kompendium kesuburan tanah dan pemupukan

KESUBURAN
TANAH
&
PEMUPUKAN
Diabstraksikan Oleh:
Smno.jurstnh.fpub.agst2012
Kesuburan tanah
Kesuburan Tanah adalah kemampuan suatu tanah
untuk menghasilkan produk tanaman yang
diinginkan, pada lingkungan tempat tanah itu
berada. Produk tanaman berupa: bunga, buah, biji,
daun, umbi, getah, akar, trubus, batang, biomassa,
naungan, penampilan estetika, dan lainnya.
Tanah memiliki kesuburan yang berbeda-beda
tergantung sejumlah faktor pembentuk tanah yang
merajai di lokasi tersebut, yaitu: Bahan induk,
Iklim, Relief, Organisme, dan Waktu.
Tanah merupakan fokus utama dalam pembahasan
ilmu kesuburan tanah, sedangkan “tanaman”
merupakan indikator utama bagi “kesuburan tanah”.
Diunduh dari: http://id.wikipedia.org/wiki/Kesuburan_tanah..
Cara Menjaga Kesuburan Tanah
Untuk menjaga kesuburan tanah bisa dilakukan dengan cara sebagai berikut :
1. Gunakan jerami. Pada tanah sawah, biasanya setelah panen padi kita
selalu membuang dan membiarkan jerami ditumpuk di pinggir sawah.
Padahal jerami itu bisa kita manfaatkan untuk menyuburkan tanah.
Sebarkan jerami tersebut ke lahan dan ratakan. Kemudian taburkan
serbuk dolomit ke atas jerami tersebut. Fungsi dolomit untuk membantu
mempercepat pelapukan daun jerami dan bisa mengatur tingkat keasaman
tanah sehingga tanah bisa lebih matang dan lahan bisa segera
ditanami.Setelah sekitar seminggu lahan tersebut bisa langsung dibajak
dan jerami yang belum lapuk bisa dibenamkan ke dalam tanah.
2. Lubang resapan Biopori. Pada taman atau halaman rumah bisa kita
lakukan metode biopori. Caranya lubangi tanah secara tegak lurus dengan
menggunakan pipa besi dengan diameter sekitar 10-20 cm dan kedalaman
tanah sekitar 100 cm. Jarak antar lubang resapan biopori adalah 50-100
cm. Kebutuhan jumlah lubang resapan biopori yang diperlukan
berdasarkan luas tutupan bangunan. Bila tutupan bangunan dengan luas
20 m2 diperlukan lubang resapan biopori sebanyak 3 unit dan setiap
tambahan luas tutupan bangunan 7 m2 diperluhan tambahan 1 unit
lubang resapan biopori. Dalam pemeliharaannya lubang resapan biopori
ini diisi sampah organik secara berkala dan mengambil sampah tersebut
setelah menjadi kompos diperkirakan 2-3 bulan setelah terjadi proses
pelapukan.
3. Tanaman Crotalaria.Untuk lahan kritis bisa dimanfaatkan untuk ditanami
tanaman crotalaria. Akar tanaman crotalaria bisa mengikat nitrogen dan
unsur lain yang sangat dibutuhkan tanah untuk menjadi subur. Daun dan
batang tanaman crotalaria sangat baik dijadikan pupuk hijau (kompos)
karena mengandung unsur-unsur yang sangat dibutuhkan tanah dan
tanaman dibanding pupuk hijau dari tanaman lain.
Diunduh dari: http://rishadicorp.blogspot.com/2011/03/cara-menjaga-kesuburan-tanah.html..
Mengelola kesuburan tanah dapat dilakukan
dengan metode-metode vegetatif dan mekanik
Upaya yang dapat dilakukan untuk menjaga keseburan tanah sebagai berikut:
a. Metode vegetatif dilakukan dengan cara-cara :
1. Penanaman tanaman secara berjalur tegak lulus terhadap arah
aliran(strip cropping).
2. Penanaman tanaman secara berjalur sejajar garis kontur (contour
strip cropping).
3. Penutupan lahan yang memiliki lereng curam dengan tanaman keras
(buffering)
4. Penanaman tanaman secara permanen untuk melindungi tanah dari
tiupan angin (wind breaks).
b. Metode mekanik yang umum dilakukan ADALAH:
1. Pengolahan lahan sejajar garis kontur (contour tilage).pengolahan
lahan dengan cara ini bertujuan untuk membuat pola ronggarongga tanah sejajar kontul dan membentuk igir-igir kecil yang
dapat memperlambat alilan air dan memperbesar infiltrasi air
2. Penterasan lahan miring (terracering).penterasan bertujuan untuk
mengurangi panjang lereng dan memperkecil kemiringan lereng
sehingga dapat memperlambat alilan air.
