Quality of soybean seeds in response to nitrogen fertilization and inoculation with Bradyrhizobium japonicum 1

Alan Mario Zuffo,Natália Trajano De Oliveira,Everton Vinicius Zambiazzi,Alan Eduardo Seglin Mendes,Joacir Mario Zuffo Júnior,Fábio Steiner,Aécio Busch

doi:10.1590/1983-40632018v4851638

Abstract

ABSTRACT Nitrogen fertilization may interfere in the quality of soybean seeds. This study aimed to determine the physiological and sanitary quality of soybean seeds, in response to levels and times of nitrogen (N) application associated with Bradyrhizobium japonicum inoculation. Treatments were arranged in a randomized block design, in a 2 × 3 × 4 factorial arrangement [two soybean cultivars (BRS 1074 IPRO and ST 797 IPRO), three application times (sowing, 30 and 50 days after emergence) and four N levels (0 kg ha-1, 20 kg ha-1, 40 kg ha-1 and 60 kg ha-1), with four replicates. The 1,000-seed mass, moisture content, germination rate, seedling height, shoot length, primary root length, total seedling dry matter, electrical conductivity, mechanical damage, vigor and viability (tetrazolium test) and sanitary quality of the seeds were measured. The use of mineral N, associated with the inoculation of B. japonicum bacteria, does not prove to be consistent, in terms of its effects on the physiological quality of soybean seeds, although the incidence of pathogens may be reduced.

Highlights

Soybean [Glycine max (L.) Merrill.] is one of the most important oilseed crops in the world, with Brazil being one of the largest producers and occupying an important position in the agricultural economy
The absence of significant interaction among the studied factors indicates that the soybean cultivars have a similar response to the different levels and times of the N fertilizer application
The results showed significant effects among soybean cultivars for the variables seed germination, shoot length, primary root length, seedling dry matter, electrical conductivity and vigor (Table 1)

Summary

Introduction

Soybean [Glycine max (L.) Merrill.] is one of the most important oilseed crops in the world, with Brazil being one of the largest producers and occupying an important position in the agricultural economy. In the 2017/2018 growing season, the soybean production area was 35.2 million hectares, resulting in 119.0 million tons of grains (Conab 2018). Due to its economic importance, it is crucial that soybean seed growers produce high-quality seeds to ensure more vigorous seedlings and the successful establishment of plants in the field (Zuffo et al 2017a). The use of fertilizers is more common than in grain production fields.

Objectives

Methods

Results