@article{vanotti_szogi_hunt_millner_humenik_2007, title={Development of environmentally superior treatment system to replace anaerobic swine lagoons in the USA}, volume={98}, ISSN={["0960-8524"]}, DOI={10.1016/j.biortech.2006.07.009}, abstractNote={A full-scale treatment system for swine manure was developed to eliminate discharge to surface and ground waters and contamination of soil and groundwater by nutrients and heavy metals, along with related release of ammonia, odor, and pathogens. The system greatly increased the efficiency of liquid-solid separation by polymer injection to increase solids flocculation. Nitrogen management to reduce ammonia emissions was accomplished by passing the liquid through a module where bacteria transformed ammonia into harmless nitrogen gas. Subsequent alkaline treatment of the wastewater in a phosphorus module precipitated phosphorus and killed pathogens. Treated wastewater was recycled to clean swine houses and for crop irrigation. The system was tested during one year in a 4400-head finishing farm as part of the Agreement between the Attorney General of North Carolina and swine producers Smithfield Foods, Premium Standard Farms and Frontline Farmers to replace traditional waste treatment anaerobic lagoons with environmentally superior technology. The on-farm system removed 97.6% of the suspended solids, 99.7% of BOD, 98.5% of TKN, 98.7% of soluble ammonia (NH(4)(+)-N), 95.0% of total P, 98.7% of copper and 99.0% of zinc. It also removed 97.9% of odor compounds in the liquid and reduced pathogen indicators to non-detectable levels. Based on performance obtained, it was determined that the treatment system met the Agreement's technical performance standards that define an environmentally superior technology. These findings overall showed that cleaner alternative technologies are technically and operationally feasible and that they can have significant positive impacts on the environment and the livestock industry.}, number={17}, journal={BIORESOURCE TECHNOLOGY}, author={Vanotti, Matias B. and Szogi, Ariel A. and Hunt, Patrick G. and Millner, Patricia D. and Humenik, Frank J.}, year={2007}, month={Dec}, pages={3184–3194} }
 @misc{vanotti_szogi_hunt_2005, title={Wastewater treatment system}, volume={6,893,567}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Vanotti, M. B. and Szogi, A. A. and Hunt, P. G.}, year={2005} }
 @article{szogi_vanotti_rice_humenik_hunt_2004, title={Nitrification options for pig wastewater treatment}, volume={47}, DOI={10.1080/00288233.2004.9513612}, abstractNote={Abstract Nitrification is a necessary and often limiting process in animal waste treatment for removal of nitrogen as N2 through biological nitrification/denitrification systems. We evaluated three technologies for enhancing nitrification of pig lagoon wastewater prior to denitrification: overland flow, trickling filter, and a bioreactor using nitrifying pellets. The overland flow system consisted of a 4 × 20‐m plot with 2% slope with a subsurface impermeable barrier receiving a total N loading rate of 64–99 kg N ha−1 day−1. Total N removal efficiency ranged from 36 to 42%, and 7% of the total N application was recovered in the effluent as nitrate. The trickling filter consisted of a 1‐m3 tank filled with marl gravel media which supported a nitrifying biofilm. Lagoon wastewater was applied as a fine spray on the surface at hydraulic loading rates of 684 litres m−3 day−1 and total N loading rates of 249 g m−3 day−1. The media filter treatment transformed up to 57% of the inflow total N into nitrate when wastewater was supplemented with lime. The nitrifying pellets technology used acclimated nitrifying cells immobilised in 3–5 mm polymer pellets. Pig wastewater was treated in an aerated fluidised reactor unit with a 15% (w/v) pellet concentration. Nitrification efficiencies of more than 90% were obtained in continuous flow treatment using total N loading rates of 438 g N m−3 day−1 and hydraulic residence time of 12 h. Two conclusions are suggested from this research: (1) that substantial nitrification of pig lagoon wastewater can be attained particularly using aerobic treatments with enriched nitrifying populations, and (2) that large mass removal of N from pig wastewater may be possible by sequencing nitrification and denitrification unit processes.}, number={4}, journal={New Zealand Journal of Agricultural Research}, author={Szogi, A. A. and Vanotti, M. B. and Rice, J. M. and Humenik, F. J. and Hunt, P. G.}, year={2004}, pages={439–448} }
