91169684 temperatur tanah karakteristik dan kualitas lahan

7/31/2019 91169684 Temperatur Tanah Karakteristik Dan Kualitas Lahan

1/103

BAHAN KAJIAN

MK. DASAR ILMU TANAH

TEMPERATUR TANAH:KARAKTERISTIK

DANKUALITAS LAHAN

Bahan kajian untuk MK Dasar Ilmu Tanah

Dihimpun oleh:

Soemarno, Jurusan Tanah, FPUB Oktober 2011


2/103

TEMPERATUR TANAH

Bahan kajian untuk MK Dasar Ilmu Tanah

Soemarno 2011

Temperatur atau Suhu adalah

tingkat kemampuan benda

dalam memberi atau

menerima panas.

Suhu seringkali jugadinyatakan sebagai energi

kinetis rata-rata suatu bendayang dinyatakan dalam derajat

suhu.


3/103

Suhu juga dinyatakan sebagai ukuran energi kinetik rata-rata dari pergerakkanmolekul suatu benda. Suhu menunjukkan sangkar cuaca yang dipergunakan untukpengamatan suhu. Pengukuran dilakukan dengan menggunakan thermometer air

raksa dan alkohol.

Dengan thermometer air raksa pengukuran dapat dilakukan dari suhu 35o

C 350C, hasilnya adalah cukup bagus karena mengingat angka pengembangan air raksapada tiap suhu lebih merata dari alkohol, sehingga untuk pengukuran suhu udara

biasanya digunakan thermometer air raksa.

. http://reflitepe08.blogspot.com/2011/03/suhu-udara-dan-suhu-tanah.html ..diunduh 3/2/2012

http://blkmtncommunitygarden.blogspot.com/2010/03/soil-temperature-chart-for-

seed.html


4/103

Pentingnya temperaturtanah?


5/103

Temperatur tanah

Salah satu sifat fisika tanah yang sangat berpengaruh terhadap proses-proses

dalam tanah, seperti pelapukan dan penguraian bahan organik dan bahan induk

tanah, reaksi-reaksi kimia , dll.

http://www.regional.org.au/au/asssi/supersoil2004/s15/oral/1502_walla.htm

diunduh 15/2/2012

Example of soil moisture and temperature during and after freezing.(Gravimetrically determined v was 11.8 % on day 0 and 11.3% on day 9.)

oil moisture measurement in the Ross Sea region of Antarctica using Hydr

soil moisture probes.

Aaron M. Wall, Megan R. Balks, Dave I. Campbell and Ron F. Paetzold


6/103

Faktor-faktor yang mempengaruhi suhutanah :

1. Faktor iklim / cuaca radiasi surya - Keawanan

Hujan - suhu udara

Angin - kelembaban udara

The soil temperature is much less influenced by climatic changes. Thegraph shows the variation in temperature over a year at different depths

(0, 2, 5 and 12 feet). As we can see, the temperature fluctuationdecreases with increasing depth.

Sumber: http://www.enviroair.ca/en/geothermal.html..... . diunduh12/2/2012


7/103

Faktor-faktor yang mempengaruhi suhu tanah:

2. Keadaan tanah tekstur tanah

kadar air tanah kandungan bahan organik

warna tanah

struktur tanah (pengolahan ddan kepadatantanah)

Depth dependence of annual range of ground temperatures in Ottawa,

anada (Williams and Gold 1976, National Research Council of Canad

2003).

Sumber: http://iopscience.iop.org/1748-9326/2/4/044001/fulltext/diunduh 12/2/2012


8/103

Faktor-faktor yang mempengaruhisuhu tanah :

. Kondisi topografi kemiringasn lereng

arah lerreng

tinggi permukaan tanah

vegetasi

efinition ofthe Temperature Vegetation Dryness Index (TVDI). TVDIfor a give

pixel (NDVI,Ts) is estimated as the relation between the distance ofthe pixel

from the wet edge (TVDI=O) and the spn ofTs in the Ts/NDVI-spacefor the

iven NDVI (the difference between Ts and the dry edge (TVDI=I) and Ts at the

wet edge).

SUMBER: http://www.tidsskrift.dk/visning.jsp?markup=&print=no&id=71866

Diunduh 12/2/2012)


9/103

Pentingnya temperatur tanah

1. Temperatur tanah mempengaruhiaktivitas biologi tanah---- tidakoptimal apabila suhu tertentu tidak

dapat dipertahankan Tingkat aktivitas optimum dari

organisme tanah adalah suhu 18 30oC

Kurang dari 10o C: menghambatperkembangan mikroba tanah danmenghambat penyerapan haraoleh akar tanaman

Lebih dari 40oC : mikroba tanahtidak aktif, kecuali mikroorganismetertentu (termofilik).


10/103

PENTINGNYA TEMPERATUR TANAH

2. Temperatur tanah juga menentukan reaksi kimia danaktivitas mikroba tanah yang dapat merombak senyawaorganik tertentu menjadi hara tersedia.

Proses nitrifikasi ( temperatur optimum 30o C ), yaitu padakondisi agak panas

http://info.cycadpalm.com/bid/57663/How-to-Fertilize-Cycads-Part-2 diunduh 15/2/2012


11/103


3. Temperatur tanah juga mempengaruhi pelapukan bahaninduk tanah

4. Temperatur tanah mempengaruhi perkembangan akar,karena ada hubungannya dengan kelengasan dan aerasi

tanah5. Temperatur tanah mempengaruhi pekecambahan biji dan

pertumbuhan kecambah

Effect of soil temperature on nitrate formation (adapted from Fredereick andBroadbent, 1966).

http://www.ipm.iastate.edu/ipm/icm/2001/10-22- 2001/why50.html diunduh15/2/2012


12/103


pertumbuhan tanaman tertentu (jenis berbeda)menghhendaki keadaan temperatur yang cocok.

http://www.cropinfo.net/AnnualReports/2003/YNSResponsetoEnvironment03.htm.... ..

Diunduh 12/2/2012


13/103

SUHU TANAH BAGI CACING

Suhu atau temperatur tanah yang ideal untuk

pertumbuhan cacing tanah dan penetasan

kokonnya berkisar antara 15oC25oC.

Suhu tanah yang lebih tinggi dari 25oC masih

cocok untuk cacing tanah, tetapi harus

diimbangi dengan kelembapan yang memadai

dan naungan yang cukup.

Oleh karena itu, cacing tanah biasanya

ditemukan hidup dibawah pepohonan atau

tumpukan bahan organik.

http://biologi.lkp.web.id/?p=604 diunduh 3/2/2012


14/103

Dimana suhu tanah diukur?


15/103

Termometer Tanah

Used to take temperatures at5 and 10 cm depths

PVCSpacer

PVC

Spacer


16/103

Kalibrasi Termometer tanah

Basically, we compare the soilthermometer to a calibrationthermometer, and adjust thesoil thermometer.

