Relationship Between Irrigation Thresholds and Potato Tuber Depth in Sandy Soil

Abstract

Soil disturbance resulting from tuber crop harvesting is a major threat to soil health. The depth of soil intervention is a critical factor that further strengthens the effects of such disturbance and makes harvest one of the most harmful cropping operations. In the case of potato, soil moisture is a determining factor for root and stolon development, hence, a deeper soil intervention may be required at harvest. While potato ranks as the fourth most cultivated crop worldwide, the impact of soil moisture on potato tuber vertical and horizontal distribution has received very little attention. The objective of this study was to evaluate the effects of four soil matric potential thresholds (SMPTs; –10, –20, –30, and –45 kPa) on the spatial (vertical and horizontal) distribution of potato tubers grown in plastic containers filled with sandy soil using an X-ray computed tomography scanner. The results of the experiments conducted in a greenhouse environment suggest that the horizontal distribution of the tubers did not differ significantly across the irrigation treatments. However, a linear relationship between SMPT, and therefore irrigation threshold, and potato tuber depth was observed. In addition, the deepest tuber position was observed under the –10 kPa SMPT, while the tubers were closer to the soil surface under the –45 kPa SMPT, which could lead to a greater preponderance of tuber diseases such as late blight or greening. Thus, potato irrigation events implementing a SMPT between –20 and –30 kPa could reduce the harvest depth, hence, decreasing the negative impacts of soil disturbance on soil structural stability and soil organic carbon degradation while mitigating the impacts of disease as well as reducing fuel costs, greenhouse gas emissions, soil loss and erosion.

Growth kinetics, spatialization and quality of potato tubers monitored in situ by MRI ‐ long‐term effects of water stress

“…In VWD plants, in accordance with the results of work aiming to improve the water management of potato crops (Matteau et al, 2022), we observed that watering conditions significantly modified tuber vertical distribution. The pattern of tuber size distribution became more marked than that in Control plants.…”

“…Indeed, the present study made it possible to observe size distribution in the early stages of tuber development and to confirm that it remained unchanged throughout plant development. More tubers with a diameter greater than 15 mm were detected in the lower parts of the pots (Figure5), which can be explained by the reduced growth of tubers near the soil surface, as leaf midday water depletion may induce a preferential water flow from these tubers closest to the leaves.In VWD plants, in accordance with the results of work aiming to improve the water management of potato crops(Matteau et al, 2022), we observed that watering conditions significantly modified tuber vertical distribution. The pattern of tuber size distribution became more marked than that in Control plants.…”

“…The monitoring of tuber development in soil, which allows access to spatial and short or long‐term temporal information on tuber quality traits during formation and growth, is less common. Only very few such studies based on underground imaging using either MRI (Musse et al, 2021, Huntenburg et al, 2023) or X‐ray computed tomography (Matteau et al, 2022, Van Harsselaar et al, 2021) have so far been attempted. This lack of information is an obstacle to further comprehensive analysis of the impacts of drought on tuber quality.…”

Cultivar-dependent differences in tuber growth cause increased soil resistance in potato fields

“…Multiplying tuber density ( circa 1067 kg m -3 - Patel et al., 2018 ) by yield per plot ( Figure 10 ) can determine the proportion of soil volume occupied by tubers. Tubers tend to be limited to the upper 20 cm of soil ( Matteau et al., 2022 ), and soil volume to this depth ranged from 0.576 m 3 (trial 2) to 0.648 m 3 (trial 1) in each plot according to its dimensions. Thus, the proportion of tuber volume in the topsoil at harvest was estimated to range from 4.6% to 9.9%, which could easily account for an increase in soil resistance as tuber expansion compacts the soil around the tubers.…”

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.…”