 @article{stone_hunt_novak_johnson_watts_humenik_2004, title={Stream nitrogen changes in an eastern Coastal Plain watershed}, volume={59}, number={2}, journal={Journal of Soil & Water Conservation}, author={Stone, K. C. and Hunt, P. G. and Novak, J. M. and Johnson, M. H. and Watts, D. W. and Humenik, F. J.}, year={2004}, pages={66–72} }
 @article{szogi_hunt_humenik_2003, title={Nitrogen distribution in soils of constructed wetlands treating lagoon wastewater}, volume={67}, DOI={10.2136/sssaj2003.1943}, abstractNote={Constructed wetlands have the potential to be used for treatment of N-rich livestock wastewater. Our objectives were to evaluate both the time effect and increasing N loading rates on soil N distribution and NH + 4 -N concentration in surface-pore water of constructed wetlands. A 5-yr study in North Carolina investigated two wetland systems that treated swine lagoon wastewater. Wetland System 1 was planted to a Schoenoplectus americanus (Pers.) Volkart ex Schinz & R. Keller, S. tabernaemontani (K.C. Gmel.) Palla, Scirpus cyperinus (L.) Kunth, and Juncus effusus L. plant community, and Wetland System 2 was planted to a Typha angustifolia L., T. latifolia L., and Sparganium americanum Nutt. plant community. Nitrogen loading rates were increased annually from 0.6 to 2.7 g m -2 d -1 . Soils were analyzed for total N annually. Surface-pore water was sampled with equilibrators and analyzed for NH + 4 -N. Although the total N accumulation significantly increased with time in both systems, total soil N accumulation by depth did not differ significantly between systems. Distribution profiles in the surface-pore water column showed that NH + 4 -N was transported upward into surface water at N loading rates from 1.2 to 2.7 g m -2 d -1 . As total N loading rates increased annually in both wetland systems, soil pore water had higher levels of NH + 4 -N but N removal efficiency of the wetlands sharply decreased. Accumulation of high levels of NH + 4 -N (>200 mg L -1 ) in soil pore water could negatively affect long-term ability of wetland systems to treat wastewater with high N levels.}, number={6}, journal={Soil Science Society of America Journal}, author={Szogi, A. A. and Hunt, P. G. and Humenik, F. J.}, year={2003}, pages={1943–1951} }
 @article{szogi_hunt_humenik_2000, title={Treatment of swine wastewater using a saturated-soil-culture soybean and flooded rice system}, volume={43}, DOI={10.13031/2013.2708}, abstractNote={Constructed wetlands have potential for treatment of livestock wastewater, but they generally contain wetland 
plants rather than agronomic crops. We evaluated two agronomic crops, saturated-soil-culture (SSC) soybean and flooded 
rice, in a constructed wetland system used for swine wastewater treatment. Both crop production and treatment efficiency 
were evaluated from 1993 to 1996 in two 4-m ×33.5-m constructed wetland cells that were connected in series. The first 
cell contained SSC soybean — four cultivars planted in a randomized complete block design with four replications. 
Flooded rice ‘Maybelle’ was planted in the second cell. From the first to fourth year, wastewater application rates were 
gradually increased to obtain rates of 2.0 to 8.8 and 0.5 to 2.2 kg ha –1 d –1 for total N and P, respectively. The best 
soybean grain and dry matter yields were 4.0 and 9.1 Mg ha –1 , respectively. These were obtained with soybean ‘Young’ at 
the lowest wastewater application rate. Increasing total N loading rates and the associated higher NH 4 -N concentrations 
depressed soybean seed yield and dry matter production. On the other hand, both rice grain and dry matter production 
were stable over the application range; mean values were 4.0 and 10.9 Mg ha –1 , respectively. Nutrient mass reductions 
were good; removal values increased linearly with loading rates (y = 0.69N load + 0.45 , R 2 = 0.99 and y = 0.45P load + 
0.20, R 2 = 0.95). At the highest loading rate, the system removed 751 and 156 kg ha –1 yr –1 N and P, respectively. It 
appears that the SSC soybean and flooded rice system could be useful for liquid manure management in confined 
livestock production. The system produced comparable treatment to systems with natural wetland plants; moreover, the 
soybean and rice are marketable crops. However, the flooded rice seems to be the more robust component for high 
wastewater application rates.}, number={2}, journal={Transactions of the ASAE}, author={Szogi, A. A. and Hunt, P. G. and Humenik, F. J.}, year={2000}, pages={327–335} }