First, we need to check thecalibration thermometer!!

by dipping it in an ice bath.


17/103

Checking CalibrationThermometer

Submerge thermometer inice-water bath

Let sit for 10-15 minutes,stirring thermometer

occasionally

Read the thermometer.If it reads between -0.5C and +0.5 C, thethermometer is fine.

If the thermometerreads greater than +0.5C, check to make surethat there is more icethan water in your ice-water bath.

If the thermometerreads less than -0.5 C,check to make sure that

there is no salt in yourice-water bath.


18/103

Kalibrasi Termometer Tamah

Add the soil thermometer to the ice bath Wait 2 minutes

Read both Soil Thermometer andcalibration thermometer.

If they agree to within 2 C, the soilthermometer is ready to use.

If not adjust the soil thermometer, usinga wrench, until it reads with 2 C of thecalibration thermometer


19/103

Kapan mengukur suhu tanah ?

Soil temperature is a weeklymeasurement, but you can do it daily.

Try to do the measurement at aboutthe same time of day

Take data near the atmosphere stationor near the soil moisture site

Also measure soil temperaturemeasurement whenever a soil moisture

data are taken Seasonally (4 times a year), measure

soil temperature every few hours duringthe day for 2 consecutive days provides a diurnal reading of soil

temperature change diurnal sampling in March, June, Sept. and

Dec. are preferred


20/103

Regim Temperatur Tanah ---

Regimtemperatur

tanah

RTTT RTTMP-RTTMD RTTMP

Pergelik

Cryik

Frigid

Isofrigid

Boreal

Mesik

IsomesikTermik

Isotermik

Hipertermik

Isohipertermi

k

< 0

08

08

08

< 8

815

8151522

1522

> 22

> 22

> 5

< 5

> 5

5

< 5

> 5< 5

Renda

h

> cryic


21/103

Estimasi temperatur berdasarkan ketinggian

tempat (elevasi)

Di tempat-tempat yang tidak tersedia data

temperatur (stasiun iklim terbatas), maka

temperatur udara dapat diduga berdasarkan

ketinggian tempat (elevasi) dari ataspermukaan laut. Pendugaan tersebut dengan

menggunakan pendekatan rumus dari Braak

(1928) dalam Mohr et al. (1972).

Berdasarkan hasil penelitiannya di Indonesia

emperatur di dataran rendah (pantai) berkisar

antara 25-27C, dan rumus yang dapat

digunakan (rumus Braak) adalah sebagaiberikut:

26,3C - (0,01 x elevasi dalam meter x 0,6C)


22/103

Berdasarkan penelitian Braak tersebut

temperatur tanah pada kedalaman 50 cm di

ndonesia lebih tinggi 3-4,5C, sehingga untukmenduga temperatur tanah pada kedalaman 50

cm, maka rerata temperatur udara ditambah

sekitar 3,5C.

Menurut Wambeke et al. (1986) temperatur

anah lebih tinggi 2,5C dari temperatur udara

Hasil pendugaan temperatur dan ditambahperbedaan temperatur udara dan temperatur

tanah tersebut digunakan untuk menentukan

ejim temperatur tanah seperti yang ditetapkan

dalam Taksonomi Tanah

(Soil Survey Staff, 1992; 1998).


23/103

RADIASI MATAHARIPermukaan bumi merupakan penyerap utama radiasi

matahari . Oleh sebab itu permukaan bumi merupakan

sumber panas bagi udara di atasnya dan bagi lapisantanah di bawahnya.

Pada siang hari suhu permukaan tanah akan lebih

tinggi dibandingkan dengan suhu pada lapisan tanah

yang lebih dalam.

Permukaan tanah menyerap radiasi matahari secara

angsung pada siang hari, setelah itu panas merambat

ke lapisan tanah yang lebih dalam.

Sebaliknya pada malam hari permukaan tanah akan

ehilangan panas terlebih dahulu, akibatnya suhu pad

permukaan tanah akan lebih rendah dibandingkan

dengan suhu pada lapisan yang lebih dalam. Pada

malam hari panas akan merambat dari lapisan yanglebih dalam menuju permukaan.

Sumber: STUDI DIFUSIVITAS TERMAL PADA MEDIUM

TANAH MELALUI PENGUKURAN SUHU. Aries AstradhaniSubgan. Natural, Oktober 2006. Vol 5. No.2


24/103

PERPINDAHAN PANAS

Proses perpindahan panas yang terjadi ddalam tanah adalah perpindahan panas

secara konduksi.

Proses perpindahan panas ini terjadikarena adanya gerakan molekul dalam

tanah.

Temperatur adalah suatu pernyataan tentanginetik energi molekul benda, adanya suatu bedasuhu di dalam suatu benda umumnya akan

menyebabkan perpindahan energi kinetik olehbanyaknya tumbukan dari molekul-molekul yang

ergerak dari daerah yang lebih panas ke daerahsekitarnya yang lebih dingin.




25/103

TRANSFER PANAS

Proses stedi (steady;) atau proses takstedi

unsteady) terjadi dalam proses transfer panas

Bilamana laju aliran panas dalam suatu sistem

tidak berubah dengan waktu (konstan), maka

suhu dititik manapun tidak berubah. Hal iniyang dikatakan kondisi keadaan-stedi.

Dengan kondisi keadaan-stedi (steady state),

kecepatan fluks-masuk pada titik manapundari sistem manapun harus tepat sama dengan

kecepatan fluks-keluar, dan tidak dapat terjadi

perubahan energi-dalam. Aliran panas dalam

suatu sistem takstedi terjadi bila suhudiberbagai titik dari sistem tersebut berubah

dengan waktu.




26/103

Dengan adanya perubahan suhu, maka akan terjadi

perubahan energi dalam.

Perubahan kandungan panas dari sebuah permukaan

tanah antara permukaan Z1 = 0 dan beberapa

kedalaman Z2 diberikan oleh :AS = - (qh2qh1)

Dimana qh positif ke arah bawah

zz

qh

Sumber: STUDI DIFUSIVITAS TERMAL PADA MEDIUM TANAHMELALUI PENGUKURAN SUHU. Aries Astradhani Subgan. Natural,

Oktober 2006. Vol 5. No.2

http://www.texas-geology.com/ac_heat

pumps.html


27/103

KERAPATAN FLUX PANAS

Kerapatan fluks panas tanah positif arahbawah ketika S = - (qh2 - qh1) positif, maka

ebih banyak panas yang masuk di bagian atas

daripada yang meninggalkan bagian bawah

lapisan tanah sehingga tanah menjadi panas.

Jika S = - (qh2 - qh1) negatif, maka lebih

banyak panas yang keluar daripada yang

masuk ke permukaan sehingga tanah menjadidingin.




