at 57 lb/acre. Two weeks after fumigation, beds were uncovered and measured amounts of each preplant fertilizer source were spread on bed tops and incorporated on the 2 inches of the soil with garden rakes. Immediately after, beds were recovered with
Bielinski M. Santos
Mark Gaskell and Tim Hartz
% as available, as inorganic fertilizer sources. High N content animal byproducts (fishery wastes, blood and feather meal, seabird guano, etc.) mineralize rapidly in warm, moist soil, with the majority of N available for plant uptake within several
Allen D. Owings, Edward W. Bush and Mitchell W. Goyne
Leachates were collected at 3-month intervals over 12 months to determine the influence of bark, controlled-release fertilizer, and dolomitic lime sources and dolomitic lime application rates on pH of nursery media. The randomized complete-block design was arranged as a factorial and included three bark sources (pinebark, hardwood, and pinebark + hardwood), two fertilizer sources (Nutricote 17-7-8 and SierraBlen 18-7-10), and two dolomitic lime sources (microencapsulated granular and pulverized). Dolomitic lime application rates were 0, 5, 10, and 15 pounds per cubic yard. Leachate pH was influenced over the one-year evaluation period by fertilizer source, bark source, and application rate of dolomitic lime. Dolomitic lime source was not a significant factor in adjustment of leachate pH. Pinebark medium had lower leachate pHs than hardwood medium and the medium containing hardwood and pinebark. Dolomitic lime influenced leachate pH of pinebark medium more than the other bark sources. SierraBlen was more acid-forming than Nutricote.
Xin Zhao, Edward E. Carey and Takeo Iwamoto
An experiment was conducted at Olathe, Kan., in Spring 2004 to investigate the influence of organic and conventional fertilizer sources and application rates on antioxidant levels of pac choi (Brassica rapa L. cv. Mei Qing) in open fields and poly-covered high-tunnel plots. Organic plots received pre-plant application of composted cattle manure and alfalfa (Hu-More 1–1–1) at 0 kg/ha N, 156 kg/ha N, or 314 kg/ha N, and conventional plots received preplant application of 13N–13P–13K at 0 kg/ha N, 78 kg/ha N, or 156 kg/ha N. Antioxidant levels were measured using the oxygen radical absorbance capacity (ORAC) assay. There were significant effects of fertilizer source and high-tunnel environment on the antioxidant capacity of pac choi. Organic fertilization significantly increased hydrophilic ORAC of pac choi in open field plots, but not in high tunnels. Regardless of the fertilizer source, pac choi grown in the open field had significantly higher hydrophilic ORAC than that grown in tunnels. Lipophilic ORAC was significantly increased by organic fertilization but was not affected by high-tunnel production. Total ORAC (hydrophilic + lipophilic) was significantly higher in pac choi from organic or open-field plots, compared to conventional and high-tunnel plots, respectively. Although fertilizer rate did not show significant impact on antioxidant level of pac choi, hydrophilic and total ORAC seemed to decrease as the fertilizer rate increased, especially under conventional fertilization, while lipophilic ORAC reached the highest level at the medium fertilizer rate. Differences in antioxidant levels were likely associated with the enhanced phytochemical content of pac choi from organically fertilized and open-field plots.
D. R. Earhart, M. L. Baker and F. J. Dainello
In a field experiment, fertilizer source (poultry litter vs. commercial), plastic mulch, row cover, and fertilizer rate (residual from 1990 study vs. additional) were applied in factorial combinations to determine the effect on vegetative growth and production of triploid watermelons. Litter (3.12 % total N) was re-applied at the rate of 13.2 Mt·ha-1 along with commercial fertilizer (6N-10.5P-20K) at 1.1 Mt·ha-1. Plastic mulch showed the greatest influence on vegetative growth and production variables by increasing vine length 26.1 cm, leaf area 61.8 cm2, yield 4207 kg·ha-1, melon number 741 ·ha-1, and average melon weight 0.8 kg, over unmulched plots. Plastic mulch with or without row cover increased melon number significantly when compared to plots without mulch or row covers. Poultry litter increased vine length, yield, and average melon weight 15.4 cm, 1971 kg·ha-1, and 0.5 kg, respectively, when compared to commercial fertilizer. Poultry litter in combination with row cover increased yield by 3864 kg ·ha-1 over commercial fertilizer with row cover, and approximately 2567 kg·ha-1 over poultry litter and commercial fertilizer without row cover. Additional fertilizer increased average melon weight 1.3 kg.
