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Long-term no-till increases soil nitrogen mineralization but does not affect optimal corn nitrogen fertilization practices relative to inversion tillage

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51 Scopus citations

Abstract

No-till management is a proven practice for increasing soil organic matter in many environments. By increasing soil organic matter, no-till may increase soil N mineralization, potentially reducing crop demand for N fertilizer relative to inversion tillage. In this study, we hypothesized that, relative to inversion tillage (moldboard plowing), long-term no-till would: i) increase total N stocks, ii) increase mineralized N during the growing season, iii) increase grain yield and N uptake, and iv) reduce reliance of corn (Zea mays L.) on N fertilizer inputs. We tested these hypotheses in a long-term, continuous corn tillage and fertilizer N rate study located in Lexington, KY. We measured the total soil N and potentially mineralizable N after 48 years, the in situ mineralized N and N uptake during two corn seasons (2018–2019), and the corn grain yield for five seasons (2015–2019). We evaluated the effect of no-till on N fertilizer reliance in two ways – the first was by measuring the agronomic optimum N rate of corn in the two tillage systems, and the second was by measuring the corn yield response to late N fertilization timing in the two tillage systems. We found that the no-till system had 1000 kg N ha−1 greater total soil N stocks in the top 20 cm, mineralized 65 kg ha−1 more N during corn growth, and resulted in 22−71 kg N ha−1 and 780−1800 kg ha−1 greater N uptake and grain yield across N rates, respectively, than the plowed system. The agronomic optimum N rate (AONR) did not differ among tillage treatments, potentially because the no-till treatment yielded more and thus demanded more N. Although corn yield responded to the late N fertilization treatment, the response was similar in both the no-till and plowed treatments. We conclude that long-term no-till increases soil N mineralization and corn yield relative to inversion tillage, with minimal effect on the AONR or optimal timing of N fertilizer application.

Original languageEnglish
Article number105080
JournalSoil and Tillage Research
Volume213
DOIs
StatePublished - Sep 2021

Bibliographical note

Publisher Copyright:
© 2021 Elsevier B.V.

Funding

This study was funded by the Kentucky Corn Growers’ Association , the University of Kentucky College of Agriculture, Food and the Environment , and the United States Department of Agriculture National Institute of Food and Agriculture Multi-State Funding . We thank Laura Harris, Tami Smith, Andres Nuñez, James Dollarhide, Jason Walton, Bob Pearce, and Congming Zou for their help with the study. We are very grateful to Bob Blevins for establishing, maintaining, and collecting data from the plots for many years. This study was funded by the Kentucky Corn Growers? Association, the University of Kentucky College of Agriculture, Food and the Environment, and the United States Department of Agriculture National Institute of Food and Agriculture Multi-State Funding. We thank Laura Harris, Tami Smith, Andres Nu?ez, James Dollarhide, Jason Walton, Bob Pearce, and Congming Zou for their help with the study. We are very grateful to Bob Blevins for establishing, maintaining, and collecting data from the plots for many years.

Funders
Kentucky Corn Growers Association
Kentucky Corn Growers Association
United States Department of Agriculture National Institute of Food and Agriculture, Agriculture and Food Research Initiative CARE
University of Kentucky College of Agriculture Food and the Environment

    UN SDGs

    This output contributes to the following UN Sustainable Development Goals (SDGs)

    1. SDG 2 - Zero Hunger
      SDG 2 Zero Hunger

    Keywords

    • Agronomic optimum N rates
    • Continuous non-tilled
    • Late-split nitrogen
    • Soil organic N storage
    • Soil organic matter

    ASJC Scopus subject areas

    • Agronomy and Crop Science
    • Soil Science
    • Earth-Surface Processes

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