3. Pembuatan pematang (guludan)dan saluran air sejajar garis
kontur.pembuatan pematangan bertujuan untuk menahan alilan air.
4. Pembuatan cekdam.pembuatan cekdam bertujuan untuk
memperbendung alilan air yang melewati parit-parit sehingga
material tanah hasil erosi yang terangkut aliran tertahan dan
terendapkan adannya cekdam menyebabkan erosi tanah dapat
dikendalikan,lapisan tanah menebal,dan produktivitas tanah
meningkat .
Diunduh dari: http://lukmanituagam.blogspot.com/2011/03/menjaga-kesuburan-tanah.html..
LIMA
FAKTOR
PENGELOLA
AN
Pengendalian
GULMA.
TANAH
PERGILIRAN TANAMAN
PENGENDALIAN HAMA &
PENYAKIT
PENYEDIAAN
UNSUR HARA
Penyediaan AIR YANG CUKUP,
Sesuai dengan kebutuhan tanaman
DINAMIK
A HARA
TANAH
Mempertahankan jumlah optimum
unsur hara hanya dapat terlaksana
dengan menciptakan keseimbangan
yang baik antara penambahan dan
kehilangannya
Benefits of Organic Matter
Benefits of Organic
Matter
Reduces compaction and bulk
density
Provides a food source for
microorganisms
Increases activities of earthworms
and other soil critters
Increases soil CEC
Stabilizes nutrients
Builds soil friability and
tilth
Reduces soil splash
Carbon Sequestration
C cycling in agroecosystems has a significant impact at the
global scale because agriculture occupies approximately 11%
of the land surface area of the earth.
POKOK-POKOK
PENGELOLAAN
KESUBURAN
TANAH.
1. Suplai nitrogen dari:
Sisa Tanaman
Pupuk kandang
Hujan & irigasi
Pupuk nitrogen
Tanaman biasa
Tanaman legume
Pupuk hijau
Kompos
2. Penambahan bahan organik
melalui:
Sisa tanaman legume dan
non legume
Pupuk kandang
Pupuk hijau
3. Penambahan kapur bila diperlukan
Batu kapur kalsit atau
dolomit yg
biasa dilakukan
4. Penambahan fosfat:
Pupuk
superfosfat, atau
Pupuk lainnya
5. Penambahan kalium
tersedia:
Pupuk kandang
Sisa tanaman
Pupuk Kalium
6. Kekurangan belerang
diatasi dg:
Belerang, gipsum,
superfosfat, Amonium
sulfat, Senyawa
belerangdalam air hujan
7.
Penambahan
unsur
mikro: Sebagai garam
terpisah atau campuran
MENGATASI
KEKURANG
AN
NITROGEN
Dinamika nitrogen
Penambahan & Kehilangan
N-tersedia
Pengikatan
Nitrogen
Simbiotik
Pupuk
Buatan
NonSimbiotik
Sisa
tanaman
Pupuk
Kandang
Ntersedia
dlm
tanah
Atmosfer
Bahan
Organik
Panen
Tanam
an
Hilang
Pencuci
an
Hilang
Erosi
MEMPERTAHA
NKAN BAHAN
ORGANIK
TANAH
Carbon Inputs to Soil
Crop residues
Cover crops
Compost , and
Manures
Carbon Substrate
The majority of C enters the soil in the form of complex
organic matter containing highly reduced, polymeric
substances.
During decomposition, energy is obtained from oxidation of
the C-H bonds in the organic material.
Soil Carbon Equilibrium
Input primarily as plant products
Output mediated by activity of decomposers
It is common that from 40 to 60% of the C taken up by
microorganisms is immediately released as CO2.
PENTINGNYA
Ca & Mg
Keseimbangan Ca dan Mg
Penambahan dan
kehilangan
Sisa
tanaman &
Pupuk
Kandang
Pupuk
Komersial
Ca dan Mg
tersedia dalam
tanah
PANEN
TANAMAN
Hilang
pencucian
Mineral
Tanah
KAPUR
Hilang Erosi
MEMPERTAHANKAN
KETERSEDIAAN
FOSFAT.
Siklus P
Kehilangan & Penambahan Ptersedia
Sisa
tanaman
Pukuk
kandang
Bahan
Organik
Tanah
Terangkut
tanaman
Pukuk
komersial
Mineral Ptanah
P-tersedia dalam
tanah
Hilang
Pencucian
Hilang
Erosi
Fiksasi
KETERSEDIAAN
KALIUM
Tanah mineral umumnya mengandung
cukup banyak kalium, kisaran 40 ton setiap
hektar lapisan olah tanah. Namun
demikian hanya sebagian kecil yangtersedia
bagi tanaman
Kehilangan & Penambahan
Kalium:
Sisa tanaman
& Pupuk
Kandang
Pupuk
komersial
Mineral-K
lambat
tersedia
K-tersedia
tanah
Terangkut
tanaman
Kehilangan
pencucian
Kehilangan
erosi
Kehilangan
Fiksasi
The Soil Food Web
In 1 teaspoon of soil there are…
5 or more ------------ Earthworms
Up to 100 ……………. Arthropods
10 to 20 bacterial feeders and a few fungal feeders …….
