Tara A. O'Brien

Growth of corn in varying mixtures of paper mill sludge and soil

To evaluate different levels of paper mill sludge as a soil amendment for the production of corn (Zea mays L.), sludge was added to 15-cm pots of soil in a greenhouse experiment. Mixtures were made from paper mill sludge (0 to 560 Mg ha− 1 wet weight) mixed with field soil (Hadley fine sandy loam with coarse, mixed, mesic, Fluventic, Dystrochrept deposits). Nitrogen (N) was added as ammonium nitrate at 0 or 200 kg N ha− 1. Eight corn seeds of ‘Pioneer Max 21’ were seeded into each pot immediately after mixing the paper mill sludge and soil or at 21 days after mixing the media. Seven days after sowing, seedlings were counted in each pot to assess germination (emergence). Delaying of sowing of seeds for 21 days increased the number of seeds that germinated. Corn plants were harvested after 35 days of growth. Plant biomass declined as amounts of sludge increased. Adding N and delaying sowing for 21 days produced the greatest amount of dry mass. Tissue (leaf) total N decreased with increasing amounts of sludge. Addition of N to the mixtures increased the average total N in corn leaves. However, leaf total N still decreased with increasing amounts of sludge added even if N at 200 kg ha− 1 was added to the media. Sowing immediately after setup showed the highest leaf total N if no sludge was added to the mixture. Sowing immediately after setup of the experiment and adding paper mill sludge at 560 Mg ha− 1 produced the lowest total N in corn leaves. Generally, the phosphorus (P) concentration in plants increased as the amount of paper sludge increased, but the increase was less with N added than in treatments without N added. At 21 days, carbon:nitrogen, pH, and salinity of the media declined relative to the initial values. Total N in the media was higher after a 21-day delay than immediately after setup. Organic matter content increased with increasing amounts of paper sludge. Results indicated that addition of paper sludge to soil increased media organic matter and P contents. Germination was hindered when seeds were sown immediately after setup of the experiment, but delaying seeding for 21 days eliminated the germination problem. Nitrogen deficiency was problematic, and more than 200 kg ha− 1 of supplemental N is recommended to overcome immobilization of N.

Evaluation of Fresh and Year-Old Solid Waste Composts for Production of Wildflower and Grass Sods on Plastic

Source of compostable materials and length of composting or aging affect quality of composts and their suitability as media for crop growth. In this experiment, year-old and fresh composts of mixed municipal solid wastes (MSW), agricultural wastes (chicken manure and cranberry pomace), and autumn leaves were evaluated for their capacities to support production of turfgrass and mixed wildflower sods. Composts were laid in 5-cm-thick layers on plastic in outdoor plots. Germination, stand establishment, biomass production, and flowering responses of grass or wildflowers were assessed for each medium. Seed germination and stand establishment were sensitive to factors present in fresh, apparently immature composts of mixed MSW or autumn leaves. Subsequent plant growth was reduced in these compost largely due to poor establishment of stands. The limiting factors were identified as excessive ammonium in the fresh MSW compost and inadequate total N in the leaf compost. Aging of the composts increased their value ...

Evaluation of ammonium and soluble salts on grass sod production in compost. I. Addition of ammonium or nitrate salts

Abstract Inhibitions in seed germination and in plant growth in some composts have been associated with high concentrations of ammonium or soluble salts in the media. This experiment was conducted to determine changes in ammonium and soluble salts in fertilizer‐amended compost with time and their impacts on plant growth. Turfgrass (Lolium perenne L.) was seeded into an ammonium‐depleted municipal solid waste (MSW) or leaf composts or into MSW or leaf composts with 1,500 or 2,300 mg N/kg (dry weight) from (NH4)2SO4 or Ca(NO3)2 added to simulate immature composts. Seeding occurred on the day that the composts were treated and applied to flats. Ammonium‐nitrogen (N) and nitrate‐N concentrations and electrical conductivity were measured on the day of seeding and after 3, 7, 14, 21, and 28 days. Germination or growth was assessed after 7, 14, 21, and 28 days. Ammonium‐N in the compost declined with time, whereas nitrate‐N and electrical conductivity initially increased then decreased with time. Ammonium‐N from...

