Growth of Ornamental Plants in Container Media Amended with Biosolids Compost

The use of biosolids compost, in the formulation of media used in the commercial production of container grown nursery crops, has been slow in the Northeast region of the United States. When biosolids compost is used in growing media, it is limited to small percentages. Regulations in Connecticut restrict the use of most biosolids compost to growing media for containerized ornamental plants and landfill cover. Information on the benefits of using biosolids compost, to grow a wide range of plant species in containers, could increase usage by nurseries. Seven species of flowering annuals, nine species of herbaceous perennials and eight species of woody ornamentals were grown in media containing 0, 25, 50, and 100 percent (by volume) biosolids compost, in combination with a mixture of bark, peat and sand. Biosolids compost came from the Metropolitan District Corporation (MDC) facility in Hartford, Connecticut. It was a mixture of wood chips and digested biosolids (3:1 by volume). Optimal plant growth generally occurred in media containing 50 and 100 percent compost. Plants growing in media high in compost were often somewhat stunted and chlorotic for several weeks after planting probably due to higher levels of salinity and ammonium nitrogen in their media. However, by the middle of the growing season these plants had recovered and at season's end, they were often superior to plants grown in media with less compost. Increasing proportions of compost generally increased the amounts of plant nutrients and heavy metals in media while decreasing air filled pore space. All heavy metal concentrations were below levels of concern.     

Corn Wastes and Peanut Shell as Growing Media for Production of Red Radish Plants in Soilless System

ABSTRACT

Peat is considered the conventional growing medium in most soilless culture systems. The high cost of peat and the urgent need of agricultural wastes recycling encouraged the scientists and soilless culture users to search for an alternative growth medium where optimal growth conditions are achieved and help in the safe disposal of wastes. In the current study, peanut shell (PS) and corn wastes (CW) were used as growing media in comparison to peat moss (PM). The tested organic wastes and peat moss were examined with sand at three mixing ratios (1:1 “M₁”, 1:2 “M₂” and 1:3 “M₃” raw material: washed sand, respectively). Red radish (Raphanus raphanistrum subsp. sativus) plant were cultivated in 5 kg pots filled with the instigated growing media. Most of the recoded growth parameters were found in PS and PM growing media, while the lowest ones were found in CW. PS medium contained available N and P higher by 141 and 29% above the PM media. Although the peat moss gave the highest values in the measured growth characteristics, its high price decreased the net profit. The highest net profit value was obtained from PSM₂ followed by PSM₁ and PSM₃. According to the obtained results, the characteristics of the growth media derived from peanut shell qualify them for use in the production of red radish in soilless culture systems.     

Leachability of Arsenic from Field Containers Filled With Plant Growth Medium Amended With Biosolids Compost

The leaching of arsenic (As) from plant growth medium, admixed with different proportions of composted biosolids in field containers, was determined over a four-month period. Eight-week-old perennial flowers, Coreopsis grandiflora L, were transplanted in the field in 2-L containers filled with plant growth media. The treatments were replicated three times and rainfall was supplemented to supply 2 cm of water per day. Water percolating through potted plant containers was collected biweekly and analyzed for As using graphite furnace atomic spectrometry. The concentrations of As in the leachates increased with increasing proportions of compost in the medium and decreased with time of leaching, generally remaining below the drinking water standard of 50 μg/L after two months. Leaching of As occurred at a rapid rate initially but then continued at a slow rate. Compared to other metals of concern, as Cd, Cr, Ni and Pb, As in the compost appeared more mobile.     

Use of Spent Coffee Ground Compost in Peat-Based Growing Media for the Production of Basil and Tomato Potting Plants

A spent coffee ground compost (SCGC) was evaluated as an alternative component of growing media to partially replace commercial peat (CP) and fertilizers in the production of potted plants. Seven mixtures (CP 100% + solid mineral fertilizers, CP 100% + liquid mineral fertilizers, CP 90% + SCGC 10%, CP 80% + SCGC 20%, CP 70% + SCGC 30%, CP 60% + SCGC 40%, and CP 100% without fertilizers) were compared for the production of basil and tomato potted plants. SCGC used in a proportion up to 40% enhanced the general plant stand by affecting the dry weight and the measured foliar parameters. Tomato and basil recorded good growth rates on SCGC-amended media, showing quality indices similar to those obtained under fertilization, evidencing compost plant nutrition provision. SCGC appears to be suitable for application as a partial peat substitute in the production of potted plants.     

