[4][5][6] Ibn Bassal's magnum opus, his treatise on agronomy entitled Dīwān al-filāḥa (ديوان الفلاحة)(An Anthology of Husbandry), was originally a copious manuscript that had been dedicated to his botanical garden of Al-Ma’mūn at Toledo.
His seminal work was subsequently abridged, during the author's lifetime, and made into a single volume, styled Kitāb al-qaṣd wa’l-bayān (The Book of Concision and Clarity).
In the book, he describes over 180 cultivated plants, including chickpeas, beans, rice, peas, flax, henbane, sesame, cotton, safflower, saffron, poppies, henna, artichoke; herbs and spices including cumin, caraway, fennel, anise, and coriander; vegetables requiring irrigation or plentiful watering such as cucumbers, melons, mandrake, watermelons, pumpkins and squash, eggplant, asparagus, caper, and colocynth; the root vegetables carrots, radish, garlic, onion, leek, parsnip, the Sudanese pepper, and the dye-yielding madder; leaf vegetables including cabbage, cauliflower, spinach, purslane, amaranth, and chard.
He also covers arboriculture, detailing the propagation of the palm, olive, pomegranate, quince, apple, fig, pear, cherry, apricot, plum, peach, almond, walnut, hazelnut, grape, citron, orange, pistachio, pine, cypress, chestnut, holm-oak, deciduous oak, tree of paradise, arbutus, elm and ash.
The sweepings from hot baths included urine and human wastes, which Ibn Bassal describes as dry and salty, unsuitable for use as fertilizer unless mixed with other types of manure.