Matrix based fertilizers reduce nitrogen and phosphorus leaching in three soils

We compared the efficacy of matrix based fertilizers (MBFs) formulated to reduce NO3-, NH4+, and total phosphorus (TP) leaching, with Osmocoate 14-14-14, a conventional commercial slow release fertilizer (SRF) and an unamended control in three different soil textures in a greenhouse column study. The MBFs covered a range of inorganic N and P in compounds that are relatively loosely bound (MBF 1) to more moderately bound (MBF 2) and more tightly bound compounds (MBF 3) mixed with Al(SO4)3H2O and/or Fe2(SO4)3 and with high ionic exchange compounds starch, chitosan and lignin. When N and P are released, the chemicals containing these nutrients in the MBF bind N and P to a Al(SO4)3H2O and/or Fe2(SO4)3 starch-chitosan-lignin matrix. One milligram (8000 spores) of Glomus intradices was added to all formulations to enhance nutrient uptake. In all three soil textures the SRF leachate contained a higher amount of NH4+, NO3- and TP than leachate from all other fertilizers. In all three soils there were no consistent differences in the amount of NH4+, NO3- and TP in the MBF leachates compared to the control leachate. Plants growing in soils receiving SRF had greater shoot, root and total biomass than all MBFs regardless of Al(SO4)3H2O or Fe2(SO4)3 additions. Arbuscular mycorrhizal infection in plant roots did not consistently differ among plants growing in soil receiving SRF, MBFs and control treatments. Although the MBFs resulted in less plant growth in this experiment they may be applied to soils growing plants in areas that are at high risk for nutrient leaching to surface waters.     

不同碳源条件下草菇内切型纤维素酶基因（eg1）转录表达的分析

利用Northernblot方法分析了不同碳源条件下草菇切型纤维素酶基因(eg1)的表达.结果发现,在含有纤维素的液体培养基中生长10d,eg1在草菇菌丝中有高效表达;纤维二糖、α-乳糖、β-乳糖,也能诱导eg1的表达,但和纤维素相比,eg1的表达量相对较低,并且它们的诱导效应在加入这类糖12h后迅速减弱;槐糖和龙胆二糖的诱导作用非常弱.在天然稻草为基质的固体栽培料生长时,草菇eg1的表达和草菇菌丝生长与出菇相对应,在菌丝生长期(d8)可见eg1的表达,d12时菌丝已长满,表达减弱,在出菇及菇体的分化及增大期,eg1的表达量逐渐增强,在成熟期达到最高水平;表明在草菇菇体发育中需要更多碳源及能源的补充,eg1在这方面起着非常重要的作用.图4参14     

Influence of solid dairy manure and compost with and without alum on survival of indicator bacteria in soil and on potato

We measured Escherichia coli, Enterococcus spp. and fecal coliform numbers in soil and on fresh potato skins after addition of solid dairy manure and dairy compost with and without alum (Al(2)(SO(4))(3)) treatment 1, 7, 14, 28, 179 and 297 days after application. The addition of dairy compost or solid dairy manure at rates to meet crop phosphorus uptake did not consistently increase E. coli and Enterococcus spp. and fecal coliform bacteria in the soil. We did not detect E. coli in any soil sample after the first sampling day. Seven, 14, 28, 179 and 297 days after solid dairy waste and compost and alum were applied to soil, alum did not consistently affect Enterococcus spp. and fecal coliform bacteria in the soil. We did not detect E. coli in any soil, fresh potato skin or potato wash-water at 214 days after dairy manure or compost application regardless of alum treatment. Dairy compost or solid dairy manure application to soil at rates to meet crop phosphorus uptake did not consistently increase Enterococcus spp. and fecal coliform numbers in bulk soil. Solid dairy manure application to soil at rates to meet crop phosphorus uptake, increased Enterococcus spp. and fecal coliform numbers in potato rhizosphere soil. However, fresh potato skins had higher Enterococcus spp. and fecal coliform numbers when solid dairy manure was added to soil compared to compost, N and P inorganic fertilizer and N fertilizer treatments. We did not find any E. coli, Enterococcus or total coliform bacteria on the exterior of the tuber, within the peel or within a whole baked potato after microwave cooking for 5 min.     

Polyacrylamide preparations for protection of water quality threatened by agricultural runoff contaminants

Waste streams associated with a variety of agricultural runoff sources are major contributors of nutrients, pesticides and enteric microorganisms to surface and ground waters. Water soluble anionic polyacrylamide (PAM) was found to be a highly effective erosion-preventing and infiltration-enhancing polymer, when applied at rates of 1-10 g m(-3) in furrow irrigation water. Water flowing from PAM treated irrigation furrows show large reductions in sediment, nutrients and pesticides. Recently PAM and PAM + CaO and PAM + Al(SO4)3 mixtures have been shown to filter bacteria, fungi and nutrients from animal wastewater. Low concentrations of PAM [175-350 g PAM ha(-1) as PAM or as PAM + CaO and PAM + Al(SO4) mixture] applied to the soil surface, resulted in dramatic decreases (10 fold) of total, coliform and fecal streptococci bacteria in cattle, fish and swine wastewater leachate and surface runoff. PAM treatment also filtered significant amounts of NH4, PO4 and total P in cattle and swine wastewater. This points to the potential of developing PAM as a water quality protection measure in combination with large-scale animal feeding operations. Potential benefits of PAM treatment of animal facility waste streams include: (1) low cost, (2) easy and quick application. (3) suitability for use with other pollution reduction techniques. Research on the efficacy of PAM for removal of protozoan parasites and viruses and more thorough assessment of PAM degradation in different soils is still needed to completely evaluate PAM treatment as an effective waste water treatment. We will present analysis and feasibility of using PAM, PAM + Al(SO4)3, and PAM + CaO application for specific applications. Our results demonstrate their potential efficacy in reducing sediment, nutrients and microorganisms from animal production facility effluents.     

Polyacrylamide + Al2(SO4)3 and polyacrylamide + CaO remove coliform bacteria and nutrients from swine wastewater

Animal wastes are a major contributor of nutrients and enteric microorganisms to surface water and ground water. Polyacrylamide (PAM) mixtures are an effective flocculent, and we hypothesized that they would reduce transport of microorganisms in flowing water. After waste water running at 60.0 1 min(-1) flowed over PAM + Al2(SO4)3, or PAM + CaO in furrows, total coliform bacteria (TC) and fecal coliform bacteria (FC) were reduced by 30-50% at 1 and 50 m downstream of the treatments compared to the control. In a column study, PAM + Al2(SO4)3, and PAM + CaO applied to sandy, sandy loam, loam, and clay soils reduced NH4+ and ortho-P concentrations in leachate compared to the source waste water and the control. PAM + Al2(SO4)3 and PAM + CaO applied to sandy, sandy loam and loam soils reduced both total and ortho-P, concentrations in leachate compared to he source wastewater and control treatment. In a field study, PAM + Al2(SO4)3, or PAM + CaO treatments did not consistently reduce NH4+, NO3-, ortho-P, and total P concentrations in wastewater flowing over any soil compared to inflow wastewater or the control treatment. With proper application PAM + Al2(SO4)3 and PAM + CaO may be able to reduce the numbers of enteric bacteria in slowly flowing wastewater running off animal confinement areas, reducing the amount of pollutants entering surface water and groundwater.     

Geographic variability of Escherichia coli ribotypes from animals in Idaho and Georgia

Several genotypic methods have been developed for determining the host origin of fecal bacteria in contaminated waters. Some of these methods rely on a host origin database to identify environmental isolates. It is not well understood to what degree these host origin isolates are geographically variable (i.e., cosmopolitan or endemic). This is important because a geographically limited host origin database may or may not be universally applicable. The objective of our study was to use one genotypic method, ribotyping, to determine the geographic variability of the fecal bacterium, Escherichia coli, from one location in Idaho and three locations in Georgia for cattle (Bos taurus), horse (Equus caballus), swine (Sus scrofa), and chicken (Gallus gallus domesticus). A total of 568 fecal E. coli isolates from Kimberly, ID (125 isolates), Athens, GA (210 isolates), Brunswick, GA (102 isolates), and Tifton, GA (131 isolates), yielded 213 ribotypes. The percentage of ribotype sharing within an animal species increased with decreased distance between geographic locations for cattle and horses, but not for swine and chicken. When the E. coli ribotypes among the four host species were compared at one location, the percent of unshared ribotypes was 86, 89, 81, and 79% for Kimberly, Athens, Brunswick, and Tifton, respectively. These data suggest that there is good ribotype separation among host animal species at each location. The ability to match environmental isolates to a host origin database may depend on a large number of environmental and host origin isolates that ideally are not geographically separated.     