 @article{hunt_stone_humenik_matheny_johnson_1999, title={In-stream wetland mitigation of nitrogen contamination in a USA coastal plain stream}, volume={28}, ISSN={["0047-2425"]}, DOI={10.2134/jeq1999.00472425002800010030x}, abstractNote={Nonpoint source N from riverine origin is a major water quality problem throughout the world. Nitrogen removal from a contaminated (6.6 mg L -1 , NO 3 -N) stream was evaluated in this study using an in-stream wetland (ISW). The ISW was established at the exit of a 425-ha USDA Water Quality Demonstration watershed in the Coastal Plain of North Carolina. It ranged in depth from about 0.2 to 2 m, and it was <1% (3.3 ha) the size of the watershed. The ISW dramatically lowered mean stream NO 3 -N from 6.6 to 2.0 mg L 1 . Nitrate-N mass removal was highly correlated to inflow NO 3 -N (r = 0.93) in the warmer months when biological processes were more active. Ammonia-N mass removal was opposite that of NO 3 -N. It was highly correlated to inflow NH 3 -N (r = 0.81) during the cooler months. Removal of both NO 3 -N and total-N (NO 3 -N + TKN) were positively correlated to temperature with r values of 0.77 and 0.62, respectively. Total annual N removal for the ISW was approximately 3 kg ha -1 d -1 , which was about 37% of the inflow N. The ISWs appear to be very good landscape features for mitigating excess nonpoint source N in the southeastern Coastal Plain of the USA. As such, they are a good complement to other best management practices for improved water quality.}, number={1}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Hunt, PG and Stone, KC and Humenik, FJ and Matheny, TA and Johnson, MH}, year={1999}, pages={249–256} }
 @article{humenik_szogi_hunt_broome_rice_1999, title={Wastewater utilization: A place for managed wetlands - Review}, volume={12}, ISSN={["1011-2367"]}, DOI={10.5713/ajas.1999.629}, abstractNote={Con~mlctcd wc:~laI1~ arc: being \I~c:<i foT rho rcmoval of nunients from livestock Wl\Stewarer. However. narurlll vegetation typically used in constructed wotlands does not have marketable value. As Iln alterlUlrive, ngronomic plnl\ts grown undcr t1oodcd Clr !'nttlT'lltc:d ~il CQI1uition.'i Ihlll promorc dc:nitrific!lrion CR11 be uscd. Snldics on constructcd wctlands for swine wastc:walt:r w~rt: cOf1uUCled in weIland cellI; that conlnined eilht:r ttuLuTlll wcllanu plants or a combination of soybcans and rice f(lr two Y~I1~ with the objective of maximum nitrogen reduction ro mittimizc thc am(l\1I1t (If lalld rc:q\li~ for tcmlinal treatment. 11\ree systems, of TWO 3.6 by 33.S m wetland cells connected in series w~re used; tWO systems tach conIflmed B different combination of emergent wetland vegetation: rush{bulrush (sYStem 1) and bur-reed/cattail (system 2). 111e third system conrail1ed soybean (G/)'cine Inox) in ~tu~tcd-:;oil-c\llrurc (SSC) iT! thc rim ccll. and floodcd ricc (Oryza sativa) in the second ccll. NitrogcfI (N) IClading nlt~ Clf 3 and 10 kg hn"1 Juil w= u."cd ill thc fi~r ~nd $ccond yca~, rcspcctivcly, Thcsc loading ~tc:s wcrc obtained by mixing :.-wino: InglXJn liquid with fr=h watcr beforc it wa., ~pplicd to thc wctJand. Thc I1\1mcnt removal o:fficic:ncy "'~ similar in the rusll/bulnlSh, bur-reed/catrnils and u!,'tutlotnic plllnl ~~l=. MO:l1n ~" rcmoval uf N Wll,; 94% tIC tho: louuil\g r-.lte of 3 kg N ha.1 day' and decreased to 71 % at tl1e higher rare of 10 kg N hll-1 uuy"l. Tho: tWO yef1rs n\eans for above-grouJ1d dry mlOtIcr proouction for ru",h/b\lITU$h~ and bur-rccdfcart:lils was 12 and 33 Mg ha'l, respecTivcly. Floodcd ricc yield was 4.5 Mg \la-I, and ...oybeall grClWIl in !llIt\lT'Scion cu]t\lrc yicldcd 2.8 Mg !la"l. Additionally, rhr:. pcrfonnancc of !'cv"n o:oybcan c\t!tivaro: \l$iI1g SSC in coru.1.ructeU wo:llundl. with !lwine wa."tcwat~r a." thc w:ttcr l'0\1rcc W:1~ cval\llltcd for Cwo YO:IIT'i. Tho: culLivur Young had tile highest yield witl1 4.0 and 2.8 Mg hCl.1 iu eIlch year. Tllis illdiculcd Ihar production of acceptable !io)'bc=.1n yiel~ in COI1StruCted wetlands seems feasible with SSC using swine lagoon liquid, Two mlCrOCOS\11S srudies were established ro furrhcr invcstigatc: thc maTlagc:mc:nt of consmlctro wotlsnds. In thc fi~t microcosm cxpcrimcnt, tho c:ffccts (If !;win~ lagoon liquid on thc growth of wc:tlunu plUf1b; III half (lIbo\lt 175 mg/1 IImmonia) and full strcngth (abO\lt 350 mgJl /lmm(1ttia.) was inv~rigat~u, Tt wu~ cuncluded IIUlt wetla.nd plll1l!S CBn grow wt:11 it! III ]O:IL"t hulf IiLTcngth l!1g~)Qn liquid. Tn Ute secoud lnicrocOSIII experin1enL sequeucing nitrification-wetland TreatmentS was studied. W11en luLrified lilgoon liquid was added in batch applic:lliol1S (48 kg N ha.1 day'l) ro wctland microcosms tho nirrogcn rcmoval rare was four to five rimcs highcr rhan when non-nirrificd 111 goon liquid was utldo:u. Welll1nd mic.-rOCObm,; with plllnlo; wo:rt: mUTO: o:r'r'cctive than those with bur" ,;oil. 11\ese rc ulc; !iuHg"sr that Vo:g~Ulled wellan~ with nitrification pretreatment an: viabl~ ltc:lllmc:nt 1i'Ylil"m~ for removal of large quantifies of nilTo~o:n [ron\ swine lagoon liquid, (A$ian-Au$. J. Anlm. Scl. 1999, Vol. 12, No.4: 629-632) Key Wnrd... : Wetland-", WlI,;to:wuter UlilizaLiolt, COtlSltUcled Wo:lluntl.;}, number={4}, journal={ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES}, author={Humenik, FJ and Szogi, AA and Hunt, PG and Broome, S and Rice, M}, year={1999}, month={Jun}, pages={629–632} }
