We have a fantastic article planned for you, all about topdressing.
The components of soil, common problems and issues, how to topdress and what topdressing material is right for you.
Watch this space, its coming soon.
We have all heard of organics, but what is it and what is the natural function of soil? Are chemical fertilizers the devil and is organics going to save the world? The modern farming revolution was built on NPK – the three most important components for plant growth. This golden ratio has become synonymous with […]
￼Here at Optigrow we understand that, happy roots = happy fruits… or nuts.
That is why soil preparation prior to planting is so important to us.
It’s common practice to plant first and feed and irrigate second.
There are many benefits to considering soil preparation prior to planting.
Not just from a plant health point of view but cost wise too.
Soil is the environment that supports plants and as we all know as farmers a well fed and stress free plant is a happy plant.
Simple steps can be taken to prepare for planting.
The earlier the better, but any preparation in advance is better than none.
Soil preparation cost per tree is a fraction of what that tree costs, therefore as an investment, it makes complete financial sense to cover this extremely important factor.
Preparation inside the plant hole is also extremely beneficial vs just building soil from the surface down.
Optigrow produces earths oldest and best soil rehabilitator and conditioner.
We suggest using vermicast in soil preparation as it seeds in all the plant beneficial micro and macro organisms, hormones, micro fungi and plant available nutrient needed to establish a healthy substrate for young developing plants.
Young plants are very susceptible to peaks and troughs in the availability of moisture and nutrient, PH and chemical imbalance in soil due to pesticide use.
Freshly prepared soil is often deep ripped, disturbing and displacing microbe colonies plants rely on for healthy growth.
Commercial farming relies on high yields and quality crops at harvest.
With this in mind after years of investment, the early formative years of trees are essential in achieving this goal.
Healthy root development in young years is first priority and soil health goes hand in hand with this.
Land preparation and planning takes time.
Once plant locations are planned and marked it is advised to begin soil prep at each planting location thereby ensuring established soil health when your investment goes into the ground.
Your trees have a better chance of “taking” in healthier soil, and that alone can offset costs of your soil preparation, not to mention the time, effort and labour to replace dead trees.
But im busy, why soil prep in the hole?
Why not just apply castings on the surface around your trees?
The short answer to this is best effect for your financial investment in soil preparation. The second is time.
Vermicast in the plant hole surrounds the roots supporting them exactly where it is needed.
Microbial colonies then populate outwards in all directions preceding and pioneering ahead of roots. With a surface application, the root supporting components of vermicast work downward towards the roots and then outwards, which takes time. Both support root development and your tree, however soil preparation in advance benefits the tree right from the start and in all the right places.
Investment in macadamias is a wise investment but with any investment it is best to do so carefully. Planning for the healthy support of your trees from young to bearing age is exceptionally important.
Ensuring that the organic function of soil is optimised means that from the start your structural, chemical and biological components of soil are in place and ready to work hand in hand with the chemicals and pesticides you use, keeping your root zones healthy and balanced.
To discuss how we can help you today or for more information on Opti-cast and what we do, please feel free to give us a call.
Nicholas and the Optigrow team.
Issues farmers face with soil degradation is the issues of soil toxicity and chemical imbalance caused by prolonged fertiliser and pesticide use.
Earthworms have been found to be a viable method of removing toxins from soils and enhance the remediation of agricultural lands polluted by chemicals the likes of for instance DDT.
Earthworms can live in highly contaminated soils.
They are generally tolerant to many chemical contaminants including heavy metals and organic pollutants in soil and can bio-accumulate them in their tissues.
Earthworms species like Eisenia fetida have been found to through the use of a special detoxifying layer in their gut and specific metal binding proteins, remove and isolate toxic heavy metals such as (Cu, Cd, Pb, Hg, Zn, etc.) and also lipophilic organic micropollutants from soil.
Chemical contaminants are absorbed through their moist body walls and mouth and are either bio-transformed or biodegrade , rendering them harmless in their bodies.
