Nitrogen recovery from fertilizer and use efficiency response to Bradyrhizobium sp. and Azospirillum brasilense combined with N rates in cowpea-wheat crop sequence

Author(s):Show less -

Galindo, Fernando Shintate ^[1] ; da Silva, Edson Cabral ^[2] ; Pagliari, Paulo Humberto ^[3] ; Fernandes, Guilherme Carlos ^[1] ; Rodrigues, Willian Lima ^[1] ; Campos Biagini, Antonio Leonardo ^[1] ; Baratella, Eduardo Bianchi ^[1] ; da Silva Junior, Castro Alves ^[1] ; Moretti Neto, Mario Joao ^[1] ; Silva, Vinicius Martins ^[1] ; Muraoka, Takashi ^[4] ; Minhoto Teixeira Filho, Marcelo Carvalho ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Dept Plant Hlth Rural Engn & Soils, Coll Engn, BR-15385000 Ilha Solteira, SP - Brazil

^[2] Goiano Fed Inst, Rio Verde Campus, BR-75901970 Rio Verde, Go - Brazil

^[3] Univ Minnesota, Southwest Res & Outreach Ctr, Dept Soil Water & Climate, Lamberton, MN 56152 - USA

^[4] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13416000 Piracicaba, SP - Brazil

• Document type: Journal article
• Source: APPLIED SOIL ECOLOGY; v. 157, JAN 2021.
• Web of Science Citations: 0

Abstract

A better understanding of nitrogen (N) behavior and agronomic practices is needed to improve biological nitrogen fixation (BNF) and N use efficiency under field conditions. This study aims on investigating the potential for the use of biological agents that can fix atmospheric N and are related to multiple mechanisms benefits to improve cowpea (Vigna unguiculata (L.) Walp.) development and productivity, leading to a positive residual effect on wheat (Triticum aestivum L.) development. The study was set up under a no-till system in a Rhodic Haplustox, in a randomized complete block design, with four replicates. Treatments were tested in a full factorial design and included: i) three types of inoculation (without inoculation - control; Bradyrhizobium sp. inoculation (strains SEMIA 6462 and SEMIA 6463) - the conventional inoculation of cowpea; and Bradyrhizobium sp. combined with A. brasilense (strains Ab-V5 and Ab-V6) - the co-inoculation); and ii) five N rates (0 to 160 kg N ha(-1)) applied as urea-N-15 isotope. The residual effects of inoculations and N application rates applied during the cowpea growing season were evaluated on wheat (successor crop). Co-inoculation was found to increase cowpea grain yield by 40.5% and 14.1% compared to the control and Bradyrhizobium sp. inoculation when N was omitted and up to 37.6% and 50.8% when N was applied. Coinoculation increased N use efficiency, N recovery and N accumulation on cowpea, leading to improved crop growth. The co-inoculation also provided a positive residual effect on wheat resulting in increased plant N accumulation, crop development, and greater wheat grain yield compared to the control (increase of 7.8%) and Bradyrhizobium sp. inoculated plants (increase of 5.8%). Co-inoculation was found to increase N use efficiency on cowpea by 216.5% and 35.5% and on wheat by 159.3% and 29.5% compared to control and Bradyrhizobium sp. inoculation, respectively. The fertilizer N recovery was, on average, 22.2% by cowpea, while fertilizer N recovery by wheat was < 2.3%. The percentage of N accumulated on cowpea was on average 30.8%, while the residual cowpea N contribution to wheat provided by co-inoculation was 18.6%. This study showed positive improvements in cowpea-wheat growth production parameters and N management as a result of co-inoculation, indicating that there is an opportunity to reduce N fertilizer input with the combined use of biological agents that promote plant growth and chemical fertilizers. (AU)

• FAPESP's process: 18/08485-7 - Nitrogen management in cowpea bean, wheat and corn: effects on plant nutrition, grain yield, and nitrogen use efficiency
• Grantee: Fernando Shintate Galindo
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate