yang berhubungan dengan pertumbuhan dan produktivitas tanaman adalah:

(i) hasil tanaman, (ii) ketersediaan air, (iii) ketersediaan hara, (iv) ketersediaan oksigen dalam zone perakaran, (v) kondisi bagi per-

kecambahan, (vi) kemuda han pengolahan, (vii) salinitas atau alkalinityas, (viii) toksisitas tanah, (ix) ketahanan terhadap erosi, (x)

bahaya banjir, (xi) rejim suhu, dan (xii) Fotoperiodik.

Diunduh dari sumbernya:

PENGELOLAAN LAHAN

Evaluasi lahan dan survei tanah, sangat dianjurkan dalam rangka untuk merencanakan dan mengkoordinir upaya perbaikan dan pengelolaan lahan pada

masing-masing tipe penggunaan atau usahatani. Kegiatan evaluasi lahan ini mesuplai petani dengan informasi secara tepat dan akurat tentang apa yang seyogyanya dikerjakan, dan perbaikan apa saja yang

diperlukan untuk pengelolaan lahannya.

Evaluasi meliputi penelitian dan penilaian tentang tekstur tanah lapisan atas, tekstur tanah lapisan bawah, kedalaman solum dan subsoil, warna tanah lapisan

atas, struktur tanah, keadaan batu-batuan, mudahnya diolah, permeabilitas subsoil, drainase permukaan, drainase internal profil tanah, kemiringan, derajat

erosi, bahaya erosi bila tanah diolah, faktor-faktor yang digunakan untuk menentukan kelas lahan, dan kelas kapabilitas lahan.

Diunduh dari sumbernya:

PENGELOLAAN LAHAN

What are some features of good soil? Any farmer will tell you that a good soil:

1. drains well and warms up quickly in the spring 2. does not crust after planting 3. soaks up heavy rains with little runoff 4. stores moisture for drought periods 5. has few clods and no hardpan 6. resists erosion and nutrient loss 7. supports high populations of soil organisms 8. does not require increasing fertilizer for high yields 9. has that rich, earthy smell 10. produces healthy, high quality crops

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www.agnet.org/library/eb/473/

Criteria of SALM can be listed as follows:

Meeting the food needs of present and future generations in terms of quantity and quality and

the demand for other agricultural products.

Providing enough jobs, securing income and creating human living and working conditions for

all those engaged in agricultural production.

Maintaining, and where possible enhancing, the productive capacity of the natural resources base

as a whole and the regenerative capacity of renewable resources, without impairing the

function of basic natural cycles and ecological balance, destroying the socio-cultural identity of

rural communities or contaminating the environment.

Making the agricultural sector more resilient against adverse natural and socio-economic

factors and other risks, and strengthening the self-confidence of rural populations.

1. A low dependence on external / purchased inputs2. Use of locally and renewable resources

3. Beneficial impacts on environment: on - farm & off - farm4. Adapted to the existing local conditions5. Long-term maintenance of productive capacity

6. Biological & cultural diversity7. Knowledge of local inhabitants

8. Adequate domestic and exportable goods. www.aars-acrs.org/.../Papers/GIS97-3.htm

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SISTEM PERTANIAN SISTEM ALAMIAH

- Panen tanaman- Teknologi Pengelolaan

- Pemupukan / perabukan- Pengolahan tanah- Pengairan- Aplikasi agrokimia- Agroteknologi lainnya.

www.kabarindonesia.com/berita.php?pil=10&jd=M...

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PUPUK - RABUK

Pemupukan meningkatkan hasil/kualitas: The law of diminishing returnDosis Optimum

Minimize Fertilizer:Sistem rotasi dg legumeManure/ Bahan organikUji tanah & analisis tanamanKultivar dg kebutuhan hara rendahTeknologi aplikasiLimbah organikMusim / waktu tanamFiksasi N-biologis

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1. Metode peramalan gangguan hama

2. Better placement & formulations

3. Cropping rotations4. Appropriate cultivations5. Time of planting/ sowing6. Controlled weed growth

practices7. Biological insecticides8. Parasites & predators of pests9. Allelochemicals, pheromones,

repellents10. Resistant cultivars11. Use of trap crops12. Innovative cultural techniques

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1. Metode peramalan penyakit2. Crop rotations3. Aplikasi - placement4. Waktu / musim tanam5. Disease antagonists6. Tolerant / resistant cultivars

growvegetables.org.uk/vegetable_crop_rotation.htm

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Mechanical weed controlCrop rotationsCover cropping

Live mulchesMycoherbicides

Pest of weeds

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1. Shallow plowing2. Chisel plowing, not

invert the soil3. Deep subsoiling4. Ridge tillages5. Shallow-tine,

menggemburkan tanah

6. Harrowing, menyiapkan bedengan

7. No-till (direct drilling)

8 …… etc.