Subhrajit K. Saha, Laurie E. Trenholm and J. Bryan Unruh
Due to increasing consumption of water in landscapes and concern over conservation of water resources, this study was conducted to determine the effect of fertilizer source on water consumption of turf and ornamentals and to compare total water use (WU) of st. augustinegrass and ornamentals. The experiment was performed in a climate-controlled greenhouse at the G.C. Horn Turfgrass Field Laboratory at the University of Florida in Gainesville. `Floratam' st. augustinegrass (Stenotaphrum secundatum Walt. Kuntze) was compared to a mix of common Florida ornamentals including canna (Canna generalis L.H. Bailey), nandina (Nandina domestica Thunb.), ligustrum (Ligustrum japonicum Thunb.), and allamanda (Allamanda cathartica L.). All plants were grown in 300-L plastic pots in Arredondo fine sand. There were three fertilizer treatments [quick-release fertilizers (QRF) 16–4–8 and 15–0–15, and slow-release fertilizer (SRF) 8–4–12] applied at 4.9 g N/m2 every 60 days. Water was applied as needed to maintain turgor and turfgrass pots were mowed weekly. Experimental design was a randomized complete block design with four replications. Visual quality ratings and time domain reflectometry (TDR) data were collected weekly. Both turf and ornamentals consumed less water and had higher water use efficiency (WUE) when treated with SRF. Ornamentals consumed from 11% to 83% more water than turf, depending on season. These results may have implications in future research on irrigation management to verify WUE between turf and ornamentals in an urban landscape.
Michael D. Frost, Janet C. Cole and John M. Dole
Improving the quality of water released from containerized production nurseries and greenhouse operations is an increasing concern in many areas of the United States. The potential pollution threat to our ground and potable water reservoirs via the horticultural industry needs to receive attention from growers and researchers alike. `Orbit Red' geraniums were grown in 3:1 peat:perlite medium with microtube irrigation to study the effect of fertilizer source on geranium growth, micronutrient leaching, and nutrient distribution. Manufacturer's recommended rates of controlled-release (CRF) and water-soluble fertilizers (WSF) were used to fulfill the micronutrient requirement of the plants. Minimal differences in all growth parameters measured between WSF and CRF were determined. A greater percentage of Fe was leached from the WSF than CRF. In contrast, CRF had a greater percentage of Mn leached from the system than WRF during the experiment. Also, regardless of treatment, the upper and middle regions of the growing medium had a higher nutrient concentration than the lower region of medium.
Allen D. Owings and Edward W. Bush
A study was initiated at Bracy's Nursery, Amite, La., in Apr. 1997 to evaluate the influence of seven controlled-release fertilizer sources and three top-dressed application rates in production of 4-gal (15.7-L) containers of `LaFeliciana' peach and swamp red maple. The fertilizers tested were Osmocote Plus 15-9-11, Osmocote Plus 16-8-12, Woodace 20-5-10, Woodace 20-4-11, Customblen 24-4-6, Nutricote (Type 270) 17-7-8, and Nutricote (Type 360) 17-6-8. Application rates were 1.75, 2.25, and 2.75 lb N per cubic yard. The experiment was completely randomized within blocks (species) and each treatment was replicated five times. A control treatment was also included. For `LaFeliciana' peach, Nutricote and Osmocote yielded the superior results when shoot height and visual quality ratings were determined in October (6 months after initiation). Increases in application rate did not significantly increase shoot height or visual quality ratings in most cases. For swamp red maple, shoot height was not affected by fertilizer source or application rate. Caliper ranged from 19.2 to 23.0 mm but was only slightly influenced by fertilizer source and application rate. Visual quality ratings were significantly higher for Osmocote Plus 16-8-12 when compared to some of the other fertilizer sources.
Kayla R. Sanders and Jeffrey S. Beasley
fertilizer source has on N and P surface runoff losses from hybrid bermudagrass ( Cynodon dactylon × C. transvaalensis ), a commonly grown turfgrass for athletic and utility sites. Materials and methods Experimental design . Two 84-d experiments were
Subhrajit K. Saha, Laurie E. Trenholm and J. Bryan Unruh
less than 2% from the turfgrass. The objectives of this study were: a) to evaluate qualitative and growth responses of turfgrass and ornamentals to different fertilizer sources, 2) to evaluate NO 3 − leaching from different fertilizer sources, and