Inoculant is used to help various legumes produce their own nitrogen. The pea is a legume and can use the nitrogen released in the root nodules by the nitrogen fixing bacteria. Inoculate pea seed if it is the first time planting on a specific soil. Inoculate the seed if the soil has not been planted with peas for at least 5 years. The inoculation of peas with nodule bacteria boosts the crop significantly. It is reported that in some cases yield increase can be up to 100% compared to peas that were not inoculated. Using the wrong incolant can have no effect too. Soils with high organic content will have lower effect or reaction to an inoculant. In most cases it is poor soils that give the best results. Better results have also been found on acid soils compared to neutral pH soils.
Always use the correct Rhizobium specie as there is a special inoculants for each legume. Obtain the inoculant in South Africa or in the country where you farm. Never import an inoculant as it may carry bacteria of fungi that is a threat to your area. It can have devastating consequences.
The average dosage rate for peas are 250g per 25kg of seed. Inoculation must be done immediately before planting. When treating seed a sticker should be used and seed must be dried in the shade before planting. Do not plant wet seed. it is important not to dry the seed in the sun. The application rate of the inoculant should be doubled it the seed is also treated to control certain soil pathogens. Seed dressing tends to make the inoculant less effective. Increase dosage to 500g per 25kg of seed.
Inoculants are very cheap but labour intensive. Many growers prefer to add a little extra nitrogen in the form of fertilizers than use an inoculant. I always think a little natural help with bacteria can do more good than harm does from increasing the salt content of the soil.