Nutrient Release Dynamics in Soils Amended With Municipal Solid Waste Compost in Laboratory Incubations

Two municipal solid waste composts were added to three agricultural soils developed over different parent material (schist, gabbro and granite) and incubated in two laboratory studies, in order to assess the effect of compost addition in the dynamics of soil Ca, Mg, K and P. Soils and mixtures of soil and compost (2.5% dry weight, roughly equivalent to 60 t ha^?1) were incubated at 25°C for three months in a first experiment, and for five months in a second experiment. The concentrations of available Ca, Mg, K and P were determined throughout both experiments. The soils amended with compost always had higher available Ca, Mg and K concentrations than the soils without amendment. The increases were approximately 800 mg kg^?1 for Ca, 30 mg kg^?1 for Mg, and 150 mg kg^?1 for K. Nevertheless, the concentrations of these elements did not increase with time. The available P concentrations were not increased by the addition of compost, an effect which is attributed both to microbial immobilization and to the P-fixation capacity of the soils. Therefore, the expected release of these elements in parallel to compost mineralization was not observed during the experiments, and the only fertilizing effect of the compost was that of their initial input in available forms.     

Evolution of Humic Fractions in Calcimagnesic Soils And Brown Isohumic Soils Amended With Compost and Manure

The composting process of organic wastes consists of the bioconversion of biologically unstable wastes to stabilized products for application to soils. This study was carried out on different soils (brown isohumic soils in Sfax region in southern Tunisia and calcimagnesic soils in Korba region in northern Tunisia). The mineralization process of organic matter is more important in isohumic soils, showing less tenors of fine fractions than in calcimagnesic soils. The study of different humic fractions in amended soils shows that humic acid tenors and the polymerization rates are linked to soil nature. Calcimagnesic soils ensure a more important humification than isohumic soils.     

Utilization of Sugarcane Compost as a Soil Amendment In a Tomato Production System

Sugarcane filtercake (a waste by-product of sugarcane processing) compost was evaluated as a partial substitute for inorganic fertilizer in a fresh-market tomato (Lycopersicon esculentum Mill.) crop production system. Plots receiving fertilization rates of 0, 50, or 100% (153N-134P- 280K, kg ha^?1) of a typical commercial application were amended with or without compost (188 t ha^?1). Tomato (cv. Sunny) seedlings were transplanted in the center of each raised bed. A randomized complete block experimental design was used with the six compost/fertilization treatments replicated four times. Plant height (22 days after transplanting), stem diameter and shoot weight (just after final harvest), fruit yields, and fruit size were measured for each plot. Plants grown with no fertilization were taller (22 days after transplanting) in plots amended with than without compost, but not at 50 or 100% fertilization rates. Plots that were amended with compost had plants with heavier shoots (kg/plant), thicker stems, higher total and early marketable fruit number and weight and larger fruit size than plots not amended with compost, regardless of fertilization rates. These results suggest that sugarcane filtercake compost can serve as a partial substitute for inorganic fertilizer while maintaining or improving tomato fruit yields and size.     

Evaluation of Compost Maturity,Hydrophysical and Physicochemical Properties: Indicators for Use as a Component of Growing Media

The cocomposting of agricultural waste is a new management priority in Tunisia. In this study, four composts were evaluated by comparing the changes in measured hydrophysical and physicochemical properties and phytotoxicity. The organic wastes used were almond shell (AS), sesame bark (SB), olive husk (OH), and green and wood wastes (GW and WW, respectively). Composts CI and CII were composed of AS/SB and OH/SB, respectively, at a ratio of 75/25 (wet weight basis). CIII consisted of OH, SB and CAS (coarsely-ground almond shell used as a bulking agent) at a ratio of 55/25/20. Finally, CIV was composed of 25%SB+9%CAS+18%GW+48%WW. The composts studied were characterized by basic pH and an electric conductivity (EC) value ranging from 1.6 to 2.4 mS/cm. The organic matter contents (OM) and C/N ratios of composts ranged from 20 to 46% and from 10 to 21%, respectively. Based on hydrophysical analyses, composts CI, CIII and CIV, containing AS, were shown to have a porosity and a water content of 10-26% and 10-20%, respectively. The phytotoxicity of composts was studied on the basis of cress seed germination. Results revealed that differences in properties are mainly related to the nature of composted waste and that some of these composts are compatible for use as constituents in growing media for horticultural soilless cultures.     

