Integrated Nutrient Management focuses on conserving and efficiently using nutrient sources, both natural and manufactured. It aims to increase crop productivity in an environmentally friendly way without compromising future soil productivity. Key components include balanced fertilizer application, nutrient conservation practices like terracing and mulching, and utilizing untapped nutrient sources like urban organic waste and nitrogen fixation. Genetic research also offers opportunities to enhance internal nutrient sources through modifying plants and microorganisms. Overall, Integrated Nutrient Management seeks to optimize nutrient cycling and minimize external input usage.

1. MANAJEMEN KESUBURAN
TANAH
Materi 11: Pengelolaan Hara
Terpadu

2. Landasan
Penurunan kesuburan tanah dan salah kelola unsur hara tanaman
menyebabkan upaya menyediakan makanan untuk penduduk dunia
pada tahun 2020 dan selanjutnya menjadi lebih sulit.
Konsekuensi negatif dari kerusakan lingkungan, keterbatasan
lahan, tekanan jumlah penduduk, dan kekurangan kelembagaan
serta terbatasnya pemahaman proses biologi yang diperlukan
untuk mengoptimalkan siklus unsur hara, meminimalkan
penggunaan input luar, dan memaksimalkan efisiensi penggunaan
input, khususnya di bidang pertanian tropis.

3. Landasan
Tetapi beberapa upaya masih dapat dilakukan untuk
menghadapi kesulitan tersenut. Upaya tersebut dilakukan
melalui pendekatan pengelolaan hara terpadu (PHT).
Pelaksanaan PHT memerlukan upaya bersama para
pelaku dari berbagai sektor, termasuk sektor swasta dan
publik, lembaga ilmiah dan kebijakan, serta Negara-
negara industri dan negara-negara berkembang.

4. Tujuan PHT
mengintegrasikan penggunaan semua unsur hara dari sumber
alam dan buatan manusia, sehingga produktivitas tanaman
meningkat dengan cara yang efisien dan ramah lingkungan,
tanpa mengorbankan produktivitas tanah generasi
mendatang.
PHT bergantung pada sejumlah faktor, termasuk aplikasi unsur
hara yang tepat dan konservasi serta transfer pengetahuan
tentang praktik PHT kepada petani dan peneliti

5. Aplikasi Hara Tanaman
Aplikasi pupuk yang berimbang dan tepat adalah komponen
utama dari PHT.
Aplikasi pupuk yang berlebihan, walaupun murah bagi petani
Negara maju, dapat memacu, tidak menyebabkan serapan
hara tanaman meningkat dan tidak memberikan hasil yang
tinggi.
Pemupukan berimbang juga harus mencakup unsur hara
makro sekunder dan unsur mikro, yang keduanya sering
banyak tersedia dari pupuk organik seperti kotoran hewan
dan pupuk hijau.

6. Konservasi dan Serapan Hara
Konservasi hara di dalam tanah adalah komponen penting lain dari
PHT.
1. praktek-praktek seperti terasering, alley cropping, dan pengolahan
tanah minimum mengubah lingkungan fisik tanah sehingga
kehilangan tanah dan unsur hara dari gerusan air.
2. aplikasi mulsa, tanaman penutup, tumpangsari, dan penambatan
nitrogen secara biologi berperan sebagai penghalang angin dan erosi
air dan membantu untuk meningkatkan karakteristik tanah dan
struktur tanah.
3. pupuk organik seperti kotoran hewan dan pupuk hijau juga
membantu konservasi tanah dengan memperbaiki struktur tanah
dan mengisi kembali unsur hara sekunder dan unsur mikro.

