Cultivated molybdenum plants are in the form of molybdate (MoO42-) and molybdenum oxide (MoO3) salts.
1. Effect of Mo on the physiological biochemistry of plants.
Mo plays an important role in many biochemical physiological processes in the plant: nutrient uptake (nitrogen fixation, nitrogen fixation and denitrification), respiration (oxidation – reduction) of photosynthesis (chlorophyll activation and CO2 initiation). Glutamate metabolism, new organ formation, stem formation, rooting, and tolerance.
The effect of Mo is found in many plants, first of all legumes, cruciferous vegetables (cabbage, cauliflower), cucurbits (melon, cucumber, cucurbits), Vegetables such as tomatoes, potatoes, oilseeds: peanuts, soybeans, sunflower and nitrogen fixing plants: algae, dahlia.
Mo is a catalyst in the fixation and utilization of plant protein, which is a component of nitrifying and nitrogens. Mo needs very little, just a few grams per 1,000 m2 but Mo deficiency has serious consequences such as deformation in broccoli.
Expression of Molybdenum-deficient plants:
Lack of leaves, green to yellowish gold, yellow spots, spots all over the leaf surface (except the veins), the bottom of the leaves secrete the resin.
Lack of molybdenum, yellow spots appear in the middle of the veins of the lower leaves, if lack of weight, these spots are widespread and dry, leaves edges also dry, less developed trees.
Mo is the only micronutrient that often occurs in the absence of acidic soils.
The Mo deficiency symptoms of the plant are similar to the lack of protein and are usually expressed in the middle leaves and the old leaves. In the absence of Mo leaves, the legumes turn yellow, the stem and leaves are violet, the nodules are small. Other species of leaves are also yellow, the leaves are narrow and bent as the leaves are worm and dry.
Symptoms of Mo deficiency in bananas, apples, potatoes and carrots
Mo deficiency in the middle of the lower leaves have yellow spots, followed by necrotic leaf edges and folded leaves, leaves are twisted and fallen stem. In vegetables, the leaf tissue is wilted, leaving only the middle of the leaves and some small leaves. Mo deficiency is most apparent in legumes, poorly planted trees, reduced nodulation, and limited nitrogen fixation.
Mo in the soil:
The amount of Mo in the soil is very low, typically around 2 ppm, usually in the 4,5,6 chemistry or in the cationic with 2,3 chemistries. Under acidic conditions, molybdates (MoO4) are absorbed by soil glue. It is also explained that Mo changes into indigestion when acidic conditions are associated with iron, aluminum, and titanium. And under sour conditions, Mo2O5 and MoO2 oxides turn very slowly into MoO3 and into molybdate.
When fertilizing multiple times, plants absorb more Mo. In contrast, more sulfate salts, the less Mo. This may be because two SO42- and MoO42- ions have the same size and electrical charge and may also be due to sulphate fertilization which makes the soil more sour.
2. Types of raw materials for the production of Mo fertilizer.
These salts are usually mixed with phosphate to form phosphate containing Mo or mixed with NPK.
People often use salt containing Mo to fertilize the soil by mixing with other fertilizers, or manure, the amount of fertilizer 100 – 200 g / ha. On the market often use supe phosphate containing 0.2% Mo.
2.1. Sodium molybdate (Na2MoO4.2H2O).
– White crystals.
– Contains 39 – 46% Mo.
2.2. Molybdenum (IV) oxide (MoO3)
– Contains 66% Mo.
2.3. Ammonium molybdate (NH4) 6Mo7O24.4H2O.
– Contains 81.5% Mo.
2.4. Minerals: Minerals used to produce Mo are MoS2 molybdenite and calcium and lead molybdates.
2.5. Industrial wastes: Waste lamps for electric lamps can also be used as Mo materials.