28/103

TRANSFER PANASTeori transfer panas dalam tanah telah digunakan untuk

menentukan sifat-sifat termal rata-rata dari regim suhu yang

diamati, juga untuk pendugaan perubahan harian dan musiman

suhu tanah. di alam, tanah yang homogen hanya terdapat pada

lapisan-lapisan yang tipis, sehingga suhu tanah umumnya

bukanlah fungsi sinus sederhana.

Sumber: STUDI DIFUSIVITAS TERMAL PADA MEDIUM TANAHMELALUI PENGUKURAN SUHU. Aries Astradhani Subgan. Natural,

Oktober 2006. Vol 5. No.2

Amplitude of seasonal

soil temperature

change as a function ofdepth below ground

surface.

http://www.builditsolar.

com/Projects/Cooling/

EarthTemperatures.htm


29/103

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24Waktu PengamatanWaktu Per 30 Menit

Grafik Fungsi Fourier Suhu Tanah BervegetasiTiap Kedalaman

Z=0 Cm

Z=5 Cm

Z=10 Cm

Z=15 Cm

Z=20 Cm

Z=25 Cm

Suhu

Tanah

(0C)

Sumber: STUDI DIFUSIVITAS TERMAL PADA MEDIUMTANAH MELALUI PENGUKURAN SUHU. Aries Astradhani

Subgan. Natural, Oktober 2006. Vol 5. No.2


30/103

Grafik Fungsi Fourier Suhu Tanah Tidak Bervegetasi

Tiap Kedalaman

19

2021

2223

2425

2627

2829

3031

323334

35

3637

3839

4041

4243

4445

46

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Waktu Pengamatan

Waktu Per 30 Menit

Z=0 Cm Z=5 Cm Z=10 Cm Z=15 Cm Z=20 Cm Z=25 Cm

uhuanah

0C)




31/103

TEMPERATUR TANAH

Temperatur (suhu) adalah salah satu sifat

tanah yang sangat penting secara langsungmempengaruhi pertumbuhan tanaman dan

juga terhadap kelembapan, aerasi, stuktur,

aktifitas mikroba, dan enzimetik, dekomposisi

serasah atau sisa tanaman dan ketersidianhara-hara tanaman.

Tenperatur tanah merupakan salah satu faktor

tumbuh tanaman yang penting sebagaimanahalnya air, udara dan unsur hara. Proses

kehidupan bebijian, akar tanaman dan mikroba

tanah secara langsung dipengaruhi oleh

temperatur tanah

Hanafiah, Kemas Ali. 2005.Dasar-dasar Ilmu Tanah. PT. Radj

Grifindo. Persada. Jakarta.


32/103

FAKTOR SUHU TANAH

Tentang suhu tanah pengaruhnya penting

sekali pada kondisi tanah itu sendiri danpertumbuhan tanaman. Pengukuran dari suhu

tanah biasanya dilakukan pada kedalaman 5

cm, 10 cm, 20 cm, 50 cm, dan 100 cm.

Faktor pengaruh suhu tanah yaitu faktor luar

dan faktor dalam.

Faktor luar yaitu radiasi matahari, awan, curahhujan, angin, kelembapan udara. Faktor

dalamnya yaitu faktor tanah, struktur tanda,

kadar iar tanah, kandungan bahan organik, dan

warna tanah. Makin tinggi suhu maka semakincepat pematangan pada tanaman

Kartasapoetra, dkk. 2005. Teknologi Konservasi Tanah. Rinekajaya. Jakarta.


33/103

FLUKTUASI SUHU TANAH

Suhu tanah beraneka ragam dengan cara khaspada perhitungan harian dan musiman.

Fluktasi terbesar dipermukaan tanah dan akan

berkurang dengan bertambahnya kedalaman

tanah.

Kelembapan waktu musiman yang jelas

terjadi, karena suhu tanah musiman lambat

bantuk fluktasi suhu pada peralihan suhudiudara atau dibawah tanah yang lebih besar.

Suhu total untuk semalam tanaman mungkin

terjadi pada tengah hari.

Dibawah 6 inch atau 15 inch terdapat variasi

harian pada suhu tanah

Sosrodorsono. 2006. Variasi Tanah. Rineka Jaya. Bogor.


34/103

TEMPERATUR TANAH

Data temperatur tanah dapat dilihat

pada Tabel 4 menunjukkan bahwa suhuharian pada permukaan tanah sangat

fluktuasi dengan pola mendekati fungsi

sinusoidal.

Fluktuasi temperatur permukaan tanahdipengaruhi oleh perubahan suhu atmosfir di

atas permukaan tanah.

Temperatur tanah pada pagi hari relatif kecil,temperatur tanah pada pagi hari di lahan

aungan cenderung lebih tinggi daripada di arealahan tanpa naungan.

PENGARUH IRIGASI DAN NAUNGAN TERHADAP PRODUKSI

TANAMAN CABE (Capsicum annum) PADA LAHAN BERPASIR

DI PANTAI GLAGAH, YOGYAKARTA

khwanuddin Mawardi dan Sudaryono. 2008. J. Hidrosfir Indonesia Vol. 3(1)

41 -49


35/103

SUHU TANAH - KEDALAMAN

Pada variasi kedalaman yaitupermukaan tanah, kedalaman 10 cm, 20

cm dan 30 cm, untuk temperatur tanahdalam naungan memiliki temperatur yang

tertinggi, sedangkan kedalaman 10 cmmempunyai temperatur tanah terendah.

Hal ini disebabkan pada pagi hari

permukaan tanah telah menerimapancaran radiasi matahari, tetapi transfer

panas belum mencapai kedalaman 10

cm.

Temperatur tanah pada kedalaman 30 cmlebih tinggi dibandingkan kedalaman 10

cm dan 20 cm, karena masih menyimpansebagian energi radiasi matahari yang

diterima sehari sebelumnya.


36/103

SUHU TANAHSIANG AHRI

Temperatur tanah pada siang hari, jikadilihat pada tabel tersebut dapat dilihat

bahwa temperatur tanah pada sing harebih panas daripada temperatur tanah

pada pagi hari.

Hal ini dapat terjadi karena pada siang

hari radiasi yang diterima oleh

permukaan tanah lebih besar.

Temperatur tanah pada siang hari di

areal lahan dengan memakai naungan

lebih tinggi daripada lahan yang tidakmemakai naungan.


37/103

SUHU TANAH - LAPISAN TANAH

Berdasarkan variasi kedalaman, maka

permukaan tanah mempunyai temperatur

anah tertinggi, sedangkan kedalaman 30cm mempunyai temperatur tanah

terendah.

Jadi pada siang hari temperatur

permukaan tanah akan lebih tinggi jika

dibandingkan temperatur pada lapisan

tanah yang lebih dalam.

Hal ini disebabkan karena permukaantanah menyerap radiasi matahari secara

langsung, baru kemudian panasdirambatkan ke lapisan tanah yang lebih

dalam secara konduksi.