Nematodes
Several thousand flagellates & amoeba
One to several hundred ciliates ……. Protozoa
6-9 ft fungal strands put end to end ………. Fungi
100 million to 1 billion …………. Bacteria
Classical C Pools
Nonhumic substances—carbohydrates, lipids,
proteins
Humic substances—humic acid, fulvic acid, humin
BOT berpengaruh
terhadap:
-Plant nutrition
-Soil and Plant health
-Soil physical, chemical and
biological
properties
BOT ----- FRAKSI RINGAN
The light fraction (LF) with a density of ~1.6
gm cm-3 is relatively mineral free and consists
of partially decomposed plant material, fine
roots and microbial biomass with a rapid
turnover time.
The LF is a source of readily mineralizable C
and N, accounts for ~50% of total soil C and
declines rapidly under cultivation.
BOT --- FRAKSI BERAT --- The Heavy
Fraction
The heavy fraction (HF) is organic matter
adsorbed onto mineral surfaces and
sequestered within organomineral aggregates.
The HF is less sensitive to disturbance an
chemically more resistant than the LF.
Bacteria vs. Fungi
Bacteria are smaller than fungi and can
occupy smaller pores and thus potentially
have greater access to material contained
within these pores.
Bacteria are less disrupted than are fungi
by tillage practices commonly used in
agriculture.
Bacteria vs. Fungi
Fungi tend to be selected for by plant residues
with high C/N ratios.
Fungi have a greater influence on
decomposition in no-till systems in which
surface residues select for organisms that can
withstand low water potentials and obtain
nutrients from the underlying soil profile.
Bacteria vs. Fungi
Fungi often produce more cell wall than cytoplasmic
material when starved for N, and thus can extend into
new regions of the soil without requiring balanced
growth conditions.
The filamentous growth structure of a fungus permits
it to access C in one location and nutrients in another.
KANDUNGAN BAHAN ORGANIK TANAH
1.
2.
3.
4.
5.
6.
How organic matter in soil influences the soil-plant
relationship?
Decomposed organic matter provides nutrients for plant growth
(Mineralization)
It determines the soil’s temperature, air ventilation, structure and
water management
It contains bioregulators which affects plant growth
It contains bioregulators, which affects plant growth (enzymes,
hormones, etc.)
Its carbon and energy content is the soil’s energy battery for future
use
It determines the soil’s capacity to compensating, regenerating and
protecting the environment regenerating and protecting the
environment
PENTINGNYA BOT
1.
2.
3.
4.
5.
Organic material in the soil is essentially derived from
residual plant and animal material, synthesised by microbes
and decomposed under influence of temperature, moisture
and ambient soil conditions
Soil organic matter is extremely important in all soil
processes
Cultivation can have a significant effect on the organic
matter content of the soil
In essentially warm and dry areas like Southern Europe,
depletion of organic matter can be rapid because the
processes of decomposition are accelerated at high
temperatures
Generally, plant roots are not sufficiently numerous to
replace the organic matter that is lost
MANFAAT BOT
➢ Storehouse for nutrients
➢ Source of fertility
➢ Contributes to soil aeration thereby reducing soil compaction
➢ Important ‘building block’ for the soil structure
➢ Aids formation of stable aggregates
➢ Improves infiltration/permability
➢ Increase in storage capacity for water.
➢ Buffer against rapid changes in soil reaction (pH)
➢ Acts as an energy source for soil micro-organisms
Degradation: HILANGNYA BOT
1.
2.
3.
4.
