Skip to main content
Category

Productivity

Halthy soil

Soil Health: The Challenge of Modern Agriculture

By Management, Productivity, Soil Health, Sustainability

Soil is essential for the maintenance of biodiversity above and below ground. The wealth of biodiversity below ground is vast and unappreciated: millions of microorganisms live and reproduce in a few grams of topsoil, an ecosystem essential for life on earth

From: Australian Soils and Landscape, An Illustrated Compendium

If it ain’t broke don’t fix it, right?… but maybe it is broke.

Over the centuries, modern agriculture has advanced significantly, leading to the highly researched, technical systems and unprecedented production levels that we have today. Developments allowing agriculture to evolve and expand include increased availability and use of synthetic fertilisers, herbicides, and pesticides; genetic improvements; increasing understanding of plant and animal nutrition and improved mechanical equipment. All leading to efficiencies for production systems and the resulting development of global markets and delivery.

Unfortunately, soil biological responses to these developments were often overlooked or not recognised, with greater emphasis on physical and chemical manipulation than on soil biology. Agriculture’s evolution has also resulted in unintended consequences, especially regarding soil health, environmental impact, and long-term agricultural sustainability.

Quality is key

Soil quality can be simply defined as “the capacity of the soil to function.” Important soil functions include water flow and retention, solute transport and retention, physical stability and support; retention and cycling of nutrients; buffering and filtering of toxic materials; and maintenance of biodiversity and habitat. Fertile soils teem with microorganisms, which directly contribute to the biological fertility and functions of that soil.  

In addition to fertility, soil microorganisms also play essential roles in the nutrient cycles that are fundamentally important to life on the planet. In the past, agricultural practices have failed to promote soil health through healthy populations of microorganisms.  Not doing this limits production yields and threatens sustainability.

So, can we fix it?

Scientific research is exploring new and exciting possibilities for the restoration and promotion of healthy microbial populations in the soil, with significant benefits in both net production and environmental outcomes. Biological fertility is under-studied and our scientific knowledge of it is incomplete, however, new research and field trials are delivering a quiet confidence that modern agriculture can again evolve, and that this evolution of biological practices will benefit the animals, the farmer and the planet.

Soil health and fixing carbon

Soil microorganisms are both components and producers of soil organic carbon, a substance that locks carbon into the soil for long periods. Abundant soil organic carbon improves soil fertility and water-retaining capacity. There is a growing body of research that supports the hypothesis that soil microorganisms, and fungi in particular, can be harnessed to draw carbon out of the atmosphere and sequester it in the soil.  

Soil microorganisms may provide a significant means of reducing atmospheric greenhouse gases and help to limit the impact of greenhouse gas-induced climate change.

Soil health and fixing nitrogen

Nitrous oxide emissions are produced by a range of bacteria in the soil, which convert nitrate into nitrous oxide. These losses are greatest when soils are warm and waterlogged, and in those with high nitrate contents. It is vital environmentally, to apply nitrogen fertilisers only at times, and in quantities and forms, useful to plants – overuse of fertiliser can vastly increase levels of emissions.  

Nitrous oxide is a more potent greenhouse gas than carbon dioxide. One unit of nitrous oxide is equivalent to 310 units of CO2. Conventional tillage also releases more CO2 into the atmosphere than no-till systems and results in more carbon being respired by the microbial community. No–till systems tend to lock up more carbon in the form of organic matter.

A large soil microbial community can tie up carbon and nitrogen that might otherwise be released into the atmosphere as greenhouse gases and in addition, make these nutrients more readily available for plant uptake.

The impact of soil health on phosphorus and biology

Phosphorus is a major nutrient with dwindling global supplies and rising prices. Only a small amount of P applied is taken up by plants in the year of application. The remaining P becomes sequestered in the soil, with limited availability to plants, or is lost by erosion and leaching to the watershed where it may impact downstream ecosystems and water quality. Similarly, only about one-quarter of annually applied N is taken up by crops in the year of application; some of the remaining N enters the watershed by leaching.

Nutrient-use efficiency is often defined based on the amount of N or P accumulated by a crop in comparison to the amount applied. However, a portion of the P and N in the crop has originated from within the soil, where it was already present and probably in a stable organic form. Therefore, traditional nutrient use efficiency calculations often overestimate the efficiency of fertiliser application and fail to reflect the applied nutrients that were lost from the soil by leaching and/or erosion.

