Unlocking Crop Potential: Organic Matter in Soil Explained

The living ecosystem of all successful gardens is based on soil organic matter (SOM). What is the organic matter of soil? It refers collectively to all the dead remnants of life; all the plant matters, animal remains and microbial biomass that decays over time forming a life web under your feet. In comparison to compost or mulch which are surface applications to temporarily maintain moisture levels and prevent weeds penetrating down the soil profile SOM is incorporated deep into the soil profile and can last months or centuries.

The percentages of the benchmarks are diverse according to the soil type: malable soils develop best with a 2-4% SOM, loamy soils with 4-8%, and clay soils with 5-10%. These degrees are associated directly with fertility, water suppression, and disease suppression. Increased SOM increases the availability of nutrients (by up to 20-50 percent), acts as a sponge (soaks up to 20 times its weight of the weight) and has microbes that crowds out pathogens. Organic matter in soil is in a word, the secret weapon to use in your garden in case of drought, pests and poor yields.

Three Types of Soil Organic Matter: Fresh, Transitional and Humus in Soil

Swellings of the soil undergo degradation into three different types that perform various functions in the soil fertility. Fresh organic matter includes fresh clippings or cover crop greens have just been added. Bacillus and Pseudomonas are bacteria which colonize very fast in hours to days to provide fast tilth improvement by loosening the structure of soil. Nonetheless, it contains a lot of nitrogen; this can temporarily render the soil inert so that the plant-available N remains immobilized in weeks.

The transitional organic matter will grow in 1-6 months whereby fungal networks of Trichoderma, Aspergillus, and Penicillium become successors. These fungi are very effective in the degradation of complex cellulose and hemicellulose beginning the aggregation process of soils into stable crumbs that improves aeration.

Humus (soil) is the stabilized final product: complex polymers developed during 6-24 months of work in compost or 5-20 + years of work in natural soils. Amazingly strong, 1 gram of humus contains 1 gram of water, has a cation exchange capacity (CEC) of 200-300 cmol(c)/kg and mineralizes at only 1-3 percent a year. This is where the construction of organic matter for soil improvement, humus, is the long run engine that propels long-term organic matter and soil fertility.

Microbial Alchemy: The way Soil Microbes change organic matter

The perfect alchemy is done by the soil microbes transforming raw materials into plant gold by their weaponry of enzymes: cellulases and hemicellulases break apart plant fibers, proteinases will break apart plant protein, and phosphatases will release free phosphorus.

The initial (hours-days) domination belongs to bacteria Bacillus and Pseudomonas that digest sugars and proteins to get ammonia and CO 2. Leading then 2-12 weeks Dung Fungi; Trichoderma, Aspergillus, attack recalcitrant cellulose, lignin.

These microbes release exopolysaccharides which behave as cement, forming water stable aggregates and three dimensional vital pore spaces to allow the roots and air to pass. They also secrete organic acids, which lowered rhizosphere pH by 0.5-2 units in order to dissolve mineral phosphates. Such soil and other microbial transformation of nitrogen in soil by this micro-organism is a demonstration of the worthiness of nature that enhances the output of gardens.

Nitrogen Cycle in Soil: The Process of Nitrogen in the Air to the Usable forms in Plants

Plants depend on organic matter, which enables the nitrogen cycle in soil to change inert nitrogen (N 2 ) in the atmosphere to forms desired by plants. It is initiated by fixation by nitrogenase enzyme through symbiotic bacteria in legumes: it ferments 100-300 kg N/hectare/year, 1-50 kg is fixed by free-living Breaker and innovative endophytes such as METILO provides 30-60 kg N/hectare via 0.75-1 ml/liter foliar sprays once a fortnight. 

Metilo is a superior nitrogen fixation product that is engineered based on the useful bacteria, Methylobacterium which is able to optimize biological fixation of nitrogen. Methylobacterium enhances the soil fertility of soils; facilitates the growth of crops in a sustainable manner and helps decrease reliance on chemical fertilizers such as nitrogen.

This is followed by mineralization where 1-3% of proteins in soil are broken down by enzymes of protease. At high C:N ratios, Straw, sawdust, etc. N is temporarily immobilized (through 4-16 weeks) to balance N requirements in microbial consumers.

Nitrification is a process that breaks down the ammonium in to nitrite (Nitrosomonas) and later nitrate (Nitrobacter) within a period of 6 weeks and up to 16 weeks. However, denitrification in flooded soils also diminishes 0.5-2 kg N/hectare/day as N 2 O- a greenhouse gas that is 310 times more significant than CO 2. Role of organic matter in the soil fertility in addition to microbial transformation of nitrogen in soil (during periods of organic matter and soil fertility) ensures a constant supply and role of organic matter in soil fertility prevents the losses.