 @inproceedings{rice_szogi_broome_humenik_hunt_1998, title={Constructed wetland systems for swine wastewater treatment}, number={1998}, booktitle={Animal Production Systems and the Environment: An International Conference on Odor, Water Quality, Nutrient Management and Socioeconomic Issues: Proceedings, July 19-22, 1998}, publisher={Ames, Iowa: Iowa State University of Science and Technology}, author={Rice, J. M. and Szogi, A. A. and Broome, S. W. and Humenik, F. J. and Hunt, P. G.}, year={1998}, pages={501–505} }
 @article{kasperbauer_hunt_1998, title={Far-red light affects photosynthate allocation and yield of tomato over red mulch}, volume={38}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1998.0011183X003800040015x}, abstractNote={Plastic mulches are frequently used by both large- and small-scale tomato (Lycopersicon esculentum Miller) growers to conserve water, control weeds, and keep fruit clean. We hypothesized that changing mulch color to reflect more red light (R) and a higher far-red (FR) to R photon ratio (FR/R) would keep those benefits and improve tomato yield by altering phytochrome-mediated regulation of photosynthate allocation. Photodegradable and nondegradable forms of red plastic mulch were developed to our specifications. Number, size, and total fruit produced over the red plastic mulches were compared with those over standard black plastic. Photodegradable red mulch (placed over a layer of black plastic) increased fruit yield while it was intact, but yield dropped to that of the black control after the red plastic degraded. Nondegradable red plastic resulted in greater yield. Early crop yield advantage of red mulch was evident whether it was placed directly over soil or over a layer of black plastic. We conclude that increased tomato yield over the new red plastic mulch was caused by reflection of FR to the growing plants and its subsequent phytochrome-mediated regulation of photosynthate allocation to developing fruit.}, number={4}, journal={CROP SCIENCE}, author={Kasperbauer, MJ and Hunt, PG}, year={1998}, pages={970–974} }
 @article{stone_johnson_novak_watts_hunt_1998, title={Flow proportional and time composite estimates of nutrient loading from an eastern Coastal Plain watershed}, volume={98}, number={2153}, journal={Paper (American Society of Agricultural Engineers)}, author={Stone, K. C. and Johnson, M. H. and Novak, J. M. and Watts, D. W. and Hunt, P. G.}, year={1998}, pages={1–14} }
 @article{stone_hunt_johnson_coffey_1998, title={GLEAMS simulation of groundwater nitrate-N from row crop and swine wastewater spray fields in the eastern coastal plain}, volume={41}, DOI={10.13031/2013.17156}, abstractNote={Nonpoint source pollution of surface and groundwater resulting from agricultural management practices is a 
major water quality problem. This problem was assessed on a demonstration watershed in the Cape Fear River Basin of North Carolina, during a five-year study. Groundwater was monitored in a row crop field (corn/wheat/soybean) and a swine waste spray field (Coastal bermuda grass). Groundwater nitrate-N concentrations averaged 6.5 mg/L in the row crop field. Nitrate-N concentrations in groundwater at the swine waste spray field exceeded 80 mg/L. Nitrate-N concentrations were simulated in both fields with the GLEAMS model. The GLEAMS model simulated groundwater nitrate-N concentrations with mean residuals (simulated-observed) ±1.3 mg/L and ±19 mg/L, respectively, for the row crop and the swine waste spray field. Groundwater nitrate-N concentrations have been reduced in the spray field by using improved management practices and the GLEAMS model simulated this nitrate-N concentration reduction. These simulation results show that the GLEAMS model can be used to predict nitrate-N loading of groundwater of these agricultural management systems.}, number={1}, journal={Transactions of the ASAE}, author={Stone, K. C. and Hunt, P. G. and Johnson, M. H. and Coffey, S. W.}, year={1998}, pages={51–57} }
