1. Baker J. L. and Johnson H. P. (1977). “Impact of subsurface drainage on water quality.” Proc. ASAE 3rd Nat. Drain. Symp. ASAE St. Joseph Mich. 91–98.
2. Nitrate‐Nitrogen in Tile Drainage as Affected by Fertilization
3. Nitrate, Phosphorus, and Sulfate in Subsurface Drainage Water
4. Belcher H. W. (1990). “Water table management to maximize the economic efficiency of biomass production ” PhD dissertation. Agricultural Engineering Dept. Michigan State Univ. East Lansing Mich.
5. Belcher H. W. (1992). “Economics of subirrigating row crops. ” Agricultural Engineering Dept. Michigan State Univ. East Lansing Mich.