At Watermelon Field Day, nutrients are at the root of the plant

Published: July 8, 2010

More than 200 people visited the field day and sampled 25 seedless watermelon and 12 mini-watermelon varieties. image by: Peter Hull

BLACKVILLE — Among the ingredients in a bag of fertilizer are three essential nutrients that form the lifeblood of plants: nitrogen, phosphorus and potassium.

Clemson University plant physiologist Christina Wells explained during the 2010 Watermelon Field Day at Clemson’s Edisto Research and Education Center here how nutrients move from soil to the plant, and that they are removed from the field as a necessity of agriculture.

Plants use nitrogen to make proteins, enzymes and DNA. They use phosphorous to make DNA, cell membranes and energy-transport molecules. Potassium activates enzymes and maintains water balance in plants.

“These are the building blocks of plants,” Wells said.

The nutrients occur naturally in soil, but as a consequence of agriculture they are removed.

Plants take these nutrients from the soil, and when plants die and decompose in the field their nutrients are returned to the soil.

But in agriculture, plants and crops are harvested and their nutrients leave with the crops. Fertilizer is needed, in part, to replace these essential nutrients.

“This is why we need to replace these key nutrients that we take away,” Wells said.

Uptake of nutrients is so important plants have extensive roots that seek out these essential building blocks. In fact, the surface area of a plant’s roots is 100 times greater than the surface area of a plant's leaves.

“It never fails to amaze me how much root there is in a plant,” Wells said.

More than 200 people attended the annual field day.

In addition to Wells’ presentation, a classroom session featured a fungicide update and a soil water holding demonstration.

Later, the tour moved outside to view field research projects and variety trials. Field discussions included watermelon insects, tools to measure soil water and a special presentation on a Gravity Flow Drip Irrigation system.

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