 @article{stone_hunt_humenik_johnson_1998, title={Impact of swine waste application on ground and stream waterquality in an eastern coastal plain watershed}, volume={41}, DOI={10.13031/2013.17342}, abstractNote={Nonpoint source pollution from agriculture has been a major concern, particularly where intensive agricultural operations exist near environmentally sensitive waters. To address these concerns, a water quality project was initiated in Duplin County, North Carolina, in the 2044-ha Herrings Marsh Run watershed. A swine farm within this monitored watershed expanded its operation from 3,300 to more than 14,000 animals. Groundwater nitrate-N increased significantly in three of the seven wells located adjacent to the spray field and in the adjoining riparian zone. Stream nitrate-N concentrations have increased after the expansion of the swine operation in the colder months, but concentrations have remained approximately the same during the warmer months. Stream ammonia-N mean concentrations after expansion have increased as well as the frequency and magnitude of ammonia-N concentration spikes. Ortho-phosphate concentrations in the stream water have been relatively consistent over the study period. The riparian zone is reducing the impact of spray field groundwater nitrate concentrations and ammonia loadings in an adjacent stream.}, number={6}, journal={Transactions of the ASAE}, author={Stone, K. C. and Hunt, P. G. and Humenik, F. J. and Johnson, M. H.}, year={1998}, pages={1665–1670} }
 @inproceedings{cook_hunt_canterberry_1998, title={Improving water quality through conservation practices}, volume={1}, booktitle={Soil and water conservation: Challenges and opportunities: 8th International Soil Conservation Conference}, publisher={Rotterdam: Balkema}, author={Cook, M. G. and Hunt, P. G. and Canterberry, J. H.}, editor={L. S. Bhushan, I. P. Abrol and Rao, M. S. Rama MohanEditors}, year={1998}, pages={304–310} }
 @article{hunt_matheny_bauer_1998, title={Influence of sample size on cotton shoot nitrogen accumulation: lint yield ratios}, volume={1}, number={1998}, journal={Beltwide Cotton Conferences. Proceedings}, author={Hunt, P. G. and Matheny, T. A. and Bauer, P. J.}, year={1998}, pages={675–677} }
 @article{stone_hunt_johnson_matheny_1998, title={Nitrate-N distribution and trends in shallow groundwater on an eastern Coastal Plains watershed}, volume={41}, DOI={10.13031/2013.17157}, abstractNote={Nonpoint source pollution from agriculture has been a major concern, particularly where intensive 
agricultural operations exist near environmentally sensitive waters. To address these nonpoint source pollution concerns, a Water Quality Demonstration Project (WQDP) was initiated on the Herrings Marsh Run (HMR) watershed in Duplin County, North Carolina. The WQDP was implemented to determine water quality benefits from voluntary adoption of improved management practices. In the WQDP, 84 groundwater monitoring well sites were established on 21 farms selected to represent the major farming practices on the watershed. On the HMR watershed, nitrate-N contamination of groundwater was not a wide spread problem. Seventy-four percent of the groundwater monitoring sites had nitrate-N less than the drinking water standard of 10 mg/L. Mean nitrate-N concentrations were below 10 mg/L on 16 of the 21 farms. Of the four farms with nitrate-N exceeding 10 mg/L, one farm had mean nitrate-N that exceeded 20 mg/L. This farm had an undersized and overloaded swine wastewater spray field. After the spray field was expanded and application rates were reduced, groundwater nitrate-N concentrations declined; but they continued to exceed 20 mg/L. Other farms with swine waste spray fields had mean groundwater nitrate-N concentrations <20 mg/L throughout the study period. Groundwater nitrate-N concentrations under row crops were <10 mg/L on all but two farms. Three of the four farms with nitrate-N concentrations exceeding 10 mg/L were in a subwatershed of the HMR that had the highest concentration of animal waste application and excess nitrogen applied. Of the 21 farms, three farms had a significant increasing trend in groundwater nitrate-N while four farms had a significant decreasing trend. The overloaded swine wastewater spray field had a significant decreasing nitrate-N trend. Most farms with concentrations less than 10 mg/L had no detectable trend in nitrate-N concentration during the study. These findings indicate that nitrate-N contamination of groundwater is not a widespread problem on the HMR watershed even though it is intensively farmed.}, number={1}, journal={Transactions of the ASAE}, author={Stone, K. C. and Hunt, P. G. and Johnson, M. H. and Matheny, T. A.}, year={1998}, pages={59–64} }