38/103

SUHU TANAH - KEDALAMAN

Temperatur tanah pada sore hari akan

lebih kecil dibandingkan dengantemperatur tanah pada pagi dan sianghari. Temperatur tanah dalam naungan

lebih tinggi daripada di areal lahan tanpanaungan.

Berdasarkan variasi kedalaman,pada kedalaman 10 cm mempunyai

temperatur tanah tertinggi sedangkan

kedalaman 30 cm memiliki temperaturtanah terendah.

Tingginya temperaturtanah pada kedalaman 10 cm dapat

disebabkan oleh akumulasi transfer panasdari permukaan atau tingginya aktivitas

mikroorganisme dalam merombak bahanorganik pada lapisan tersebut.


39/103


Bila dilihat dari hasil pengamatan

selama 3 bulan, baik itu pagi, siang dansore hari terlihat temperatur tanah

berfluktuasi, dan cenderung lebih stabil

seiring dengan bertmbahnya umur

tanaman.

Fluktuasi temperatur padapermukaan tanah lebih besar daripada

kedalaman 10 cm, 20 cm dan 30 cm. Hal

ini tidak terlepas dari pengaruh intensitasradiasi matahari yang diterima oleh

permukaan tanah.

adi intensitas radiasi matahari yang berfluktuas

akan menyebabkan temperatur tanah jugaberfluktuasi.


40/103

Alison L. SpongbergKevin P. Czajkowski

Jason Witter

University of Toledo


41/103


42/103


43/103

Soil temperatures over three days at different depths.

Sumber:

http://www.learner.org/jnorth/tm/tulips/SoilTempBack.html.....diunduh 12/2/2012


44/103

Our goal at UT:

Study temporal and spatial

relationships between soil temperature

and various factors

Diurnal and seasonal variation

Modify current protocol

Other latitudes 2-5 years

Study global energy flux.

We need soil temperature variations

throughout the year, without theconfounding influence of diurnal

variations.

Could we arrive at an algorithm todetermine soil temperature at depth

from the shallow measurements?


45/103

15 Field Sites

2-4 week intervals since 12/2002.

Collected within 3 hours of Solar Noon.Each site same time every collection when

possible

Collected to 1 meter depth at 10cm

intervals

Temperature (Air and surface

included)

Wind Speed (1 min average)

Moisture (surface also)pH

Soil texture

Land Cover, Shade Conditions

Cloud CoverSnow/Ice

Water Table


46/103

Automated Data Collection

Temperature (10, 20, 30, 40, 50, 60,80, 100cm) 4 channel HOBO

External Dataloggers

4 sites: 2 clay soils (Lake ErieCenter), 2 sandy soils (Stranahan

Arboretum)

Each has 1 open site and 1 forested

site. Collects every 2.5 minutessince September 2003

Soil texture and pH


47/103

The R. A. Stranahan Arboretum, University of Toledo

47 acre property- ponds, forest,

prairie, wetland, and open areas.

andy Soils (Bixler, Lamsom) Sisson

Loam dunes formed from paleo-lakeshorelines.

Yellow Dots Represent

Sites. 13, 9, and LEC are

also data-logger sites.


48/103

Local Climate/Ground Cover


49/103


50/103


51/103

Left: cyclic nature of

yearly temp and

turnover dates is

generalized here.

Below left: annual

change with depth.

Below right:

relationship between

soil moisture andtemperature decreases

with depth.


52/103

Temperature Profile for Several Sites showing spatial

variation of temperature during two collection dates in the

oldest and warmest months for surface temperature in 2003


53/103

Soil Texture -Particle Size Analysis


54/103

Soil TextureSoil moisture at shallower

depths

Water flow though the soilCloud cover

Land cover


55/103

Suhu Tanah

Relation of Soil & Air Temp

Net heat absorbed by the Earth =

heat lost in form of longwaveradiation

Photoperiod affected by

latitude

Soil temp can change by soildepth & time of day

Takes significant air temp changesto change soil temp deeper than 12

(& more than just daily range)


56/103

Suhu Tanah

Avg. summer & winter soil temps @

3 rarely differ by more than 9 F.

Factors Affecting Soil Temp

How much heat reaches the soil

surface Tutupan muka tanah

Mulsa plastik

Sudut datang radiasi matahari

Arah Muka Lereng

Tanah


57/103

Suhu Tanah

What happens to the heat in thesoil (dissipation)

Amount of heat needed to change soiltemp = heat capacity

Greatly affected by soil water content

How?

Thermal conductivity increases

w/ soil-water content increasing,decreases as air-filled poresincrease

Moist soils resist temp change, butconduct heat readily

Dry soils change temp faster, butconduct heat poorly What does this mean for the soil,

which is better?


58/103

Suhu Tanah

Living w/ Existing Temps Maximizing seed germination &

growth Wheat 40 to 50 F

Corn 50 to 85 F

When using anhydrous Apply when soil temp @ 4 is 50 For less

Mereduksi kehilangan N

Freeze/thaw May cause heaving resulting in

death of shallow rooted crops


59/103

Suhu tanah

Responsible for bringingstones to the surface in fields

Modifying Temp Effects

If you have crops that arefeasible/profitable to do so

Clear plastic surface covers Increases soil temp faster

Clear plastic mulches

Can speed growth & maturity ofsweet corn & strawberries


60/103

CIRI THERMAL TANAH

The thermal properties of soil are acomponent of soil physics that has found

important uses in engineering, climatology

and agriculture.

These properties influence how energy ispartitioned in the soil profile. While related to

soil temperature, it is more accurately

associated with the transfer of heat throughou

the soil, by radiation, conduction andconvection.

The main soil thermal properties are:

Volumetric heat capacity, SI Units: J.m-3K-1Thermal conductivity, SI Units: W.m-1K-1

Thermal diffusivity , SI Units: m2s-1

http://en.wikipedia.org/wiki/Soil_thermal_properties.. Diunduh 4/2/2012


61/103


62/103

CIRI-CIRI THERMAL TANAH

So, in order to determine the skin temperatureof the soil, it is important to understand how

heat is transferred upward and and downward

through the soil. The important heat transfer

mechanism in this problem is conduction.Then, the ground heat flux at any depth in the

soil can be given as:

where kg is the thermal diffusivity of the soil.

ttp://apollo.lsc.vsc.edu/classes/met455/notes/section

/2.html .... diunduh 5/2/2012


63/103

Using the Second Law of Thermodynamics, show tha

a prognostic equation for the soil temperature can be

given by:

(2)

where Cg is the soil heat capacity (Cg= soil density, r

times the soil specific heat, c)combining (2) with (1) yields:

(3)

where vg = kg/Cg = soil thermal diffusivity.