This makes earthworms perfect for soil remediation in both agricultural and industrial settings.
Soil, our silent and often underappreciated friend is the backbone of all the plants we see around us, gardens, agriculture and our entire food system.
Wikipedia defines soil rather simply, “Soil is a natural body, it exists as a mixture of minerals, organic matter, gases, liquids and a myriad of organisms that can support plant life.”
Where soil is a natural body, healthy soil is a living and complex web of life, an organism formed of a myriad of complex symbiotic relationships.
Nutrient and minerals playing their part in a complex soil food web consisting of different organisms and microbes (beneficial bacteria, fungi, nematodes and protozoa) living together in symbiotic relationships increasing nutrient availability for plants and transforming the physical and chemical properties of the soil into an environment perfectly suited to plants, organisms and microbes alike.
The focus of modern agriculture in the past has been to add NPK (Nitrogen, Phosphorus and Potassium) fertilizers to boost plant growth. As time has progressed evidence has shown that this is not sustainable as a sole approach.
Inorganic fertilizers add refined base nutrients to the soil, but solely without the beneficial microbes, fungi, minerals, nematodes, enzymes and co-enzymes needed to participate in the geochemical cycling of nutrients, the process is unsustainable and there will be no support for full nutrient uptake.
This approach works for the short term by getting nutrient to the plant in large quantities but this imbalanced approach often kills, impedes or disrupts the balance of the food soil web that makes these nutrients readily available to your plants. As a result a decrease of nutrient uptake by the plant will be experienced as the physical and biological structure of the soil degrades.
Hard working microbes are probably the most overlooked and vital component within our soil, they help make many micro-nutrients more available to plants like in the case of calcium and iron where large amounts would otherwise be unavailable to plants and lost to drain away.
Healthy soil structure is also vital to plant health. As soil health degrades one can be left with a dead sandy soil where through water and nutrient will quickly leach out, leaving plants in a stressful environment of feast and famine. Sandy soil may also not hold plant roots securely and yet an excess of clay creates a dense environment where air, water and roots cannot move freely and the food soil web cannot function.
Healthy soil consists of a combination of organic matter, rock particles and water, capable of maintaining a consistent structural, chemical and biological environment. An environment where all plants needs are catered for. A stress free environment with ample access to air, water, nutrient and micronutrient in a form that is plant available. A spectrum of all their dietary needs, a soil structure that supports their roots and maintains a comfortable moisture level.
What plants and trees provide in the way of fruits, veggies or flowers so we need to replace within our soil, closing the circle and completing the cycle. By implementing sustainable techniques were we feed and encourage the soil food web to continue to thrive, so your soil will continue to support and encourage your plants and trees to bare crops till the end of time.
An important and often unrecognized feature of vermicast is its cationic exchange rate. This is the rate at which the cationic soil trace elements can attach themselves to vermicast.
Everything in nature has an electrical charge. Some charges are positive, cations, and some are negative, anions. Organic vegetative matter is anionic and, because vermicast is highly vegetative matter, it is strongly anionic. Most trace elements are cationic.
In simple terms this means that trace elements are attracted to vermicast and readily bond to it in the same way that opposite poles of a magnet attract each other. Plants have a stronger pull than the vermicast and can therefore draw the trace elements away from the vermicast and into their roots.
Atiyeh et al. (2000) found that compost was higher in ammonium, while Vermicompost tended to be higher in nitrates, which is the more plant-available form of nitrogen.
Vermicasts are excellent media for harbouring N-fixing bacteria (Bhole, 1992).
Earthworms have multiple, interactive effects on rates and patterns of nitrogen mineralization and immobilization in natural and managed ecosystems (Edwards and Lofty, 1977; Lee, 1983; Lavelle and Martin, 1992; Blair et al., 1995b).
