Let’s have a short insight on inoculant products.
- One of the most important characteristics of a good inoculant is its concentration (titre of alive bacteria per gram or milliliter). There have been conducted many trials in different countries to define optimal concentration and to understand its correlation with yield of soybeans. These trials show that in order to get good inoculation results each seed should get from 100 thousand up to 1 million bacteria. The number depends on whether there has been a history of soybean growing or not in the country. In countries new to soybeans the absolute minimum should be 1 million bacteria per seed. It is so called optimum that ensures good yields even at unfavorable weather conditions.
That’s why it is not a good idea to save on inoculants and use cheap low concentrated ones (1-2 milliard/ml) if you do not have a history of soybeans in your fields.
You take a risk not to see any nodules using low concentrated inoculants (especially without extenders or protectors) if:
– you tank mix inoculants and chemical treatments;
– there is a long draught at sowing or during vegetation;
– there are excessive precipitationsat sowing or during vegetation;
– pH levels are lower than 5,5 or higher than 7,5;
– you apply generic soil herbicides or use some micronutrients which can be harmful to bacteria (molybdenum or cobalt).
There are some suppliers who play with rates and recommend you decreased rates per T of seeds of already low concentrated inoculants. It seems that you pay them less per ton of seeds but if you do your math, you will see that you overpay per active ingredient in 1 ml or gram. Moreover, you take a risk to get low yields and lose your profits in the end.
If you buy a highly concentrated inoculant (1х10¹⁰) with a Bioprotector (on seed survival 90 days) for treating 1 T of seeds at a rate of 2,5/T it will cost you only 1,7 times more than if you bought a low concentrated (2x 10⁹) inoculant with an extender for max 21 day on seed survival.
Very often suppliers of low concentrated inoculants recommend risky rates which are 1,5 times lower than the optimum!
In other words, buying an inoculant with 5 times less bacteria and applying it at a rate 1,5 times less than needed, you get 6,5 less bacteria per ton of seeds.
In the end you overpay for the active ingredient and take high risks not to get sufficient yields.
Another important factor while selecting a right inoculant is type of bacteria and their strains.
There are inoculants with one strain inside (HiCoat®Super, HiStick® – Bradyrhizobium japonicum strain: C 532) or with several strains (AgriBacter® and RhizoFix® – Bradyrhizobium elkanii strains U1301 and U1302).
There are inoculants with different bacteria (BioBoost®+ (Liquid) –Bradyrhizobium japonicum a N-fixing and Delftia acidovorans – phosphorus mobilizing and growth promoting).
Different strains have different modes of action. The more strains there are in the product the higher probability that it will work under stressful weather conditions.
Methods of inoculation
In furrow application
The best way to apply inoculants is in furrow application: rate of AgriBacter® (or HiCoat®Super) from 12,5 up to 25 ml of the mixture per 500 m of the row
1,4 L/ha (row width = 35 cm)
1,1 L/ha (row width = 45 cm)
0,71 L/ha (row width =70 cm)
Total slurry with water may reach 30-50 L/ha
This method is most efficient as bacteria get directly into the soil without contacting chemical slurry; bacteria do not desiccate neither are they exposed to direct sun light.
Seed planters with applicators for liquid fertilizers can be used for in furrow inoculation.
Instruction for in furrow inoculation while uploading soybean seeds through a screw auger
1. Remove bag from box.
- Attach applicator cap and tubing (application kit sold separately).
- Hang bag and calibrate.
- Proper rate of the inoculant is when seed first becomes properly coated and glistens.
- Initially calibrate the inoculant flow below the recommended rate, and then increase to proper rate.
- Operate the auger at half capacity for best mixing.
Inoculation with continuous flow mobile treaters (with G3 applicators)
If you treat your soybean seeds with fungicides or insecticides then the best inoculant formulation for you is liquid pre-inoculant (with extender of Bioprotector). It will work well if tank mixed with original chemicals because extender protects bacteria against harmful influence of chemical active ingredients.
Today there are mostly auger type seed treatres (like PS) in Ukraine. But within the last several years you can also find Canadian mobile seed treating systems on the market. They consist of applicators with nozzles for spraying liquid product on seeds. The machines can easily be integrated into overhead seed bins existing at farms, or can be attached to any conveyor belts, bucket elevators (like Fadeyev bucket elevator made in Ukraine).
G3 Treating system can accurately apply chemical treatments and inoculants through different nozzles, so that 2 products meet only on top of seeds. It works for many different types of seeds.
Its optimum throughput is 15-45 т/h.
Wet inoculation method
“Agritema” together with “KTEP” Melitopol machinery producer have elaborated a new modification of mobile auger type seed treater PSH 3-02 which allows applying thick liquid products onto seeds. This treater is the best option for applying wet peat inoculants in a slurry.