Edward A. Hanlon

Cadmium, Copper, Lead, Nickel and Zinc Concentrations In Tomato and Squash Grown In MSW Compost-amended Calcareous Soil

Vegetables grown in compost containing cadmium, copper, lead, nickel, and zinc in low concentrations should be safe for human consumption unless the crop acts as a bioaccumulator. The effects of amending soil with compost products made from municipal solid waste (MSW) on cadmium, copper, lead, nickel, and zinc concentrations in tomato and squash were investigated. For each crop, three inorganic nitrogen treatments were applied 1) 72, 2) 143, or 221 kg N ha−1 for tomato 1991 and 1992 and 40, 80, or 120 kg N. ha−1 for squash 1991 and 1992. Each fertilizer treatment was subdivided into three MSW compost treatments. For the compost treatments, the following products were incorporated into calcareous limestone soil at rates suggested by the manufacturers: 1) Agrisoil compost, a processed MSW, at 48 t. ha−1, 2) Eweson co-composted MSW and biosolids at 24 t. ha−1, or 3) no MSW compost. The experimental design, strip-split plot with four replications was conducted in 1991 and repeated in 1992. Compost treatments ...

Impact of Organic Amendments on Groundwater Nitrogen Concentrations for Sandy and Calcareous Soils

Experiments were conducted on calcareous and sandy soils to investigate the effects of organic amendments for vegetable production on groundwater nitrogen (N) concentration in south Florida. The treatments consisted of applying yard and food residuals compost, biosolids compost, a cocompost of the municipal solid waste and biosolids, and inorganic fertilizer. Nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), and total N concentrations were collected for a period of two years for both soils. Statistical analysis results revealed that for the three species tested, there were no significant differences among treatments. NO3-N concentrations for all treatments remained less than the maximum contamination level (10 mg/L). NO3-N transport to groundwater was higher in calcareous soil (mean=5.3 mg/L) than in sandy soil (mean=0.6 mg/L). NH4-N concentrations ranged from 0 to 13.6 mg/L throughout the experiment. Calcareous soil had lower NH4-N concentrations (mean=0.1 mg/L) than sandy soils (mean=0.7 mg/L). Total N ranged from 0.4 to 21.7 mg/L for all treatments for both soils reflecting high adsorption of dissolved organic N in both soils. Overall, results indicated that all the compost treatments were comparable to inorganic fertilizer with regard to N leaching and N concentrations in the groundwater while producing similar or higher yields.

Groundwater Phosphorus and Trace Element Concentrations from Organically Amended Sandy And Calcareous Soils of Florida

The effects of organic amendments on vegetable crop production, phosphorus (P), and trace element (Zn, Cu, Mn, B, Cd, Pb, Ni) concentrations in groundwater were investigated on calcareous and sandy soils in south Florida. Treatments consisted of applying yard trash and food compost, biosolids compost, a cocompost of municipal solid waste and biosolids, and inorganic fertilizer. A randomized complete block design with four replications was used at both study sites. Total Kjeldahl phosphorus (TKP) and soluble reactive phosphorus (SRP) were periodically measured in grab samples collected for two years for both soils from wells above and below the spodic horizon at Ft. Pierce and from one depth at Homestead. Treatments were similar (P > 0.05) except on two sampling dates from the deep wells in the sandy soil at Ft. Pierce, one for SRP and one for TKP. Phosphorus concentrations for all treatments averaged < 1.2 mg SRP L−1 at Ft. Pierce and 0.04 mg SRP L−1 for the calcareous soil at Homestead. From solely a P consideration, organic P sources could be used to offset all or a portion of P required to satisfy vegetable crop nutrient requirements. This statement is consistent with crop yields at Ft. Pierce where yields from the three organic sources were equal to or exceeded inorganic fertilization yields. Micronutrient and trace element concentration responses to organic treatments were more pronounced at Ft. Pierce, perhaps due to soil chemical conditions including lower soil pH. The cocompost should be used cautiously to avoid contamination problems, especially when application rates are based on N fertilization as in this study. Due to the calcareous soil at Homestead, trace element concentrations in the groundwater were considerably lower than Ft. Pierce concentrations. However, the cocompost source was elevated for lead (Pb) (P < 0.05) compared with all other treatments, although higher concentrations were observed only on one sampling date. Results from this study indicated that, combined with the environmental benefits of recycling waste, the use of these organic amendments is a viable alternative to inorganic P fertilizers in the sandy and calcareous soils of peninsular Florida. The compost treatments were comparable to inorganic fertilizer with regard to P concentrations in the groundwater while producing similar or higher vegetable crop yields.

Nitrogen mineralization in histosols of the everglades agricultural area

Abstract A long‐term soil incubation and column nutrient leaching study was conducted to determine nitrogen (N)‐mineralization rates of selected Florida Histosols with drained and intermittent‐flooded conditions. Five surface soils from the Everglades Agricultural Area (EAA) were packed in columns (5‐cm i.d. containing the 0‐ to 15‐cm depth of each soil) and leached with 0.01M CaC12 followed by distilled water every 25 d for 1 yr. Drained columns were treated with a minus‐nitrogen‐phosphorus (NP) solution followed by applying ‐0.97 MPa tension to remove excess solution. Flooded columns received the same minus‐NP solution, but were flooded to a depth of 3 cm. Both treatments were incubated for 25‐d periods, solution sampled, and treatments reapplied. Because flooding conditions could not be maintained during the sampling period, this treatment is referred to as intermittent flooded. The ammonium‐nitrogen (NH4 +‐N) released from drained soils accounted for less than 6% of the total soluble N released from a...