Given proper boundary conditions, (3) can be solved to find the

soil temperature at different levels as a function of time. With

appropriate boundary conditions, solutions to (3) show that soil

temperature decreases exponentially with depth and that the

phase of the temperature changes with depth as well, consistent

with the figures shown above.

ttp://apollo.lsc.vsc.edu/classes/met455/notes/section/2.html .... diunduh 5/2/2012


64/103

Typical values of the mass density, specific heat,

thermal conductivity and thermal diffusivity for

different materials

ttp://apollo.lsc.vsc.edu/classes/met455/notes/section6/2.html ...Diunduh 6/2/2012

MATERIAL

CONDITION

MASSDENSITY (r)(kg m-3 x 103)

SPECIFICHEAT (c) (J

kg-1 K-1 x103)

THERMALCONDUCTIVITY (kg) (W m

-

2 K-1)

THERMALDIFFUSIVITY

(vg) (m2 s-1 x10-6)

Air20 DegC, Still

0.0012 1.01 0.025 20.5

Water20 DegC, Still

1.00 4.19 0.57 0.14

Ice0 Deg C,

Pure0.92 2.10 2.24 1.16

Snow Fresh 0.10 2.09 0.08 0.38

Snow Old 0.48 2.09 0.42 0.05

SandySoil

Fresh 1.60 0.80 0.30 0.24

ClaySoil Dry 1.60 0.89 0.25 0.18

PeatSoil

Dry 0.30 1.92 0.06 0.10

Rock Solid 2.70 0.75 2.90 1.43


65/103


Soil temperature variations decrease

exponentially with depth. only smallfluctuations are observed at depths of about 1

meter. much smaller fluctuations are observed

at depths of 10 meters.

ttp://apollo.lsc.vsc.edu/classes/met455/notes/section6/2.html ...Diunduh 6/2/2012


66/103

KAPASITAS PANAS VOLUMETRIK

Volumetric heat capacity (VHC), alsotermed volume-specific heat capacity,

describes the ability of a given volume of a

substance to store internal energy while

undergoing a given temperature change, butwithout undergoing a phase change.

It is different from specific heat capacity in

that the VHC depends on the volume of the

material, while the specific heat is based onthe mass of the material (or occasionally the

molar quantity of the material).

If given a specific heat value of a substance,one can convert it to the VHC by multiplying

the specific heat by the density of the

substance.

http://en.wikipedia.org/wiki/Volumetric_heat_capacity diunduh

5/2/2012


67/103

KAPASITAS PANAS

Dulong and Petit predicted in 1818 that the product o

solid substance density and specific heat capacity

(cp) would be constant for all solids. This amountedto a prediction that volumetric heat capacity in solids

would be constant.

This quantity was proportional to the heat capacity peatomic weight (or per molar mass), which suggested

that it is the heat capacityper atom (not per unit of

volume) which is closest to being a constant in solids

Eventually (see the discussion in heat capacity) it hasbecome clear that heat capacities per particle for all

ubstances in all states are the same, to within a factor

of two, so long as temperatures are not in the

cryogenic range.

For very cold temperatures, heat capacities falldrastically and eventually approach zero as

temperature approaches zero.


5/2/2012


68/103

KAPASITAS PANAS VOLUMETRIK.

The heat capacity on a volumetric basis in solid

materials at room temperatures and above varies morewidely, from about 1.2 to 4.5 MJ/mK, but this is

mostly due to differences in the physical size of

atoms.

f all atoms were the same size, molar and volumetricheat capacity would differ by a single constant

reflecting ratios of the atomic-molar-volume of

materials (their atomic density), plus an additional

number between 1 and 2 which reflects degrees of

freedom for the atoms compositing the substance at

various temperatures.

For liquids, the volumetric heat capacity is narrower:

in the range 1.3 to 1.9 MJ/Mk.

This reflects the modest loss of degrees of freedom fo

particles in liquids as compared with solids.


5/2/2012


69/103

KAPASITAS PANAS VOLUMETRIK

Sincethe bulk density of a solid chemical element isstrongly related to its molar mass (usually about 3 Rper

mole, as noted above), there exists noticeable inversecorrelation between a solids density and its specific heatcapacity on a per-mass basis. This is due to a very

approximate tendency of atoms of most elements to beabout the same size, despite much wider variations in

ensity and atomic weight. These two factors (constancy o

atomic volume and constancy of mole-specific heatcapacity) result in a good correlation between the volume

of any given solid chemical element and its total heatcapacity. Another way of stating this, is that the volume-

specific heat capacity (volumetric heat capacity) of solidelements is roughly a constant.

The molar volume of solid elements is very roughlyonstant, and (even more reliably) so also is the molar hea

capacity for most solid substances. These two factorsdetermine the volumetric heat capacity, which as a bulk

property may be striking in consistency.

For example, the element uranium is a metal which has adensity almost 36 times that of the metal lithium, but

uranium's volumetric heat capacity is only about 1.2 timeslarger than lithium's.


5/2/2012


70/103

.

KONDUKTIVITAS THERMAL

Thermal conductivity, k, is the property of amaterial's ability to conduct heat. It appears

primarily in Fourier's Law for heat

conduction.

Heat transfer across materials of high thermalconductivity occurs at a higher rate than

across materials of low thermal conductivity.

Correspondingly materials of high thermal

conductivity are widely used in heat sinkapplications and materials of low thermal

conductivity are used as thermal insulation.

Thermal conductivity of materials istemperature dependent. The reciprocal of

thermal conductivity is thermal resistivity.


5/2/2012


71/103

SUHU TANAH - MUSIMAN

Soil temperature varies from month to month as a function of

ncident solar radiation, rainfall, seasonal swings in overlying ai

emperature, local vegetation cover, type of soil, and depth in theearth.

Due to the much higher heat capacity of soil relative to air and

the thermal insulation provided by vegetation and surface soil

layers, seasonal changes in soil temperature deep in the ground

re much less than and lag significantly behind seasonal changein overlying air temperature.

Thus in spring, the soil naturally warms more slowly and to a

lesser extent than the air, and by summer, it has become cooler

than the overlying air and is a natural sink for removing heatfrom a building. Likewise in autumn, the soil cools more slowly

nd to a lesser extent than the air, and by winter it is warmer than

the overlying air and a natural source for adding heat to a

building.

At soil depths greater than 30 feet below the surface, the soilemperature is relatively constant, and corresponds roughly to th

water temperature measured in groundwater wells 30 to 50 feet

deep. This is referred to as the mean earth temperature.


5/2/2012


72/103

SUHU TANAHFLUKTUASI MUSIMAN

The amplitude of seasonal changes in soil

temperature on either side of the mean earth

temperature depends on the type of soil and

depth below the ground surface.

In Virginia the amplitude of soil temperature

hange at the ground surface is typically in the

ange of 20-25F, depending on the extent andtype of vegetation cover.

At depths greater than about 30 feet below the

urface, however, the soil temperature remainsrelatively constant throughout the year, as

shown in Figure 3, below.


