Jonathan L. Deenik

Charcoal ash and volatile matter effects on soil properties and plant growth in an acid ultisol.

There is a growing interest in converting organic wastes to charcoal for use as a sustainable soil amendment with a potential to improve soil productivity and sequester C. Three consecutive greenhouse experiments were conducted to investigate the effects of charcoal with different ash and volatile matter (VM) contents on soil properties and maize (Zea mays) growth and to evaluate the effect of time on charcoal performance. Five charcoal amendments (high-VM corncob, low-VM corncob, Kiawe, Binchotan, and a gasification charcoal of Leucaena leucocephala) applied at a 2.5% (wt/wt) rate were compared with a zero-charcoal control with and without fertilization. Only the gasification charcoal significantly increased maize growth without fertilization. The low-VM corncob charcoal with fertilization significantly increased maize growth by 164% compared with the fertilized control in the first planting cycle. Maize growth in the high-VM corncob charcoal supplemented with fertilizer treatment was significantly lower than that of the fertilizer-alone treatment in the first planting cycle. The negative effect of the high-VM charcoal on the fertilizer was caused by bioavailable carbon in the charcoal, which increased soil microbial activity and could have caused N immobilization. Both the beneficial and detrimental effects of charcoal did not persist beyond the first planting cycle, suggesting that charcoal impacts are temporary. Whereas charcoal ash and VM content seem to be important parameters for predicting charcoal behavior in the short-term, more research is needed to examine a broader spectrum of feedstocks exposed to varying thermal treatments.

Children’s Healthy Living (CHL) Program for remote underserved minority populations in the Pacific region: rationale and design of a community randomized trial to prevent early childhood obesity

BackgroundAlthough surveillance data are limited in the US Affiliated Pacific, Alaska, and Hawaii, existing data suggest that the prevalence of childhood obesity is similar to or in excess of other minority groups in the contiguous US. Strategies for addressing the childhood obesity epidemic in the region support the use of community-based, environmentally targeted interventions. The Children’s Healthy Living Program is a partnership formed across institutions in the US Affiliated Pacific, Alaska, and Hawaii to design a community randomized environmental intervention trial and a prevalence survey to address childhood obesity in the region through affecting the food and physical activity environment.Methods/DesignThe Children’s Healthy Living Program community randomized trial is an environmental intervention trial in four matched-pair communities in American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, and Hawaii and two matched-pair communities in Alaska. A cross-sectional sample of children (goal n = 180) in each of the intervention trial communities is being assessed for outcomes at baseline and at 24 months (18 months post-intervention). In addition to the collection of the participant-based measures of anthropometry, diet, physical activity, sleep and acanthosis nigricans, community assessments are also being conducted in intervention trial communities. The Freely Associated States of Micronesia (Federated States of Micronesia, and Republics of Marshall Islands and Palau) is only conducting elements of the Children’s Healthy Living Program sampling framework and similar measurements to provide prevalence data. In addition, anthropometry information will be collected for two additional communities in each of the 5 intervention jurisdictions to be included in the prevalence survey. The effectiveness of the environmental intervention trial is being assessed based on the RE-AIM (reach, effectiveness, adoption, implementation, maintenance) framework.DiscussionThe Children’s Healthy Living Program environmental trial is designed to focus on capacity building and to maximize the likelihood of sustainable impact on childhood obesity-related behaviors and outcomes. The multiple measures at the individual, community, and environment levels are designed to maximize the likelihood of detecting change. This approach enhances the likelihood for identifying and promoting the best methods to promote health and well-being of the children in the underserved US Affiliated Pacific Region.Trial registrationNIH clinical trial # NCT01881373

Fertilization response and nutrient diagnosis in peach palm (Bactris gasipaes): a review

Peach palm (Bactris gasipaes Kunth) is a relatively new food crop with great potential for the humid tropics. Native to tropical America, it is commercially grown to produce hearts-of-palm and, to a lesser extent, an edible fruit. Peach palm is well adapted to nutrient poor, acid soils, and is cultivated in Brazil and Costa Rica on highly weathered soils with low pH, high aluminum saturation and, often, low organic matter content. Fertilization trials on peach palm have shown significant responses to applied nitrogen while the response to other nutrients such as phosphorus has been less frequent. Additional research, however, is necessary to determine soil and foliar nutrient critical levels and to address questions concerning peach palm growth responses to nutrient additions varying in time and space. Recycled nutrients likely contribute significantly to peach palm nutrition because plant residues are produced in considerable amounts and can decompose rapidly in commercial peach palm plantation in humid environments where cut leaves and stems are left in the field following harvest. On the other hand, nutrient exports from the system are relatively small (e.g., 4.8–6.4 kg P ha-1yr-1, 28–32.3 kg N ha-1 yr-1, 31–45.2 kg K ha-1 yr-1). As for most perennial tree crops, diagnosis of nutrient deficiencies in peach palm is less clear than in annual crops because of factors such as nutrient cycling, internal retranslocation, stand age, foliage age and position within the crown, and seasonal and climatic variations. Some studies on peach palm have examined variation in nutrient content within leaves and plants, and among plants as well, but the sensitivity of different plant tissues to reflect changes in nutrient uptake and response to nutrient additions should be investigated in controlled field experiments.

