Potassium, Calcium and Magnesium -Cycle

Calcium Potassium and Magnesium

Cycle

KALIUM (POTASSIUM)

•Berperan pada metabolism•Meningkatkan ketahanan terhadap kerebahan•Meningkatkan ketahanan terhadap hama-penyakit•Meningkatkan ketahanan terhadap situasi embun•Berperan dalam mengatur penyerapan air•Berperan dalam metabolism N•Meningkatkan kualitas tanaman

Potassium• Unique because it isn’t incorporated into some

molecule in the plant. It exists in its ionic, K+ form, in solution in cytoplasm

• Tissue levels of 1.5 - 4.0%• Functions as a catalyst for biochemical reactions• Functions in maintaining turgor• Functions in carbohydrate synthesis• Deficiencies hard to diagnose

Potassium

• Functions• Used to form carbohydrates &

proteins.• Formation and transfer of starches,

sugars, & oils.• Increases disease resistance, vigor, &

hardiness.

Potassium

• Deficiency Symptoms• Mottled, spotted,

streaked or curled leaves.

• Scorches, burned, dead leaf tips & margins.

Adequate PotassiumAdequate Potassium Increases root growth Increases disease and environmental stress

tolerance (?) Increases wear tolerance It sounds like a magic elixir! But the

beneficial effects are realized only when compared to K deficient conditions. There is little benefit from adding K to an already sufficient soil!

Diserap tanaman dalam bentuk Ca+2

Berasal dari mineral seperti kalsit CaCO3

Berfungsi untuk mengeraskan batang serta merangsang pembentukan biji-bijian

Kekurangan kalsium menyebabkan proses pembelahan sel terhambat, daun keriput dan tanaman lemah

Calcium enters from biosphere in dust or from organisms

Like phosphorous, there is no gaseous state so it does not stay in the atmosphere

When animals die, the calcium in their bodies are decomposed and go into soil

Water can carry calcium to or from soil through weathering

When in the soil, calcium is in an insoluble form until it is broken down by microbes into a usable form

Mineralization can store calcium in rocks Calcium can be returned from root

leakage Calcium can be absorbed by plant roots

When absorbed by plants, calcium is now in an organic state

The calcium can continually be recycled between the plant roots and soil

OR herbivores can eat the plants or drink the water and the calcium returns to the biosphere

If the plant or animal dies, decomposers break down the organism and calcium is returned to water or soil

Calcium is a mineral necessary for life In early life, calcium helps build strong

bones and teeth Helps with muscle contraction and

other body processes Plants need calcium to help in cell wall

development and their metabolism; stronger cell walls protect from pathogens

• Form taken up by plantsCa+2

• Mobility in Soil

No, slight mobility in soil solution • Mobility in plant

Movement occurs in xylem to the leaves (one way ticket)

• Role of nutrient in plant growth:

Required for cell wall rigidity, cell division of meristems and root tips, normal mitosis, membrane function, acts as a secondary messenger, aids in storage of phosphates in vacuoles, actively involved in photosynthesis and found in the endoplasmic reticulum

• Role in microbial growth:Needed for Rhizobium and Azotobacter

• Interactions with other nutrients: – Since Ca+2 is so directly related to pH in solution, it

effects all of the other nutrients. When NO3-N is applied to soil, Ca+2 absorption increases in the plant. Increases in Ca+2 in soil decreases Al+3 in acid soils, as well as decreasing Na+ in sodic soils. Increases in Ca+2 taken up by plants cause deficiencies of Mg+2 and K+. MoO4

-2 and H2PO4-

availability increases with increases in Ca+2 concentrations.

• Concentration in plants:– Fresh weight of plants typically contains 0.1-5.0%,

can contain up to 10% dry weight in leaves before plant experiences toxicity

• Deficiency symptoms:

– First seen in the younger leaves of plants, loss in plant structure, under extreme deficiencies gel-like conditions, root development no longer takes place, stunted plant growth

• Content present in soils:– Tropical soils: 0.1-0.3%– Temperate soils: 0.7-1.5%– Calcareous soils: >3.0%– Largely dependent on parent material of soil and

rainfall

Main Cycle More Info

• Effect of pH on availability:Depends on mineral

• Sources of Calcium: – Lime (CaO) (Ca(OH)2), Calcite (CaCO3), Dolomite

(CaMg(CO3)2, Gypsum (CaSO4.2H2O), any

Phosphorus fertilizer, Anorthite (CaAl2Si2O3),

biotite, apatite, augite & hornblende.

Calcium deficiency sympton Calcium deficiency symptoms appear initially as

localized tissue necrosis leading to stunted plant growth, necrotic leaf margins on young leaves or curling of the leaves, and eventual death of terminal buds and root tips. Generally, the new growth and rapidly growing tissues of the plant are affected first. The mature leaves are rarely if ever affected because calcium accumulates to high concentrations in older leaves

Apple 'Bitter pit' – fruit skins develop pits, brown spots appear on skin and/or in flesh and taste of those areas is bitter. This usually occurs when fruit is in storage, and Bramley apples are particularly susceptible. Related to boron deficiency, "water cored" apples seldom display bitter pit effects.

FertilizerCa(NO3)2

CaSO4*2H2OAll P Fertilizers

LimeCaO, Ca(OH)2

CaCO3

CaMg(CO3)2

OtherShellsSlagMarl

Moisture

Dissolution pH of Soil

Temporarily held on exchange sites, but tightly held on charged soils

Calcium MineralsLime, Calcite, Dolomite, Gypsum, Florapatite, Plagioclases, Gabbro, Basalts

LeachingCaCl2, CaSO4

Major Form

Moisture

Plants

Animals

Mining

Weathering(dissolution)

Decomposition of Plantand Animal Residues

Movement of calciumIn the presents of moisture

Moisture

Ca2+ removed As plant matter 4x in leaves vs. grain

Uptake decreases withPresence of high Al3+

Soil Microbes

Higher availability of Ca2+

Improves uptake of NH3

MAGNESIUM (Mg)

PENDAHULUAN

Magnesium merupakan nutrisi utama sekunder bagi tanaman.Magnesium dalam tanah terdiri atas magnesium yang terkandung dalam lempung dan partikel organik dalam tanah, dan magnesium yang larut dalam air.

Magnesium diambil oleh tanaman sebagai ion magnesium (Mg2+). Ini berperan kunci di dalam

proses fotosintesis

merupakan bahan yang penting untuk klorofil, pewarna hijau pada daun dan dahan.

Juga mrp bagian dari enzim nitrogenase.

Kehadiran kation lain dalam tanah, atau penggunaan pupuk buatan dapat menyebabkan penurunan penyerapan magnesium oleh tanaman, misalnya kalsium (Ca2+), potassium (K+), soda (Na+) dan amonium (NH4+).

Oleh sebab itu, diperlukan masukan berupa pupuk Mg untuk mendukung pertumbuhan tanaman.

Animalmanures

and biosolids

Mineralfertilizers

Crop harvest

Runoff anderosion

Leaching

Soil solution potassium (K+)

Plant residues

Plantuptake

Mineralpotassium

Fixedpotassium

Exchangeable potassium

Input to soilComponent Loss from soil