Nitrogen and phosphorus distribution in plant, soil and leachate as affected by liquid hog manure and chemical fertilizers

A two-year field study was conducted on a coarse textured soil in Manitoba, Canada, to investigate the effects of liquid hog manure (LHM) and chemical fertilizer application on barley (2005) and red spring wheat (2006) yields, crop nutrient uptake and nitrogen (N) and phosphorus (P) movement to the environment. The treatments were LHM applied at two rates as 22000 L ha-1 (2500 gal ac-1, abbreviated as M2500) and 43000 L ha-1 (5000 gal ac-1, abbreviated as M5000) and two rates of chemical fertilizer to match total N and P in LHM treatments, F2500 and F5000, along with an unamended control. The M5000 and M2500 treatments showed similar grain yield and N and P uptake. However, M5000 and M2500 significantly increased grain yield by 67% and 78%, respectively, compared to the control in 2005. In 2006, wheat grain yields from M2500 and M5000 were 71% and 86% greater than the control. In 2005, leachate NO3-N concentrations and leaching loads were higher with chemical fertilizers than M2500. In 2005, the apparent recovery of applied N as leachate was 35% and 23% in F5000 and F2500 treatments, whereas it was 6% and 7% of applied N in M5000 and M2500 plots, respectively. However, the application of M5000 resulted in P accumulation near the surface and may increase the potential risk of P loss with runoff. Our results show that applying LHM at moderate rates (M2500) may ensure desirable crop yields comparable to higher rates of nutrient application with minimal potential losses relative to higher rates.

Impact of liquid hog manure applications on antibiotic resistance genes concentration in soil and drainage water in field crops

Agricultural practices such as manure applications could contribute to the spread of antibiotic resistance genes (ARGs) within the environment. Our objective was to assess the impact of certain fertilization methods (mineral or manure) and tillage practices (reduced or conventional) on the presence of ARGs and bacteria in soil and drainage water under wheat and grain corn crops. Targeted ARGs tet(T), sul1, and blaCTX-M-1 in liquid hog manure, soil, and water samples were quantified by qPCR. Conventional PCR was used to detect mcr-1 and mcr-2. ARGs in control plots were detected despite the absence of manure, representing an environmental reservoir of resistant microorganisms. The manure application rate higher than 39 m3/ha increased tet(T) and sul1 gene concentrations in soil for more than 180 days. Tillage practices had no impact on ARG concentrations in soil and water samples. The blaCTX-M-1 gene was only detected in seven water samples in 2016, but no link was established with the treatments. The mcr-1 and mcr-2 genes were not detected in all tested samples. This study demonstrated that tet(T) and sul1 gene concentrations increased in soil after liquid hog manure application as well as in drainage water in the next weeks.

The Anthropocene stinks! Odor, affect, and the entangled politics of livestock waste in a rural Iowa watershed

Recent interventions in geography regarding the Anthropocene have demonstrated how Western logics of order and containment have produced massive geologic transformations. This paper focuses on odor as a sense that, when engaged critically, disrupts those logics by exposing the porousness of the body to other bodies and spaces. Visceral reactions to smell produce affective responses in the body which are informed by circulating political discourses. Thus, this paper explores how research focused on odor can reveal the complicated dynamics through which bodies are enrolled into subject formation and become a terrain of political struggle. Research on the everyday experience of hog manure in a rural Iowa watershed forms the case study through which these questions are raised. Since the transition to concentrated livestock agriculture at the end of the twentieth century, the disposal of animal waste has caused serious concern. This waste is often collected and later spread on fields across the state, producing foul odors and potential toxins. Political discourses that maintain this system claim waste is ordered and properly maintained, generating positive affective responses to foul odors and thereby maintaining support for industrialized agriculture.

Brief Communication: Analysis of the Fatalities and Socio-Economic Impacts Caused by Hurricane Florence

Florence made landfall on the southeastern coast of North Carolina (NC) generating torrential rainfall and severe flooding that led to 53 fatalities in three states (NC, SC, and VA) and $16–$40 billion in damage. Seventy-seven percent (77%) of the fatalities occurred in the rural flood plains of NC with Duplin county reporting a high of eight deaths. Approximately 50% of the total number of hurricane-related fatalities across the three states were vehicle-related. The predominant demographic at risk were males over the age of 50 years. The type of property damage was in line with other major hurricanes and predominantly affected residential structures (93% of the total number of damaged buildings). Florence is among the top 10 costliest hurricanes in U.S. history with approximately 50% of the damage projected as uninsured losses due to residential flooding. The cumulative 5-day rainfall resulted in major flooding along the Cape Fear, Lumberton, and Neuse rivers where many industrial waste sites (hog manure lagoons and coal ash pits) are located. Several of these waste sites located in the flood plain were breached and have likely cross-contaminated the waterways and water treatment operations. The observed extent of the flooding, environmental contamination, and impact to public health caused by Florence will add to the long-term disaster related mortality and morbidity rates and suggests an expansion of the 100-yr flood hazard zone to communicate the expanded risk to the public.

Rotating alfalfa with dry bean as an alternative to corn-soybean rotations in organic systems in the Upper Midwest

Dry bean (Phaseolus vulgaris) can be grown as a local food source and as an alternative to soybean (Glycine max) to diversify organic crop rotations. To understand the benefits of diversification of organic cropping systems, the effects of preceding alfalfa (Medicago sativa) and corn (Zea mays) crops on yields of five dry bean types and one soybean type, and the effect of bean type on following spring wheat (Triticum aestivum) yields, were tested at four Minnesota locations. Dry bean and soybean yields following alfalfa were 25% greater than yields following corn at two of four locations, though bean yields following corn were greater at one location. A preceding alfalfa crop benefited bean yields at locations where hog manure or no manure was applied to corn, whereas bean yields following corn fertilized with cow manure were similar to or greater than bean yields following alfalfa. Among dry bean types, black bean yielded similarly to soybean at three of four locations, but dark red kidney bean consistently yielded 25–65% lower than soybean. Navy, pinto and heirloom dry bean types yielded similarly to soybean at two of four locations. Across locations, weed biomass was 3–15 times greater in dry bean than in soybean and dry bean yield response to weed competition varied among bean types. However, dry bean, regardless of the preceding crop, demonstrated the potential to produce yields comparable with soybean in organic systems and the substitution of dry bean for soybean did not affect subsequent wheat yields. More studies are needed to identify nitrogen fertility dynamics in organic systems as they relate to dry bean yield.

From backyard to commercial hog production

Purpose – The purpose of this paper is to analyze the impact of structural changes in hog production manure management practices. Design/methodology/approach – The data used in this study are obtained from a large-scale nationwide hog producers’ survey in rural China conducted by the Center for Chinese Agricultural Policy, Chinese Academy of Sciences, in 2010. A descriptive analysis between hog manure management and its main determinants was conducted. Based on the collected data, an econometric model on the determinants of hog manure management was constructed and used for analysis. Findings – The results of this study suggest that the scale of hog production has an important impact on the pattern of hog manure management. Moreover, the results from descriptive statistics and multivariate estimation suggest that smaller hog producers are more likely to apply hog manure to their own lands, while larger hog producers are more likely to sell the manure or find other ways to dispose of it. Originality/value – This study contributes to the existing literature by examining the impact of structural changes in hog production on hog manure management and the environment.