Anaerobically digested dairy fiber in soilless potting media for poinsettias

Abstract

Purpose Sphagnum peat moss has been a primary component of soilless potting media for decades. Concerns over the sustainability of harvesting peat have fostered a search for renewable media components. Anaerobically digested dairy fiber (ADDF), a by-product of methane production, shows promise as an alternative to peat. Methods Poinsettias (Euphorbia pulcherrima 'Classic Red') were grown in media containing peat-perlite in a 4:1 ratio or peat-ADDF-perlite in a 2:2:1 ratio. Bulk density, container capacity, water-holding capacity, pH and EC of both mixes were evaluated before planting. Shoot height, shoot fresh weight, shoot dry weight and leaf tissue nutrient concentrations of plants were measured at commercial maturity. PourThru samples were taken from pots regularly to evaluate phosphate leaching potential from ADDF. Results There were no differences in physiochemical properties between mixes. Poinsettias grown in the peat-ADDF-perlite were significantly taller and had greater shoot fresh weight, shoot dry weight and leaf tissue N, P, Mn, Na and Zn concentrations than control plants. PourThru samples from pots containing peat-ADDF-perlite had greater phosphate concentrations than peat-perlite for approximately 5 weeks. Conclusions The ADDF used in this trial can be used as a 50 % substitute for peat in potting media for poinsettias and contains significant amounts of plant available nutrients. Additional nutrients supplied by ADDF should be carefully managed as they can contribute to plant growth or leaching pollution. Using ADDF in media could provide growers with a local, renewable substitute for peat and provide supplemental income to dairy farmer.

Physio-chemical characterization of indigenous agricultural waste materials for the development of potting media

“…“Coconut coir” is imported from Sri Lanka and other countries and bears an expensive cost so that it can be replaced with indigenous crops-based sources as alternatives ( Robertson, 1993 ), but also due to inconsistent supply ( Bullock et al, 2012 ). The various organic products of crops and dairy animals due to fiber and minute nutrient quantity ( Lamont and Elliott, 2016 ), wood biochar ( Steiner and Harttung, 2014 ), pine tree substrate ( Jackson et al, 2008 ), date palm wastes ( Ghehsareh et al, 2012 , Mohammadi Ghehsareh and Ghehsareh, 2013 ), vermicomposts ( Gupta et al, 2014 ) “corn cob” ( Haghighi et al, 2016 ), peanut shells ( Mohammadi Torkashvand et al, 2015 ), and sunflower empty head and cotton spent mushroom compost ( Lopes et al, 2015 ), have been identified as potting ingredients. The coconut peat exhibit hydrophobic properties due to fine particle size, while coir is hydrophilic due to its coarse particle size in the potting ingredients produce unsatisfactory results ( Chong, 2015 ).…”

Approaches for adding value to anaerobically digested dairy fiber

“…Properly treated, typically by composting or AD, organic wastes have the potential to substitute for peat and bark as components of the growth substrates in containerized plant production systems [37,46,47,48]. Specific to AD fiber, there is a small but growing body of research showing that AD fiber has the potential to meet the requirements for a component of high-quality growth substrates [49,50,51,52,53,54,55]. To produce container crops according to schedule, greenhouse and nursery growers must have reliable source of high quality growth substrates that are consistent over time and that have appropriate physical and chemical properties for their crops [34,46,56,57].…”

“…Root growth of plants in the experimental substrates was similar to the controls in both irrigation systems. In two recent works, Lamont and Elliot [54,55] Although not anaerobically digested, screened solids from a 1600-cow Florida dairy were processed through a horizontal drum digester or composter to produce a dairy manure peat-substitute marketed as cowpeat [61]). In experiments with foliage plants, Li et al [62]) replaced peat with cowpeat at 10 % increments from 10 to 60 % in 9 the propagation substrate for germinating Asparagus densiflorus seeds and for rooting cuttings of Epipremnum aureum, Philodendron scandens ssp.…”

Process and quality evaluation of different improved composts made with a smart laboratory pilot plant

“…Sometimes, other organic materials are incorporated into the growth media such as bark, wood fibres, rice husks, etc., as well as composted materials, especially when available locally; inorganic materials are often also added, such as perlite, vermiculite, expanded clay and pumice, above all to improve the physical properties of the substrate. However, research recently emphasized the prospect to obtain high quality horticultural productions using substrates including compost mixed with other components [ [15] , [16] , [17] , [18] , [19] ]. Composting normally takes place in three phases which follow the temperature pattern: increasing at the beginning, up to a thermophilic stage (T ≈ 60 °C); decreasing after the peak, in the mesophilic phase (T < 45 °C) and constant, in the curing phase (≈ room temperature).…”