Ammonia (ammonium): a compound of nitrogen readily usable as a plant food. It is one of the products of decay.
Annual: a plant that bears seed during the first year of its existence and then dies.
Anther: the part of a stamen that bears the pollen.
Atmospheric nitrogen: nitrogen in the air. Great quantities of this valuable plant food are in the air; but, strange to say, most plants cannot use it directly from the air, but must take it in other forms, as nitrates, etc. The legumes are an exception, as they can use atmospheric nitrogen.
Available plant food: food in such condition that plants can use it.
Bacteria: a name applied to a number of kinds of very small living beings, some beneficial, some harmful, some disease-producing. They average about one twenty-thousandth of an inch in length.
Balanced ration: a ration made up of the proper amounts of carbohydrates, fats, and protein, as explained in text. Such a ration avoids all waste of food.
Biennial: a plant that produces seed during the second year of its existence and then dies.
Blight: a diseased condition in plants in which the whole or a part of a plant withers or dries up.
Bluestone: a chemical; copper sulphate. It is used to kill fungi, etc.