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Can soil compete with hydro yields? Please read

Discussion in 'Indoor Growing' started by Nirod, Jan 6, 2017.

  1.  
    The_Enthusiast

    The_Enthusiast Active Member

    Okay, most books i have are hard copy but i have one digital and hard copy - Soilless Culture - Theory and Practice - M. Raviv, J. Lieth (Elsevier, 2008) BBS.

    I'll copy paste a page 6-10 - chapter 1.3 (i am sorry if formatting isn't right) if someone wants this i can upload it somewhere:


    1.3 SOILLESS PRODUCTION AGRICULTURE
    World agriculture has changed dramatically over the last few decades, and this change continues, since the driving forces for these changes are still in place. These forces consist of the rapid scientific, economic and technological development of societies throughout the world. The increase in worlds’ population and the improvement in the standard of living in many countries have created a strong demand for high-value foods and ornamentals and particularly for out-of-season, high-quality produce. The demand for floricultural crops, including cut flowers, pot plants and bedding plants, has also grown dramatically. The result of these trends was the expanded use of a

    wide variety of protected cultivation systems, ranging from primitive screen or plastic film covers to completely controlled greenhouses. Initially this production was entirely in the ground where the soil had been modified so as to allow for good drainage. Since the production costs of protected cultivation are higher than that of open-field production, growers had to increase their production intensity to stay competitive. This was achieved by several techniques; prominent among these is the rapid increase in soilless production relative to total agricultural crop production. The major cause for shift away from the use of soil was the proliferation of soilborne pathogens in intensively cultivated greenhouses. Soil was replaced by various substrates, such as stone wool, polyurethane, perlite, scoria (tuff) and so on, since they are virtually free of pests and diseases due to their manufacturing processes. Also in reuse from crop to crop, these materials can be disinfested between uses so as to kill any microorganisms. The continuing shift to soilless cultivation is also driven by the fact that in soilless systems it is possible to have better control over several crucial factors, leading to greatly improved plant performance. Physical and hydraulic characteristics of most substrates are superior to those of soils. A soil-grown plant experiences relatively high water availability immediately after irrigation. At this time the macropores are filled with water followed by relatively slow drainage which is accompanied by entry of air into the soil macropores. Oxygen, which is consumed by plant roots and soil microflora, is replenished at a rate which may be slower than plant demand. When enough water is drained and evapotranspired, the porosity of the soil is such that atmospheric oxygen diffuses into the root zone. At the same time, some water is held by gradually increasing soil matric forces so that the plant has to invest a considerable amount of energy to take up enough water to compensate for transpiration losses due to atmospheric demand. Most substrates, on the other hand, allow a simultaneous optimization of both water and oxygen availabilities. The matric forces holding the water in substrates are much weaker than in soil. Consequently, plants grown in porous media at or near container capacity require less energy to extract water. At the same time, a significant fraction of the macropores is filled with air, and oxygen diffusion rate is high enough so that plants do not experience a risk of oxygen deficiency, such as experienced by plants grown in a soil near field capacity. This subject is quantitatively discussed in Chap. 3 and its practical translation into irrigation control is described in Chap. 4. Another factor is that nutrient availability to plant roots can be better manipulated and controlled in soilless cultivation than in most arable soils. The surface charge and chemical characteristics of substrates are the subjects of Chap. 6, while plant nutrition requirement and the methods of satisfying these needs are treated in Chap. 8. Chapter 7 isdevotedtothedescriptionoftheanalyticalmethods,usedtoselectadequatesubstrate for a specific aim, and other methods, used to control the nutritional status during the cropping period, so as to provide the growers with recommendations, aimed at optimizing plant performance. Lack of suitable soils, disease contamination after repeated use and the desire to apply optimal conditions for plant growth are leading to the worldwide trend of growing plants in soilless media. Most such plants are grown in greenhouses, generally