5/2/2012


73/103

SUHU TANAHKEDALAMAN PROFIL.

http://www.geo4va.vt.edu/A1/A1.htm . Diunduh5/2/2012


74/103

SUHU TANAH - VARIASI HORISONTAL

Vertical closed-loop earth heat exchangers are

installed in boreholes 200 to 300 feet deep, where

seasonal changes in soil temperature are completelydamped out. Well-based open-loop systems also

extend to this depth or deeper. These ground loop

configurations are thus exposed to a constant year-

round temperature.

On the other hand, horizontal-loop, spiral-loop, andorizontal direct-expansion (DX) loops are installed in

trenches that usually are less than 10 feet deep. For

these types of ground loops, it is important to

accurately know the expected seasonal changes in thesurrounding soil temperature.

The extra cost of installing such systems in deeper

trenches may be outweighed by the gain in thermal

performance, since deeper soils have less pronouncedseasonal temperature changes and are thus closer to

oom temperature, which reduces the work load of the

heat pump units.

. http://www.geo4va.vt.edu/A1/A1.htm . Diunduh 5/2/2012


75/103

SUHU TANAHKEDALAMAN

Deeper soils not only experience less extreme seasonal

variations in temperature, but the changes that do occurlag farther behind those of shallower soils. This shifts thesoil temperature profile later in the year, such that it more

closely matches the demand for heating and cooling.

he maximum soil temperature occurs in late August (whe

cooling demand is high) at a depth of 5 feet below theground surface, but occurs in late October (after the

heating season has begun) at a depth of 12 feet below thesurface.

Thus a deeper ground loop installation would lower theannual operating cost for electrical energy to run the heatpumps, and over the life of a GHP system, these

accumulated savings may more than offset the highercapital cost of burying the ground loop more deeply.

In order to determine the optimal depth of burial, it ismportant to accurately know how the seasonal change in

soil temperature varies with depth, which is mainlydetermined by the soil's thermal properties.



76/103

Seasonal soil temperature change as a function of

epth below ground surface for an average moist soil.



77/103

CIRI-CIRI THERMAL TANAH

Heat capacity (also known as specific heat) indicates

the ability of a substance to store heat energy; the

greater its heat capacity, the more heat it can gain (orlose) per unit rise (or fall) in temperature.

The heat capacity of dry soil is about 0.20 BTU per

pound per F of temperature change, which is only

one-fifth the heat capacity of water. Therefore, moist

or saturated soils have greater heat capacities,

typically in the range of 0.23 to 0.25 BTU/lb/F.

The light dry soils experience greater seasonaltemperature swings at a given depth than wet soils.

This is because their lower heat capacity causes their

temperature to rise or fall more than wet soils for a

given amount of heat energy gained in the spring orlost in the fall.



78/103

KONDUKTIVITAS THERMAL

(KT) Thermal conductivity is another soil property thatmust be known in order to design a closed-loop or directexpansion GHP system. This indicates the rate at whichheat will be transferred between the ground loop and the

surrounding soil for a given temperature gradient.

The thermal conductivity of the soil and rock is the criticavalue that determines the length of pipe required, which in

turn affects the installation cost as well as the energyequirements for pumping working fluid through the groun

loop.

KT - TANAH BERAGAM DENGAN TEKSTURNYA.

Heat transfer capability tends to increase as soil texturebecomes increasingly fine, with loam mixtures having anntermediate value between sand and clay. As also shownin this figure, the thermal conductivity of any soil greatlyimproves if the soil is saturated with water. This effect is

much greater for sandy soils than for clay or silt, sincecoarse soils are more porous and therefore hold morewater when wet.



79/103

Konduktivitas thermal berbgaai tipe

tekstur tanah.



80/103

KONDUKTIVITAS PANAS

he soil thermal conductivity has a significant impact on the siz

of the earth-coupled heat exchanger. Thus in sandy soils for

example the required length of the ground loop could be as low

s 200 feet per system ton if the soil is saturated with water, or ahigh as 300 feet per ton if the soil is dry.

Soil thermal conductivity is of even greater importance to DX

systems and designers might consider the deployment of a

soaker hose for horizontal DX ground loops in dry areas or ifthe project site is higher than the sounding terrain.

The maps presented in the next section below enable rough

estimates of soil properties for regional screening purposes, but

any sort of detailed feasbility assessment or design study should

engage a contractor for in-situ soil thermal conductivity testing.

The range in ground loop lengths over the typcial range of soil

thermal conductivities is 200 to 300 feet per system ton, which

translates into a 30-50% difference in required land area, and a

10-20% difference in total system capital cost.

In-situ conductivity testing minimizes the uncertainty in

estimating this key thermal property and avoids undersizing or

oversizing the ground loop.



81/103

Thermal conductivity influence on number of

boreholes and total length of the earth-coupled heat

exchanger per 10 tons of load for a vertical closed-

loop GHP system.



82/103

SUHU TANAH

Amplitude: Amplitude is a parameter characterizing the annual

variation of soil temperature around an average value. If the

variation in temperature within a day is averaged out over manyyears, the annual amplitude is one-half the difference between

this annual averaged maximum and annual averaged minimum

temperatures within a year.

Damping depth: Damping depth is a constant characterizing the

decrease in amplitude with an increase in distance from the soilsurface. It is defined as (2Dh/w)1/2, where D h is the thermal

diffusivity and w is the frequency of a temperature fluctuation.

For annual fluctuation w =2 p /365 d-1.

Thermal diffusivity: Thermal diffusivity is the change intemperature produced in a unit volume by the quantity of heat

owing through the volume in unit time under a unit temperatur

gradient. It can be calculated from thermal conductivity and

volumetric heat capacity.

Time lag: Time lag is the number of days from an arbitrary

starting date to the occurrence of the minimum temperature in ayear.



83/103

SUHU TANAH - WAKTU DAN

KEDALAMAN

Soil temperature fluctuates annually and daily

affected mainly by variations in air temperature

and solar radiation.

The annual variation of daily average soil

temperature at different depths can be estimated

using a sinusoidal function (Hillel, 1982;

Marshall and Holmes, 1988; Wu and Nofziger,

1999).

This program estimates daily soil temperatures

and displays these values as functions of time or

depth for user defined input parameters.

ttp://soilphysics.okstate.edu/software/SoilTemperature/document.pdf . DIUNDUH 5/2/2012


84/103

MODEL VARIASI SUHU TANAH

The annual variation of daily average soil temperature

at different depths is described with the

following sinusoidal function ( Hillel, 1982):

where T(z,t) is the soil temperature at time t (d) and

depth z (m), T a is the average soil temperature (oC),

A0 is the annual amplitude of the surface soil

temperature (oC), d is the damping depth (m) ofannual fluctuation and t0 is the time lag (days) from

an arbitrary starting date (taken as January 1 in this

software) to the occurrence of the minimum

temperature in a year.

The damping depth is given by d = (2D h/w )1/2,

where Dh is the thermal diffusivity and w = 2

p /365 d-1 .