 @inproceedings{vanotti_szogi_hunt_humenik_rice_1998, title={Nitrification options for swine wastewater treatment}, number={1998}, booktitle={Animal Production Systems and the Environment: An International Conference on Odor, Water Quality, Nutrient Management and Socioeconomic Issues: Proceedings, July 19-22, 1998}, publisher={Ames, Iowa: Iowa State University of Science and Technology}, author={Vanotti, M. B. and Szogi, A. A. and Hunt, P. G. and Humenik, F. J. and Rice, J. M.}, year={1998}, pages={795–800} }
 @article{vanotti_hunt_1998, title={Nitrification treatment of swine wastewater by encapsulated nitrifiers}, volume={98}, number={4124}, journal={Paper (American Society of Agricultural Engineers)}, author={Vanotti, M. B. and Hunt, P. G.}, year={1998}, pages={1–10} }
 @article{hunt_bauer_camp_matheny_1998, title={Nitrogen accumulation in cotton grown continuously or in rotation with peanut using subsurface microirrigation and GOSSYM/COMAX management}, volume={38}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1998.0011183X003800020023x}, abstractNote={Excessive N application to cotton (Gossypium hirsutum L.) is an unnecessary cost and a potential cause of elevated groundwater N. The objectives of this study were to determine if seed yields or excess N were affected by timing of N application via buried microirrigation tubing, tubing spacing, or peanut (Arachis hypogaea L.) rotation. The experimental design was a randomized complete block in split-plot arrangement with four replications. The main plots (continuous cotton and peanut-cotton rotation) were planted with cotton cultivar PD 3 in May of 1991 through 1994 on an Eunola loamy sand (fine-loamy, siliceous, thermic Aquic Hapludult). Water and N were applied through microirrigation tubing that was buried 0.30 m directly under each row (IR) or under alternate row middles (AM). Sidedress-N was applied in one 112-kg ha -1 application (STD); five, 22-kg ha -1 increments (INC); or 11- to 22-kg ha -1 increments when required by GOSSYM/COMAX (GC) [a cotton growth model/expert system]. Rotation did not significantly affect any of the measured parameters. Cotton managed with the IR-STD treatment had the highest seed yield, 2.02 Mg ha -1 yr -1 . The GC management did not improve seed yield, but it did reduce excess N (fertilizer N - seed N) to <20 kg ha -1 y -1 . The best overall treatment was AM-GC. It had 1.87 Mg ha -1 yr -1 seed yield, 8 kg ha -1 yr -1 excess N, 45 kg less N applied, and 50% less tubing installed. Cotton managed by AM-GC also had a low (9.2) ratio of accumulated shoot N per 100 kg of lint.}, number={2}, journal={CROP SCIENCE}, author={Hunt, PG and Bauer, PJ and Camp, CR and Matheny, TA}, year={1998}, pages={410–415} }
 @article{novak_watts_stone_johnson_hunt_1998, title={Pesticides and metabolites in the shallow groundwater of an eastern Coastal Plain watershed}, volume={41}, DOI={10.13031/2013.17312}, abstractNote={The occurrence of pesticides in drinking water sources is a public concern because of potential adverse health 
effects. We report the results of a three-year study to assess the occurrence of pesticides and metabolites in shallow 
groundwater in a USDA Water Quality Demonstration Project (WQDP). The Herrings Marsh Run (HMR) watershed is 
located in the eastern Coastal Plain region of North Carolina and has similar characteristics of other regional 
agricultural-intensive watersheds. Ninety-two shallow groundwater wells were installed on farms around the watershed in 
late 1992 and early 1993. Water samples were collected monthly from March 1993 to March 1995 and collected quarterly 
for the remainder of 1995 and early 1996. The samples (n = 2598) were initially screened for 11 pesticides (8 triazines, 2 
chloroactamides, 1 methylester) using immunoassay techniques. The positive detections (n = 266) were further analyzed 
by gas chromatographic (GC) and GC/MS (mass spectrometric) procedures. During the study period, we found that the 
majority (91%) of the wells had no detections for 11 compounds commonly used in the watershed. Pesticides were 
consistently detected in four wells, but the concentrations were usually below the health advisory limit (HAL). Overall, 
alachlor was the most frequently detected pesticide. The lack of 11 commonly used pesticides in a high number of wells 