Iron Chlorosis in Gerber as Related to Properties of Various Types of Compost used as Growing Media

Abstract

Nutrient deficiencies in crop plants may be influenced by a number of properties of the growing media. Some peat‐substitute substrates can promote iron (Fe) chlorosis in sensitive plants, which has traditionally been ascribed to the elevated pH of growing media. To identify the origin of this problem in various types of composted organic residues used as growing media and possible corrections, a complete randomized experiment on gerber (Gerbera jamesonii Adlam) as an Fe‐chlorosis sensitive crop involving three factors (growing medium, medium acidification, and the medium treatment with Fe) was performed.

Although the Fe content in plants decreased with increasing pH in the growing medium, the chlorophyll content as measured using a chlorophyll meter (Minolta Soil Plant Analysis Development, SPAD) was not significantly related to pH. The SPAD readings and Fe concentrations in plants, dry matter, and flower production were not significantly related to diethylenetriaminepentaacetic acid (DTPA)–extractable Fe in the growing media. The addition of Fe‐chelate significantly increased yield (P<0.01), and SPAD at 65 and 96 days after planting (P<0.001 and P<0.01, respectively). However, the effect of the acid treatment was, different depending on the growing media. When the acidification promoted a positive effect on SPAD readings, this was nonsignificantly different than that obtained with the application of Fe‐chelate. The estimated amount of available Fe in the growing media was not relevant, which explains the incidence of chlorosis as physiological factors related to pH.     

Growth of Rhododendron,Rudbeckia and Thujia and the Leaching of Nitrates as Affected by the pH of Potting Media Amended with Biosolids Compost

A conventional potting media containing peat moss, softwood bark and sand was amended to contain 0,25,50,75 and 100 (percent vol^?1) municipal compost made from yard waste and biosolids. Each medium was adjusted with limestone and sulfur to an approximate pH of 5.0, 6.0 or 7.0. Rhododendron Panticum L. ‘Anah Kruschke’ (Rhododendron), Thujia occidentalis L. (Arborvitae) and Rudbeckia hirta L. ‘Goldilocks’ (Black-eyed Susan) were grown in each medium and pH level for 18 months. Leachate from pots was tested for NO₃-N and NH₃-N+NH₄-N to determine how media pH and the amount of compost effected the potential for potting media to be a source of nitrate in surface and ground water.

Media pH affected plant growth more than the percent compost. Compared to media with a pH of 7.0, statistically significant increases in the growth of Rhododendron occurred in media with a pH of 5.0 or 6.0. This pH effect was similar but less pronounced for Thujia. Growth of Rudbeckia was not effected by media pH or percent compost. Media with 0 and 25 percent compost leached the least nitrogen regardless of pH. Media with 75 and 100 percent compost at pH 5.0 and 6.0 leached the most nitrogen. The increase in nitrogen leaching in the more acidic media was associated with higher concentrations NH₃-N+NH₄-N. Nitrogen in leachate was greatest during the four weeks immediately after the pots were placed in the field and four weeks after fertilizer was applied in June of the second year of the experiment.     