Influence of polyacrylamide application to soil on movement of microorganisms in runoff water

Polyacrylamide (PAM) use in irrigation for erosion control has increased water infiltration and reduced soil erosion. This has improved runoff water quality via lower concentrations of nitrogen, phosphorous, and pesticides, and decreased biological oxygen demand. Since non-toxic high molecular weight anionic PAMs removed clay size sediment particles in flowing water, we hypothesized that PAM would effectively remove or immobilize microorganisms in flowing water. In an agricultural field, we determined the efficacy of PAM-treatment of furrow irrigation water to remove several categories of microorganisms in the inflow and runoff. Treatments were: (1) PAM application and a control; (2) three flow rates; (3) two distances from the inflow point; and (4) three times during each irrigation. After water traveled 1 m at 7.5 and 15.5 l min(-1), PAM-treatment reduced total bacterial and microbial biomass and total fungal biomass relative to the control treatment. After water traveled 40 m at 7.5, 15.5, and 22.5 l min(-1), PAM-treatment reduced algae, the numbers active and total bacteria, active and total fungal length, and total bacterial biomass, total fungal and microbial biomass relative to the control treatment. Although specific organisms were not identified or monitored in this study, the results clearly have implications for controlling the spread of soil-borne plant pathogens and other classes of harmful organisms within and among fields via irrigation water and in re-utilized return flows. Beyond furrow-irrigated agriculture, new methods to manage overland transmission of harmful microorganisms could potentially help control transport of pathogens from animal waste in runoff and groundwater.     

Water quality characterization in the Northern Florida everglades based on three different monitoring networks

The Loxahatchee National Wildlife Refuge (Refuge) is affected by inflows containing elevated contaminant concentrations originating from agricultural and urban areas. Water quality was determined using three networks: the Northern Refuge (NRN), the Southern Refuge (SRN), and the Consent Decree (CDN) monitoring networks. Within these networks, the Refuge was divided into four zones: (1) the canal zone surrounding the marsh, (2) the perimeter zone (0 to 2.5 km into the marsh), (3) the transition zone (2.5 to 4.5 km into the marsh), and (4) the interior zone (>4.5 km into the marsh). In the NRN, alkalinity (ALK) and conductivity (SpC) and dissolved organic carbon, total organic carbon, total dissolved solids (TDS), Ca, Cl, Si, and SO₄ concentrations were greater in the perimeter zone than in the transition or interior zone. ALK, SpC, and SO₄ concentrations were greater in the transition than in the interior zone. ALK, SpC, and TDS values, Ca, SO₄, and Cl had negative curvilinear relationships with distance from the canal toward the Refuge interior (r ²?=?0.78, 0.67, 0.61, 0.77, 0.62, and 0.57, respectively). ALK, TB and SpC, and Ca and SO₄ concentrations decreased in the canal and perimeter zones from 2005 to 2009. Important water quality assessments using the SRN and CDN cannot be made due to the sparseness and location of sampling sites in these networks. The number and placement monitoring sites in the Refuge requires optimization based on flow pattern, distance from contaminant source, and water volume to determine the effect of canal water intrusion on water quality.     

Movement of coliform bacteria and nutrients in ground water flowing through basalt and sand aquifers

Large-scale deposition of animal manure can result in contamination of surface and ground water and in potential transfer of disease-causing enteric bacteria to animals or humans. We measured total coliform bacteria (TC), fecal coliform bacteria (FC), NO3, NH4, total P, and PO4 in ground water flowing from basalt and sand aquifers, in wells into basalt and sand aquifers, in irrigation water, and in river water. Samples were collected monthly for 1 yr. Total coliform and FC numbers were always higher in irrigation water than in ground water, indicating that soil and sediment filtered most of these bacteria before they entered the aquifers. Total coliform and FC numbers in ground water were generally higher in the faster flowing basalt aquifer than in the sand aquifer, indicating that the slower flow and finer grain size may filter more TC and FC bacteria from water. At least one coliform bacterium/100 mL of water was found in ground water from both basalt and sand aquifers, indicating that ground water pumped from these aquifers is not necessarily safe for human consumption according to the American Public Health Association and the USEPA. The NO3 concentrations were usually higher in water flowing from the sand aquifer than in water flowing from the basalt aquifer or in perched water tables in the basalt aquifer. The PO4 concentrations were usually higher in water flowing from the basalt aquifer than in water flowing from the sand aquifer. The main concern is fecal contamination of these aquifers and health consequences that may arise from human consumption.