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WHEN it comes to accuracy with fertigation programs , soils inhibit accurate feeding schedules as they are often heavily amended with fertilizer products .”
The water retention of soilless substrates is an often overlooked yet important factor when developing a cultivation plan . Modern gardeners choose their cultivation media based on several factors , including operational logistics , fertigation programs , and environmental constraints . To illustrate , organic soils are attractive in a logistical sense because the same soil can be reused each growing season . However , when it comes to accuracy with fertigation programs , soils inhibit accurate feeding schedules as they are often heavily amended with fertilizer products . Conversely , soilless substrates generally don ’ t perform well outdoors in hot , arid conditions as they don ’ t retain water well enough to support plant growth in such extreme climates . When planning a garden operation , these factors should be considered before deciding to purchase a specific substrate in bulk .
Soilless Media Gaining Ground
For controlled environment agriculture ( CEA ), the use of soilless cultivation media is consistently growing in popularity . Most CEA horticulturists favor the use of these substrates because they are inert , meaning that they contain nearly no additional fertilizers or amendments . Point being , most soilless mediums allow growers exact control over what they are feeding their plants , which is an obvious extension of CEA methodology . The most popular types of soilless cultivation media are coco coir , stone wool , clay pebbles , perlite , and some proprietary products . Most hobbyist gardeners are not aware of how horticulture is nuanced by different cultivation media . The exact same species and strain of a plant will grow differently in a slightly different substrate . This notion is important because if a grower decides to switch their substrate , they must pivot their entire feeding and watering methodology to accommodate for this infrastructural change . As different soilless media retain water at different capacities , these irregularities must be accounted for in the development of successful irrigation and fertigation regimes . Yet , most horticulturists don ’ t have the luxury of implementing trial-and-error runs to decipher how water retention in soilless mediums will affect their garden ’ s overall performance .
To shed some insight onto the complexities of water retention in soilless substrate growing , Maximum Yield reached out to highly accomplished horticulturist Doug Millar . Over the past 20 years , Millar has worked in various capacities related to modern gardening , including commercial floriculture cultivation , greenhouse equipment design , hydroponic product development , and vertical farming . For the last 10 years , he has studied and worked for Symbi Biological , a research group in the San Francisco Bay area that specializes in sustainable food systems development . Millar ’ s latest project at Simbi Biological is a closed loop aquaponics system . This cutting-edge research combines elements of traditional biology and modern gardening technology with the aim of helping solve food production issues worldwide .
Of the soilless mediums , which is the most difficult to use and why ?
Each medium has its own learning curve . There is a difference between surviving and thriving — finding that sweet spot is really a matter of trial and error for most growers when using a new medium . I ’ d say clay pebbles are likely the most difficult simply because they often look dry on the top but hold moisture on the bottom . This issue often leads to problems with overwatering and pests . Materials handling is also a factor with pebbles as all the other options are much lighter to lift and move .
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