suggests that these pesticides have had a minimal impact on the quality of HMR shallow groundwater.}, number={5}, journal={Transactions of the ASAE}, author={Novak, J. M. and Watts, D. W. and Stone, K. C. and Johnson, M. H. and Hunt, P. G.}, year={1998}, pages={1383–1390} }
 @article{rizzuti_cohen_hunt_vanotti_1998, title={Testing of peats for removal of odors from liquid swine manure}, volume={33}, ISSN={["1532-4117"]}, DOI={10.1080/10934529809376814}, abstractNote={Abstract This paper reports on research designed to investigate the capacities of different kinds of peat to remove odor‐causing compounds from liquid swine manure (LSM). Two experiments were conducted. In experiment #1, five different peat types (both wet and dry) representing a wide range of properties were tested. Eight percent slurries (of peat/LSM) were measured for odor changes at 6, 24, and 96 hours using odor panel and GC/FID analysis. Experiment #2 was designed to determine more precisely the kinds of odor‐causing compounds thatwere changing during treatment. Two extremely different wet peat types were tested in 8 percent slurries after 24 hours of treatment. Odor changes were evaluated using both an odor panel and GC/MS, head‐space, solid‐phase, microextraction (HSM). The GC/FID and odor panel results indicated that wet peats were much more effective in removing odor‐causing compounds from LSM than were dry peats. Wet peats significantly reduced the LSM odor intensity after 6 hours of treatment,...}, number={8}, journal={JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING}, author={Rizzuti, AM and Cohen, AD and Hunt, PG and Vanotti, MB}, year={1998}, pages={1719–1739} }
 @inbook{humenik_rice_cook_broome_hunt_szogi_stem_sugg_scalf_1997, title={Constructed wetland to treat swine wastewater, Duplin County, North Carolina}, booktitle={Constructed wetlands for animal waste treatment: A manual on performance, design, and operation with case histories}, publisher={Payne Engineering and CH2M Hill}, author={Humenik, F. and Rice, M. and Cook, M. and Broome, S. and Hunt, P. and Szogi, A. and Stem, G. and Sugg, M. and Scalf, G.}, year={1997}, pages={II.1–4} }
 @inproceedings{hunt_vanotti_szogi_humenik_rice_1997, title={Constructed wetlands for animal wastewater treatment}, number={1997}, booktitle={Proceedings of the Southeastern Sustainable Animal Waste Management Workshop: February 11-13, 1997, Rural Development Center, Tifton, Georgia}, publisher={Athens, Ga.: University of Georgia}, author={Hunt, P. G. and Vanotti, M. B. and Szogi, A. A. and Humenik, F. J. and Rice, J. M.}, year={1997}, pages={161–175} }
 @article{hunt_bauer_matheny_1997, title={Crop production in a wheat-cotton doublecrop rotation with conservation tillage}, volume={10}, ISSN={["0890-8524"]}, DOI={10.2134/jpa1997.0462}, abstractNote={Cotton (Gossypium hirsutum L.) production has dramatically increased in the Southeast, but the role of conservation tillage in doublecropped cotton systems has not been clearly defined. Therefore, from 1988 to 1994, we investigated double-cropped wheat (Triticum aestivum L.) and cotton on plots that had been in continuous conservation vs. conventional tillage since 1979. The experimental site was located near Florence, SC, on a Norfolk loamy sand (fine-loamy, siliceous, thermic Typic Kandiudult). Conventional tillage consisted of multiple diskings and cultivations; surface tillage was eliminated for conservation tillage. Wheat yields were not significantly affected by tillage, but cotton yields were significantly higher for conservation tillage (P less than or equal to 0.01). Cotton planting dates ranged from 7 to 18 June, and 5 of the 7 yr hd more than 145 frost-free days. Two years had crop failure because of early freezes, and a June drought prevented the planting of cotton in 1 yr. In 4 yr with harvestable yields, seed cotton yields among the eight cultivars ranged from about 500 to 2200 and 300 to 1850 lb/acre for conservation and conventional tillage, respectively. The early maturing cultivar, 'Deltapine (DP) 20,' had the highest seed cotton yields with mens of 1442 and 1123 lb/acre for conservation and conventional tillage, respectively. Development of earlier maturing cotton and wheat cultivars will be important for this cropping system in the northern Coastal Plain portion of the Cotton Belt.}, number={3}, journal={JOURNAL OF PRODUCTION AGRICULTURE}, author={Hunt, PG and Bauer, PJ and Matheny, TA}, year={1997}, pages={462–465} }
