Vigna unguiculata

i was on campus at about 9:30 a.m. to check out the garden and to plant some cowpeas. i have put almost three-quarters of a ton of compost and composted manure on the garden from last october to the last time i hilled the potatoes a couple of weeks ago. it has been done incrementally, and has exhausted my compost pile. bagged, organic compost isn't difficult to find, fortunately, and it isn't prohibitively expensive either, so i've made up my compost pile's shortfall by going to lowes. i also plan to mulch the yams and garlic for winter with compost this year instead of straw and landscaping fabric, so that will be that much more organic matter added. i have been reading alot about intercropping lately...expanding a garden's, or farm's, growing season and protecting its productivity from drought, disease, or insect infestation, by growing a diversity of plant species. what can harm one won't necessarily harm all. included in this concept is the idea of "green manure", plants that help to increase the soil's fertility. cowpeas are one plant that is a green manure. they work in a relationship with the soil bacteria rhizobium. the bacteria makes atmospheric nitrogen available to the plant and in return the bacteria utilizes sugars from the cowpea's root system. the plant cannot use all the nitrogen the bacteria produces so the excess nitrogen remians "fixed" in the soil for future use. cowpeas and the bacteria can produce up to one hundred pounds of excess nitrogen per acre. i paid three bucks for a pound of seeds that will easily see me through the season both on campus and at home, and today i planted thirty-four of them along the margins of the garden and around and between the asparagus which are notoriously heavy feeders. the plant is an annual so i will turn them under this fall when i mulch the garden and provide more organic matter for those red wigglers i put in earlier this year. we may actually be cutting back the diversity of plants in the garden next year to take a closer look at tubers and grasses, but i think we'll keep inter cropping things like cowpeas and velvet beans to suppliment our compost use and to keep us organic.