Association between irrigation thresholds and promotion of soil organic carbon decomposition in sandy soil

Abstract

Soil organic carbon (SOC) has a significant effect on the carbon cycle, playing a vital role in environmental services and crop production. Increasing SOC stock is identified as an effective way to improve carbon dioxide sequestration, soil health, and plant productivity. Knowing soil water is one of the primary SOC decomposition driver, periods in the crops growth stages with increased water movement might influence the SOC dynamics. Here, we evaluate the temporal effect of four precision irrigation thresholds ($$-15$$ - 15 , $$-30$$ - 30 , $$-45$$ - 45 , and $$-60$$ - 60 kPa) in potato crop on SOC dynamics using the Partial Least Square algorithm and the Tea Bag Index in a sandy soil under potato production. The difference of SOC decomposition rate between the precision irrigation thresholds is developed in the second quarter of the growing season, between 38 and 53 days after planting. This critical period occurred in a stage of strong vegetative growth and rapid irrigation cycles. The precision irrigation threshold affected the decomposition rate of SOC. A faster decomposition of labile organic carbon was promoted by water excess ($$-15$$ - 15 kPa). The dryer ($$-30$$ - 30 , $$-45$$ - 45 , and $$-60$$ - 60 kPa) precision irrigation thresholds did not show any differences. The advancement of this knowledge may promote soil health conservation and carbon sequestration in agricultural soil.

Potential of implementing irrigation in rainfed agriculture in Quebec: A review of climate change‐induced challenges and adaptation strategies

“…These practices vary from water table management to microirrigation (subsurface drip and sprinkler irrigation). For example, for a potato crop under drip irrigation in sandy loam soil, optimal irrigation scheduling is recommended to occur at soil matric potential ( ) thresholds between −10 and −24 kPa (Jacques et al, 2020; Matteau et al, 2021a,b; Matteau, Célicourt, Létourneau, et al, 2022; Matteau, Celicourt, Shahriarina, et al, 2022; Table 1). Such an approach increased crop yield and water productivity while reducing irrigation water use.…”

Mapping Soil Organic Carbon in Floodplain Farmland: Implications of Effective Range of Environmental Variables

“…Many studies have found that environmental variables only have an impact on SOC within a certain range [31][32][33][34]. For example, Chen, et al [34] found that the amount of soil loss rapidly decreases when the vegetation coverage increases from 0 to 80%, but the amount of soil loss remains basically unchanged when the vegetation coverage increases from 80% to 100%.…”