An excerpt from the document “Vermicast explained: what it is and how it works.” to read the full article, see our commercial documents section, otherwise
Edwards and Arancon (2004) report that “…we have researched the effects of relatively small applications of commercially-produced vermicomposts, on attacks by Pythium on cucumbers, Rhizoctonia on radishes in the greenhouse, and by Verticillium on strawberries and Phomopsis and Sphaerotheca fulginae on grapes in the field.
In all of these experiments, the Vermicompost applications suppressed the incidence of the disease significantly.”
Earthworms not only disperse microorganisms important in food production but also associated with mycorrhizae and other root symbionts, biocontrol agents and microbial antagonists of plant pathogens as well as microorganisms that act as pests (Edwards and Bohlen, 1996).
An excerpt from the document “Benefits of Vermicast in point form” to read the full article, see our commercial documents section, otherwise
Chitin is a compound that makes up the main component of the exoskeleton of insects.
Chitosan is a compound that is created from the breakdown of chitin.
Chitinase is the naturally occurring enzyme that breaks chitin down into chitosan.
These worm castings contain enzymes known as various forms of chitinase of which insects have a strong aversion.
The worm castings also have the ability to activate multiplication of the chitinase-producing bacteria found naturally in plants.
Testing has shown that the natural level of chitinase found in most plants is not sufficient to repel insects. The level of chitinase is multiplied to a repulsion level with the use of worm castings.
The level of the chitinase enzyme for effective repellence is in the range of 1 million cfu/gdw (Colony Forming Units/ gram dry weight). Worm castings were submitted for tests to determine the level of the chitinase enzyme production. The tests showed concentrations of chitinase in the range of 54 million CFU/gdw. This is concentration is over 50 times the estimated level for repellence.
It was observed that ants refuse to cross a layer of worm castings.
It has been found that worm castings can be used effectively to repel insects that feed on the internal liquid or nectar of various plants.
These include a large array of insect pests including white fly, aphids, spider mites, fruit flies, and other nectar-sucking insects.
When worm castings are put into the soil of the plant feeding area (stem to drip line), the evidence indicates that the worm castings activate an increase in the internal concentration of chitinase.
The level of chitinase in the nectar of leaves before treatment with worm castings is low.
When the chitinase concentration is low, insects are not repelled.
The increase in the chitinase level on small plants to a level sufficient to repel small insects occurs in a few weeks. The increase in the level of chitinase in large plants sufficient to repel the insects takes longer.
The time to increase the level of chitinase in a large plant such as a full grown hibiscus can take several months and trees will take longer.
The pollination nectar and pollen do not appear to get an increased level of chitinase producing organisms with the use of worm castings.
White fly infested hibiscus plants were treated with worm castings.
Worm castings were applied in a ½ inch layer from the stems to the drip line.
In about two months all white fly residue and cocoons were gone.
White flies from neighbouring plants, which had not been treated, would fly around the treated leaves but not land on these leaves.
An excerpt from the document “Benefits of Vermicast in point form” to read the full article, see our commercial documents section, otherwise
Could vermicast be a solution to my soil bourne Nematode problem?
Well, first of all what are Nematodes and are they all bad.
Soil Nematodes By Elaine R. Ingham covers this nicely, see the full article here.
THE LIVING SOIL: NEMATODES
Nematodes are non-segmented worms typically 1/500 of an inch (50 µm) in diameter and 1/20 of an inch (1 mm) in length. Those few species responsible for plant diseases have received a lot of attention, but far less is known about the majority of the nematode community that plays beneficial roles in soil.
An incredible variety of nematodes function at several trophic levels of the soil food web. Some feed on the plants and algae (first trophic level); others are grazers that feed on bacteria and fungi (second trophic level); and some feed on other nematodes (higher trophic levels).
Free-living nematodes can be divided into four broad groups based on their diet.
· Bacterial-feeders consume bacteria.
· Fungal-feeders feed by puncturing the cell wall of fungi and sucking out the internal contents.
· Predatory nematodes eat all types of nematodes and protozoa. They eat smaller organisms whole, or attach themselves to the cuticle of larger nematodes, scraping away until the prey’s internal body parts can be extracted.
