Biochar and Quicklime Co-Application Enhances Soil Fertility and Nut Yield in Acidic Pecan Orchards

Area of Science:

• Agronomy
• Soil Science
• Horticulture

Background:

• Acidic red soils pose significant challenges to pecan (Carya illinoinensis) cultivation due to soil acidification and poor nutrient availability.
• The combined effects of quicklime and biochar on pecan orchards in these specific soil conditions are not well understood.

Purpose of the Study:

• To evaluate the impact of sole and combined applications of biochar and quicklime on soil properties, fruit yield, and quality in pecan orchards on acidic red soils.
• To determine optimal application ratios for enhancing pecan productivity and fruit quality.

Main Methods:

• A field experiment was conducted on 8-year-old pecan trees in an acidic red soil region.
• Treatments included sole and combined applications of biochar and quicklime at varying ratios.
• Soil properties, fruit yield, and fruit quality parameters were assessed after 12 months.

Main Results:

• Combined biochar and quicklime treatments significantly increased soil pH and improved soil nutrient status (SOM, TN, TP, AK) compared to single amendments.
• The medium-dose combined treatment (2 kg biochar + 1.5 kg quicklime) yielded the highest single-tree yield (26.80 kg/tree), a 24.25% increase over the control.
• Different application ratios influenced fruit traits: low-dose improved physical traits, medium-dose maximized yield, and high-dose enhanced nutritional content (amino acids, vitamin E).

Conclusions:

• Integrated application of biochar and quicklime effectively alleviates soil acidification and enhances soil fertility in acidic red soils.
• This combined approach significantly improves pecan fruit yield and quality, with specific ratios optimizing different traits.
• The findings provide a scientific basis for sustainable and high-quality pecan production in acidic red soil regions.