Sea Minerals Reduce Dysbiosis, Improve Pasture Productivity and Plant Morphometrics in Pasture Dieback Affected Soils

Abstract

Pasture dieback (PD) is a grassland deteriorating syndrome resulting in grass loss and weed expansion in Australian pastures, with current estimates indicating that over four million hectares are affected. PD creates financial losses to the industry by reducing animal carrying capacity and producing poor-quality feed, resulting in diminished productivity. After more than a decade since PD first appeared in Australia, the causes and effective treatments are still unknown. Suggested causes include soil microbiota dysbiosis, pathogens, insects, climate change and overuse of chemical fertilisers. Sea minerals have been suggested as capable of improving plants’ yield, quality, taste, and nutritional value, but were never brought into conventional practice as an alternative to chemical fertilisers. Here, we investigated the capacity of sea minerals to improve grass health and yield of PD-affected soil. The replicate plots were treated with water or with 4 mL/m2 of commercially available sea mineral product to investigate the soil chemistry profile, plant morphometrics, pasture productivity, soil microbiota profile, and microbiota-nutrient interactions. Sea mineral application significantly increased total dry matter 20 weeks after a single application, translating to an additional 967 kg/ha; this benefit was still present at 498 kg/ha six months post a single application. Sea mineral application improved soil microbiota by boosting beneficial taxa while reducing genera associated with arid and toxic soils. Additionally, sea mineral application increased the number of grassroots up to six months post a single application. Our data suggest the benefits of sea mineral application to damaged, unproductive or exhausted soils could be further explored as a natural, affordable, and non-toxic alternative to chemical fertilisers.

Humate application alters microbiota–mineral interactions and assists in pasture dieback recovery

“…Together, these four genera contribute to 15% of the differences between Hum and Ctr plots. This is very comparable to the use of sea minerals [ 12 ] and tri-sodium salt of trimercapto-S-triazine (TMT) and humate mix treatments of PD [ 13 ], which also provided several improvements in plant morphometrics and pasture yield via altering the same genera. This reproducibility could indicate that successful remediation of pasture dieback research should focus on soil microbial community restoration.…”

“…Despite numerous suspected factors, there are no peer-reviewed publications, conclusive results or enough data to claim causality, and the principal source of PD remains unknown. Some improvements were recently reported using a single application of sea minerals [ 12 ] and a product containing commercial plant growth stimulant tri-sodium salt of trimercapto-S-triazine (TMT) and potassium humate as active ingredients [ 13 ]. Both treatments resulted in various soil microbiome and pasture yield improvements.…”

Application of Phytogenic Liquid Supplementation in Soil Microbiome Restoration in Queensland Pasture Dieback

“…Pasture dieback is a systematic ecological problem influenced by multiple factors, with no clear causes identified more than two decades after it first appeared. The short-term beneficial effects of some soil supplements, such as sea minerals [ 35 ] and a mix of humate and a common soil heavy metal remediation chemical [ 36 ], are promising, and their combinations with phytogenic liquid should be further investigated. We presented abundant evidence suggesting that blends of phytogens present a viable and highly promising option for the remediation and recovery of damaged and poor soils and plant promotion under stressful growing conditions.…”