Research aims to reduce inputs, while increasing the amount being provided by the soil through biologically fixed N, or mineralisation of P and N from organic matter. In the case of P, there are substantial amounts of P already in the soil, unavailable to plants without the appropriate microorganisms and proper levels of activity. By considering the nutrient balance of the entire system, agricultural soils could be managed to stabilise at lower soil nutrient levels that make more efficient use of soil mineral resources.  

Some P exported with the crop will have to be replenished from external sources, but there is great room for improvement in promoting organic P cycling in soils and biological mobilisation of “occluded” P already present in the soil.

It’s time to do something different

The challenge for modern agriculture, going forward, is to implement more sustainable farming systems that are economically viable and accommodate changing technologies and climate. The production of food and fibre continues to increase agriculture’s carbon footprint through the increased use of fuel and fertiliser and contributes to widespread soil and water quality degradation. To decrease this footprint, nutrient management and soil health in sustainable systems must be a top priority.

Soil biology is the foundation for soil health and the biological processes which determine nutrient availability to plants allowing for a decreasing reliance on synthetic fertilisers. You can see nature in action in our blog post on the Kauri forests in Waipoua.

In addition, helping to buffer plants from changes in water availability and pest, pathogen, and weed pressures. It is key to reversing the degradation of soils by modern agriculture practices; key in the evolution of agriculture in both an environmental and economically sustainable manner; key to ensuring the enduring ability to “Feed the World.” 

amino-acids

Amino Acids Part 2: The secret compound for all living things and sustainable farming.

By All, Animal Health, Productivity, Regulation, Soil Health, Sustainability

In Part 1 of this series I gave you a high level understanding of amino acids, their extraction and uses in agriculture.  In this Part 2 of the series, we will cover the importance of amino acids to plants and the benefits of amino acids to land management practices and sustainable farming. You have already heard about how amino acids help increase the health of the soil and everything that grows in it, how the proteins found in amino acids help the soil absorb and store more nutrients, but I haven’t discussed how that relates to sustainable farming and importantly reduced dependancy on synthetic fertilisers for productivity.

Let’s first start by understanding how amino acids support plant growth;

1. Amino acids help photosynthesis

Amino acids provide many different benefits to plant health, beginning with the process of photosynthesis. Without proper photosynthesis, plants will not grow. This process relies on the production of chlorophyll, which needs to absorb energy from the sun.  Amino acids help in the production of chlorophyll, which leads to quality photosynthesis.

2. Amino acids help increase nutrient absorption

Plant leaves consist of stomata, which are small pores that help plants absorb gas and nutrients. When there is no light and low humidity, the stomata will close to help to reduce photosynthesis and absorption of nutrients.  When the sky however is clear and sunny, and the humidity is higher, the stomata will then open. This will help plants to get the proper nutrition from rain, sunlight, and soil.

With sufficient concentration of amino acids in the soil, L-glutamic acid is a type of amino acid that protects stomata cells with a microscope. This encourages the leaves to remain open, allowing the plants to absorb more nutrients.

Amino acids are also known as having the ability to chelate when proteins are combined with other sub-nutrients. Plants can use sub-nutrients more efficiently. These benefits result in increased nutrient intake.

3. Amino acids reduce stress-related problems

The plant is able to withstand stress, such as from high temperatures, low humidity, and other serious problems. Amino acids help to fight stress and help plants to recover quickly and to maintain denser growth.

4. Amino acids support plant hormones

Amino acids also support the growth of plant hormones, which is called phytohormone. The Phytohormones control the development of healthy plants by supporting tissues and cells. Almost all stages of plant growth are involved in hormonal control. The use of amino acids with soil can promote production phytohormones without having to use separate supplements.

5. Amino acids help improve microbial activity

Protein is important for all living cells, including microbial cells that support healthy soil. L-methionine, one of the amino acids, can help increase the health of microbial cells, promote better microbial activity. One of the main roles of microbes is to help circulate nutrients, including carbon, nitrogen, phosphorus, and sulfur. The activities of healthy microbes control these components. Without microbial activity, most fertilizer is not effective. Microbes help convert organic compounds into inorganic forms, such as changing proteins from amino acids to carbon dioxide and ammonium. In general, microbes decompose compounds so that plants can absorb nutrients. Adding amino acids to the soil will improve this process.

6. Amino acids are a source of nitrogen

Adding amino acids to the soil can help increase nitrogen content by limiting the need for fertiliser with a high nutrient concentration. Plants can pick up amino acids from the soil to receive organic nitrogen. Amino acids are found naturally in the soil can provide protein with nitrogen. However, to get nitrogen, Plants must first digest proteins, which must have microbial activity in the soil. Amino acids help improve microbial activity. Soil supplementation with this substance can help the entire nitrogen cycle.