· Omnivores eat a variety of organisms or may have a different diet at each life stage. Root-feeders are plant parasites, and thus are not free-living in the soil.
What Do Nematodes Do?
Nutrient cycling. Like protozoa, nematodes are important in mineralizing, or releasing, nutrients in plant-available forms. When nematodes eat bacteria or fungi, ammonium (NH4+) is released because bacteria and fungi contain much more nitrogen than the nematodes require.
Grazing. At low nematode densities, feeding by nematodes stimulates the growth rate of prey populations. That is, bacterial-feeders stimulate bacterial growth, plant-feeders stimulate plant growth, and so on. At higher densities, nematodes will reduce the population of their prey. This may decrease plant productivity, may negatively impact mycorrhizal fungi, and can reduce decomposition and immobilization rates by bacteria and fungi. Predatory nematodes may regulate populations of bacterial-and fungal-feeding nematodes, thus preventing over-grazing by those groups. Nematode grazing may control the balance between bacteria and fungi, and the species composition of the microbial community.
Dispersal of microbes. Nematodes help distribute bacteria and fungi through the soil and along roots by carrying live and dormant microbes on their surfaces and in their digestive systems.
Food source. Nematodes are food for higher level predators, including predatory nematodes, soil microarthropods, and soil insects. They are also parasitized by bacteria and fungi.
Disease suppression and development. Some nematodes cause disease. Others consume disease-causing organisms, such as root-feeding nematodes, or prevent their access to roots. These may be potential biocontrol agents.
Using vermiculture to control Nematode populations.
M.H. Panhwar and Farzana Panhwar in there paper “EARTHWORMS, VERMICASTS AND VERMI-CULTURE EXPERIENCE IN SINDH” say, Worms eat soil nematodes and reduce their population to almost one third. Thus no chemical nematocides are needed when adequate mulching is done.
Blueprint for a Successful Vermiculture Compost System. Developed by Dan Holcombe and J.J. Longfellow 1995 says, Redworm castings contain a high percentage of humus. Humus helps soil particles form into clusters, which create channels for the passage of air and improve its capacity to hold water. Humic acid present in humus, provides binding sites for the plant nutrients but also releases them to the plants upon demand. Humus is believed to aid in the prevention of harmful plant pathogens, fungi, nematodes and bacteria.
R.E. Gaddie and D.E. Douglas, Earthworms For Ecology and Profit, Vol. I “Scientific Earthworm Farming,” 1975, p. 175. Earthworm castings, in addition to their use as a potting soil, can be used as a planting soil for trees, vegetables, shrubs, and flowers. They may be used as a mulch so that the minerals leach directly into the ground when watered. The effects of earthworm castings used in any of these ways are immediately visible. They make plants grow fast and strong. Nematodes and diseases will not ruin gardens or plants if the soil is rich enough for them to grow fast. It is the weak plant in poor soil that is destroyed by nematodes and diseases.
Clive A. Edwards, Norman Q. Arancon, Eric Emerson, and Ryan Pulliam, Soil Ecology Laboratory, The Ohio State University, Columbus, OH.
SUPPRESSION OF PLANT PARASITIC NEMATODES AND ARTHROPOD PESTS BY VERMICOMPOST ‘TEAS’ says We have demonstrated clearly that solid vermicomposts can suppress plant parasitic nematodes in the field (Arancon et al, 2003). Our experiments on the effects of vermicompost ‘teas’ on nematodes were in the laboratory and greenhouse, in soils that had been artificially infested with the root knot of nematode (Meloidogyne incognita), which is a very serious pest of a wide range of crops all over the world. Read the full paper here.
So vermicast will indeed help with your nematode problem.
By boosting plant immune systems, creating a healthy balanced soil food web environment and introducing earthworm populations to control your nematode population.
An Excerpt from
Am-Euras. J. Agric. & Environ. Sci., 5 (S): 01-55, 2009
Earthworms Vermicompost: A Powerful Crop Nutrient over the Conventional Compost & Protective Soil Conditioner against the Destructive Chemical Fertilizers for Food Safety and Security
View the complete document here.
