Long-term effects of tillage, nitrogen, and rainfall on winter wheat yields

Response of Douglas-fir seedlings to nitrogen, sulfur, and phosphorus fertilizers

M. A. Radwan

Nitrogen in Agricultural Landscape

Lech Wojciech Szajdak

The European nitrogen assessment

Mark A. Sutton

Lactic Acid Fermentation of Human Excreta for Agricultural Application

Nadejda Andreev

Natural gas

United States. General Accounting Office

Pesticides and Nitrogen Cycle Nature and Habitats of Effects of Pesticides

Rup Lal

The Alchemy of Air

Thomas Hager

Nitrogen Fluxes in Intensive Grassland Systems

G. C. Ennik

Enriching the Earth

Vaclav Smil

1948 Fertilizer Supplies

United States. Congress. House. Committee on Agriculture