7. Amino acids increase calcium absorption

Chelating substances such as amino acids will help increase the absorption of nutrients. After plants absorb minerals, the rest will be decomposed into dissolved organic nitrogen or used directly as an amino acid.  Chelaing will have effects to help with plant health from increased calcium absorption, making plants to have more calcium and to help strengthen the vascular system, strong nutrients conveyor system. Plants will be able to absorb more water and nutrients. This calcium increase may help prevent pests and diseases. When plants are weak, there will be water in the cells which attracts the growth of mold and insects. With healthy plants, there will be more pectin in the cell wall. Thicker cell walls are less likely to be attacked. Increased calcium absorption also helps prevent pests. When these problems occur, plants release calcium and produce defenses that help repel insects.

essential-amino-acids

Amino Acids Part 1: The secret compound for all living things and sustainable farming.

By All, Animal Health, Productivity, Regulation, Soil Health, Sustainability

Amino acids, often referred to as the building blocks of proteins, are compounds that play many critical roles in the health of all living things. They are the essential compounds for life and as such are needed for vital processes like the building of proteins and synthesis of hormones and neurotransmitters.

Humans may also take additional amino acids in supplement form for a natural way to boost athletic performance or improve mood.

Soil amino acids are important sources of organic nitrogen for plant nutrition, in fact amino acids serve as a key mobilisable source of nitrogen in plants, and their transport across cell membranes is necessary for uptake of nutrients from soil.

This two part blog tells you everything you need to know about essential amino acids, including how they function, sources and methods of extraction, their importance to plants and benefits to sustainable farming.

What are amino acids?

Amino acids are organic compounds composed of nitrogen, carbon, hydrogen, and oxygen, along with a variable side chain group. When a series of amino acids are joined by peptide bonds, proteins are formed. Proteins are important macromolecules involved in all aspects of the growth and development of plants.

There are about 20 amino acids that can help plants, animals, and humans grow and develop. Though all 20 of these are important for health, they are individually required for specific functions.

The amino acids responsible for chlorophyll synthesis are Alanine, Arginine, and Glycine. For the development of the root or to delay the senescence, there are Arginine and Methionine. If we want to achieve a chelating effect on the soil and better development of shoots and leaves plants use Glycine. For the resistance systems of the plant, the best types are lysineglutamic acid, and glycine.

Sources and methods of extraction

The main sources of amino acids are extracted from vegetables, animals, fish or synthetics. Those obtained by plants are extracted from vegetable waste of soybean, cereals, fish, etc. 

Traditionally, two processes are used in agriculture to obtain amino acids. These processes are known as, acid hydrolysis and enzymatic hydrolysis.

Acid hydrolysis method is the most basic and low-cost option. It is achieved by prolonged boiling of the protein with an acid solution. The method is quite aggressive, so the resulting amino acids are of low quality, creating a high percentage amino acids destroyed during the process. 

The enzymatic hydrolysis process is much less aggressive. It is not necessary to apply extreme temperature and instead of an acid solution, an enzyme is used. The process is more expensive and complex, but the percentage of free amino acids are much higher, so in contrast to the acid hydrolysis approach the resulting composition is mostly usable by the plant.

Benefits of applying amino acids

Plants synthesise amino acids from the N absorbed as nitrate or ammonium that is in the soil. During the process of absorbing nitrogen from the soil, the plant consumes a considerable amount of energy which is diverted from the plant’s growth activities. The main reason why it is so important to applicate these products in agriculture is the energy savings that they achieve. The energy saved is diverted to other important processes such as sprouting, flowering, or fruiting. The outcome of which is an increase in the quality and the production of the crop or pasture.

In part two of this series we will look at the relationship amino acids have with synthetic nitrogen and benefits to sustainable farming.

Recent Articles

How To

Sustainable Farming: Where on Earth Do You Start?

Farmers are currently facing unprecedented pressure to change their farming systems from traditional practices towards…
aeration-let-the-soil-breathe
How To

Aeration: Let Your Soil Breathe

We all aim to set ourselves up to get through winter as best we can…
Customer Stories

Full Circle: Old Goldmine to new Goldmine

Cam and Kayleigh McKay.  Round Hill, Southland.  200 Ha – 125 Ha effective.  Dry stock…