1987/05/19 Integrated nutrient supply Improved fallow Nitrogen transfer from legumes Cover crops on acid soils Sunnhemp Rock phosphate Micro-nutrient drain Soil conservation and shifting cultivators Cycles of poverty
1986/01/01 Esta serie de lecciones tiene como proposito explicar en la forma mas sencilla posible, la naturaleza de la tierra y las practicas que podemos usar para asegurarnos de que nuestras tierras siempre esten en la mejor condicion posible. Vamos a estudiar algunas cosas algo complicadas, como la acidez...
1971/01/01 It is the purpose of this booklet to suggest some ways of studying plants that may involve students more fully, especially in the design and development of elementary research suitable for school laboratories. Educational Products Division, LaMotte Chemical Products, Chestertown, MD 74 pages,...