During field operations, fresh topsoil becomes exposed and
dries rapidly on the surface
Organic compounds are released to the atmosphere result
from breakdown of soil aggregates bound together by humic
materials
Unless the organic matter is quickly replenished, the system
is in a state of degradation leading eventually to unsustainability
The removal of crop residues in dry ecosystems, which are
inherently marginal, can cause such systems to be quickly
transformed from a stage of fragility to total exhaustion and
depletion
FAKTOR YG PENGARUHI BOT
Natural factors:
➢ Climate
➢ Soil parent material: acid or alkaline (or even saline)
➢ Land cover and or vegetation type
➢ Topography – slope and aspect
Human-induced factors:
➢Land use and farming systems
➢Land management (cultivation)
➢Land degradation
FAKTOR IKLIM PENGARUHI BOT:
Temperature:
OM decomposition rapid in warm climates
OM Decomposition is slower for cool regions
Result:
Within zones of uniform moisture and comparable vegetation -Av total OM increases 2x to 3x for each 10 deg C fall in mean
temperature
Moisture:
OM decomposition rapid in warm climates
OM Decomposition is slower for cool regions
Result:
Under comparable conditions
Av total OM increases as the effective moisture increases
Sumber: pgsgrow.com/blog/tag/organic-gardening/
Structure of soil, indicating presence of bacteria, inorganic,
and organic matter
Sumber: www.cartage.org.lb/en/themes/sci...ones.htm
23
PUPUK - PEMUPUKAN
• Fertilizer is one management
option used almost universally
• Must replace soil nutrients lost
by harvest
• Over-fertilization can result in
dangerous pollution
• Technology has increased
fertilizer efficiency
PENGELOLAAN KESUBURAN
TANAH
Goals regarding fertility
–
–
–
–
Increase yield
Reduce costs/unit production
Improve product quality
Avoid environmental
pollution
– Improve environmental
health & aesthetics
TUJUAN PENGELOLAAN KESUBURAN
TANAH
• Efficient land managers: spend
<20% of production costs on
fertilizers, expect >50% increase in
yields
• Fertilizers may not be profitable if:
– Water is the most limiting factor
– Other growth hindrances – insects,
diseases, acidity, extreme cold
– Increased yield has less market value
than the cost of buying/app of
fertilizer
TUJUAN PENGELOLAAN KESUBURAN
TANAH
• Fertilizers – generally most
profitable farm input
• Soil fertility problems
usually the easiest to solve
• Soil nutrients typically
present in finite amounts,
don’t replenish themselves
• Crops typically contain: (in
rank of amount found in the
plant) N, K, Ca, P, Mg, S
TUJUAN PENGELOLAAN KESUBURAN
TANAH
• Utilizing fertilizers may
help cut unit cost of
production by maximizing
yield
– Improved fertility =
improved yields, improved
aesthetic appeal
• Environmental concerns
abound
– Fertilizer laws viewed as lax
by some
– Farmers may be the primary
cause of non-point-source
pollution
TUJUAN PENGELOLAAN KESUBURAN
TANAH
– Three common pollutants:
• Nitrates
– Percolate through to
groundwater
– Not safe to drink
– Cause “Blue-baby” syndrome –
inhibits oxygenation of blood
– Becoming common near
heavily fertilized fields,
feedlots, dairies
• Phosphates
– Pollute surface waters by
runoff
– Promotes algae growth in
rivers/ponds
– Depletes available oxygen in
the water for fish
TUJUAN PENGELOLAAN KESUBURAN
TANAH
– Wise use of fertilizers
must be encouraged,
actually improve the
environment
• Crops, trees, etc. remove more CO2,
decrease sediment, dust,
erosion
• Plays important role for
future of the planet
PENGELOLAAN LAHAN
• Large- & Medium-Scale
Management
– Large-Scale
• Low levels of operational
precision, little reliance on
sophisticated technology
• May be most feasible/profitable
for some
• Simple & low-tech
• Some shy away from high tech
for other reasons
PENGELOLAAN LAHAN
• Disadvantages
– Some parts of field may receive too
much/little fertilizer or pesticide
– Less than optimal yields
– Inefficient use of fertilizers &
pesticides
– Higher cost of production/unit
– Environmental pollution due to over
application
• Advantages
– Minimal technological training &
instrumentation needed
– Field operations can be performed
w/ standard, readily available,
cheaper equipment
PENGELOLAAN LAHAN
– Medium-Scale
• Subdivide field into two+
management units
– Delineation may be based on:
» Soil types
» Past management differences
» Farmer’s observations
• Ex. High, medium, low N
application areas in the field
• Same equipment/technology needs
as for large-scale management
farmers
PENGELOLAAN LAHAN
• Does improve efficiency
of farm inputs
• Can reduce excessive
applications of
chemicals/fertilizers
– May do spot
treatments/applicatio
ns w/in a field due to
field observations
• Small-Scale Management
(Precision Farming)
– Global Positioning System
(GPS) – network of U.S.
satellites w/ a signal
detection system used to
locate positions on the
ground
PENGELOLAAN LAHAN
– Soil sample fields on a grid
– Data collection points no
more than a few feet apart
– Each sample site mapped
using GPS
– Custom applicators can
custom apply fertilizers at
variable rates that change
constantly as the applicator
travels the field – variable
rate application, site-specific
management, precision
farming
PENGELOLAAN LAHAN
– Potential to substantially
decrease
fertilizer/chemical
application rates
– Berpotensi menurunkan
biaya sarana produksi
– Does require expensive
technology, equipment &
extensive technical
knowledge
PENGAMBILAN CONTOH TANAH
Metode baku penentuan
kesuburan tanah
Use w/ precision farming
to minimize inputs
Accuracy of sample is
key!!!!