Systematic Review of Prevalence of Young Child Overweight and Obesity in the United States–Affiliated Pacific Region Compared With the 48 Contiguous States: The Children’s Healthy Living Program

We estimated overweight and obesity (OWOB) prevalence of children in US-Affiliated Pacific jurisdictions (USAP) of the Childrens Healthy Living Program compared with the contiguous United States. We searched peer-reviewed literature and government reports (January 2001-April 2014) for OWOB prevalence of children aged 2 to 8 years in the USAP and found 24 sources. We used 3 articles from National Health and Nutrition Examination Surveys for comparison. Mixed models regressed OWOB prevalence on an age polynomial to compare trends (n = 246 data points). In the USAP, OWOB prevalence estimates increased with age, from 21% at age 2 years to 39% at age 8 years, increasing markedly at age 5 years; the proportion obese increased from 10% at age 2 years to 23% at age 8 years. The highest prevalence was in American Samoa and Guam.

Nutrient concentrations within and below root zones from applied chicken manure in selected Hawaiian soils

The objective of this study was to evaluate the effects of chicken manure (CM) application rates on nutrient concentrations within and below the root zone of sweet corn (Zea mays L. subsp. mays) under Hawaiian conditions. The research was conducted in leeward (Poamoho) and windward (Waimanalo) areas of Oahu, Hawaii, where contrasts exist in both climatic and soil conditions. Suction cup were used to collect soil solutions from 30 and 60 cm depths. Soil solutions were collected six times during the growing season at each location and analyzed for different nutrients (N, P, K, Ca, Mg, Na, Fe, Mn, Zn, and Cu), nitrate-nitrogen (NO3–N), ammonium-nitrogen (NH4–N), electrical conductivity (EC), and pH. Analysis showed that CM rates significantly affected the concentration of macro-nutrients below the root zone at Poamoho and within the root zone at Waimanalo. In general, nutrient concentration increased with the increasing rates of CM application. There was a significant effect of CM on micro-nutrients except below the root zone at Poamoho. CM significantly affected NO3–N concentration within the root zone for 15, 60 days after planting (DAP) at Poamoho, and 16, 28 DAP at Waimanalo. The effect was also significant on total nitrogen (N) concentration in the root zone across the two growing seasons at Waimanalo. There was a highly significant correlation between total N and NO3–N, and EC within and below the root zone.

Belowground impacts of perennial grass cultivation for sustainable biofuel feedstock production in the tropics

Perennial grasses can sequester soil organic carbon (SOC) in sustainably managed biofuel systems, directly mitigating atmospheric CO2 concentrations while simultaneously generating biomass for renewable energy. The objective of this study was to quantify SOC accumulation and identify the primary drivers of belowground C dynamics in a zero‐tillage production system of tropical perennial C4 grasses grown for biofuel feedstock in Hawaii. Specifically, the quantity, quality, and fate of soil C inputs were determined for eight grass accessions – four varieties each of napier grass and guinea grass. Carbon fluxes (soil CO2 efflux, aboveground net primary productivity, litterfall, total belowground carbon flux, root decay constant), C pools (SOC pool and root biomass), and C quality (root chemistry, C and nitrogen concentrations, and ratios) were measured through three harvest cycles following conversion of a fallow field to cultivated perennial grasses. A wide range of SOC accumulation occurred, with both significant species and accession effects. Aboveground biomass yield was greater, and root lignin concentration was lower for napier grass than guinea grass. Structural equation modeling revealed that root lignin concentration was the most important driver of SOC pool: varieties with low root lignin concentration, which was significantly related to rapid root decomposition, accumulated the greatest amount of SOC. Roots with low lignin concentration decomposed rapidly, but the residue and associated microbial biomass/by‐products accumulated as SOC. In general, napier grass was better suited for promoting soil C sequestration in this system. Further, high‐yielding varieties with low root lignin concentration provided the greatest climate change mitigation potential in a ratoon system. Understanding the factors affecting SOC accumulation and the net greenhouse gas trade‐offs within a biofuel production system will aid in crop selection to meet multiple goals toward environmental and economic sustainability.