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1. Pupuk mempengaruhi pertumbuhan gulma = tanaman

2. Pupuk dapat meningkatkan gangguan Hama / Penyakit

3. BO dpt mereduksi hangguan hama & penyakit

4. BO dapat merangsang populasi fungi pengendali NEMATODA

5. BO dapat menjerap hara dan pestisida

6. BO dpt menjadi makanan alternatif bagi marginal pests

1. Kultivasi dapat meningkatkan atau menurunkan gangguan hama atau penyakit

2. Kultivasi mengendalikan gangguan gulma

3. Kultivasi mempengaruhi dosis pupuk yang diperlukan

4. Kultivasi meningkatkan efektivitas pestisida

5. Kultivasi membenamkan/mengubur BO ke dalam tanah

www.omafra.gov.on.ca/.../2007/03cpo07a2.htm

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1. Herbisida mempengaruhi keparahan gangguan hama/penyakit

2. Pestisida mempengaruhi organisme tanah dekomposer

3. Insektisida mereduksi gangguan virus dan penyakit

4. Insektisida meningkatkan populasi gulma

5. Insektisida membunuh musuh alami6. Fungisida membunuh fungi tanah

pengendali insek dan nematoda7. Fungisida mereduksi populasi

dekomposer dan antagonist8. Pestisida menekan populasi cacing

tanah9. …… ?

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SUSTAINABLE AGRIC. SYSTEM: SOIL EROSION & LAND DEGRADATION

1. Zero or Reduced tillage2. Life mulching --- legume civer

crops3. Alley cropping & agroforestry4. Supplying mulch: Erosi dan

BOT 5. Fiksasi N2 dan daur ulang

hara6. Minimizing fallowing7. Integrasi food crops, trees,

pasture / livestock8. Mulsa plastik

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SUSTAINABLE AGRIC. SYSTEM: SOIL EROSION & LAND DEGRADATION

Organic matter

mulching --- decomposition of OM

wvlc.uwaterloo.ca/.../module8/soil/chap2d.htm

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RN = (AP + AR - RM - L)

RN : hara dalam tanah pada akhir periode t

AP : hara dalam tanah pada awal periode t

AR : hara yang ditambahkan ke tanah selama periode t

RM: hara yang dipanen selama periode t

L : hara yg hilang selama periode t

t : periode waktu tertentu

Diunduh dari sumbernya: foto.regina.mahawu.2012

PENGELAOLAAN LAHAN

Pengolahan tanah menurut garis kontur untuk mengendalikan runoff dan erosi

• When land cleared of its natural vegetation, the soil begins to lose its fertility– Physical erosion

• Became a global issue in the world– Intense plowing + drought– Loosened soil blow away

Diunduh dari sumbernya: ………… 20/10/2012

TANAH YANG TEREROSI = LAHAN KRITIS

Diunduh dari sumbernya: ………… 20/10/2012

• The land that became the Dust Bowl had been prairie– Deep rooted grasses that held soil in place– After plowing soil exposed to elements

• When original vegetation is cleared soil changes– Crops harvested and removed, less organic matter

returning to soil– Soil exposed to sunlight which speeds rate of

decomposition

Diunduh dari sumbernya: ………… 20/10/2012

TANAH YANG TEREROSI = LAHAN KRITIS

• Traditionally decline in soil fertility combated using organic fertilizers– Animal manure

• In the 20th century crop production increased – Chemical or artificial fertilizers– Add nitrogen and phosphorous to the soil

Diunduh dari sumbernya: ………… 20/10/2012

TANAH YANG TEREROSI = LAHAN KRITIS

TANAH YANG TEREROSI = LAHAN KRITIS

Diunduh dari sumbernya: http://gerbangtani.wordpress.com/2012/08/18/perbaikan-lahan-kritis/ ………… 22/10/2012

Lahan kritis telah mengalami kerusakan baik secara fisika,

kimia, maupun biologi. Jumlah lahan kritis di Indonesia semakin

meningkat seiring adanya pembukaan dan penggundulan

hutan, penambangan, serta eksploitasi yang berlebihan

terhadap tanah. Diperkirakan saat ini luas lahan

kritis mencapai 77,8 juta hektare, yang terdiri dari lahan agak kritis mencapai 47,6 juta hektar, lahan kritis seluas 23,3 juta hektar, dan lahan sangat kritis mencapai 6,8

juta hektar.

Kemana material tanah yang tererosi

• A lot of it travels down streams and rivers– Deposited at their mouths– Fill in water ways – Damage fisheries and coral reefs

• Sedimentation has chemical effects– Enrichment of waters, eutrophication– Transport of toxic chemical pesticides

Diunduh dari sumbernya: ………… 20/10/2012

Bagaimana melestarikan tanah

• Soil forms continuously– But very slowly– 1mm of soil formation takes 10-40 years

• To be truly sustainable soil lost should equal amount of new soil produced

Diunduh dari sumbernya: ………… 20/10/2012

Pengolahan tanah menurut kontur

• Land is plowed perpendicular to the slopes and as horizontally as possible.– One of the most effective ways to reduce soil

erosion– Also uses less fuel and time

Diunduh dari sumbernya: ………… 20/10/2012

Pertanian Tanpa Olah Tanah (TOT)