Evaluation of Field-Applied Fresh Composts for Production of Sod Crops

Application of compost to cropland potentially can use large quantities of compost and serve as an alternative to waste disposal into landfills. This study was conducted to evaluate the suitability of field-applied composts of mixed municipal solid wastes, biosolids, leaves, and agricultural wastes for production of wildflower and grass sods. The composts were applied one inch thick on the soil surface. In half the plots, the composts were left on the surface as a mulch and in the other half, composts were worked into the top two inches of soil. The effects of the composts on wildflower, grass, and weed germination and growth and on wildflower diversity and flowering were investigated for two growing seasons. Wildflower and grass quality did not differ whether the composts were applied as a mulch or incorporated into the soil. In the first year, limited growth in apparently immature biosolids-woodchips and mixed MSW composts was attributed to high concentrations of ammonium or soluble salts. The detriment...

Evaluation of ammonium and soluble salts on grass sod production in compost. II. Delaying seeding after compost application

In some composts, seed germination and plant growth have been inhibited by high concentrations of ammonium or soluble salts. Ammonium and salt concentrations in media decrease with time after appli...

Paper Sludge as a Soil Amendment for Production of Corn

To evaluate paper sludge as a soil amendment for the production of corn (Zea mays indentata Bailey ‘Pioneer 35N05’), sludge was added to field plots (0 to 448 Mg wet mass ha−1 in 112 Mg units) in May 1998 and was incorporated into the top 15-cm of soil. No sludge was applied in the second year of cropping (1999). In 1998 and 1999, nitrogen (N) was added at 200 or 400 kg ha−1 as ammonium nitrate. Grain or stover yields in 1998 or 1999 were not affected by the addition of paper sludge. Grain yields did not differ between years, but stover production was greater in 1998 than in 1999. Grain analysis showed an increase in N, phosphorus (P), potassium (K), magnesium (Mg), zinc (Zn), manganese (Mn), and boron (B) concentrations in the year after application of sludge. Also, stover concentrations of copper (Cu) and B were greater in the second growing season than in the first year. Soil analysis showed a decrease in nitrate and calcium (Ca) concentrations with addition paper sludge in 1998. In 1999, nitrate and Ca concentrations did not vary with addition of paper sludge. Soil cation exchange capacity was greater in 1999 than in 1998, with the base saturation being dominated by Ca. Soil pH was 7.0 in 1998 and 7.2 in 1999. Adding paper sludge did not increase soil organic matter, which averaged 2.5%. Results from this study indicated that additions of paper sludge to soil added some nutrients to the crop and did not suppress corn yields.

Container production of tomato with food by‐product compost and mineral fines

Abstract Agricultural applications are sought for by‐products from agricultural, municipal, and industrial operations. Incorporation into media for container production of crops is a suggested use of organic and mineral by‐products. Composted food by‐products generated by grocery stores and restaurants and mineral fines from the aggregate industry were assessed in the formulation of media for tomato (Lycopersicon esculentum Mill.) production in containers. The basic medium was compost and perlite (2 compost: 1 perlite, v:v). This medium was mixed with basalt fines or glacial moraine fines added separately at 60 or 120 g L‐1. Nitrogen (N) fertilizer was added weekly to the media except for one treatment that included the basic medium without N. Incorporation of mineral fines into the food by‐product compost produced an early stimulation of vegetative growth, but did not affect fruiting of tomatoes significantly; however, fruiting was heavy in the containers to which N was added, with an average of nearly 2...

Acidification of lime‐stabilized biosolids in formulation of synthetic topsoil

Abstract Uses of lime‐stabilized biosolids in container media or topsoil formulations may be limited by alkalinity imparted by lime added for reductions in vector attraction and pathogens and for suppression of odors. This experiment was conducted to assess the suitability of quicklime‐stabilized biosolids mixed with calcareous or noncalcareous sand and with sulfur or aluminum sulfate as acidifying agents for development of synthetic topsoil for turfgrass (Lolium perenne L.) production. Grass emergence and growth were inhibited in media that were not amended with an acidifying agent. Additions of aluminum sulfate were more effective in acidification than sulfur, causing an immediate drop in pH, whereas additions of sulfur required about 2 months for a depression in media pH. With time, electrical conductivities were higher in media with additions of sulfur than in media with additions of aluminum sulfate. Calcareous sand mixed with biosolids (2 sand: 1 biosolid, v: v) gave a better medium for growth of tu...