Ceramic Aggregate Sorption and Desorption Chemistry: Implications for Use as a Component of Soilless Media

Ceramic aggregates (Turface® and Profile®) are common soilless media components, but their sorption/desorption chemistry is poorly understood. We investigated: labile (readily desorb-able or readily plant-available) ion concentrations; the effect of rinsing and soaking pretreatments on labile ions; sorption of applied nutrients; and nutrient uptake from the aggregates by plants. Variability in labile ions was extremely high among bags of aggregates. Manganese, boron, magnesium, calcium, sulfur and potassium were most likely to desorb in excess for plants. Phosphorus, iron, copper and zinc were sorbed by the aggregates; only copper was found nearly deficient in plant tissue. Rinsing and soaking pretreatments adjusted labile ions to more suitable concentrations for plants. However, growth data suggested a worst-case scenario of high levels of labile ions may not be mitigated by these pretreatments. With frequent leaching after planting or where the aggregates are a minor component of media, excessive nutrient uptake would likely be limited.     

Evaluation of Different Organic Growing Media for Growth and Flowering of Petunia

Studies were carried out at Punjab Agricultural University Landscape Nursery from November 2009 to July 2010 to evaluate the different soil-based and soilless media compositions on growth and flowering of petunia hybrids. Different media compositions comprising leaf mold, sewage sludge, vermicompost, farmyard manure, cocopeat, and soil were evaluated in definite ratios to select an ideal potting media for raising potted (6-inch pots) petunia plants. Results revealed that media composition M6 was the best potting media to raise petunia plants. Petunia plants raised in this media [soil + sewage sludge (K) (2:1)] exhibit maximum (55.3 days) number of days of flowering duration, maximum (129.5 days) number of days to flowering withering, recorded minimum (74.2 days) number of days to bud emergence, and counted more (30.0) number of buds and maximum (15.0) number of branches. This media composition was observed to be ideal for raising petunia seedlings to full-grown floriferous potted petunia plants with all the desirable characteristics essential for a specimen display.     

Recycling of Organic Wastes Amended with Trichoderma and Gluconacetobacter for Sustenance in Soil Health and Sugarcane Ratoon Yield in Udic Ustochrept

A field experiment was conducted with the objectives to relate the changes in the physical properties, soil organic carbon (SOC), nutrient availability, and uptake and output input ratios for sustaining sugarcane ratoon growth and yield in an Udic ustochrept. Eight combinations of trash and farmyard manure (FYM) with and without Trichoderma viride and Gluconacetobacter diazotrophicus were applied in two sugarcane ratoon (first and second ratoon in succession) crops. Application of Trichoderma-enriched trash showed the lowest bulk density (1.36 Mg m^?3) and the greatest infiltration rate (4.5 mm h^?1). Greater rate of increase in SOC was observed under inoculation of Trichoderma with FYM compared to trash mulch. The output/input ratios were greater in plots having trash-based treatments compared to FYM and inorganic fertilizers. Bioagent-inoculated FYM produced greater mean sugar yield (8.89 t ha^?1) compared to bioagent-inoculated trash (7.97 t ha^?1).     

Desorption Characteristics of Three Mineral Oxides and a Non-crystalline Aluminosilicate for Supplying Phosphate in Soilless Root Media

The objective was to evaluate phosphate desorption characteristics of synthetic hematite, goethite, and allophane and commercial alumina after loading at maximum adsorbed phosphate levels to determine their potential to release phosphate at a constant, low level to sustain plant growth in soilless media and reduce phosphate leaching. Desorption isotherms were measured at pH 6.4 ± 0.1 using a continuously stirred-flow reactor. The time period during which dissolved phosphate was maintained within the range of 5–0.2 mg·L^?1 phosphate-P decreased in the order: allophane (12.4 d) > alumina (4.6 d) > goethite (3.6 d) > hematite (1.9 d). Allophane released the most phosphate during the desorption process (40% of maximum adsorbed phosphate; 12.7 mg?g^?1) followed by alumina and goethite (19–20%; ≈2.5 mg?g^?1) and lastly hematite (5%; 0.1 mg?g^?1). Allophane demonstrated the greatest potential as a phosphate-charged source for soilless root media, in amount and duration of phosphate release.     