PENGAMBILAN CONTOH TANAH
• Depth & Number of Samples
– Sampling depth – 7-12” for
typical soil analysis
• Shallower depth for no-till/sod crops
– acid-layer can form at very top of
soil structure
• For accurate N analysis – 24-36”
depth
– For composite sampling – fewer #
samples decreases accuracy of
analysis
PENGAMBILAN CONTOH TANAH
• Sampling Frequency, Time, &
Location
– New land, land new to you –
yearly for 1st few yrs until you
understand the soil
– Every 2-3 yrs, unless concern for
environmental problems
– Analysis – determines which
nutrients can be made available
in the soil & which will need to
be supplied
– Samples often pulled in fall to
provide enough time for
analysis/amendments
PENGAMBILAN CONTOH TANAH
• Spring sampling is more
accurate, but conditions
may not be favorable, or
not sufficient time
– Sampling row crops
problematic
• Can hit a fertilizer zone
• Hard to get enough
representative samples
PENGAMBILAN CONTOH TANAH
• Uniformity of Sampling Areas
– Examine field for differences in
soil characteristics, past
treatments
– PERHATIKANLAH:
•
•
•
•
•
•
•
Uniformity of productivity
Topografi dan relief
Tekstur tanah
Struktur tanah
Drainage
Kedalaman/warna topsoil
Pengelolaan hama-penyakit
tanaman
PENGAMBILAN CONTOH TANAH
– Sampling area
• Each composite sample
should represent <12.5
ac
– Grid sampling can be as
small as you need
– 5-10 ac grids are common
• Providing Detailed Soil &
Cropping Background
– Helps to provide w/ soil analysis
to increase accuracy of fertilizer
recommendations
PENGAMBILAN CONTOH TANAH
– Perhatikan juga hal-hal
berikut:
•
•
•
•
•
•
•
•
Previous crop
Crop (s)) to be grown
Realistic yield goal
Last liming & fertilization
rates
Manure applications
Soil series (if known)
Drainage info
If irrigation used
UJI TANAH = Soil Tests
Law of the Minimum: growth of
the plant is limited most by the
essential plant nutrient present
in the least relative amount
(first-limiting)
• Soil Acidity Evaluation
– pH measured w/ electrode &
solution
– Lime requirement – amount of
lime required to achieve desired
pH
• Reported as buffer pH
UJI TANAH = Soil Tests
Uji tanah untuk N
– No good tests for soil available
N
– Most states provide N
recommendations based on yrs
of field plots trials on various
crops, soils, management,
fertilizers
– N recommendations consider:
•
•
•
•
•
Previous crops
Estimates N carryover
N needed to decompose residues
Projected yields
Climate
UJI TANAH = Soil Tests
– Lab N tests accurate, but
nearly impossible to
interpret
• Some will discourage
N testing
– Behavior of carryover N
unpredictable – can make
analyses invalid
• Leaching
• Denitrification
• Mineralization
• Climate
UJI TANAH = Soil Tests
– N recommendations
based on yield goals
rather than soil reserves
– Corn Rule – 1.21.4#N/bu of yield goal
• How much N should be
recommended for corn
following corn, expected
yield 120 bu/ac?
• How much N should be
recommended for corn
following soybeans,
expected yield 195
bu/ac?
UJI TANAH = Soil Tests
• Soil Tests for P & K
– Widely used to predict
probability of crop response
to fertilization
– Survey:
• 47% soil tested medium to
low for P
• 43% soil tested medium to
low for K
• P & K soil levels
declining in many states
– P testing
• Quite reliable – soil P is
very stable from yr to yr
UJI TANAH = Soil Tests
• Most soil P unavailable to crops
• Soil test extracts & measures
what may actually be available
– K testing
• Tests both exchangeable &
soluble reserves
• Conflicting testing procedures
over which is most accurate
– Some estimate upper
threshold needs ~159246#/ac (above which no
response to K fertilizer)
– Others - 335#/ac on clay
soils (calculated based on
soil CEC – higher CEC =
decreased available K)
– Some experimentation w/ soil probes
checking K, NO3, PO4, SO4
UJI TANAH = Soil Tests
Uji Tanah untuk Ca dan Mg
– Related to need for lime
– Well-limed soils rarely Ca & Mg
deficient
– Mg deficiency more common
than Ca
• Coarse-textured or acidic soils
• Many yrs using non-Mg containing
lime
– Uji tanah untuk Mg :
• Exchangeable soil Mg
• % Mg saturation of soil colloids
• Ratio of K:Mg
UJI TANAH = Soil Tests
Uji tanah untuk S dan B
– S testing inaccurate –
acts much like N
• Can test – but must take
variability into account
– Boron level
recommendations
• <1.0 ppm – deficient for
plant growth
• 1-5.0 ppm – adequate
• >5.0 ppm –
excess/toxicity risks
UJI TANAH = Soil Tests
Uji tanah untuk kebutuhan
hara mikro:
– Difficult to develop accurate
tests due to relatively
infrequent need for field
supplementation
– Can be done, if requested for
a specific need
– Adds expense to soil analysis
UJI TANAH = Soil Tests
• Bagaimana Uji-Tanah yang
bagus?