SOME SIGNIFICANT PROPERTIES OF VERMICOMPOST OF GREAT AGRONOMIC VALUES
a) High levels of bio-available nutrients for plants: Vermicompost contains most nutrients in plant-available forms such as ‘nitrates’ (N), ‘phosphates’ (P), ‘soluble’ potassium (K), & magnesium (Mg) and ‘exchangeable’ phosphorus (P) & calcium’ (Ca) (70 & 73). Vermicomposts have large particulate surface areas that provides many micro-sites for microbial activities and for the strong retention of nutrients (13 & 14).
b) High level of beneficial soil microorganisms promoting plant growth: Vermicomposts are rich in ‘microbial populations & diversity’, particularly ‘fungi’, ‘bacteria’ and ‘actinomycetes’ (45; 50; 154; 166 & 188). Teotia (187) and also Parle (134) reported bacterial count of 32 million per gram in fresh vermicast compared to 6-9 million per gram in the surrounding soil. Scheu (154) reported an increase of 90% in respiration rate in fresh vermicast indicating corresponding increase in the microbial population. Suhane (182) found that the total bacterial count was more than 1010per gram of vermicompost. It included Actinomycetes, Azotobacter, Rhizobium, Nitrobacter & phosphate solubilizing bacteria which ranged from 102 – 106per gm of vermicompost. The PSB has very significant role in making the essential nutrient phosphorus (P) ‘bio-available’ for plant growth promotion (147). Although phosphates are available in soils in rock forms but are not available to plant roots unless solubilized.
Pramanik (138) studied the microbial population in vermicompost prepared from cow dung and municipal solid wastes (MSW) as substrates (raw materials) and found that it was in highest abundance in cow dung vermicompost. The total bacterial count was 73 x 108 , the cellulolytic fungi was 59 x 106 and the nitrogen-fixing bacteria was 18 x 103 . It was least in vermicompost obtained from MSW. The total bacterial count was 16 x 108 , the cellulolytic fungi were 21 x 106 and the nitrogen-fixing bacteria were 5 x 103. Application of lime in the substrate enhanced the population of all above mentioned microbes irrespective of the substrates used for vermicomposting. Plant growth promoting bacteria (PGPB) directly stimulates growth by nitrogen (N) fixation, solubilization of nutrients, production of growth hormones such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase and indirectly by antagonising pathogenic fungi by production of siderophores, chitinase, ß-1,3-glucanase, antibiotics, fluorescent pigments and cyanide (95).
There is also substantial body of evidence to demonstrate that microbes, including bacteria, fungi, actinomycetes, yeasts and algae, also produce ‘plant growth regulators’ (PGRs) such as ‘auxins’, ‘gibberellins’, ‘cytokinins’, ‘ethylene’ and ‘ascorbic acids’ in appreciable quantities and as their population is significantly boosted by earthworms large quantities of PGRs are available in vermicompost (79).
c) Rich in growth hormones: Biochemical stimulating total plant growth: Researches show that vermicompost further stimulates plant growth even when plants are already receiving ‘optimal nutrition’. Vermicompost has consistently improved seed germination, enhanced seedling growth and development and increased plant productivity much more than would be possible from the mere conversion of mineral nutrients into plant-available forms. Arancon (12) found that maximum benefit from vermicompost is obtained when it constitutes between 10 to 40% of the growing medium. Neilson (126 & 127) and Tomati (192) have also reported that vermicompost contained growth promoting hormone ‘auxins’, ‘cytokinins’ and flowering hormone ‘gibberellins’ secreted by earthworms. It was demonstrated by Grappelli (90) & Tomati (190;191 & 192) that the growth of ornamental plants after adding aqueous extracts from vermicompost showed similar growth patterns as with the addition of auxins, gibberellins and cytokinins through the soil.