Composts as Media Constituents for Vegetable Transplant Production

The use of compost with high salt concentration was evaluated, under commercial conditions, as a potential growing media constituent for vegetable transplant production. Two composts were prepared from sweet sorghum bagasse, pine bark, and either urea (compost A) or brewery sludge (compost B) as N source. Three vegetable species — broccoli (Brassica oleracea), tomato (Lycopersicum esculentum), and onion (Allium cepa) with different tolerance to salinity were used. Eleven substrates were formulated and tested: a control consisting of a moss peat-based commercial substrate; compost A; compost B; and, eight mixtures containing 33 or 67% by volume of each compost with either raw peat moss or commercial substrate as diluent. All the substrates prepared had suitable physical, physicochemical and chemical properties for use as growing media, except for the electrical conductivity (ranging from 3.20 to 13.21 dS m^?1) which was above the reference levels for soilless cultivation. Broccoli was the least affected by substrate salinity whilst tomato was the most. Onion transplants had an intermediate response to saline conditions. Tomato seed germination was markedly reduced when compost A, with a higher salt concentration, was used at a rate higher than 67%. Media prepared with either of the composts, and mixed with either a commercial substrate or peat in a rate up to 67%, did not cause any detrimental effect on the growth and nutritional status of broccoli, tomato and onion transplants, despite the high initial salinity of the substrates. These composts appear to be acceptable substitutes for Sphagnum peat in seed sowing mixtures.     

Evaluation of New Container Media for Aglaonema Production

Mandated processing of waste by‐products in the United States has inspired national interest in addressing the effectiveness of using composted biosolids and yard trimmings to grow containerized plants. Diamond bay Chinese evergreen (Aglaonema ‘Diamond Bay’) was transplanted in containers filled with one of eight formulated media (components added by volume). Medium 1 was a standard mix commonly used in Aglaonema production (5:2:3 peat–vermiculite–perlite); medium 2 was formulated on site to contain peat–bark–stalite–rice hulls–coir (2:2:3:1:2); media 3 and 4 contained 40% biosolid–yard waste compost instead of peat and with or without 20% stalite, respectively; and media 5, 6, 7, and 8 were commercially formulated to contain peat–bark–perlite–rice hulls–coir (4:1.5:2.5:1:1, 4:1.5:2.5:1:1, 4:2:2:1:1, and 3.0:2.5:2:1:1.5, respectively). Physical and chemical properties of the eight media were in ranges 50–65% container water‐holding capacity, 2.9–7.8% air‐filled porosity, 55–80% moisture (w/w), 0.11–0.37 g·cm³ bulk density, 0.34–0.96 g·cm³ particle density, 4.2–7.2 pH, 0.12–4.4 dS·m^?1 electrical conductivity (EC), 27.3–54.5 meg/100 g cation exchange capacity (CEC), 17.9–39.0% carbon (C), and 0.22–1.7% nitrogen (N). Medium 4 (40% compost) had 5.5 times more ammoniacal N (NH₄‐N) and 1.7 times more nitrate N (NO₃‐N) than that of the standard commercial mix. At week 8, plants grown in media 2 and 5 were 8.9% to 9.5% taller than plants grown in medium 1 (commercial standard). At week 16, there were no significant differences in plant heights or growth indices among media. At week 24, there were no significant differences in plant height, growth index, visual quality, shoot dry weight, and root dry weight among media. However, cumulative phosphorus (P) leaching from media 1, 4, and 5 was significantly more than leaching from media 2 and 8. This study suggests that compost may serve as a horticulturally suitable and cost‐effective alternative to peat‐based media for Aglaonema production.     

A Comparison of Static Pile and Turned Windrow Methods for Poultry Litter Compost Production

Alternate technologies of compost manufactured from poultry litter (manure) were studied as a means of producing a value-added product for the landscape and nursery industry. Static pile and turned windrow technologies were investigated on a commercial scale with the composting of nearly 300 tons of material. The major difference between the technologies is the amount of energy and labor required. Static pile systems require less energy but more time than windrow turned systems. There was no process advantage found for passively aerated static piles over static piles but costs of passive aeration for pipes and labor were higher than for static piles. Machine turned windrows completed active temperature production within 100 days while portions of both the static and passively aerated piles continued to actively compost past 300 days. Process operational costs and compost quality were similar among the compost methods studied. Production operational cost is driven by the cost of compost ingredients and accounted for 60 to 70% of the cost in the pilot study. Ingredients were poultry litter, wood chips and sawdust. Screened compost was produced at an operational cost of $30 while unscreened compost could be produced for $20 per ton of compost. A production scheme where poultry litter is static pile composted on farms for later transport to regional processing centers appears feasible. This two-part composting procedure will eliminate the transport of raw litter and improve poultry biosecurity. Most likely, a private compost business would provide the expertise, on-farm compost procedures and operate the regional facility.     