Anthropometric measurement standardization in the US‐affiliated pacific: Report from the Children's Healthy Living Program

Anthropometric standardization is essential to obtain reliable and comparable data from different geographical regions. The purpose of this study is to describe anthropometric standardization procedures and findings from the Childrens Healthy Living (CHL) Program, a study on childhood obesity in 11 jurisdictions in the US‐Affiliated Pacific Region, including Alaska and Hawai‘i.

NITROGEN MINERALIZATION POTENTIAL AND NUTRIENT AVAILABILITY FROM FIVE ORGANIC MATERIALS IN AN ATOLL SOIL FROM THE MARSHALL ISLANDS

Soil nutrient deficiencies are a major constraint to crop production on the low-lying atoll soils of the Marshall Islands. Despite the critical role organic matter plays in controlling the fertility of these soils, there is little information on the use of organic inputs to improve soil fertility and crop production. In this study, we evaluated the N mineralization potential and nutrient supplying capacity of five organic soil amendments (Vigna marina and Cocos nucifera leaves, chicken manure, fish meal, and copra cake) available in the Marshall Islands. Nitrogen mineralization kinetics were best described by using a modified Gompertz equation with three parameters estimating N mineralization potential (N0), mineralization rate (k), and mineralization lag phase (&lgr;). There were significant differences in Chinese cabbage growth in the soil amended with the different organic amendments. Chinese cabbage growth in the Vigna and chicken manure treatments was similar to the chemical control, but the fish meal and copra cake treatments showed significantly less biomass production than the chemical control. The reduced growth in the fish meal treatment was attributed to K deficiency due to the low K supplying capacity of the amendment. The soil amended with coconut leaves showed the lowest biomass production, and the poor growth was attributed to net N immobilization. Optimum corn growth was achieved by adding fresh Vigna leaves at 8.9 T ha−1 (dry weight), and Vigna seems to be a good locally available soil amendment that corrects the multiple nutrient deficiencies found in Marshall Island soils.

Prevalence of obesity and acanthosis nigricans among young children in the children's healthy living program in the United States Affiliated Pacific.

Abstract Estimate prevalence of obesity and acanthosis nigricans (AN) among children in United States Affiliated Pacific (USAP) jurisdictions. Cross-sectional measurement of weight, height, and AN in 5775, 2 to 8 years old in 51 communities—Hawai‘i, Alaska, Commonwealth of the Northern Mariana Islands, Guam, American Samoa, Palau, Republic of the Marshall Islands (RMI), 4 Federated States of Micronesia (Pohnpei, Yap, Kosrae, Chuuk). Analyses weighted to jurisdiction-specific sex and age distributions accounting for clustering of communities within jurisdictions. Prevalence of obesity was 14.0%, overweight 14.4%, healthy weight 68.9%, and underweight 2.6%, higher in males (16.3%) than females (11.6%), higher among 6 to 8 years old (16.3%) than 2 to 5 years old (12.9%), highest in American Samoa (21.7%), and absent in RMI. In total, 4.7% of children had AN, with no sex difference, higher in 6 to 8 years old (6.8%) than 2 to 5 years old (3.5%) and highest in Pohnpei (11.9%), and absent in Alaska. Obesity was highly associated with AN (odds ratio = 9.25, 95% confidence interval = 6.69–12.80), with the strongest relationships among Asians, followed by Native Hawaiians and Pacific Islanders (NHPI). Obesity, age, and Asian and NHPI race were positively associated with AN.

Quality assurance of data collection in the multi-site community randomized trial and prevalence survey of the children’s healthy living program

AbstractBackgroundQuality assurance plays an important role in research by assuring data integrity, and thus, valid study results. We aim to describe and share the results of the quality assurance process used to guide the data collection process in a multi-site childhood obesity prevalence study and intervention trial across the US Affiliated Pacific Region.MethodsQuality assurance assessments following a standardized protocol were conducted by one assessor in every participating site. Results were summarized to examine and align the implementation of protocol procedures across diverse settings.ResultsData collection protocols focused on food and physical activity were adhered to closely; however, protocols for handling completed forms and ensuring data security showed more variability.ConclusionsQuality assurance protocols are common in the clinical literature but are limited in multi-site community-based studies, especially in underserved populations. The reduction in the number of QA problems found in the second as compared to the first data collection periods for the intervention study attest to the value of this assessment. This paper can serve as a reference for similar studies wishing to implement quality assurance protocols of the data collection process to preserve data integrity and enhance the validity of study findings. Trial registration: NIH clinical trial #NCT01881373