TY - JOUR

T1 - Competition of plants and microorganisms for added nitrogen in different fertilizer forms in a semi-arid climate

AU - Koch, Markus

AU - Akshalov, Kanat

AU - Carstens, Jannis Florian

AU - Shibistova, Olga

AU - Stange, Claus Florian

AU - Thiedau, Simon

AU - Kassymova, Alfiya

AU - Sauheitl, Leopold

AU - Meinel, Tobias

AU - Guggenberger, Georg

N1 - Funding Information: Acknowledgments: We thank the team Soil Biology and Plan Nutrition of the University of Kassel for giving us the opportunity to conduct the chloroform fumigation extraction in their laboratory and for measuring these extracts. We are also grateful to Frank Schaarschmidt from the Institute of Biostatistics of the Leibniz University Hanover for helping us to develop the model used to account for spatial sampling. The publication of this article was funded by the Open Access Fund of the Leibniz Universität Hannover.

PY - 2021/12

Y1 - 2021/12

N2 - In nitrogen (N)-limited agricultural systems, a high microbial immobilization of applied fertilizer-N can limit its availability to plants. However, there is scarce information on the effect of the form of fertilizer used on the plant–microorganism competition in clay-rich soils under a severe semi-arid climate. In a field study, we investigated the wheat–microorganism competition after the direct application of NH415 NO3 closely to seeds in arable fields in North Kazakhstan, documenting the effect of the use of liquid versus granular fertilizer and mini-tillage versus no-tillage. Our results barely showed any fertilizer-N translocation in the soil. Plants outcompete microorganisms for fertilizer-N during the vegetation period. Microbial-to-plant15 N ratios revealed a predominant fertilizer-15 N uptake by plants. The strong competition for N was mainly related to the placement of the fertilizer close to the seeds. Moreover, the long time interval between fertilization and sampling enhanced the competition for N, meaning that previously microbially immobilized N became available to plants through the death of microorganisms and their subsequent mineralization. The fertilizer distribution between microorganisms and plants did depend on the form of fertilizer used, owing to the good solubility of granular fertilizer. The smaller fertilizer-N uptake under the no-tilling condition was probably due to the more intense soil compaction, which caused a reduction in plant growth. The application of fertilizer close to the seeds and the small fertilizer translocation during the vegetation period ultimately resulted in a high level of plant N being derived from the fertilizer.

AB - In nitrogen (N)-limited agricultural systems, a high microbial immobilization of applied fertilizer-N can limit its availability to plants. However, there is scarce information on the effect of the form of fertilizer used on the plant–microorganism competition in clay-rich soils under a severe semi-arid climate. In a field study, we investigated the wheat–microorganism competition after the direct application of NH415 NO3 closely to seeds in arable fields in North Kazakhstan, documenting the effect of the use of liquid versus granular fertilizer and mini-tillage versus no-tillage. Our results barely showed any fertilizer-N translocation in the soil. Plants outcompete microorganisms for fertilizer-N during the vegetation period. Microbial-to-plant15 N ratios revealed a predominant fertilizer-15 N uptake by plants. The strong competition for N was mainly related to the placement of the fertilizer close to the seeds. Moreover, the long time interval between fertilization and sampling enhanced the competition for N, meaning that previously microbially immobilized N became available to plants through the death of microorganisms and their subsequent mineralization. The fertilizer distribution between microorganisms and plants did depend on the form of fertilizer used, owing to the good solubility of granular fertilizer. The smaller fertilizer-N uptake under the no-tilling condition was probably due to the more intense soil compaction, which caused a reduction in plant growth. The application of fertilizer close to the seeds and the small fertilizer translocation during the vegetation period ultimately resulted in a high level of plant N being derived from the fertilizer.

KW - N

KW - Ammonium nitrate

KW - Granular fertilizer

KW - Liquid fertilizer

KW - Mini-till

KW - No-till

UR - http://www.scopus.com/inward/record.url?scp=85121664904&partnerID=8YFLogxK

U2 - 10.3390/agronomy11122472

DO - 10.3390/agronomy11122472

M3 - Article

AN - SCOPUS:85121664904

VL - 11

JO - Agronomy

JF - Agronomy

SN - 2073-4395

IS - 12

M1 - 2472

ER -