The Phosphorus Cycle Unlocking Locked Nutrients with the Piracy of Microbes

The phosphorus cycle in soil presents a paradox, the total P in soil is 500-1000 mg/kg, whereas the available P is often below 10 mg/kg, in insoluble forms such as Ca 3 (PO4) 2, FePO 4 and AlPO 4, which insoluble salts lock 50-80 percent. The organic P decomposes through phosphatase enzymes, and every year 1-5 percent is released. This is enhanced by phosphate-solubilizing bacteria (PSB) such as Bacillus subtilis, licheniformis and megaterium, which secret organic acids that acidify the rhizosphere to 0.5-2 pH.

There are products such as Novobac Soil Vigor which increases the effects such as adding 2-3 kg/acre as a soil drench during planting and on a regular schedule of 4-8 weeks to increase available P by 20-40%. Mycorrhizae grow roots leading to a 10-100x increase. The sequestration of organic matter for soil improvement combines these cycles well.

Five Major Advantages of Organic Matter for Soil Improvement  that Every Gardener Must Take Advantage of

Amplification of SOM opens up transformational advantages hence organic matter to improve soil is essential. 

One, water retention: 1 gram of humus retains 1 gram of water, therefore, going up by 25 per cent of humus to 5 per cent capacity rises capacity by 25-30 per cent and drought tolerance by 2-3 weeks.

Second, reservoir of nutrients: SOM releases 25-40% within the first year, 10-20% within the second to third year and less than 5 years thereafter, which is fully in synchronisation with plant needs and importance of organic matter in soil.

Third, CEC improvement: 150-300 cmol(c)/kg (20-30x clay), 1% SOM amendment increases soil CEC 20-40% reducing 50-80% nutrient leaching and re-establishing the role of organic matter in soil fertility.

Fourth, suppression of disease: When SOM is 1% it contains 10-100 billion microbes / gram which crowd out Pythium, Rhizoctonia, Fusarium and Verticillium; Trichoderma by itself reduces Fusarium wilt by 30-50%. This is connected to the dynamics of the organic matter and soil fertility.

Fifth, soil structure: Soil polysaccharide microaggregates create the water-stable aggregates, which spike infiltration 100-1000x (1-5 to 50-200 mm/hour), enhancing the aeration and root development.

On-farm Soil Culture Practical Strategies: Bridging the gap between theory and practical

Here are the factors affecting soil organic matter. SOM is a project that requires strategy. Begin with various inputs to achieve C:N 25:1- 35:1- use 2-4 tons/acre at planting and 1-2 tons/year mixture of legumes (15:1), compost (20:1) and straw (80:1).

Add microbes: Soil Vigor (Bacillus + Trichoderma) is a microbe that enhances the decomposition of soil 25-50% and nutrients 20-40% at 2-3 kg/acre and used with METILO foliar.

No-till to reduce the cost of reduced losses (5-15 percent/year) to 2-5 percent/year, with carbon accumulation 0.2-0.5 tons/hectare/year and faster infiltration of 2-5 times - transition in 2-3 years.

Keep at 40-60% water holding capacity; beyond 60% activates the nitrogen cycle in soil, such as denitrification. Measure test baselines every 1 year, expecting 0.5-1.5 per cent improvement: poor soils to 5-6-1/2, average to 6-8-1/2, veggies to 8-10. 

Cool climates accumulate 30-50% of the faster pH 6.5-7.5; sandy requires more input and clay is stored best. Spot white mycelium, more than 50 earthworms/ sq ft, earthly smells, and more than 50 mm/ hour infiltration of more than 4 per cent SOM. Use organic matter for soil improvement and organic matter and soils fertility to achieve long-term outcomes.

Reference:

• Pereyra, S. M., A. de L Avila, and E. Orecchia. "La biofumigación y el metam sodio como alternativas al uso de bromuro de metilo: Efecto sobre el control de malezas y las características químicas del suelo." Agriscientia 25.2 (2008): 75-80.
• Gonzalez, I. Myo-inositol-14C, phytic acid-14C and ferric phytate-14C metabolism through microbian action in an andosol soil. No. INIS-mf--4239. Universidad Autonoma del Estado de Mexico, Toluca. Escuela de Ciencias Quimicas, 1977.