The use of a BioStart biostimulant program in a commercial citrus orchard on red sands in NSW has increased soil moisture retention in the top 66 cm of soils, potentially reducing the irrigation required by 33 per cent.

Further trials in Victoria show faster orchard establishment of larger and more uniform trees, along with better water penetration and lateral water movement.

The NSW trial included two biostimulants from the BioStart range, applied over 12 months starting in January 2024. The Victorian trial applied Mycorrcin monthly. 

BioStart Mycorrcin, a soil biostimulant, was applied at a rate of 1 L/ha per month through the fertigation system. 

Mycorrcin is designed to activate beneficial soil microbes which improve soil structure, nutrient uptake and healthy root growth, ensuring rapid orchard establishment.

BioStart Foliacin, a foliar-applied biostimulant, was applied with cover sprays at a rate of 0.5 L/ha. Foliacin is designed to stimulate foliar biology to repair the plant’s foliar biofilm, activate the plant’s immune system, and lift photosynthesis.

The program in all trials was initially applied in these orchards for the well-known benefits of enhanced nutrient uptake, faster tree establishment, improved plant resilience to environmental stress such as drought and heat, and improved yield and fruit quality.

The citrus orchard establishment rate was faster in the Victorian trial, with improvements in tree uniformity, trunk cross-sectional area (+5 per cent), and canopy width (+12 per cent) at 15 months. 

Changes in soil structure were noticeable, with improved soil wetting and increased lateral water movement of the red sand soils.

In the NSW orchard trial, differences in soil structure and appearance were noticeable 10 months after the program was started, and the soil moisture levels were found to be higher.

Soil moisture increases were detected by the soil sensors at all depths:

At 20 cm: 25 per cent untreated versus 35 per cent treated — a 41 per cent increase.

At 41 cm: 20 per cent untreated versus 40 per cent treated — a 97 per cent increase.

At 66 cm: 34 per cent untreated versus 56 per cent treated — a 63 per cent increase.

At the same time, the orchard irrigation monitoring system alerted the irrigation manager that they should reduce water application in the BioStart-treated blocks by a third.

Soil moisture sensors indicated the moisture levels were also maintained at a steadier level between irrigation applications.

To explore the soil moisture measurements further, BioStart installed four additional soil moisture monitors across the treated block and an adjacent untreated block to measure soil moisture during December 2024 and January 2025.

During the two-month measurement period, the soil moisture levels were significantly higher in BioStart-treated soils at all three of the moisture probe depths: 20 cm, 41 cm, and 66 cm.

These results show the BioStart biostimulant program optimised both soil and plants, allowing orchards to establish faster while using water more efficiently. 

Further trials in other orchards are showing higher moisture levels starting at three months.