NONFICTION : IN DEEP: COUNTRY ESSAYS by Maxine Kumin (Viking: $16.95; 180 pp.).

Maxine Kumin, novelist, essayist and Pulitzer Prize-winning poet, has given us a new book of essays. “In Deep” is a collection of reflections about her life on her New Hampshire farm and how that life gives base to her writing. She offers us information on horses, mushrooms and mules and serves us generously with poetry.

The book is, essentially, about the making of poetry, for it comes directly from her life. Poetry is never far from her as she goes about work with her animals and in her garden.

“Today, in the dying butternut tree . . . a barred owl. He arrives, like a poem, unnannounced.”

And of course a poet, even when she is writing prose, commits poetry. Lines of poetry spring out of these essays.

On making maple syrup: “The sap freezes almost as much as it drips, forming a great colorless cake of possibility.”

On the first hard freeze of autumn: “Nothing green can be had in trade this night.”

On variety among mushrooms: “Each genus is as distinct as beet from rutabaga.”

Some of the essays in this collection are formal in structure and might be used as textbook examples of the essayist’s art (and indeed Kumin has taught--at Columbia, Princeton and elsewhere) but I liked the journal-like snippets best of all. Each one is a picture deftly drawn.

“7 March. The chickadees have changed their tune and are now singing their mating song. Those same beggars who perched on my arm in January while I was filling their feeder now stay away most of the morning. They are citizens of independent means.

“11 March. Everything is softening. The change, when it came was direct, happened overnight. In spite of longing, reaching for it for weeks, we were still overtaken. . . .”

This is a book to read slowly and to re-read often.