7. Integrated Nutrient Management:
Nutrient Conservation and Uptake
 Most crops make inefficient use of N
 Volatilization of ammonia into the atmosphere can account for a
large share of the lost N. In flooded rice, volatilization can cause
20-80 % of N to be lost from fertilizer sources
 How to recudes losses ?.
 Deep placement of fertilizers in soil provides a physical barrier that
traps ammonia.
 The use of inhibitors or urea coatings that slow the conversion of urea
to ammonium.
 better timing, and more concentrated fertilizers, nutrient uptake
efficiency can be expected to improve by as much as 30%

8. Sumber Hara Tidak
Termanfaatkan
daur ulang sampah organik dari perkotaan ke daerah
pedesaan merupakan potensi sumber unsur hara bagi
pertanian dan kebutuhan tanaman, terutama pada lahan
pertanian di dekat pusat-pusat perkotaan.
contoh, air limbah yang tidak diinginkan lingkungan telah digunakan untuk
mengairi ladang dan mengemabalikan unsur hara dan bahan organik ke
tanah.
Seperti pupuk organik, lumpur limbah perkotaan merupakan sumber unsur
hara utama, meskipun relatif miskin dibandingkan dengan pupuk komersial.
Lumpur dan limbah perkotaan biasanya mengandung sekitar 3,3 persen
nitrogen, fosfor 2,3 persen, dan 0,3 persen kalium, meskipun mencapai
setinggi 10 persen nitrogen dan fosfor 8 persen pada basis berat kering.

9. Integrated Nutrient Management:
Untapped Nutrient Sources
 If used appropriately, the recycling of organic waste from urban to rural
areas is a potential, largely untapped, source of nutrients for farm and
crop needs
 Like organic manure, urban waste sludge is a source of primary
nutrients.
 Stabilized municipalwaste sludge typically contains about 3.3% N, 2.3%
P, and 0.3% K
 Benefits:
 improve soil structure
 a source of the secondary nutrients and micronutrients
 transforms material that would otherwise be slated for costly disposal
into a useful farm product

10. Integrated Nutrient Management:
Untapped Nutrient Sources
 Urban waste needs to be treated carefully because it may
contain heavy metals, parasites, and other pathogens.
 Monitoring is needed to ensure that heavy metal and overall
nutrient concentrations do not reach toxic levels and do not
damage the environment through leaching and eutrophication.
 Urban waste also contains organic compounds such as dyes,
inks, pesticides, and solvents that are often found in commercial
and industrial sludge: causing genetic damage, while others,
such as bacteria, protozoa, and viruses can cause
salmonellosis, amoebic dysentery, and infectious hepatitis

11. Integrated Nutrient Management:
Internal Nutrient Sources
One option is to compost the sludge: helping to kill
disease-causing organisms, slow the release of
nitrogen that might otherwise percolate into
groundwater, and eliminate aesthetically
objectionable odors
Effective use of urban waste is hampered by its high
water content, bulkiness, distance from rural areas,
contamination with nondecomposable household
items, and high handling, storage, transport, and
application costs.

12. Integrated Nutrient Management:
Internal Nutrient Sources
 Genetic engineering offers the potential for plants themselves to
generate some of the nutrients they require through nitrogen
fixation. In this process, rhizobium bacteria infect, invade, and
draw energy from leguminous plants, and in return the bacteria
convert and store atmospheric nitrogen in a form that the plant
can use for growth
 Besides helping the plants themselves, cereals grown in rotation
with leguminous plants can absorb the nitrates released from the
decaying roots and nodules of the leguminous plants.
 Experiments have shown that ricelegume rotations can result in
a 30 percent reduction in chemical fertilizer use

13. Integrated Nutrient Management:
Internal Nutrient Sources
 Genetic research offers the opportunity of altering or developing
microorganisms that can fix nitrogen in non-leguminous plants,
such as cereals.
 Some 17 genes code the enzymes involved in nitrogen fixation.
Since these genes, as well as the genes necessary for nodule
formation, need to be transferred, the process is complex and its
realization will be costly.
 Because the amount of energy required to fix 150 kg N/ha could
reduce wheat yields by 20-30%, an appropriate balance needs
to be found between the nutrient-supply-enhancing benefits of
nitrogen fixation and the potential reduction in yields

14. Akhir materi 11