– Analyses recalibrated
regularly based on field trial
studies
– Validity of analysis related
directly to accuracy of
sample, information provided
to the lab
– Soil analyses generally very
valid for: P, K, soluble salts,
pH, lime
• Other tests should only be
used on as-needed basis
– Extra cost
– Less accurate
ANALISIS TANAMAN
Cara untuk memastikan
ketersediaan hara dalam tanah
Analisis Tanaman vs. Uji Tanah
– Plant most accurate report on
what nutrients are actually
available
– Plant analysis leaves little to no
room for amendments to the soil
– When deficiencies are
acknowledged, yield usually
already affected
ANALISIS TANAMAN
– When is plant analysis most
helpful?
• Treatment of an easilycorrected deficiency
• Long-growing crops: turf, tree
fruits, forests, sugar cane
• Quick Tests in the Field
– Can test for N, K status in plants
• Collect ~20 leaves for sample
– Must be random from
different locations
– Don’t select only affectedlooking leaves
ANALISIS TANAMAN
• Chop/mix, squeeze sap & test
• Most effective for
greenhouse/nursery growers
– Amendments can easily be
made
– High possible economic
losses
• Total Plant Analysis
– Done in a lab
– Should be tested by stage of
development
– Random sampling key
ANALISIS TANAMAN
– Indicate part of plant
sampled & be consistent
– Dry to prevent spoilage
(confounds results)
– Wrap in paper and mail
w/ complete report –
complete history,
information critical
ANALISIS TANAMAN
• Interpreting Plant Analyses
– Accurate interpretation difficult
if not all critical information
provided
– Element classified as deficient if
below threshold nutrient levels
• Levels change through season,
stage of development, etc.
– Some general disagreement from
scientists on what threshold
levels are
ANALISIS TANAMAN
• Critical Nutrient
Range
– CNR – ranges at
which nutrients are:
•
•
•
•
•
Visually deficient
Hidden deficient
Slightly deficient
Sufficient supply
Toxic
ANALISIS TANAMAN
Gejala Defisirensi Hara
– Chlorosis – yellowish to
whitish appearance to
foliage, stem
– Necrosis – dead tissue
– Causes: disease, insect
damage, salt
accumulation, stress,
nutrient deficiencies
– Some visual symptoms
same for many
diseases/deficiencies
ANALISIS TANAMAN
– Nutrients are relocated in the plant
by two pathways
• Xylem – water-carrying vessels
– All nutrients can pass
through
• Phloem – sugar-carrying vessels
– Not all nutrients can
relocate
– Mobile nutrients – travel
freely
– Immobile nutrients – can’t
be moved from their
location in the plant
– Mobile nutrient deficiencies tend to
occur on older leaves – plant
sacrifices old for new tissue
ANALISIS TANAMAN
– Immobile nutrient
deficiencies – symptoms
on shoot/root tips, fruits
• Can’t be treated from the
soil w/ fertilizer – plant
can’t send Ca (ex) to the
ripening fruit
– Mobile nutrients:
• N, P, K, Cl, Mg, S
– Immobile nutrients:
• Cu, Mn, Zn, Fe, Mo, S
– Very immobile nutrients:
• B, Ca
REKOMENDASI PUPUK
Different labs make different
recommendations
Traditional philosophies
being challenged:
• Dosis aplikasi pupuk P
• Rekomendasi N berbasis hasil
tanaman
REKOMENDASI PUPUK
• Menyusun rekomendasi
pemupukan:
– Must have sufficient plot data to
correlate yields & nutrient needs
– Once a general amount of
fertilizer is known:
• Subtract for manure application
• Subtract for residual P or N
• Add/subtract for N, P, S because of
soil organic matter levels – can
count on them supplying some
REKOMENDASI PUPUK
Laporan Uji Tanah
– Labs usually full-service
• Soil, plant, manure,
irrigation water testing
KUALITAS PUPUK
Fertilizer grade – amounts
of N, P, K in a fertilizer
required by law to be
listed
• Also required:
– Weight of material,
manufacturer
• Optional:
– Filler composition, acidity in
soil potential
Menghitung jumlah pupuk
N, P, K
• 10-20-10
• 15-12-18
KUALITAS PUPUK
• Amounts listed as: elemental N,
phosphate, potash (not direct
indication of elemental P, K
supplied)
• Acidity & Basicity of Fertilizers
– Most affect soil acidity in some
regard
• Superphosphate,
Triplesuperphosphate, Potash –
neutral
• MAP, DAP, all N fertilizers –
acidifiers
KUALITAS PUPUK
• Solubility & Mobility in
Soil
– Function of:
• Elemental charge
• Tendency to form
insoluble compounds
• Adsorption ability
• Soil texture
• Water movement
• Concentration of other
ions
KUALITAS PUPUK
– Contoh-contoh
• Mobilitas P dalam tanah snagat
terbatas, hanya beberapa cm
– Pupuk P harus ditempatkan pada zone
jangkauan akar
• N dapat bergerak mengikuti
pergerakan air tanah
PERHITUNGAN PUPUK
• Menghitung pupuk
majemuk / Campuran:
– Mixing 34-0-0 ammonium
nitrate & 0-46-0 TSP to get
1 ton mixture of 15-10-0
• How much of each do we
need?