    under near-optimal production conditions. An inherent drawback of soilless vs. soilbased cultivation is the fact that in the latter the root volume is unrestricted while in containerized culture the root volume is restricted. This restricted root volume has several important effects, especially a limited supply of nutrients (Dubik et al., 1990; Bar-Tal, 1999). The limited root volume also increases root-to-root competition since there are more roots per unit volume of medium. Chapter 2 discusses the main functions of the root system while Chap. 13 quantitatively analyses the limitations imposed by a restricted root volume. Various substrates of organic origin are described in Chap. 11, while Chap. 12 describes substrates of inorganic origin and the issue of potting mixes. In both the chapters, subjects such as production, origin, physical and chemical characteristics, sterilization, re-use and waste disposal are discussed. Container production systems have advantages over in-ground production systems in terms of pollution prevention since it is possible, using these growing systems, to minimize or eliminate the discharge of nutritional ions and pesticide residues thus conserving freshwater reservoirs. Simultaneously, water- and nutrient-use efficiencies are typically significantly greater in container production, resulting in clear economic benefits.Throughoutthedevelopedcountriesmoreandmoreattentionisbeingdirected to reducing environmental pollution, and in the countries where this type of production represent a large portion of agricultural productivity, regulations are being created to force recirculation so as to minimize or eliminate run-off from the nurseries and greenhouses. The advantages and constraints of closed and semi-closed systems in an area that is currently seeing a lot of research and the state-of-the-art is described in Chap. 9. The risk of disease proliferation in recirculated production and the methods to avert this risk are described in Chap. 10. The book concludes with a chapter (Chap. 13) dealing with operational conclusions. In many cases practitioners are treating irrigation as separate from fertilization, and in turn as separate from the design and creation of the substrate in which the plants are grown. This chapter addresses the root-zone as a dynamic system and shows how such a system is put together and how it is managed so as to optimize crop production, while at the same time respecting the factors imposed by society (run-off elimination, labour savings, etc.). Another subject which is mentioned in this chapter is the emerging trend of ‘Organic hydroponics’ which seems to gain an increasing popularity in some parts of the world. One of the main future challenges for global horticulture is to produce adequate quantities of affordable food in less-developed countries. Simple, low-cost soilless production systems may be part of the solution to the problems created by the lack of fertile soils and know-how. The fact that a relatively small cultivated area can provide food for a large population can stimulate this development. This, in turn, should stimulate professionals to find alternatives to current expensive and high-tech pieces of equipment and practices, to be suitable and durable for the needs of remote areas. One of the most important advantages of soilless cultivation deserves mentioning in this context: in most of the developing countries, water is scarce and is of low quality. By superimposing the FAO’s hunger map (Fig. 1.4) on the aridity index map (Fig. 1.5), it is clear that in many regions of the world such as sub-Sahalian Africa, Namibia,
    FIGURE 1.4 Percentage of undernourished population around the globe (see also Plate 2; with kind permission of the FAO).
    FIGURE 1.5 Aridity index around the globe (see also Plate 3; with kind permission of the FAO).
    10 Chapter 1 Significance of Soilless Culture in Agriculture
    Mongolia and so on, a large part of the population suffers hunger mainly due to water scarcity. Since water-use efficiency of soilless plant production (and especially in recirculated systems) is higher than that of soil-grown plants, more food can be produced with such systems with less water. Also, plants growing in such systems can cope better with higher salinity levels than soil-grown plants. The reason for this is the connection between ample oxygen supply to the roots and their ability to exclude toxic ions such as Na+ and to withstand high osmotic pressure (Kriedemann and Sands, 1984; Drew and Dikumwin, 1985; Drew and Lauchli, 1985). It is interesting to note, in this respect, that soilless cultivation is practised in large scale in very arid regions such as most parts of Australia, parts of South Africa, Saudi Arabia and the southern part of Israel. In none of these countries, hunger is a problem. Thescienceofplantproductioninsoillesssystemsisstillyoung,andalthoughmuch work has been done, many questions still remain unanswered. One of the purposes of this book is to focus on the main issues of the physical and chemical environment of the rhizosphere and to identify areas where future research is needed so as to take further advantage of the available substrates and to propose desirable characteristics for future substrates and growing practices to be developed by next generation of researchers.
     
  2.  
    The_Enthusiast

    The_Enthusiast Active Member

    Also check Hydroponic Food Production by Howard M Resh, Ph.D chapter 2 Plant nutrition.
     
  3.  
    Rrog

    Rrog Well-Known Member

    This is actually one dude's opinion piece. Here's the motivation and orientation: "The major cause for shift away from the use of soil was the proliferation of soilborne pathogens in intensively cultivated greenhouses."

    Dumb Greenhouse Manager, but a poor reason to summarize / generalize that we've outgrown soil. Generally, it's more logical to renew poorly managed soil rather than convert serious volume food production to hydroponic.
     
