A plant is quite simple in theory – it requires the sunlight, water, and nutrients. If sufficient amounts of the essentials are provided, the plant will flourish.
In row crops, there isn’t much you can do about sunlight, and so we turn our focus to what we can control – your Soil.
While Soil Health and Soil Productivity are not synonymous, they are without doubt correlated. While both intensive nutrient/water management and increased biological functionality can be highly productive systems, intensive management strategies can often degrade soil health making it difficult to maintain productivity over the long term.
In this case, we consider Soil’s productivity as the ability for soil to provide access to water and nutrients. Below are 5 ways to improve your soil’s productivity that are founded in an understanding of the interworking’s of soils chemical, physical, and biological components.
1 - Improve soil structure
The Physical attributes of soil are very important and play a large role in soil’s productivity. Sand, Silt, and Clay percentages are in most cases uncontrollable – meaning what you have is what you’ve got. However, there are methods for improving and maintaining the structure of your soil leading to increased water infiltration, water holding capacity, and aerobic conditions near the root zone. This encourages large root networks that aren’t confined by compaction layers, and therefore increases accessibility to water and nutrients within the soil’s profile.
The most impactful sustainable management practices you can implement to improve your soil’s structure and physical characteristics is a no-till strategy with cover cropping. This can make dramatic improvements in soil organic matter and the root systems from cover crops can begin to penetrate compaction layers. Root development of your cash crop will proliferate, and your fertilization efficiency will dramatically increase.
2 - Plan for Crop Deficiencies
There is a theory in agronomy called ‘Liebig’s law of the minimum’. It states that “A the growth of a plant is dictated not by the total resources available, but by the scarcest resource.” While this theory may over-simplify the soil-plant interaction, it is an important concept to grasp when thinking about soil productivity.
To improve the productivity of your soil, you need to be prepared to mitigate whatever deficiency is being experienced by the crop, both short-term and long-term. This requires pro-active management in the form of soil and leaf sampling, followed by soil amendments and foliar sprays to supplement identified nutritional and microbial deficiencies.
( *Terraforma’s Soil and Leaf analytics can inform the farmer on immediate and future deficiencies, and suggest products and solutions to mitigate deficiencies.)
Fortunately, when the soil has adequate microbial Biomass, Activity, and Diversity a plant can orchestrate nutrient recruitment through a process called nutrient cycling. Together, the factors that enhance nutrient cycling make up the biological functionality of the soil.
3 - Increase the Microbial Biomass of the Soil
Microbial biomass makes up a highly concentrated source of nutrients within the soil. You can consider the biomass as a nutrient reserve that is released through the process of predation, the best part is that the nutrients sequestered through biomass are often 0 cost to the farmer!
Improving soil biomass is primarily achieved by creating a habitat conducive to population growth. This means maintaining adequate levels of soil organic matter and carbon, or using additions of aerobic compost, green mulch, cover plants, and biochar.
It is important that the habitat provided should best match the successional level of the crop for the greatest impact. Additionally, the increased microbial biomass will aid in providing soil structure through fungal hyphae networks that bind soil particulate together and tunneling by larger organisms that sit higher in the food chain. The effects on nutrient and water availability lead to improved soil productivity, plant resiliency, and nutrient recruitment through plant/microbe interactions.
4 - Manage the Microbial Activity of the Soil
Nutrient cycling takes place if, and only if, microorganisms are active. Normally only a fraction of the biomass in the soil will be active at a given time, to get the most from your soil the biological activity needs to be optimized.
This doesn’t mean that 100% biomass activity is optimal – there is a balance that must be managed. For example, if activity is too high for too long, it is possible to metabolize more organic matter and nutrients than your crop needs, thereby wasting resources. In contrast, where activity is too low, organic matter may build but little benefit is transferred to the crops.
Understanding what stage the crop is in (vegetative, budding, fruiting, etc), and then managing activity with microbial stimulants is the best way to facilitate the highest rates of nutrient cycling without sacrificing future yield.
5 - Elevate the Microbial Diversity in the Soil
It may be obvious, but different microorganisms have different functions and thrive in different conditions. For example, a bacterium may solubilize potassium at a pH of 6.7, but become dormant at a pH of 7.1. For this reason, it is important to have a diverse community of microorganisms to be sure that nutrient cycling can occur at varying conditions (humidity, temperature, oxygen levels, pH, and the various exudates provided by the plant).
Additionally, microbial diversity plays a critical role in pest and pathogen suppression.
(Photo taken from Terraforma project. A red-rust thrip has been infected with Beauveria Bassiana, and has now become a host for the entomopathogenic fungi. In this photo, the B. Bassiana has entered its reproductive phase and will release spores which will continue to infect other insect pests.)
While there are still countless microorganisms yet to be identified, the fact is that increasing microbial diversity benefits nutrient cycling and pest suppression. What is also clear is that conventional fertilizers and other chemical inputs have a detrimental effect on many microorganisms.
To reinvigorate biodiversity in cropping systems, you can apply different microbial innocula. One option is to apply biological isolates, which can be a great option when a specific type of organism is required, while others focus on cultivating and reinstating a broadly diverse ecosystem. At Terraforma we have develop one such system, the TerraPod, an on-site bioreactor that cultivates an ecosystem of local and diverse microorganisms that can be used to bring back the biodiversity that has been lost through time. Using these diverse inoculums is a fantastic way to jumpstart the biodiversity on any farm, but it is also important to take note of the practices that limited the diversity initially so we can build a more diverse soil year after year.
The results of (1) Improving soil Structure, (2) Planning for and remediating crop deficiencies, and increasing the microbial (3) Biomass, (4) Activity, and (5) Diversity of soil, all lead back to having a highly productive soil that provides plants access to the necessities: water and nutrients.
Considering Leibig’s law of Minimum – a highly productive soil will allow for plants to experience minimal ‘scarcities’ – a soil with biological functionality will grow plants to their physiological limits.
The financial implications of improving the health and productivity of soil are significant, as a farmer can minimize inputs while maximize outputs with a greater level of tolerance to environmental changes.