莱斯利·谢尔曼

这是从马里兰州的切斯特镇出发的徒步旅行., to Guapilis, Costa Rica—about 2,100 miles in fact—and the long, flat fields of Maryland’s Eastern Shore are a world away from the lush landscape and tropical fecundity of Central America. Connection, though, is all about common ground, and Professor 莱斯利·谢尔曼 found plenty of that during her recent sabbatical 在地球大学.

谢尔曼说，海洋之神590网址的W. Alton Jones Associate Professor of Chemistry and director of the 环境mental Science and Studies program, is a soil scientist, and much of her work at WC has focused on the native grassland restoration project at the Chester River Field Research Station at Chino Farms. 在那里，她研究了变化的过程 the 土地使用 from traditional agriculture (corn, soybeans) to native grasses affected 土壤长期. Traveling to Costa Rica on a faculty enhancement grant, she studied the same issue, only here the crop was pineapples, and the question focused more closely on a single intense 土地使用 over time.

“I’ve always wanted to study a tropical system both because the soils are fascinating and because the agriculture is so different,” Sherman says. 她以工作为基础 of 地球上大学, which offers students from Latin America, the Caribbean, Africa, and Asia a program in agricultural sciences and natural resources management. 三名来自莫桑比克的学生， Ecuador, and Bolivia helped Sherman with her with lab and field work.

Pineapples are a major crop, and Sherman was curious how the plants manage to grow so well on highly weathered, nutrient-poor soils, especially considering how densely planted they are—about 75,000 plants per hectare (2.5英亩)，以及它们有多强烈 managed with pesticides and fertilizers. “In three years you get two whole crops. 所以这是非常有效的. I was interested in how these decades of highly intensive agriculture are impacting the soil quality. It’s still productive, but is anything 从长远来看?”

Sherman studied one plantation, taking samples in plots five to seven years old and plots 25 years old, as well as samples from a bordering pasture, a remnant of a previous 土地使用. She found that the organic matter, which provides structure for the plants, nutrients, and helps keep the soil moist, was not degraded in the cultivated plots, probably because after every planting cycle, the growers chop all the residue plant 将其混合到土壤中. “After every crop they did this, and since it was the tropics it gets incorporated very quickly.” However, the older plot showed a build-up of acidity being held in the soil, which in the long run may prove to be a problem.

Sherman also explored some of Costa Rica’s world-famous biological diversity and natural 美. One of her favorite trips was to Tortuguero National Park, where she witnessed one of nature’s most miraculous and mysterious 事件, the arribada, or arrival, of female green sea turtles. After traveling thousands of miles through unknown reaches of the sea, for one night they come ashore to the beach where they themselves hatched to lay their eggs in the sand. 她说，当时的场面“是公正的 令人惊异的.”

Much of what she learned will make its way into her classes, from discussions about the tension between conservation of biodiversity and the necessity of agricultural operations, to the potential benefits of ecotourism to help protect endangered species 比如海龟. 

• 谢尔曼L.A. 和K. Brye. 2019. Soil chemical property changes in response to long-term pineapple cultivation in Costa Rica. Agrosyst. Geosci. 环境. 第2卷第1期. http://doi.org/10.2134/age2019.07.0052