Availability of Nitrogen in Soil for Irrigated Cotton Following Application of Urea and 3,4-Dimethylpyrazole Phosphate-Coated Urea in Concentrated Bands.

Autor: Pittaway PA; Centre for Agricultural Engineering, University of Southern Queensland, Toowoomba, QLD 4350, Australia., Antille DL; Centre for Agricultural Engineering, University of Southern Queensland, Toowoomba, QLD 4350, Australia.; CSIRO Agriculture and Food, Black Mountain Science and Innovation Precinct, Canberra, ACT 2601, Australia., Melland AR; Centre for Agricultural Engineering, University of Southern Queensland, Toowoomba, QLD 4350, Australia., Marchuk S; Centre for Agricultural Engineering, University of Southern Queensland, Toowoomba, QLD 4350, Australia.
Jazyk: angličtina
Zdroj: Plants (Basel, Switzerland) [Plants (Basel)] 2023 Mar 03; Vol. 12 (5). Date of Electronic Publication: 2023 Mar 03.
DOI: 10.3390/plants12051170
Abstrakt: Low nitrogen (N) fertilizer use efficiency for irrigated cotton has been attributed to the limited ability of tap roots to access N from concentrated subsurface bands, or the preferential root uptake of microbially-mineralized dissolved organic N. This work investigated how applying high-rate banded urea affects the availability of N in soil and the capacity of cotton roots to take up N. Soil was analyzed for water-extractable total dissolved N and inorganic N species after urea or urea coated with 3,4-dimethylpyrazole phosphate (DMPP) was applied at concentrations of 261, 455, 461, and 597 mg N kg -1 of (air-dry) soil (mean bulk density: 1.01 g cm -3 ). A mass balance was used to compare N applied as fertilizer and in unfertilized soil (supplied N) with the N recovered from soil within the cylinders (recovered N) at five plant growth phases. Root uptake was estimated by comparing ammonium-N (NH 4 -N) and nitrate-N (NO 3 -N) in soil sampled from within cylinders with soil sampled from immediately outside. Recovered N was up to 100% above supplied N within 30 days of applying urea above 261 mg N kg -1 of soil. Significantly lower NO 3 -N in soil sampled from immediately outside the cylinders suggests urea application stimulates cotton root uptake. The use of DMPP-coated urea prolonged high NH 4 -N in soil and inhibited the mineralization of released organic N. These results imply the release of previously sequestered soil organic N within 30 days of applying concentrated urea enhances the availability of NO 3 -N in the rhizosphere, reducing N fertilizer use efficiency.
Competing Interests: No conflicts of interest were identified by the authors. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
Databáze: MEDLINE
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