AUTHOR=Singh Manpreet , Singh Sukhbir , Parkash Ved , Ritchie Glen , Wallace Russell W. , Deb Sanjit K. 

TITLE=Biochar Implications Under Limited Irrigation for Sweet Corn Production in a Semi-Arid Environment

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.853746

DOI=10.3389/fpls.2022.853746

ISSN=1664-462X

ABSTRACT=<p>The integration of biochar and deficit irrigation is increasingly being evaluated as a water-saving strategy to minimize crop yield losses under reduced irrigation in arid and semi-arid regions such as West Texas. A 2-year (2019 and 2020) open-field study evaluated the effect of two types of biochar amendments (hardwood and softwood) and three irrigation rates [100, 70, and 40% crop evapotranspiration (ET<sub><italic>c</italic></sub>) replacement] on the physiology, plant growth, and yield of sweet corn in semi-arid West Texas. All experimental units were replicated four times in a split-plot design. The chlorophyll content (Chl<sub><italic>SPAD</italic></sub>) in 40% ET<sub><italic>c</italic></sub> dropped significantly compared to 100% ET<sub><italic>c</italic></sub> and 70% ET<sub><italic>c</italic></sub> during the reproductive phase. Although water stress under 40% ET<sub><italic>c</italic></sub> decreased photosynthesis (<italic>P</italic><sub><italic>n</italic></sub>) to limit transpiration (E) by stomatal closure, it improved intrinsic water use efficiency (iWUE). The above-mentioned gas exchange parameters were comparable between 100% ET<sub><italic>c</italic></sub> and 70% ET<sub><italic>c</italic></sub>. Both biochar treatments increased Chl<sub><italic>SPAD</italic></sub> content over non-amended plots, however, their effect on gas exchange parameters was non-significant. All growth and yield-related parameters were comparable between 100% ET<sub><italic>c</italic></sub> and 70% ET<sub><italic>c</italic></sub>, but significantly greater than 40% ET<sub><italic>c</italic></sub>, except water productivity (WP). Both deficit irrigation treatments improved WP over full irrigation in 2019, but in 2020, the WP gains were observed only under 70% ET<sub><italic>c</italic></sub>. Hardwood biochar decreased soil bulk density and increased soil porosity, but it had a marginal effect on the water retention characteristics. These results suggest that 70% ET<sub><italic>c</italic></sub> can be used as an alternative to full irrigation to save water with a minimal yield penalty for sweet corn production in the West Texas region. The hardwood biochar application improved the vegetative biomass significantly but yield marginally during the first 2 years of application. A long-term study is required to test the effect of biochar under deficit irrigation beyond 2 years.</p>