Evaluation of Compost for Use as a Soil Amendment in Corn and Soybean Production

The purpose of this research project was to 1) evaluate rate of compost application and 2) to compare compost with uncomposted raw material and inorganic fertilizer N application upon maize and soybean growth and productivity, and upon soil characteristics. During the first three years of the study, the source of uncomposted material and compost was food waste and ground newsprint. During years 4 to 9 of the study, the source of uncomposted material and compost was dairy cow manure and wood chips. Application rates in field site 1 were 0, 11.2, 22.4, 33.6 and 44.8 Mg ha^?1 compost, 44.8 Mg ha^?1 uncomposted material and 140 kg ha^?1 fertilizer N (as urea). Application rates in field site 2 were 0, 22.4, 44.8, 67.2 and 134.4 Mg ha^?1 compost, 134.4 Mg ha^?1 uncomposted manure and 180 kg ha^?1 fertilizer N (dry matter basis). The high rates of compost application significantly raised organic matter levels, and available P and K compared to inorganic fertilizer N. Uncomposted manure and increasing compost application rates significantly increased grain yield, number of kernels per plant and plant weight. Composting significantly reduced pathogen indicator bacteria concentrations. The data of this study suggest that on these high organic matter soils 22.4 Mg ha^?1 to 44.8 Mg ha^?1 are optimal compost application rates.     

Best Nitrogen and Irrigation Management Practices for Citrus Production in Sandy Soils

Drinking water monitoring data have indicated anincrease in nitrate-nitrogen (NO₃-N) concentration ingroundwater in some parts of the citrus production region ofFlorida. A proactive, incentive-based program of developingcrop-specific best management practices (BMP) began with theFlorida N-BMP legislation passed in 1994. A combination ofcareful irrigation and nitrogen (N) management is needed toimprove N uptake efficiency and to minimize potential leaching ofnitrate (NO₃-N) to the groundwater. An improved Nmanagement practice is considered as a BMP, only if that practiceis proved to decrease NO₃-N leaching into groundwater incommercial groves without adversely impacting the economics ofproduction. Therefore, long-term evaluation of horticulturalresponses as well as monitoring of groundwater NO₃-N wereconducted in five commercial groves representing different soiltypes, citrus variety and rootstock, tree age, and culturalpractices to determine the impact of changes in N managementand/or irrigation scheduling. Groundwater NO₃-N, leafnutrient concentrations, fruit yield and fruit quality weremonitored for 15 months under the growers' routine managementand, subsequently for 48 months, with improved N and irrigationmanagement practices. The N management practices evaluated inthis study included broadcast application of a combination ofwater soluble and slow release granular products, fertigation,and a combination of foliar application and fertigation. Irrigation management was improved by using tensiometer set pointof 10 and 15 cbar. This article presents the fruit yield, andconcentrations of N, P, K in six-month spring flush during thestudy period. The study showed that 5 to 8 yr old Valenciatrees on Volkamar lemon rootstock produced high quality fruit inthe range of 59 to 81 Mg ha^-1 with 168 kg N ha^-1 asfertigation combined with improved irrigation scheduling. Fruityield of 36 yr old Valencia orange trees on Rough lemonrootstock was greater with application of 180 kg N ha^-1 yr^-1 as fertigation compared to that of the trees whichreceived a similar rate of N as three broadcast applications ofgranular product. Fertilizer program comprising three foliarapplications of N using low biuret urea to deliver 66 kg N ha^-1 yr^-1 and an additional 76 kg N ha^-1yr^-1as fertigation was the most effective for decreasing the surficialgroundwater NO₃-N while maintaining optimal fruit productionand nutritional status of the leaves. This study demonstratedthat economically and technically feasible N-BMPs can bedeveloped for citrus grown on sandy soils with a combination ofimproved N management and irrigation scheduling.