– How about if we needed a
12-14-6 fertilizer for a
customer?
• What might we use for each
ingredient?
• How much of each would
we need?
PERHITUNGAN PUPUK
• Weights of Fertilizer to
Apply
– Planting corn expected
to yield 125 bu/ac
• How much N do we
need?
• Soil analysis
recommended 88#/ac
phosphate
• How much ammonium
nitrate & TSP do we
need?
• What is our final
application rate?
PERHITUNGAN PUPUK
• Perhitungan yang
melibatkan aplikasi
pupuk cair
– Use dry fertilizer
calculation if sold by
weight
– If sold by volume,
usually applied by
volume
APLIKASI PUPUK
• Starter (Pop-Up) Fertilizers
– Addition of fertilizer w/ the seed
during planting, dribbled in a
strip near the see, banding w/in
2” of seed
– Most beneficial for P, K – some
for N, but not as necessary
– Advantages:
• Cold soils
• Low nutrient levels in the root
zone
• Fast-growing plants
APLIKASI PUPUK
– Disadvantages:
• Slows planting
• Can burn seedling, if placed too
close
• Broadcast Application
– Uniform application across entire
surface
– Left on surface, or incorporated
– Somewhat less efficiency of
fertilizer
• Especially when not incorporated
quickly
• Why?
APLIKASI PUPUK
– Reasons to broadcast:
• Only practical method
of application –
pastures, turf, etc.
• Low-fertility soils
needing high fertilizer
rates
• Easy, cheap, personal
preference
• Flexible – split
applications, ability to
add after crop is
growing
APLIKASI PUPUK
• Deep Banding
– Application of strips
into the soil
– Either between/side of
row, where the seed
may be planted
– Typically 4-12” depth
– Knifing in anhydrous
most common
• Gas able to dissolve in
soil water before it
escapes
• Losses can be high if dry,
sandy
APLIKASI PUPUK
– Disadvantages:
• Strong equipment needed
• High fuel costs
• Danger of dealing w/
anhydrous
– Advantages:
• High yield response
potential
• Puts fertilizer where
most roots are, very
efficient use
APLIKASI PUPUK
• Split Application
– Divided total fertilizer
rates delivered in 2+
applications
– Reasons to split
applications
• If large applications are
needed – increase
efficiency of nutrient use
• Soil conditions dictate –
risk for high nutrient losses
• Control vegetative growth
in early stages
APLIKASI PUPUK
– Advantages:
• Increased efficiency of N
utilization
• Provide a “boost” to the plant
during growth
– Disadvantages:
• Extra pass through field
• Not effective for P, K because
of immobility
APLIKASI PUPUK
• Side-Dressing or
Topdressing
– Side-dressing – surface or
shallow band application
put on after crop is
growing
• Broadcast, surface stripped,
sprayed, knifed
– Principles to consider:
• Decreases potential N losses
• Added in the furrow to
allow water to help w/
infiltration
• Not effective for P, K
APLIKASI PUPUK
• Point Injector Application
– place P, K into soil in the
root zone w/out significant
root damage
– Used more in small plots,
gardens
– Push stick, rod into soil, fill
w/ fertilizer, cover
– Effective for: fruit trees,
grapes, shrubs, etc.