85/103

MODEL SINUS VARIASI SUHU TANAH

Assumptions and Simplifications

The sinusoidal temperature model was derived by

solving the following partial differential

equation ( Hillel, 1982 ; Marshall and Holmes, 1988)

where T(z,t) is the soil temperature at time t and depthz and Dh is the thermal diffusivity.



86/103

VARIASI SUHU TANAH

The following assumptions are employed in the

derivation of the temperature model:

1. A sinusoidal temperature variation at the soilsurface z = 0. That is

where Ta is the average soil temperature, A0 is the

amplitude of the annual temperature function, t0 a

time lag from an arbitrary starting date (selected as

January 1 in this software) to the occurrence of the

minimum temperature in a year.

2. At infinite depth, the soil temperature is constant

and is equal to the average soil

temperature.

3. The thermal diffusivity is constant throughout the

soil profile and throughout the year.



87/103

Measured mean and predicted soil temperatures at

four depths based on measured soil

surface temperatures.



88/103

Suhu tanah pada berbagai kedalaman:

Diprediksi berdasarkan suhu udara.



89/103

Konduktivitas dan difusivitas thermal tanah:

Dipengaruhi kadar air, kadaungan liat, dan bobot isi

tanah.



90/103

Volumetric heat capacity for three bulk densities for soils whose thermal

conductivity and diffusivity.

http://www.usyd.edu.au/agric/web04/Temperature%20Waves_final.htm


91/103

SUHU TANAH - PENANAMAN

Whether youre planting seeds or targeting weeds, its important to check your

soil temperature before beginning.

Even the best-planned garden project can fall flat if temperatures are notappropriate for the occasion! For example, did you know that you should:

Plant spring bulbs when the soil temperature drops below 60 F.

Apply crabgrass control in spring, when soil temperatures reach 55 F for 4-5

days in a row.

Plant cool-season grass seed once soil temperatures are in the 50s F.

Give your new shrubs time to grow roots before soil temperatures fall below 40

F.Be very careful when starting vegetable seeds, since germination temperature is

vital to the seeds success and every vegetable is different.

http://www.usyd.edu.au/agric/web04/Temperature%20Waves_final.htm.

http://www.dannylipford.com/how-to-measure-soil-temperature-for-planting/

Soil temperature plays an important role in soil chemical reactions and biological

interactions, particularly nutrient and fertilizer transformations, solute transport, gas

exchange and the transformation and transport of contaminants (Buchan 2001).

Soil temperature varies in response to exchange processes that take place primarilythrough the soil surface. These effects are propagated into the soil profile by transport

processes and are influenced by such things as the specific heat capacity, thermal

conductivity and thermal diffusivity.

Soil temperature can vary greatly throughout the day with increasing and decreasing

solar radiation. Soil temperatures also vary greatly with depth from the surface, as

well as with differences in soil cover (mulch) and soil water content. The thermal

properties of a soil have been found to be indicative of the soil water content. Water is

a better thermal conductor than air. The thermal conductivity of soil increases withincreasing water contents (Fredlund, 1992).

Buchan, G.D., (2001) Soil Temperature Regime, in Smith, K.A., and Mullins, C.E. (Eds). Soil and

Environmental Analysis: Physical Methods 2nd Ed. 2001. Marcel Dekker. pp, 539-594.

Fredlund, D.G. (1992). Background, Theory, and Research Related to the Use of Thermal

Conductivity Sensors for Matric Suction Measurement. Soil Science Society of America. Advances

in Measurement of Soil Physical Properties: Bringing Theory into Practice, 249-261.


92/103

TERMOMETER TANAH

You can purchase a simple soil thermometer at your local garden centerfor just a few dollars.

The most economical ones are glass bulb thermometers with a strongmetal point. However, any thermometer will do, as long as it measurestemperatures down to freezing (medical thermometers usually dont go

low enough).

http://www.ipm.iastate.edu/ipm/icm/2001/10-22- 2001/why50.html diuduh 15/2/2012

Influence of soil temperature on nitrification.

Ammonium sulfate nitrification after 24 days. Soils held at either constanttemperature (80, 60, or 40F) for 24 days, or the temperature varied (between 80,

60, and 40F sequences) by 8- or 12-day intervals over the 24 days.

Adapted from Chandra, P. 1962. Note on the effect of shifting temperatures on

nitrification in a loam soil. Can. J. Soil Sci. 42:314-315.

Temperature Sequence % Nitrification

Continuous at 80F for 24 days 100

12 Days at 80F-12 days at 40F 96

8 Days at 80F-8 days at 60F-8 daysat 40F

74

12 Days at 40F-12 days at 80F 62



56


45



93/103

BAGAIMANA MENGUKUR SUHU TANAH?.

Measure the Right Depth: If you are planting seeds or

new plants, take your measurement at the recommendedplanting depth. If youre measuring for a mixed garden,check at least 5-6 inches deep.

Make a Pilot Hole: Use a screwdriver to make a pilot holeo that you dont break your thermometer by pushing it into

hard soil.ollow Directions: Refer to your thermometer package fospecific instructions. With most glass bulb thermometers,make sure it is firmly touching the soil, and allow a few

minutes for the temperature to register.

Provide Shade: If the sun is bright, shade thehermometer with your hand to keep the reading accurate

Multiple Measurements: Take a reading in the morningnd late afternoon, then average the two numbers. If your

seeding a lawn, take readings on all four sides of yourhouse, since some areas warm more quickly than others.

Check Reading: To double-check, refer to these handySoil Temperature Maps from Greencast for a comparison

with your soil reading.


94/103

SUHU TANAH PERKECAMBAHAN BENIH

The soil temperature for planting vegetables should be:40 F or warmer: Lettuce, kale, peas, spinach.

50 F or warmer: Onions, leeks, turnips, Swiss chard.60 F or warmer: Broccoli, cabbage, cauliflower, carrots, beans, beets.

70

F or warmer: Tomatoes, squash, corn, cucumbers, melons, peppers.

The seed germination temperature is often much warmer than the plants growing

temperature. Once established, many veggies can handle much cooler airtemperatures as long as the soil is warm enough.

o get a head start on spring planting, plant seeds indoors or use plastic row coversto warm the soil more quickly.

