Soil microbes - the missing link
With climate change increasing the frequency and severity of droughts and floods, maximising infiltration rates and water holding capacity of soils is becoming increasingly important. Not only does it affect grass quality and yields, but it also influences how long cattle can graze pasture and therefore the duration (and costs) of housing.
Ultimately, your fields ability to absorb and retain water has a significant, but often underestimated, bearing on costs of milk production.
When we consider the complex relationships between plants and water, it’s natural to focus on the physical aspects – roots drinking up water from the soil, leaves transpiring to release excess moisture into the air. However, the role of soil microorganisms in facilitating plant-water interactions is equally important.
Soil microbes are a diverse group of microorganisms that inhabit the soil environment, including bacteria and fungi. These tiny organisms play a vital role in breaking down organic matter, releasing nutrients for plant uptake, and facilitating water transport. In this blog, explore how soil microbes help plants access water.
How soil microbes facilitate grass' water uptake
Soil microbes influence grass uptake of water in several ways:
1. Modifying soil structure: Many fungi and bacteria produce compounds that are sticky and hold small soil particles together in clumps. This is known as ‘aggregation’ and improves water infiltration and reduced runoff as the spaces between the clumps are channels through which water can flow. Aggregation also increases the water surface area of soil, enabling it to hold more water which plants can access during drought.
Fungi go further by establishing a network of hyphae (long branching filaments which are like fungi’s roots, stems and leaves). These hyphae further aggregate soil particles, by holding those smaller clumps into large ones ‘macro-aggregation’.
The pores between aggregates are also easy channels for roots to follow, improving their growth and reach.
2. Extending the root network: Plants commonly form symbiotic relationships with bacteria and fungi, which are mutually beneficial to both. Plants produce exudate, a rich energy source, for these microorganisms to attract and retain them, exchanging these exudates for water and nutrients that the bacteria and fungi can access (but the plants cannot). Depending on their needs, plants can even change the composition of their exudates to recruit specific microbes that are adept at supplying certain nutrients and/or water.
Fungi’s vast network of hyphae, or mycelium, as it is known, is particularly important as its reach is extensive and can greatly increase plant’s access to water, particularly in droughts.
3. Reducing surface tension: Certain bacteria, such as Pseudomonas and Bacillus species, produce surfactants (surface-active agents) that reduce the surface tension of water. This allows roots to take in more water by reducing the energy required for water uptake.
Consequences of Soil Microbe-Mediated Water Uptake
The effects of soil microbes on plant-water interactions are far-reaching:
1. Water conservation: By improving soil structure microbes help plants conserve water by allowing them to penetrate soils reducing evaporation from the soil surface.
2. Reducing flooding: With water able to infiltrate soils more quickly, there’s less pooling on the soil surface.
3. Drought tolerance: Soil microbes can enhance plants drought tolerance by increasing the resources they can access.
4. Reducing erosion: Soil that is held together with healthy grass roots, fungi’s network of hyphae, is less prone to erosion.
5. Plant growth promotion: Microbial activities promote healthy plant growth by providing essential nutrients, consistent access to water and improving soil conditions. This improves grass quality and yields. Microbes can also release essential nutrients that are bound up in soil and would otherwise be unavailable to the plants.
6. Resilience to poaching and compaction: grassland that is underpinned by a healthy soil, strong grass roots and above ground cover has more resilience to poaching and compaction.
How can SlurryForSoil help?
SlurryForSoil contains a diverse range of soil-born bacteria and fungi. Each has been chosen for its scientifically proven abilities to improve soil and plant health including soil aggregation and water transportation.
Slurry is effectively used as a medium for growing and multiplying these soil microbes. As the bacteria and fungi feed, the organic material in slurry is broken down into simpler compounds that are more bioavailable for the existing soil microbes in pasture to utilise.
This has the advantages of liquefying slurry (making it easier to store and apply) and capturing the nutrients.
Even where the soil biome is already in good health, improving the composition of slurry with SlurryForSoil has shown to significantly improve grass quality and yields and reduce the need for synthetic fertiliser.
Find out more about SlurryForSoil here.
For a deeper dive into the soil microbe’s and how they can improve grassland quality and yield, click here.