  4.  
    The_Enthusiast

    The_Enthusiast Active Member

    For real? Are you okay man? Okay I'm ending my discussion with you now - as I suspect Harry Potter is you reading maximum...
    https://en.wikipedia.org/wiki/Elsevier
     
    Dr.Nick Riviera likes this.
  5.  
    greasemonkeymann

    greasemonkeymann Well-Known Member

    you know, you are right, only it wasn't an assumption, it was a mistaken-identity
    I thought you were the dude saying that it tastes like dirt and your customers couldn't discern the difference, my bad my man
    i'll edit the post
    quoted the wrong homie
     
    growingforfun likes this.
  6.  
    shadow_moose

    shadow_moose Well-Known Member

    While I have never grown my own hydro weed, and probably never will (my soil setup is just so easy), I regularly pull 2 pounds+ from a 4x4 indoors, and 3 pounds per plant outdoors in big beds.

    Indoors, I put 3 plants in my own knock off octopots I put together, each 25 gallons. I love the taste/quality of my weed, but honestly I think that all comes down to cure + genetics.

    At the end of the day the only single end-all answer you can give is this: it depends.
     
  7.  
    meangreengrowinmachine

    meangreengrowinmachine Well-Known Member

    hmm 25 gallon diy octopots sounds right up my alley! any insight into your process would be awesome!
     
  8.  
    Rrog

    Rrog Well-Known Member

    Hydro inherently leaves out the microbes. Now you have to manage everything. I get it that some folks don't like the dialog. I think it's great that folks grow weed in hydro. It's not great when they tout this as superior to soil, because it isn't on many levels.

    It was then asserted that hydro is reasonable to consider on large scale (the article posted), and I again say this is not practical / feasible for the reasons I've outlined.
     
    greasemonkeymann likes this.
  9.  
    greasemonkeymann

    greasemonkeymann Well-Known Member

    not to mention the fact that our way doesn't require phosphate mining, and the pollution of the water, amongst other things
     
    Urbz, meangreengrowinmachine and Rrog like this.
  10.  
    shadow_moose

    shadow_moose Well-Known Member

    People really don't realize how incredibly destructive synthetic fertilizer production is. Even if hydro yielded twice as much as soil reliably, I would forego those benefits. Why the hell does anyone want to buy nutrients that have been mined and refined by under paid workers in third world countries, using unsafe labor and environmental practices, often resulting in the death and injury of many people?

    Not to mention habitat destruction as a result of mineral extraction, changing eco-systems due to industrial fert run off, carbon impacts of phosphate refinement, carbon impacts of supply chain (hint: this is massive), and the fact that by buying hydro products most people are supporting big corporations.

    All of that together just seems like a really shitty moral proposition to me. I don't care if I yield a tiny bit less, at least my red wrigglers and my fungi aren't contributing the systematic destruction of this planet's ecosystems and those who inhabit them.
     
  11.  
    greasemonkeymann

    greasemonkeymann Well-Known Member

    applause.gif
    snoop.gif
    drop the mike.gif
     
    giglewigle, Urbz, Rrog and 1 other person like this.
  12.  
    Chunky Stool

    Chunky Stool Well-Known Member

    Many of the chemicals used in synthetic fertilizer production come from petroleum.
    Fossil fuels are not sustainable. (Captain Obvious says "you're welcome".)
     
  13.  
    greasemonkeymann

    greasemonkeymann Well-Known Member

    well of course they are silly
    don't you see mass amounts of dinosaurs dying and then decomposing for millions of yrs?
    yea...
    we all drive our cars on decayed dinosaur juice
    except Christians, cuz dinosaurs didn't exist and the earth is 2000 yrs old
    they run their cars on......
    brawdo.jpg
     
  14.  
    Glrrr

    Glrrr Member

    I agree, so tired of bland ass oranges at shaw's :(
     
  15.  
    meangreengrowinmachine

    meangreengrowinmachine Well-Known Member

    It's what plants crave! Why in the hell would we give our plants water... like from the toilet....
     
    greasemonkeymann likes this.
  16.  
    Rrog

    Rrog Well-Known Member

    Toilet water on dirt
     
  17.  
    Chunky Stool

    Chunky Stool Well-Known Member

    What processes do they use to turn shit into synthetic products? What are the brand names of these products?
     
  18.  
    meangreengrowinmachine

    meangreengrowinmachine Well-Known Member

    I think they are classified as that because you can not classify something as "organic" if it is made from human waste
     
    Last edited: Jan 6, 2017
  19.  
    Chunky Stool

    Chunky Stool Well-Known Member

    My waste sure smells organic.
    Just sayin... :P
     
  20.  
    meangreengrowinmachine

    meangreengrowinmachine Well-Known Member

    Hey I didn't make the usda rules lol
     
    Chunky Stool likes this.

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