Internal breakdown, mineral element concentration, and weight of mango fruit

Abstract Internal breakdown in mango fruit is a disorder often attributed to a nutrient deficiency, particularly of calcium (Ca), in the fruit. The relationship between internal breakdown in mango fruit and fruit mineral element concentrations and fresh weight was investigated. Fruit were collected weekly from a commercial orchard beginning 4 weeks after fruit set (WAFS) until the fruit were ripe. The concentrations of nitrogen (N), phosphorus (P), potassium (K), Ca, magnesium (Mg), zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), and boron (B) and fresh weight of ‘Tommy Atkins’ mango fruit with and without internal breakdown were compared. Disordered fruit weighed more than healthy fruit 4 WAFS. However, when fruit were ripe there were no significant differences in fruit weight between healthy and disordered fruit. Disordered fruit contained significantly higher concentrations of N, P, Ca, and B than the healthy mango fruit, 4 WAFS. When fruit were ripe, there were no differences in N, K, Ca, Mg, Zn, M...

Ammonium bicarbonate‐DTPA extraction of elements from waste‐amended calcareous soil

Abstract Use of soil testing for both nutrient and heavy metal interpretations could prove to be a readily available tool for management of calcareous soils amended with solid waste products. The ammonium bicarbonate‐DTPA (di‐ethylenetriaminepentaacetic acid) [AB‐DTPA] extradant was used in this study, based on its successful use in other calcareous regions, and existence of interpretations for both nutrients and selected heavy metals. In southern Florida, addition of large volumes of composted waste products to shallow agricultural soils formed from crushed Oolitic limestone appears to be a viable disposal alternative to rapidly expanding lanfills or incineration. For two years, the effects of processed wastes (PW) on selected, AB‐DTPA‐extractable soil mineral element concentrations were determined for tomato (Lycospresicon esculentum Mill.) and squash (Cucurbita maxima Duch. Ex Lam.) grown with three different irrigation rates (3.78, 2.53, or 1.25 L/min). The PW composts were added at supplier‐recommend...

Investigation of long-term trends in selected physical and chemical parameters of inflows to Everglades National Park, 1977-2005

Data of seven water-quality parameters from inflows to the Everglades National Park were collected at three monitoring stations and analyzed for temporal trends. The best-fit models for the existence of trends were evaluated. The Kolmogorov–Smirnov test was used to select the theoretical distribution which best fit the data. Simple regression was used to examine the parameters for concentration–discharge relationships. The power and linear models were found to better describe the concentration–discharge relationships. Loess trend lines indicated a similar trend period of color value change during the selected period at three stations. The sharp decrease in color after 1990 at each station is consistent with the beneficial impacts of control measures, which include Best Management Practices implementation in the Everglades Agricultural Area, water management improvement, and the construction of additional stormwater treatment areas. The existence of trend analysis was performed by using the uncensored seasonal Kendall test. Conductivity and color decreased significantly at two (S12A and S333) of three stations. Alkalinity decreased significantly at S333. A “best-fit” model was selected to describe a trend change with statistical significance; the second-order equation provides a better description of the trend. This study also indicates that by using the routinely measured water-quality parameters, it may be easier to quantify the changes in water quality to aid in making water resources management decisions.

Leaf Analysis in Citrus: Developments in Analytical Techniques

The complexity and sophistication of instruments for plant tissue analysis continues to advance, both in research laboratory grade instruments as well as for field use. These advances are seen in direct measurement of nutrients and trace elements, as well as indirect measurement, especially as statistical approaches improve through modeling of relationships between direct and indirect methods. This chapter has given an overview of recent advances, often using review articles followed by selected applications to citrus leaf analysis, but also offering other venues for using these analytical tools to aid both research and precision citrus management.

Effects of Fertilizer and Organic Amendments on Groundwater Nitrogen Transport in South Florida

Experiments were conducted on calcareous and sandy soils to investigate the effects of organic amendments for vegetable production on groundwater nitrogen (N) concentration in south Florida. The treatments consisted of applying yard and food compost, biosolids compost, a co-compost of the municipal solid waste and biosolids, and inorganic fertilizer for comparison. Nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), and total N concentrations were collected for a period of two years at both sites. Statistical analysis indicated that for the three species tested, there were no significant differences among treatments. NO3-N concentrations remained less than the maximum contamination level (10 mg/L) for all treatments. NO3-N transport was more prominent in calcareous soil (mean=5.3 mg/L) than in sandy soil (mean=0.6 mg/L). NH4-N concentration was relatively low throughout the experiment (0-13.6 mg/L). Calcareous soil had lower NH4-N concentrations (mean=0.1 mg/L) than sandy soils (mean=0.7 mg/L). Total N was also low for all treatments (0.4-21.7 mg/L) for both soils reflecting high adsorption of dissolved organic N in both soils. The results indicated that compost was comparable to inorganic fertilizer with regard N leaching and N concentrations in the groundwater.