 @article{mathis_mcmillin_champion_hunt_1997, title={Genetic variation in two cultures of Bradyrhizobium japonicum 110 differing in their ability to impart drought tolerance to soybean}, volume={35}, ISSN={["0343-8651"]}, DOI={10.1007/s002849900269}, number={6}, journal={CURRENT MICROBIOLOGY}, author={Mathis, JN and McMillin, DE and Champion, RA and Hunt, PG}, year={1997}, month={Dec}, pages={363–366} }
 @article{stone_hunt_johnson_matheny_1997, title={Ground water nitrate-N concentrations on an eastern Coastal Plains watershed}, volume={97}, number={2152}, journal={Paper (American Society of Agricultural Engineers)}, author={Stone, K. C. and Hunt, P. G. and Johnson, M. H. and Matheny, T. A.}, year={1997}, pages={1–15} }
 @article{bauer_hunt_camp_1997, title={In-season evaluation of subsurface drip and nitrogen-application method for supplying nitrogen and water to cotton}, volume={1}, number={1}, journal={Journal of Cotton Science}, author={Bauer, P. J. and Hunt, P. G. and Camp, C. R.}, year={1997}, pages={29–37} }
 @article{camp_bauer_hunt_1997, title={Subsurface drip irrigation lateral spacing and management for cotton in the southeastern Coastal Plain}, volume={40}, DOI={10.13031/2013.21351}, abstractNote={The cost of drip irrigation can be reduced by using both wider lateral spacings and the same laterals for 
multiple years, as with subsurface placement. Multiple, low-rate fertilizer and water applications may reduce N fertilizer 
needs by improving efficiency and limiting the potential for leaching. The combination of these technologies may make 
drip irrigation of cotton profitable. Four years of continuous cotton and two years of cotton rotated with peanut were 
evaluated. Two subsurface drip irrigation lateral spacings (every row, 1 m, and alternate furrow, 2 m) and three 
sidedress-nitrogen methods (STD, single application of 112 kg/ha; INC, 112 kg/ha in five equal applications; and GOS, 
applications determined by GOSSYM/COMAX) were evaluated for cotton during 1991-1994. Two of the sidedressnitrogen 
methods (STD and GOS) were evaluated for a rainfall-only treatment. Lint yields did not differ between the 
lateral spacings in any year. Yields for irrigated treatments were 16 and 65% greater than rainfall-only yields in 1992 and 
1993, respectively. The GOSSYM/COMAX-managed nitrogen treatment received 30% less nitrogen fertilizer than other 
treatments, but had similar lint yield. Several fiber physical properties were affected by irrigation and nitrogen, but these 
effects were small and inconsistent. For continuous cotton, or cotton rotated with peanut, the wider lateral spacing is 
preferred to the every-row spacing because of its lower initial cost (about 30%). The combination of lower system cost, 
longer system life, and lower N-fertilizer requirements could make subsurface drip irrigation of cotton profitable for 
southeastern Coastal Plain soils, and reduce the potential for ground water contamination.}, number={4}, journal={Transactions of the ASAE}, author={Camp, C. R. and Bauer, P. J. and Hunt, P. G.}, year={1997}, pages={993–999} }
 @article{szogi_humenik_rice_hunt_1997, title={Swine wastewater treatment by media filtration}, volume={32}, ISSN={["1532-4109"]}, DOI={10.1080/03601239709373115}, abstractNote={A media filter was constructed to treat swine wastewater after anaerobic lagoon treatment. The media filter consisted of a tank (1.5-m-diameter x 0.6-m-height) filled with marl gravel. The marl gravel had a carbonate content of 300 g kg-1. Gravel particle size distributions were 85 and 14% in the 4.7- to 12.7-mm and 12.7- to 19-mm size classes, respectively. Pore space of the filtration unit was 57%. Wastewater flow rate was 606 L m-2 d-1, and total Kjeldahl nitrogen (TKN) load was 198 g m-2 d-1. The media filter removed 54% of chemical oxygen demand (COD) content after one cycle, but increased cycling did not produce additional COD reduction. Total suspended solids (TSS) removal after one cycle was 50% of initial levels, and additional cycling reduced TSS levels at a much lower rate of 7% per cycle. Removal efficiencies for total phosphorus (TP) ranged from 37% to 52% (one to four cycles), but long-term phosphorus removal would be limited by the sorption capacity of the gravel. Up to 24% of TKN was converted to nitrate-plus-nitrite-N (NO3+NO2-N). Effluents with high NO3+NO2-N levels can be treated further for denitrification with constructed wetlands or anaerobic lagoon. This is important in cases where land is limited for wastewater application.}, number={5}, journal={JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART B-PESTICIDES FOOD CONTAMINANTS AND AGRICULTURAL WASTES}, author={Szogi, AA and Humenik, FJ and Rice, JM and Hunt, PG}, year={1997}, pages={831–843} }