John M. Jemison

Predicting bromide leaching under field conditions using slim and macro

The updated versions of the SLIM and MACRO computer simulation models were evaluated using 3 years of bromide leaching data from a field experiment conducted on Hagerstown silt loam soil (fine, mixed, mesic Typic Hapludalf) with a well developed structure in central Pennsylvania. An application of potassium bromide (KBr) tracer was broadcast to 18 plots at 100 kg ha−1 at planting on May 13, 1988. Eighteen zero-tension pan lysimeters (0.456 m2) were placed at a depth of 1.2-m below the soil surface to collect gravitational water samples. Average pan collection efficiency was 52%, with a CV of 44%. Model simulations of Br− leaching for 1988, 1989, and 1990 were compared with the mean of pan efficiency-corrected measured data. There were no statistical differences between the SLIM and MACRO model predictions and, the experimental data for 1988 except for 1 or 2 months for each model. The SLIM model accurately predicted Br− leaching in 1989 but significantly underestimated Br− leaching from October 1990 through February 1991. The MACRO model significantly underestimated Br− leaching from May to November 1989 and performed well in 8 of 12 months in 1990. The overall simulations for 3 years of each model were compared with the overall field measurements of Br− leaching. The statistical evaluation criteria indicated that the SLIM model performed somewhat better than the MACRO model through the 3-year period. The results given in this study indicate that both models have good potential for conservative tracer simulation

Use of Nurse Crops in Potato Production to Protect Soils from Erosion

Because potatoes emerge slowly following planting, soils are susceptible to erosion. Planting a fast emerging nurse crop as a short-term cover crop could reduce potential soil erosion. In 2016 and 2017, research was conducted to address nurse crop seeding rates, necessity to kill the nurse crop with an herbicide, and optimal nurse crop growth period before destroying it through hilling. Winter rye (Secale cereale L.) plots were sown at 2.5 and 5 million seeds ha−1, hilled or killed with herbicide prior to one-pass hilling, and allowed to grow for approximately three or four weeks. Allowing nurse crops to grow four weeks without use of an herbicide prior to hilling appeared to reduce yields one year in two. Grown for three weeks, nurse crops provided effective soil protection and did not affect potato yield or nitrogen status at either seeding rate with or without herbicide use.ResumenDebido a que las papas emergen lentamente después de plantadas, los suelos son susceptibles a la erosión. Sembrando un cultivo de cobertura de rápida emergencia, como una cubierta de corto plazo, pudiera reducir la erosión potencial del suelo. En 2016 y 2017, se condujo una investigación para identificar niveles de siembra de un cultivo de cobertura, la necesidad de matar a dicho cultivo con un herbicida, y el período óptimo del cultivo de cobertura antes de destruirlo mediante el aporque. Se sembraron lotes de centeno blanco (Secale cereale L.) en una densidad de 2.5 y 5 millones de semillas ha-1, con aporque o muertas con herbicida antes de un paso de aporque, y se les permitió crecer por aproximadamente tres o cuatro semanas. Al permitir los cultivos de cobertura, su crecimiento por cuatro semanas sin el uso de herbicidas antes del aporque pareció reducir los rendimientos en uno de dos años. Cultivados por tres semanas, los cultivos de cobertura proporcionaron protección efectiva del suelo y no afectaron el rendimiento de papa o la situación del nitrógeno a ningún nivel de semilla con y sin el uso de herbicida.

GROW: Green Organic Vegetable Gardens to Promote Older Adult Wellness: a Feasibility Study

ABSTRACT Protecting older adult’s cognitive health is a public health priority. Wellness behaviors within 6 domains have demonstrated effectiveness in protecting older adult’s cognitive abilities. Interventions targeted to low-income older adults are needed because these populations experience greater social and physical health disparities compared to adults in higher socioeconomic statuses. This study examined the feasibility of engaging independent, community-dwelling older adults living in low-income senior housing in cultivating raised-bed gardens and reviewed the improvements in cognition and nutrition. Ten participants received ergonomic garden tools, seeds, waist-height garden beds, and weekly garden education. Participants planted vegetables of their choosing and tended to their garden beds for 17 weeks. Cognition and nutrition outcomes were measured before and after the intervention. Adults successfully engaged in the intervention throughout the duration and experienced improvement in cognitive and nutrition outcomes.