The Benefits of Composting

(gentle music) A summer day is an exceptional time for many seasonal fruits. The watermelons are starting to ripen, the peaches and plums are juicy, and the cantaloupe are soft and sweet, an ideal mixture for a fruit salad. Today, let's stop to consider the food waste created by these fruits because, interestingly, when paired with other gardens scraps and byproducts, that waste can become a valuable part of a cycle that will keep renewing itself year after year, the composting cycle. If you look around your garden this year, you may be thrilled to see that everything is growing so well. Was it this year's abundant sunshine you wonder, all those well-timed rain showers? Yes, in part, but you should also remember the nutrients that compost put into the soil when it was till just before planting. When making a fruit salad or cutting any vegetables throughout the year, you might reflexively put the offcuts into the compost bin, but how does something that's as solid as a watermelon rind one day become a dark, brown, crumbly material full of nutrients and minerals the next? What happens in the compost pile involves taking a source of carbon and a source of nitrogen, using oxygen from the air, and letting the available microorganisms go to work, but it is not as simple as throwing your discarded scraps into a bin and walking away. All these ingredients work together in a complex dance. First, you need a certain amount of carbon required by the bacteria to make their cell walls and other internal structures. Carbon is found in autumn leaves, straw, wood chips, sawdust, bark, and even shredded paper. Second, micro organisms need nitrogen for making proteins, enzymes as well as for the DNA, which bacteria needs to double if it's going to divide in two. Nitrogen is found in the fruit and vegetable scraps, in coffee grounds, and in grass clippings, for example. Oxygen is the third critical ingredient because the micro organisms that are doing the work are oxygen lovers. Our air is 21% oxygen, which is ideal, but it can have trouble penetrating the mixture. Stirring the compost in a bin or rotating it in a drum will allow for the right amount. Finally, you need a source of microorganisms because the bacteria and molds are going to do the work of breaking down the vegetable and fruit discards. The most obvious source is leftover compost as the bacteria are still there inside it or you can use shovel fulls of garden soil straight from the earth. When the ideal amounts are there and some moisture, the decomposition of the watermelon rind, peach pits, and cantaloupe skins go on quite an adventure in the weeks to months that pass. The temperature of the pile spikes to 160 degrees Fahrenheit before returning to the ambient one. The acidity drops very low, rises very high. and finally settles back to neutral and the pile of recognizable scraps transforms into a...