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Root Leachate Treatment Increased Melon Plant Growth in Low Desert Growing Conditions

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Philip Waisen
UCCE Riverside
Palm Desert


Vegetable field soils in low desert valleys of California are characterized by soil organic matter (SOM) content below 1%. This is attributed to high summer soil temperatures burning SOM to negligible levels, especially when the soil is undergoing bare fallow. Because SOM accommodates soil-dwelling beneficial microbes to perform important ecosystem services like decomposition, low SOM can compromise microbial activity and overall soil health. One way to address this challenge could be to condition planting beds with root leachate as pre-plant treatment. Root leachate is composed of sugars that can recruit and nourish microbes or be a source of microbes to innoculate and jumpstart microbial activity in SOM-deficient soils in the low desert. In addition, root leachate treatment can induce systemic resistance against a wide range of diseases or break the dormancy of weed seeds, survival structures of soilborne pathogens, and nematodes which can be controlled by pre-plant chemigation. A field trial was conducted to examine with and without tomato root leachate treatments on melon in Coachella Valley, Riverside, CA. Root leachate treatment significantly increased canopy cover by 4%. The published photo shows visual differences in melon plants as affected by root leachate treatment; the left row was treated with root leachate and the right row was not treated. The findings were published in UC Imperial County Ag Briefs 26(6):83-87 reaching more than 500 subscribers to the Ag Briefs. The Ag Brief can be accessed here. In addition, a YouTube Shorts taken from the opposite end of the field was posted on June 7, 2023, raking in 1,328 views and 23 likes. More research is needed to dissect the mechanism and optimize the application but root leachate treatment appeared to be a promising organic option for the growers in the desert.

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