Nodulation and vegetative growth in soybean under different ways of applying liquid inoculant

Abstract

The inoculation is one of the main cultural practices in leguminous crop such as soybean, providing economy of resources on high doses of mineral nitrogen. The objective of this work was to verify the effect of different ways of applying liquid inoculant on soybean. The experimental design was randomized blocks, in a total of 10 treatments with 5 replications. The treatments were: application of liquid inoculant on the seeds, on the soil, inside de seeds, with the aid of a syringe, besides the application via foliar on the vegetative stages V1, V3, V5 and V8, in addition to treatments with nitrogen fertilization. The treatments did not affect the total number of leaves, chlorophyll index and the number of nonviable nodules. For plant height the inoculation inside the seed, on the soil or via foliar in V3 stage provided the best results. For foliar area and dry mass of aerial part and root the use of mineral nitrogen harmed the crop, it had no inoculation effect compared to the witness treatment. The nitrogen supply harmed the stem diameter and the different ways of inoculation were superior to the witness, except the foliar application in V8 stage. Independent of the way, the inoculation caused an increase in the total number of nodules, being superior to the witness and the use of nitrogen, which did not differ between them. Only the application of mineral nitrogen impaired the number of viable nodules, not having difference of the witness in relation to the treatments with inoculation.