• Involves not plowing the land, using herbicides and integrated pest management to keep down weeds, and allowing some weeds to grow.– The goal is to suppress and control weeds but not

eliminate them at the expense of soil conservation

– Additional benefit reduces the release of CO2

Diunduh dari sumbernya: ………… 20/10/2012

Grazing on Rangelands

• Almost half of the Earth's land area is used as rangeland– 30% of Earth’s land area is arid rangeland

• Arid rangeland easily damaged especially in time of drought

• Steams and rivers also damaged– Trampling banks and fecal matter

Diunduh dari sumbernya: ………… 20/10/2012

Traditional and Industrial Use of Grazing and Rangelands

• In modern industrialized agriculture– Cattle initially raised on open range– Then transport to feed lots– Major impact is local pollution from manure

• Traditional herding practices – Damage land through overgrazing– Impact varies depending on density relative to

rainfall and soil fertility

Diunduh dari sumbernya: ………… 20/10/2012

Biogeografi Ternak-Pertanian

• Everyplace people have dispersed they have bought animals w/ them– Pre-industrial and throughout western civilization

• Environmental effects of introductions– Native vegetation may be greatly reduced and

threatened w/ extinction– Introduced animals may compete w/ native herbivores,

threatening them w/ extinction as well

Diunduh dari sumbernya: ………… 20/10/2012

DAYA DUKUNG LAHAN GEMBALAAN

• Carrying capacity- – the maximum number of species per unit area that can

persist w/o decreasing the ability of that population or its ecosystem to maintain that density in the future.

• When the carrying capacity is exceeded, the land is overgrazed.

Diunduh dari sumbernya: ………… 20/10/2012

• Overgrazing– Slows the growth of vegetation– Reduces the diversity of plant species– Leads to dominance by plant species that are

relatively undesirable to the cattle– Hastens loss of soil by erosion– Subject the land to further damage from trampling

Diunduh dari sumbernya: ………… 20/10/2012

DAYA DUKUNG LAHAN GEMBALAAN

PERKEMBANGAN DESERT (GURUN)• Deserts occur naturally where there is too little

water for substantial plant growth.– The warmer the climate the greater the rainfall

needed to convert an area from desert to non-desert– The crucial factor is available water in the soil for

plant use– Factors that destroy the ability of a soil to store water

can create a desert

Diunduh dari sumbernya: ………… 20/10/2012

• Earth has five natural warm desert regions– Primarily between 15o and 30o north and south of

the equator• Based on climate 1/3 of Earth’s land area

should be desert– 43% of land is desert– Addition area due to human activities

Diunduh dari sumbernya: ………… 20/10/2012

PERKEMBANGAN DESERT (GURUN)

• Desertification – the deterioration of land in arid, semiarid, and dry sub humid areas due to changes in climate and human activities.

• Serious problem that affects 1/6 of world population (1 billion people)

PERKEMBANGAN DESERT (GURUN)Hamparan lahan kering di

musim kemarau di Sumbawa(foto.ieke.2012)

• The leading cause of desertification are bad farming practices.– Failure to use contour plowing– To much farming– Overgrazing– Conversion of rangelands to croplands in marginal

areas– Poor forestry practices

Diunduh dari sumbernya: ………… 20/10/2012

APA YANG MENYEBABKAN DESERTS

APA YANG MENYEBABKAN DESERTS• Desert like areas can be created anywhere by

poisoning of the soil– World wide chemicals account for 12% of soil

degradation– Irrigation in arid lands can cause salts to build

up to toxic levels

Diunduh dari sumbernya: ………… 20/10/2012

MENCEGAH PERKEMBANGAN DESERT

• Tahap pertama adalah mendeteksi gejala-gejala– Lowering of water table– Increase in the salt content of soil– Reduced surface water– Increased soil erosion– Hilangnya vegetasi alamiah

• Dapat dicapai dnegan sisitem pemantauan yang bagus

• Next step– Proper methods of

soil conservation, forest management and irrigation

• Good soil conservation includes– Use of wind breaks– Reforestation

Diunduh dari sumbernya: foto.ieke.2012

MENCEGAH PERKEMBANGAN DESERT

Pohon kelapa juga berfungsi sebagai penahan angin

APAKAH PERTANIAN MENGUBAH Biosphere?

• 1st – Pertanian mengubah tutupan lahan– Resulting in changes in reflected light– The evaporation of water– The roughness of the surface– Rate of exchange of chemical compounds

• 2nd – Pertanian modern meningkatkan emisi CO2– Major user of fossil fuels– Clearing land speeds decomposition

Diunduh dari sumbernya: ………… 20/10/2012

• 3rd Affect climate through fires– Associated w/ clearing land– Add small particulates to the atmosphere

• 4th Artificial production of nitrogen– Alters biogeochemical cycle

• 5th Affects species diversity– Reduces diversity and increases # of endangered

species

Diunduh dari sumbernya: ………… 20/10/2012

APAKAH PERTANIAN MENGUBAH Biosphere?