– Not common in field use
APLIKASI PUPUK
• Fertigation – application of
fertilizer w/ irrigation water
– Can apply large quantities of
nutrients
– Very effective for N
• Some see 30-50% more efficient use
of N
• Cut of 50% in N rates w/
same/better yield
– Must be careful of potential
problem w/ salts
APLIKASI PUPUK
1. Mampu memupuk pada
saat puncak kebutuhan
tanaman
2. Immediate/convenient
application
3. Most effective on soils w/
poor nutrient retention &
for mobile nutrients
4. Chemigation also possible
– not discussed in depth
here
APLIKASI PUPUK
Foliar Application – foliage
wetted to maximize nutrient
absorption through leaf
stomata & epidermis
– Feasible for: N supplementation,
pesticides, micronutrients, etc.
– Guidelines:
• Only suited for applications of
small amount (can burn plant)
• Decreased rates can be used
APLIKASI PUPUK
• Need wetting agent to help
the spray to distribute evenly
across surface
• Helpful when root conditions
restrict nutrient uptake
• Quick response/remedy to
deficiency (also short
residual)
• Wind must be calm, humidity
>70%, temp <85° F
APLIKASI PUPUK
• Fertilizing in Paddy &
Other Waterlogged
Soils
– Paddy rice – production
on water covered soils
• Water 2-6” deep
• One of very few crops
that tolerate anaerobic
conditions
– Difficult to fertilize due
to high nutrient loss
risks
EFISIENSI PUPUK
Great focus on increasing
efficiency of fertilizer
use
• Research
• Real-time sensors in
soils that immediately
detect nutrient
deficiency
• Transgenic plants
Fertilizer Efficiency –
fraction/percentage of
added fertilizer that is
actually used by the
plant
EFISIENSI PUPUK
• Typical fertilizer efficiencies:
– 30-70% for N
– 5-30% for P
– 50-80% for K
• Maximum profits rarely at
maximum yields
– Last amounts of fertilizer to produce
more yield cost more than yield
increase
– Management also key
• Use of BMP’s increasing
– Encourage environmental protection
– Couple w/ agronomic success
– Increase economic yields, leading to
sustainable ag
EFISIENSI PUPUK
• Plant Root Systems
– Some plants better
scavengers than others
– Absorption greatly
affected by fertilizer
distribution
– Smaller root system =
shorter growing season =
>dependence on fertilizer
– Growth rates & size also
effect amount of nutrients
demanded
EFISIENSI PUPUK
Gulma:
– Response to fertilizer much
like crops
– N fertilization may increase
weed growth > crop growth
– Application method can also
affect weed growth
• Ex – broadcast fertilizer can
tend to help weeds get good
start
EFISIENSI PUPUK
Interaksi Pupuk dengan Air:
– Availability of nutrients
directed impacted by soil
water content
– Drip fertigation may be
most efficient use of water
& fertilizer
• Common in greenhouses
• Can be effective in field use
– Israeli farming uses drip
irrigation
EFISIENSI PUPUK
Memupuk yang efisien:
– Guides to optimal fertilization:
• Avoid large additions of N or
K (50#/ac +) on sandy soils –
use split application
• Avoid broadcast applications
of urea & ammonia on
warm/moist soils – volatilizes
easily – incorporate
• Avoid N losses on poorly
drained soils by using
ammonium
• Band P
• Menggunakan pupuk starter
EFISIENSI PUPUK
1. Keep N & K fertilizers out
of seedling zone to avoid
burn
2. Reduce leaching by
avoiding application before
rain or irrigation
3. Foliar apply, if
feasible/appropriate
4. Know nutrient demands of
crop
5. Improve management
6. Remember law of minimum
7. Uji Tanah
PUPUK KANDANG
Many benefits of using manure:
• Recycles nutrients
• Potential to reduce
pollution
• Adds C to soil
• Improve aggregation,
infiltration, microbial
vigor
Risks:
• Increased weed pressure
• High cost of
obtaining/applying if you
don’t own it
PUPUK KANDANG
Risiko Pupuk Kandang
• Tidak semudah aplikasi pupuk
buatan komersial
• Ancaman pencemaran air.
• Nutrient Production & Recovery
– Production rates predictable &
measurable
– Ration has heavy influence on
nutrients in manure
PUPUK KANDANG
• Manure & Nutrient
Budgets
– Generous applications of
manure no longer norm
• Some states require &
enforce strict manure
management guidelines
– Restricted application
due to soil P levels
instead of N
– Manure still can’t meet
plant needs alone
• Crops remove much
higher levels of
nutrients/ac
PUPUK KANDANG
Penggunakan pupuk kandang
1. Most recognize advantages of
using manure
2. Manure production unevenly
distributed in farmland
3. Expensive to transport very
far
4. Too abundant in areas, not
enough land for application
PUPUK KANDANG
– Keseimbangan tiga faktor
berikut:
• Supply crop nutrients
• Dispose of waste
• Protect environment
– More focus on manure later