d) Rich in humic acids: Biochemical promoting root growth & nutrient uptake: Atiyeh (17; 18 & 19) speculates that the growth responses of plants from vermicompost appears more like ‘hormone-induced activity’ associated with the high levels of humic acids and humates in vermicompost rather than boosted by high levels of plant-available nutrients. This was also indicated by Canellas (49) who found that humic acids isolated from vermicompost enhanced root elongation and formation of lateral roots in maize roots. Pramanik (138) also reported that humic acids enhanced ‘nutrient uptake’ by the plants by increasing the permeability of root cell membrane, stimulating root growth and increasing proliferation of ‘root hairs’.
e) Vermicompost is free of pathogens: Nair (125) studied that 21 days of a combination of thermocomposting and vermicomposting produced compost with acceptable C:N ratio and good homogenous consistency of a fertilizer. The study also indicated that vermicomposting leads to greater reduction of pathogens after 3 months upon storage. Whereas, the samples which were subjected to only thermofilic composting, retained higher levels of pathogens even after 3 months.
f) Vermicompost is free of toxic chemicals: Several studies have found that earthworms effectively bioaccumulate or biodegrade several organic and inorganic chemicals including ‘heavy metals’, ‘organochlorine pesticide’ and ‘polycyclic aromatic hydrocarbons’ (PAHs) residues in the medium in which it inhabits.
g) Vermicompost protects plants against various pests and diseases: There has been considerable evidence in recent years regarding the ability of vermicompost to protect plants against various pests and diseases either by suppressing or repelling them or by inducing biological resistance in plants to fight them or by killing them through pesticidal action (3 & 5).
i) Induce biological resistance in plants: Vermicompost contains some antibiotics and actinomycetes which help in increasing the ‘power of biological resistance’ among the crop plants against pest and diseases. Pesticide spray was significantly reduced where earthworms and vermicompost were used in agriculture.(168 & 182).
ii) Repel crop pests: There seems to be strong evidence that worms varmicastings sometimes repel hard-bodied pests (3 & 12). Edwards & Arancon (74) reports statistically significant decrease in arthropods (aphids, buds, mealy bug, spider mite) populations and subsequent reduction in plant damage, in tomato, pepper and cabbage trials with 20% and 40% vermicompost additions. George Hahn, doing commercial vermicomposting in California, U.S., claims that his product repels many different insects pests. His explanation is that this is due to production of enzymes ‘chitinase’ by worms which breaks down the chitin in the insect’s exoskelton (124).
iii) Suppress plant disease: Edwards & Arancon (74) have found that use of vermicompost in crops inhibited the soil-born fungal diseases. They also found statistically significant suppression of plant-parasitic nematodes in field trials with pepper, tomatoes, strawberries and grapes. The scientific explanation behind this concept is that high levels of agronomically beneficial microbial population in vermicompost protects plants by out-competing plant pathogens for available food resources i.e. by starving them and also by blocking their excess to plant roots by occupying all the available sites. This concept is based on ‘soil-foodweb’ studies pioneered by Dr. Elaine Ingham of Corvallis, Oregon, U.S. (http://www.soilfoodweb.com). Edwards and Arancon (74) reported the agronomic effects of small applications of commercially produced vermicompost, on attacks by fungus Pythium on cucumber, Rhizoctonia on radishes in the greenhouse, by Verticillium on strawberries and by Phomposis and Sphaerotheca fulginae on grapes in the field. In all these experiments vermicompost applications suppressed the incidence of the disease significantly. They also found that the ability of pathogen suppression disappeared when the vermicompost was sterilized, convincingly indicating that the biological mechanism of disease suppression involved was ‘microbial antagonism.
Szczech (186), Orlikowski (130) Rodriguez (148) and Zaller (213) also found that the aqueous extracts of vermicomposts depress soil-borne pathogens and pests. They found in their field experiment that only half as many plants of tomatoes sprayed with aqueous extract of vermicompost were infected with Phytopthora infestans (that cause ‘late-blight’ disease) as those of control ones.