Temperature has a large influence on rate of seed water uptake, speed of germination, and rate of plant

mergence. As temperature increases, both the rate of water uptake and speed of germination increase and

time to emergence decreases for winter wheat

he effect of soil temperature on speed of germination and emergence of Norstar winter wheat (from

Lafond and Fowler, 1989).

http://www.usask.ca/agriculture/plantsci/winter_cereals/Winter_wheat/CHAPT11/cvchpt11.php


95/103

Soil temperature and vegetable seed germination

http://www.waldeneffect.org/blog/Soil_temperature_and_vegetable_se

d_germination/Diunduh 5/2/2012

Vegetable Minimum temp.(degrees F)

Optimum temp.(degrees F)

Beans 60 60-85

Cabbage 40 45-95

Carrots 40 45-85

Corn 50 60-95

Cucumbers 60 60-95

Lettuce 35 40-80

Muskmelons 60 75-95

Okra 60 70-95

Onions 35 50-95

Parsley 40 50-85

Peas 40 40-75Peppers 60 65-95

Pumpkins 60 70-90

Spinach 35 45-75

Squash 60 70-95

Swiss chard 40 50-85

Tomatoes 50 70-95

Turnips 40 60-105

Watermelons 60 70-95


96/103

SUHU TANAH - TANAMAN

he temperature of a soil is important as it affects how fast plants can grow. Soil temperatur

also affects how quickly plants take up water and nutrients. Clay soils are cold, wet soils.

Germination and seedling growth is usually slow.

ecause sandy soils don't contain much water but lots of air, they warm up quickly. They ar

useful for growing early crops.

Soil temperature affects the speed of chemical reactions. Warm temperatures speed up

actions and colder ones slow them down. Soil temperature affects the breakdown of paren

material and how fast micro-organisms work. Both are important in adding and returning

nutrients to the soil.

Soil temperature is influenced by the climate of the area and the season of the year.

ttp://www.correspondence.school.nz/departments/horticulture/ht106_p7.html. .... Diunduh

5/2/2012

Effect of soil temperature and water potential on emergence time of Norstar winter

wheat (from Lafond and Fowler, 1989).

tp://www.usask.ca/agriculture/plantsci/winter_cereals/Winter_wheat/CHAPT11/cvchpt11.p

hp


97/103

SUHU TANAH - POSISI LERENG

The slope of the land and the direction that it faces

directly affects the temperature of a soil. Sun will fall

on north-facing land during the day in both summerand winter.

ttp://www.correspondence.school.nz/departments/horticulture/h

106_p7.htmlDiunduh 5/2/2012


98/103

SUHU TANAHKEDALAMAN TANAH

The deeper you go down in a soil profile the less the

soil temperature will fluctuate

ttp://www.correspondence.school.nz/departments/horticulture/h

106_p7.htmlDiunduh 5/2/2012

Soil is a good

insulator. It can take a

while for the soil at

the bottom of a profile

to heat up, but it will

also take a longer timefor it to lose the heat

that is stored there.


99/103

SUHU TANAH DAN AKTIVITAS BIOLOGIS

TANAH

Soil temperature affects the speed of plant growth and soil processes.

Soil temperature is influenced by: climate, season, aspect, water levels, soil colourplant cover and soil depth.he temperature in a soil will determine the speed of chemical and biological activity

Clay soils take a long time to warm up but are also slower to cool down. Theemperature in a sandy soil can change rapidly. Wet soils also take longer to warm

up.

http://www.correspondence.school.nz/departments/horticulture/ht106_p7.html

Diunduh 5/2/2012

Amplitude of seasonal soil temperature change as a function of depth below ground surface

http://www.builditsolar.com/Projects/Cooling/EarthTemperatures.htm diunduh 15/2/2012


100/103

SUHU-TANAH OPTIMUM BAGI TANAMAN

Corn requires a soil temperature of 50 F to germinateand grow and soybeans require a soil temperature of

54 F.

Temperatures below the optimum will cause seeds to sit dormantand become more vulnerable to diseases, insects, and animal

predators.

Crops should be planted when soil temperatures are optimal and

within the target dates for the region.

Keep in mind these dates are based on the average year and the use

of short or long relative maturity corn products will affect these

target dates.Planting into cold and/or wet soils can lead to numerous problems.

tp://munsonhybrids.com/tidbits/Plant%20Corn%20and%20Soybean%20By%20Soil%20Tmperature%20and%20Conditions%20Not%20According%20To%20The%20Calendar%20-

%20IA.pdf .. Diunduh 5/2/2012

Aqua ammonia incubated in soil at controlled temperature.

http://www.ipm.iastate.edu/ipm/icm/2001/10-22-2001/why50.html


101/103

SUHU TANAH DAN PERTUMBUHAN

BIBIT

Soil temperature is more important than air temperature

when planting seeds or seedlings. You can have in the

spring a warm spell of temps in the 70s while the soil

temp is still in the 40s. Every vegetable has a preferred

soil temp for seeds or transplants. A soil thermometer is

essential for determining the proper planting time.Planting too early, before the soil has had time to warm

up, can lead to seed rot, slowed germination, poor

growth and disease.

Use the following guide for minimum soil temperatures

for seeds and transplants:

60o F - tomatoes, cucumbers, snap beans65o F - sweet corn, lima beans, mustard greens

70o F - peppers, watermelons, squash, southern peas

75o F - okra, cantaloupe, sweet potatoes

ttp://yardener.com/YardenersPlantHelper/FoodGardening/BasicsofVegetableGa

ening/SoilBuildingandManagementintheVegetableGarden/SoilTemperatureIsIm

portant

Diunduh 5/2/2012


102/103

Soil Temperature Germination Ranges for Select Vegetables

TEMP (F) PLANT

3575 spinach (optimum 68)

3580lettuce and most salad greens (at more than 80,

germination rate drops 50%)

4075 peas (optimum 75)

4585cabbage, kale, broccoli, collards (germinate well at 85,

seedlings prefer 4565)

4595 radishes (optimum 85)

5085 onions (optimum 75)

5085 beets, Swiss chard (optimum 85)

6085 beans, snap and dry (optimum 80)

6095 corn (optimum 95)

6095 peppers (optimum 85)

65100 cucumbers, melons, squash (optimum 8095)

6582 tomatoes (optimum 80)7085 beans, lima (optimum 85)

From: Market News, March 1995.

tp://yardener.com/YardenersPlantHelper/FoodGardening/BasicsofVegetableGardening/Soi

BuildingandManagementintheVegetableGarden/SoilTemperatureIsImportantDiuinduh 5/2/2012


103/103

Daftar Pustaka

deVries, D. A., 1963. Thermal Properties of Soils.In W.R.

van Wijk (ed.) Physics of Plant Environment. North-Holland Publishing Company, Amsterdam.

de Vries, D. A. 1975. Heat Transfer in Soils. In D.A. de

Vries and N.H. Afgan (ed.) Heat andMass Transfer in the

Biosphere. Pp.5-28. Scripta Book Co., Washington, DC.

Farouki, O.T. 1986. Thermal Properties of Soils. Series on

rock and soil mechanics. Vol. 11. Trans Tech Publ.,

Clausthal-Zellerfeld, Germany.

Hillel, D. 1982. Introduction to soil physics. AcademicPress, San Diego, CA.

Marshall, T. J. and J. W. Holmes 1988. Soil Physics. 2nd

91169684 temperatur tanah karakteristik dan kualitas lahan

Documents